Prior exercise training blunts short-term high-fat diet-induced weight gain.

PubMed

Snook, Laelie A; MacPherson, Rebecca E K; Monaco, Cynthia M F; Frendo-Cumbo, Scott; Castellani, Laura; Peppler, Willem T; Anderson, Zachary G; Buzelle, Samyra L; LeBlanc, Paul J; Holloway, Graham P; Wright, David C

2016-08-01

High-fat diets rapidly cause weight gain and glucose intolerance. We sought to determine whether these changes could be mitigated with prior exercise training. Male C57BL/6J mice were exercise-trained by treadmill running (1 h/day, 5 days/wk) for 4 wk. Twenty-four hours after the final bout of exercise, mice were provided with a high-fat diet (HFD; 60% kcal from lard) for 4 days, with no further exercise. In mice fed the HFD prior to exercise training, the results were blunted weight gain, reduced fat mass, and a slight attenuation in glucose intolerance that was mirrored by greater insulin-induced Akt phosphorylation in skeletal muscle compared with sedentary mice fed the HFD. When ad libitum-fed sedentary mice were compared with sedentary high-fat fed mice that were calorie restricted (-30%) to match the weight gain of the previously trained high-fat fed mice, the same attenuated impairments in glucose tolerance were found. Blunted weight gain was associated with a greater capacity to increase energy expenditure in trained compared with sedentary mice when challenged with a HFD. Although mitochondrial enzymes in white adipose tissue and UCP-1 protein content in brown adipose tissue were increased in previously exercised compared with sedentary mice fed a HFD, ex vivo mitochondrial respiration was not increased in either tissue. Our data suggest that prior exercise training attenuates high-fat diet-induced weight gain and glucose intolerance and is associated with a greater ability to increase energy expenditure in response to a high-fat diet. Copyright © 2016 the American Physiological Society.

Influence of vitamin C and vitamin E on redox signaling: Implications for exercise adaptations.

PubMed

Cobley, James N; McHardy, Helen; Morton, James P; Nikolaidis, Michalis G; Close, Graeme L

2015-07-01

The exogenous antioxidants vitamin C (ascorbate) and vitamin E (α-tocopherol) often blunt favorable cell signaling responses to exercise, suggesting that redox signaling contributes to exercise adaptations. Current theories posit that this antioxidant paradigm interferes with redox signaling by attenuating exercise-induced reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation. The well-documented in vitro antioxidant actions of ascorbate and α-tocopherol and characterization of the type and source of the ROS/RNS produced during exercise theoretically enable identification of redox-dependent mechanisms responsible for the blunting of favorable cell signaling responses to exercise. This review aimed to apply this reasoning to determine how the aforementioned antioxidants might attenuate exercise-induced ROS/RNS production. The principal outcomes of this analysis are (1) neither antioxidant is likely to attenuate nitric oxide signaling either directly (reaction with nitric oxide) or indirectly (reaction with derivatives, e.g., peroxynitrite); (2) neither antioxidant reacts appreciably with hydrogen peroxide, a key effector of redox signaling; (3) ascorbate but not α-tocopherol has the capacity to attenuate exercise-induced superoxide generation; and (4) alternate mechanisms, namely pro-oxidant side reactions and/or reduction of bioactive oxidized macromolecule adducts, are unlikely to interfere with exercise-induced redox signaling. Out of all the possibilities considered, ascorbate-mediated suppression of superoxide generation with attendant implications for hydrogen peroxide signaling is arguably the most cogent explanation for blunting of favorable cell signaling responses to exercise. However, this mechanism is dependent on ascorbate accumulating at sites rich in NADPH oxidases, principal contributors to contraction-mediated superoxide generation, and outcompeting nitric oxide and superoxide dismutase isoforms. The major conclusions of this review are: (1) direct evidence for interference of ascorbate and α-tocopherol with exercise-induced ROS/RNS production is lacking; (2) theoretical analysis reveals that both antioxidants are unlikely to have a major impact on exercise-induced redox signaling; and (3) it is worth considering alternate redox-independent mechanisms. Copyright © 2015 Elsevier Inc. All rights reserved.

Virtual reality pain control during physical therapy range of motion exercises for a patient with multiple blunt force trauma injuries.

PubMed

Hoffman, Hunter G; Patterson, David R; Soltani, Maryam; Teeley, Aubriana; Miller, William; Sharar, Sam R

2009-02-01

Patients with severe blunt force trauma injuries (e.g., multiple fractures and/or internal injuries) often experience severe to excruciating pain during medical procedures. We explored the adjunctive use of immersive virtual reality (VR) to distract a patient with multiple blunt trauma injuries from his procedural pain during physical therapy. The patient was a 32-year-old male hospitalized after suffering upper and lower extremity injuries when he was hit by a semi truck as a pedestrian. While a nurse assisted the patient's passive range of motion (ROM) leg exercises over two days, the patient spent a total of 10 minutes of physical therapy with no distraction and 10 minutes in VR (within-subjects design, order randomized). Three 0 to 10 graphic-rating-scale pain scores for each of the two treatment conditions served as the primary dependent variables. The patient reported a reduction in pain when distracted with VR. "Pain unpleasantness" ratings during physical therapy dropped from "severe" (mean = 8.5) to "mild/moderate" (4.5). The patient's ROM was 1 degree less during VR on day 1, but the patient achieved 15 degrees greater ROM during VR on day 2. The present study provides preliminary evidence that immersive VR can be an effective adjunctive, nonpharmacologic pain-reduction technique for a patient with multiple blunt trauma injuries experiencing severe pain during physical therapy. The potential utility of VR analgesia for movement or exercise therapy for patients with blunt force trauma injuries should be explored in controlled studies.

Abnormal Neurocirculatory Control During Exercise in Humans with Chronic Renal Failure

PubMed Central

Park, Jeanie; Middlekauff, Holly R.

2014-01-01

Abnormal neurocirculatory control during exercise is one important mechanism leading to exercise intolerance in patients with both end-stage renal disease (ESRD) and earlier stages of chronic kidney disease (CKD). This review will provide an overview of mechanisms underlying abnormal neurocirculatory and hemodynamic responses to exercise in patients with kidney disease. Recent studies have shown that ESRD and CKD patients have an exaggerated increase in blood pressure (BP) during both isometric and rhythmic exercise. Subsequent studies examining the role of the exercise pressor reflex in the augmented pressor response revealed that muscle sympathetic nerve activity (MSNA) was not augmented during exercise in these patients, and metaboreflex-mediated increases in MSNA were blunted, while mechanoreflex-mediated increases were preserved under basal conditions. However, normalizing the augmented BP response during exercise via infusion of nitroprusside (NTP), and thereby equalizing baroreflex-mediated suppression of MSNA, an important modulator of the final hemodynamic response to exercise, revealed that CKD patients had an exaggerated increase in MSNA during isometric and rhythmic exercise. In addition, mechanoreflex-mediated control was augmented, and metaboreceptor blunting was no longer apparent in CKD patients with baroreflex normalization. Factors leading to mechanoreceptor sensitization, and other mechanisms underlying the exaggerated exercise pressor response, such as impaired functional sympatholysis, should be investigated in future studies. PMID:25458430

Is blunted cardiovascular reactivity in depression mood-state dependent? A comparison of major depressive disorder remitted depression and healthy controls.

PubMed

Salomon, Kristen; Bylsma, Lauren M; White, Kristi E; Panaite, Vanessa; Rottenberg, Jonathan

2013-10-01

Prior work has repeatedly demonstrated that people who have current major depression exhibit blunted cardiovascular reactivity to acute stressors (e.g., Salomon et al., 2009). A key question regards the psychobiological basis for these deficits, including whether such deficits are depressed mood-state dependent or whether these effects are trait-like and are observed outside of depression episodes in vulnerable individuals. To examine this issue, we assessed cardiovascular reactivity to a speech stressor task and a forehead cold pressor in 50 individuals with current major depressive disorder (MDD), 25 with remitted major depression (RMD), and 45 healthy controls. Heart rate (HR), blood pressure and impedance cardiography were assessed and analyses controlled for BMI and sex. Significant group effects were found for SBP, HR, and PEP for the speech preparation period and HR, CO, and PEP during the speech. For each of these parameters, only the MDD group exhibited attenuated reactivity as well as impaired SBP recovery. Reactivity and recovery in the RMD group more closely resembled the healthy controls. Speeches given by the MDD group were rated as less persuasive than the RMD or healthy controls' speeches. No significant differences were found for the cold pressor. Blunted cardiovascular reactivity and impaired recovery in current major depression may be mood-state dependent phenomena and may be more reflective of motivational deficits than deficits in the physiological integrity of the cardiovascular system. Copyright © 2013 Elsevier B.V. All rights reserved.

Is blunted cardiovascular reactivity in depression mood-state dependent? A comparison of major depressive disorder remitted depression and healthy controls

PubMed Central

Salomon, Kristen; Bylsma, Lauren M.; White, Kristi E.; Panaite, Vanessa; Rottenberg, Jonathan

2015-01-01

Prior work has repeatedly demonstrated that people who have current major depression exhibit blunted cardiovascular reactivity to acute stressors (e.g., Salomon et al., 2009). A key question regards the psychobiological basis for these deficits, including whether such deficits are depressed mood-state dependent or whether these effects are trait-like and are observed outside of depression episodes invulnerable individuals. To examine this issue, we assessed cardiovascular reactivity to a speech stressor task and a forehead cold pressor in 50 individuals with current major depressive disorder (MDD), 25 with remitted major depression (RMD), and 45 healthy controls. Heart rate (HR), blood pressure and impedance cardiography were assessed and analyses controlled for BMI and sex. Significant group effects were found for SBP, HR, and PEP for the speech preparation period and HR, CO, and PEP during the speech. For each of these parameters, only the MDD group exhibited attenuated reactivity as well as impaired SBP recovery. Reactivity and recovery in the RMD group more closely resembled the healthy controls. Speeches given by the MDD group were rated as less persuasive than the RMD or healthy controls' speeches. No significant differences were found for the cold pressor. Blunted cardiovascular reactivity and impaired recovery in current major depression may be mood-state dependent phenomena and may be more reflective of motivational deficits than deficits in the physiological integrity of the cardiovascular system. PMID:23756147

Endurance exercise training blunts the deleterious effect of high-fat feeding on whole body efficiency

PubMed Central

Holloway, Cameron J.; Murray, Andrew J.; Knight, Nicholas S.; Carter, Emma E.; Kemp, Graham J.; Thompson, Campbell H.; Tyler, Damian J.; Neubauer, Stefan; Robbins, Peter A.; Clarke, Kieran

2011-01-01

We recently showed that a week-long, high-fat diet reduced whole body exercise efficiency in sedentary men by >10% (Edwards LM, Murray AJ, Holloway CJ, Carter EE, Kemp GJ, Codreanu I, Brooker H, Tyler DJ, Robbins PA, Clarke K. FASEB J 25: 1088–1096, 2011). To test if a similar dietary regime would blunt whole body efficiency in endurance-trained men and, as a consequence, hinder aerobic exercise performance, 16 endurance-trained men were given a short-term, high-fat (70% kcal from fat) and a moderate carbohydrate (50% kcal from carbohydrate) diet, in random order. Efficiency was assessed during a standardized exercise task on a cycle ergometer, with aerobic performance assessed during a 1-h time trial and mitochondrial function later measured using 31P-magnetic resonance spectroscopy. The subjects then underwent a 2-wk wash-out period, before the study was repeated with the diets crossed over. Muscle biopsies, for mitochondrial protein analysis, were taken at the start of the study and on the 5th day of each diet. Plasma fatty acids were 60% higher on the high-fat diet compared with moderate carbohydrate diet (P < 0.05). However, there was no change in whole body efficiency and no change in mitochondrial function. Endurance exercise performance was significantly reduced (P < 0.01), most probably due to glycogen depletion. Neither diet led to changes in citrate synthase, ATP synthase, or mitochondrial uncoupling protein 3. We conclude that prior exercise training blunts the deleterious effect of short-term, high-fat feeding on whole body efficiency. PMID:21632846

Blunted Myoglobin and Quadriceps Soreness after Electrical Stimulation during the Luteal Phase or Oral Contraception

ERIC Educational Resources Information Center

Anderson, Lindsey J.; Baker, Lucinda L.; Schroeder, E. Todd

2017-01-01

Purpose: Acute muscle damage after exercise triggers subsequent regeneration, leading to hypertrophy and increased strength after repeated exercise. It has been debated whether acute exercise-induced muscle damage is altered under various premenopausal estrogen conditions. Acute contraction-induced muscle damage was compared during exogenous (oral…

Biological mechanisms underlying the role of physical fitness in health and resilience

PubMed Central

Silverman, Marni N.; Deuster, Patricia A.

2014-01-01

Physical fitness, achieved through regular exercise and/or spontaneous physical activity, confers resilience by inducing positive psychological and physiological benefits, blunting stress reactivity, protecting against potentially adverse behavioural and metabolic consequences of stressful events and preventing many chronic diseases. In this review, we discuss the biological mechanisms underlying the beneficial effects of physical fitness on mental and physical health. Physical fitness appears to buffer against stress-related disease owing to its blunting/optimizing effects on hormonal stress responsive systems, such as the hypothalamic–pituitary–adrenal axis and the sympathetic nervous system. This blunting appears to contribute to reduced emotional, physiological and metabolic reactivity as well as increased positive mood and well-being. Another mechanism whereby regular exercise and/or physical fitness may confer resilience is through minimizing excessive inflammation. Chronic psychological stress, physical inactivity and abdominal adiposity have been associated with persistent, systemic, low-grade inflammation and exert adverse effects on mental and physical health. The anti-inflammatory effects of regular exercise/activity can promote behavioural and metabolic resilience, and protect against various chronic diseases associated with systemic inflammation. Moreover, exercise may benefit the brain by enhancing growth factor expression and neural plasticity, thereby contributing to improved mood and cognition. In summary, the mechanisms whereby physical fitness promotes increased resilience and well-being and positive psychological and physical health are diverse and complex. PMID:25285199

Biological mechanisms underlying the role of physical fitness in health and resilience.

PubMed

Silverman, Marni N; Deuster, Patricia A

2014-10-06

Physical fitness, achieved through regular exercise and/or spontaneous physical activity, confers resilience by inducing positive psychological and physiological benefits, blunting stress reactivity, protecting against potentially adverse behavioural and metabolic consequences of stressful events and preventing many chronic diseases. In this review, we discuss the biological mechanisms underlying the beneficial effects of physical fitness on mental and physical health. Physical fitness appears to buffer against stress-related disease owing to its blunting/optimizing effects on hormonal stress responsive systems, such as the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system. This blunting appears to contribute to reduced emotional, physiological and metabolic reactivity as well as increased positive mood and well-being. Another mechanism whereby regular exercise and/or physical fitness may confer resilience is through minimizing excessive inflammation. Chronic psychological stress, physical inactivity and abdominal adiposity have been associated with persistent, systemic, low-grade inflammation and exert adverse effects on mental and physical health. The anti-inflammatory effects of regular exercise/activity can promote behavioural and metabolic resilience, and protect against various chronic diseases associated with systemic inflammation. Moreover, exercise may benefit the brain by enhancing growth factor expression and neural plasticity, thereby contributing to improved mood and cognition. In summary, the mechanisms whereby physical fitness promotes increased resilience and well-being and positive psychological and physical health are diverse and complex.

Impaired Muscle Oxygenation and Elevated Exercise Blood Pressure in Hypertensive Patients: Links With Vascular Stiffness.

PubMed

Dipla, Konstantina; Triantafyllou, Areti; Koletsos, Nikolaos; Papadopoulos, Stavros; Sachpekidis, Vasileios; Vrabas, Ioannis S; Gkaliagkousi, Eugenia; Zafeiridis, Andreas; Douma, Stella

2017-08-01

This study examined in vivo (1) skeletal muscle oxygenation and microvascular function, at rest and during handgrip exercise, and (2) their association with macrovascular function and exercise blood pressure (BP), in newly diagnosed, never-treated patients with hypertension and normotensive individuals. Ninety-one individuals (51 hypertensives and 40 normotensives) underwent office and 24-hour ambulatory BP, arterial stiffness, and central aortic BP assessment, followed by a 5-minute arterial occlusion and a 3-minute submaximal handgrip exercise. Changes in muscle oxygenated and deoxygenated hemoglobin and tissue oxygen saturation were continuously monitored by near-infrared spectroscopy and beat-by-beat BP by Finapres. Hypertensives had higher ( P <0.001) central aortic BP and pulse wave velocity versus normotensives and exhibited (1) a blunted tissue oxygen saturation response during occlusion, with slower ( P =0.006) deoxygenation rate, suggesting reduced muscle oxidative capacity, and (2) a slower reoxygenation rate and blunted hyperemic response ( P <0.05), showing reduced microvascular reactivity. Muscle oxygenation responses were correlated with aortic systolic and pulse pressure and augmentation index ( P <0.05; age and body mass index (BMI) adjusted). When exercising at the same submaximal intensity, hypertensives required a significantly greater ( P <0.001) increase in BP for achieving similar muscle oxygenation levels as normotensives. This response was correlated with the magnitude of microvascular hyperemia and aortic BP. In conclusion, nontreated patients with hypertension exhibit prominent reductions in in vivo indices of skeletal muscle oxidative capacity, suggestive of mitochondrial dysfunction, and blunted muscle microvascular reactivity. These dysfunctions were associated with higher aortic systolic BP and arterial stiffness. Dysregulations in muscle oxygen delivery/utilization and microvascular stiffness, in hypertensive patients, partially contribute to their exaggerated BP during exercise. © 2017 American Heart Association, Inc.

One day of moderate energy deficit reduces fasting and postprandial triacylglycerolemia in women: the role of calorie restriction and exercise.

PubMed

Maraki, Maria; Magkos, Faidon; Christodoulou, Nektarios; Aggelopoulou, Niki; Skenderi, Katerina P; Panagiotakos, Demosthenes; Kavouras, Stavros A; Sidossis, Labros S

2010-08-01

Fasting and postprandial hypertriacylglycerolemia are important cardiovascular risk factors in women. We sought to examine the effects of acute (1 day), moderate ( approximately 2 MJ) energy deficit induced by calorie restriction, exercise, or combination of both on fasting and postprandial triacylglycerol (TAG) metabolism in women. Six healthy premenopausal women performed four oral fat tolerance tests in the morning after a day of a) rest (control), b) calorie restriction ( approximately 2 MJ), c) exercise (net deficit of approximately 2 MJ) and d) calorie restriction-plus-exercise (total energy deficit of approximately 2 MJ). All energy deficit trials significantly reduced fasting and postprandial total plasma TAG concentrations by 15-23% and 12-23%, respectively, and triacylglycerol-rich lipoprotein TAG concentrations by 37-43% and 25-39%, respectively, compared with the control condition (P<0.05). Postprandial, but not fasting, total TAG concentrations were approximately 12% lower after exercise compared with diet-induced energy deficit (P=0.05). Acute, moderate energy deficit independently of its origin (i.e. diet or exercise or combination of both) reduces fasting and postprandial triacylglycerolemia in women. Exercise elicits a somewhat greater effect than calorie restriction in the postprandial state. The acute effect of diet and exercise should be taken into account when studying the long-term effects of weight loss and exercise training on TAG metabolism. Copyright 2009 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Effects of body position on the ventilatory response following an impulse exercise in humans.

PubMed

Haouzi, Philippe; Chenuel, Bruno; Chalon, Bernard

2002-04-01

The aim of this study was to identify some of the mechanisms that could be involved in blunted ventilatory response (VE) to exercise in the supine (S) position. The contribution of the recruitment of different muscle groups, the activity of the cardiac mechanoreceptors, the level of arterial baroreceptor stimulation, and the hemodynamic effects of gravity on the exercising muscles was analyzed during upright (U) and S exercise. Delayed rise in VE and pulmonary gas exchange following an impulselike change in work rate (supramaximal leg cycling at 240 W for 12 s) was measured in seven healthy subjects and six heart transplant patients both in U and S positions. This approach allows study of the relationship between the rise in VE and O2 uptake (VO2) without the confounding effects of contractions of different muscle groups. These responses were compared with those triggered by an impulselike change in work rate produced by the arms, which were positioned at the same level as the heart in S and U positions to separate effects of gravity on postexercising muscles from those on the rest of the body. Despite superimposable VO2 and CO2 output responses, the delayed VE response after leg exercise was significantly lower in the S posture than in the U position for each control subject and cardiac-transplant patient (-2.58 +/- 0.44 l and -3.52 +/- 1.11 l/min, respectively). In contrast, when impulse exercise was performed with the arms, reduction of ventilatory response in the S posture reached, at best, one-third of the deficit after leg exercise and was always associated with a reduction in VO2 of a similar magnitude. We concluded that reduction in VE response to exercise in the S position is independent of the types (groups) of muscles recruited and is not critically dependent on afferent signals originating from the heart but seems to rely on some of the effects of gravity on postexercising muscles.

Blunted Dopamine Transmission in Addiction: Potential Mechanisms and Implications for Behavior.

PubMed

Trifilieff, Pierre; Ducrocq, Fabien; van der Veldt, Suzanne; Martinez, Diana

2017-01-01

Positron emission tomography (PET) imaging consistently shows blunted striatal dopamine release and decreased dopamine D2 receptor availability in addiction. Here, we review the preclinical and clinical studies indicating that this neurobiological phenotype is likely to be both a consequence of chronic drug consumption and a vulnerability factor in the development of addiction. We propose that, behaviorally, blunted striatal dopamine transmission could reflect the increased impulsivity and altered cost/benefit computations that are associated with addiction. The factors that influence blunted striatal dopamine transmission in addiction are unknown. Herein, we give an overview of various factors, genetic, environmental, and social, that are known to affect dopamine transmission and that have been associated with the vulnerability to develop addiction. Altogether, these data suggest that blunted dopamine transmission and decreased D2 receptor availability are biomarkers both for the development of addiction and resistance to treatment. These findings support the view that blunted dopamine reflects impulsive behavior and deficits in motivation, which lead to the escalation of drug use. Copyright © 2017 Elsevier Inc. All rights reserved.

Appetite and Energy Intake Responses to Acute Energy Deficits in Females versus Males

PubMed Central

ALAJMI, NAWAL; DEIGHTON, KEVIN; KING, JAMES A.; REISCHAK-OLIVEIRA, ALVARO; WASSE, LUCY K.; JONES, JENNY; BATTERHAM, RACHEL L.; STENSEL, DAVID J.

2016-01-01

ABSTRACT Purpose To explore whether compensatory responses to acute energy deficits induced by exercise or diet differ by sex. Methods In experiment one, 12 healthy women completed three 9-h trials (control, exercise-induced (Ex-Def) and food restriction–induced energy deficit (Food-Def)) with identical energy deficits being imposed in the Ex-Def (90-min run, ∼70% of V˙O2max) and Food-Def trials. In experiment two, 10 men and 10 women completed two 7-h trials (control and exercise). Sixty minutes of running (∼70% of V˙O2max) was performed at the beginning of the exercise trial. The participants rested throughout the remainder of the exercise trial and during the control trial. Appetite ratings, plasma concentrations of gut hormones, and ad libitum energy intake were assessed during main trials. Results In experiment one, an energy deficit of approximately 3500 kJ induced via food restriction increased appetite and food intake. These changes corresponded with heightened concentrations of plasma acylated ghrelin and lower peptide YY3–36. None of these compensatory responses were apparent when an equivalent energy deficit was induced by exercise. In experiment two, appetite ratings and plasma acylated ghrelin concentrations were lower in exercise than in control, but energy intake did not differ between trials. The appetite, acylated ghrelin, and energy intake response to exercise did not differ between men and women. Conclusions Women exhibit compensatory appetite, gut hormone, and food intake responses to acute energy restriction but not in response to an acute bout of exercise. Additionally, men and women seem to exhibit similar acylated ghrelin and PYY3–36 responses to exercise-induced energy deficits. These findings advance understanding regarding the interaction between exercise and energy homeostasis in women. PMID:26465216

Complete occlusion after blunt injury to the abdominal aorta.

PubMed

Meghoo, Colin A L; Gonzalez, Ernest A; Tyroch, Alan H; Wohltmann, Christopher D

2003-10-01

Injury to the abdominal aorta after blunt trauma is uncommon. When this injury results in complete vessel occlusion, the presentation is dramatic. Timely intervention is essential. After a case report, we examined all reported cases of complete occlusion after blunt injury to the abdominal aorta and reviewed the cause, presentation, and management of this injury. Complete vessel occlusion arises from intimal injury. The most frequent mechanism is compression from a seat belt or steering wheel during a motor vehicle crash. Patients present with absent femoral and distal pulses in association with lower extremity neuropathy. Intervention commonly involves bypass grafting of the abdominal aorta. Complete occlusion after blunt trauma to the abdominal aorta is rare. Neurologic deficits most commonly arise from peripheral nerve ischemia. Reperfusion within 6 hours confers a greater chance of limb salvage and neurologic recovery.

Thermoregulatory and Immune Responses During Cold Exposure: Effects of Repeated Cold Exposure and Acute Exercise

DTIC Science & Technology

2000-03-01

shivering thermogenesis and vasoconstriction) during cold exposure is unknown. Thus, a series of experiments were executed to determine if serial cold ...to cold exposure? The results of these studies suggest that 1) serial cold water blunts shivering leadmg™ower core temperatures, 2) thermoregulatory...fatigues (i.e., causes blunted shivering thermogenesis and vasoconstriction) during cold exposure is unknown. Thus, a series of experiments were

Physical exercise prevents short and long-term deficits on aversive and recognition memory and attenuates brain oxidative damage induced by maternal deprivation.

PubMed

Neves, Ben-Hur; Menezes, Jefferson; Souza, Mauren Assis; Mello-Carpes, Pâmela B

2015-12-01

It is known from previous research that physical exercise prevents long-term memory deficits induced by maternal deprivation in rats. But we could not assume similar effects of physical exercise on short-term memory, as short- and long-term memories are known to result from some different memory consolidation processes. Here we demonstrated that, in addition to long-term memory deficit, the short-term memory deficit resultant from maternal deprivation in object recognition and aversive memory tasks is also prevented by physical exercise. Additionally, one of the mechanisms by which the physical exercise influences the memory processes involves its effects attenuating the oxidative damage in the maternal deprived rats' hippocampus and prefrontal cortex.

Equilibrium radiative heating tables for Earth entry

NASA Astrophysics Data System (ADS)

Sutton, Kenneth; Hartung, Lin C.

1990-05-01

The recent resurgence of interest in blunt-body atmospheric entry for applications such as aeroassisted orbital transfer and planetary return has engendered a corresponding revival of interest in radiative heating. Radiative heating may be of importance in these blunt-body flows because of the highly energetic shock layer around the blunt nose. Sutton developed an inviscid, stagnation point, radiation coupled flow field code for investigating blunt-body atmospheric entry. The method has been compared with ground-based and flight data, and reasonable agreement has been found. To provide information for entry body studies in support of lunar and Mars return scenarios of interest in the 1970's, the code was exercised over a matrix of Earth entry conditions. Recently, this matrix was extended slightly to reflect entry vehicle designs of current interest. Complete results are presented.

Dietary thiols in exercise: oxidative stress defence, exercise performance, and adaptation.

PubMed

McLeay, Yanita; Stannard, Stephen; Houltham, Stuart; Starck, Carlene

2017-01-01

Endurance athletes are susceptible to cellular damage initiated by excessive levels of aerobic exercise-produced reactive oxygen species (ROS). Whilst ROS can contribute to the onset of fatigue, there is increasing evidence that they play a crucial role in exercise adaptations. The use of antioxidant supplements such as vitamin C and E in athletes is common; however, their ability to enhance performance and facilitate recovery is controversial, with many studies suggesting a blunting of training adaptations with supplementation. The up-regulation of endogenous antioxidant systems brought about by exercise training allows for greater tolerance to subsequent ROS, thus, athletes may benefit from increasing these systems through dietary thiol donors. Recent work has shown supplementation with a cysteine donor (N-acetylcysteine; NAC) improves antioxidant capacity by augmenting glutathione levels and reducing markers of oxidative stress, as well as ergogenic potential through association with delayed fatigue in numerous experimental models. However, the use of this, and other thiol donors may have adverse physiological effects. A recent discovery for the use of a thiol donor food source, keratin, to potentially enhance endogenous antioxidants may have important implications for endurance athletes hoping to enhance performance and recovery without blunting training adaptations.

Impairments in central cardiovascular function contribute to attenuated reflex vasodilation in aged skin

PubMed Central

Stanhewicz, Anna E.; Proctor, David N.; Alexander, Lacy M.; Kenney, W. Larry

2015-01-01

During supine passive heating, increases in skin blood flow (SkBF) and cardiac output (Qc) are both blunted in older adults. The aim here was to determine the effect of acutely correcting the peripheral vasodilatory capacity of aged skin on the integrated cardiovascular responses to passive heating. A secondary aim was to examine the SkBF-Qc relation during hyperthermia in the presence (upright posture) and absence (dynamic exercise) of challenges to central venous pressure. We hypothesized that greater increases in SkBF would be accompanied by greater increases in Qc. Eleven healthy older adults (69 ± 3 yr) underwent supine passive heating (0.8°C rise in core temperature; water-perfused suit) after ingesting sapropterin (BH4, a nitric oxide synthase cofactor; 10 mg/kg) or placebo (randomized double-blind crossover design). Twelve young (24 ± 1 yr) subjects served as a comparison group. SkBF (laser-Doppler flowmetry) and Qc (open-circuit acetylene wash-in) were measured during supine heating, heating + upright posture, and heating + dynamic exercise. Throughout supine and upright heating, sapropterin fully restored the SkBF response of older adults to that of young adults but Qc remained blunted. During heat + upright posture, SkBF failed to decrease in untreated older subjects. There were no age- or treatment-related differences in SkBF-Qc during dynamic exercise. The principal finding of this study was that the blunted Qc response to passive heat stress is directly related to age as opposed to the blunted peripheral vasodilatory capacity of aged skin. Furthermore, peripheral impairments to SkBF in the aged may contribute to inapposite responses during challenges to central venous pressure during hyperthermia. PMID:26494450

Ageing and cardiorespiratory response to hypoxia.

PubMed

Lhuissier, François J; Canouï-Poitrine, Florence; Richalet, Jean-Paul

2012-11-01

The risk of severe altitude-induced diseases is related to ventilatory and cardiac responses to hypoxia and is dependent on sex, age and exercise training status. However, it remains unclear how ageing modifies these physiological adaptations to hypoxia. We assessed the physiological responses to hypoxia with ageing through a cross-sectional 20 year study including 4675 subjects (2789 men, 1886 women; 14-85 years old) and a longitudinal study including 30 subjects explored at a mean 10.4 year interval. The influence of sex, training status and menopause was evaluated. The hypoxia-induced desaturation and the ventilatory and cardiac responses to hypoxia at rest and exercise were measured. In men, ventilatory response to hypoxia increased (P < 0.002), while desaturation was less pronounced (P < 0.001) with ageing. Cardiac response to hypoxia was blunted with ageing in both sexes (P < 0.001). Similar results were found in the longitudinal study, with a decrease in cardiac and an increase in ventilatory response to hypoxia with ageing. These adaptive responses were less pronounced or absent in post-menopausal women (P < 0.01). At exercise, desaturation was greater in trained subjects but cardiac and ventilatory responses to hypoxia were preserved by training, especially in elderly people. In conclusion, respiratory response to hypoxia and blood oxygenation improve with ageing in men while cardiac response is blunted with ageing in both sexes. Training aggravates desaturation at exercise in hypoxia, improves the ventilatory response and limits the ageing-induced blunting of cardiac response to hypoxia. Training limits the negative effects of menopause in cardiorespiratory adaptations to hypoxia.

Speech Deficits in Serious mental Illness: A Cognitive Resource Issue?

PubMed Central

Cohen, Alex S.; McGovern, Jessica E.; Dinzeo, Thomas J.; Covington, Michael A.

2014-01-01

Speech deficits, notably those involved in psychomotor retardation, blunted affect, alogia and poverty of content of speech, are pronounced in a wide range of serious mental illnesses (e.g., schizophrenia, unipolar depression, bipolar disorders). The present project evaluated the degree to which these deficits manifest as a function of cognitive resource limitations. We examined natural speech from 52 patients meeting criteria for serious mental illnesses (i.e., severe functional deficits with a concomitant diagnosis of schizophrenia, unipolar and/or bipolar affective disorders) and 30 non-psychiatric controls using a range of objective, computer-based measures tapping speech production (“alogia”), variability (“blunted vocal affect”) and content (“poverty of content of speech”). Subjects produced natural speech during a baseline condition and while engaging in an experimentally-manipulated cognitively-effortful task. For correlational analysis, cognitive ability was measured using a standardized battery. Generally speaking, speech deficits did not differ as a function of SMI diagnosis. However, every speech production and content measure was significantly abnormal in SMI versus control groups. Speech variability measures generally did not differ between groups. For both patients and controls as a group, speech during the cognitively-effortful task was sparser and less rich in content. Relative to controls, patients were abnormal under cognitive load with respect only to average pause length. Correlations between the speech variables and cognitive ability were only significant for this same variable: average pause length. Results suggest that certain speech deficits, notably involving pause length, may manifest as a function of cognitive resource limitations. Implications for treatment, research and assessment are discussed. PMID:25464920

Speech deficits in serious mental illness: a cognitive resource issue?

PubMed

Cohen, Alex S; McGovern, Jessica E; Dinzeo, Thomas J; Covington, Michael A

2014-12-01

Speech deficits, notably those involved in psychomotor retardation, blunted affect, alogia and poverty of content of speech, are pronounced in a wide range of serious mental illnesses (e.g., schizophrenia, unipolar depression, bipolar disorders). The present project evaluated the degree to which these deficits manifest as a function of cognitive resource limitations. We examined natural speech from 52 patients meeting criteria for serious mental illnesses (i.e., severe functional deficits with a concomitant diagnosis of schizophrenia, unipolar and/or bipolar affective disorders) and 30 non-psychiatric controls using a range of objective, computer-based measures tapping speech production ("alogia"), variability ("blunted vocal affect") and content ("poverty of content of speech"). Subjects produced natural speech during a baseline condition and while engaging in an experimentally-manipulated cognitively-effortful task. For correlational analysis, cognitive ability was measured using a standardized battery. Generally speaking, speech deficits did not differ as a function of SMI diagnosis. However, every speech production and content measure was significantly abnormal in SMI versus control groups. Speech variability measures generally did not differ between groups. For both patients and controls as a group, speech during the cognitively-effortful task was sparser and less rich in content. Relative to controls, patients were abnormal under cognitive load with respect only to average pause length. Correlations between the speech variables and cognitive ability were only significant for this same variable: average pause length. Results suggest that certain speech deficits, notably involving pause length, may manifest as a function of cognitive resource limitations. Implications for treatment, research and assessment are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

High protein diet maintains glucose production during exercise-induced energy deficit: a controlled trial

USDA-ARS?s Scientific Manuscript database

Inadequate energy intake induces changes in endogenous glucose production (GP) to preserve muscle mass. Whether addition provision of dietary protein modulates GP response to energy deficit is unclear. The objective was to determine whether exercise-induced energy deficit effects on glucose metaboli...

Modulation of postjunctional α-adrenergic vasoconstriction during exercise and exogenous ATP infusions in ageing humans

PubMed Central

Kirby, Brett S; Crecelius, Anne R; Voyles, Wyatt F; Dinenno, Frank A

2011-01-01

Abstract The ability to modulate sympathetic α-adrenergic vasoconstriction in contracting muscle is impaired with age. In young adults, adenosine triphosphate (ATP) has been shown to blunt sympathetic vasoconstrictor responsiveness similar to exercise. Therefore, we tested the hypothesis that modulation of postjunctional α-adrenergic vasoconstriction to exogenous ATP is impaired in ageing humans. We measured forearm blood flow (FBF; Doppler ultrasound) and calculated vascular conductance (FVC) to intra-arterial infusions of phenylephrine (α1-agonist) and dexmedetomidine (α2-agonist) during rhythmic handgrip exercise (15% MVC), a control non-exercise vasodilator condition (adenosine), and ATP infusion in seven older (64 ± 3 years) and seven young (22 ± 1 years) healthy adults. Forearm hyperaemia was matched across all vasodilatating conditions. During adenosine, forearm vasoconstrictor responses to direct α1-stimulation were lower in older compared with young adults (ΔFVC =−25 ± 3%vs.−41 ± 5%; P < 0.05), whereas the responses to α2-stimulation were not different (−35 ± 6%vs.−44 ± 8%; NS). During exercise, α1-mediated vasoconstriction was significantly blunted compared with adenosine in both young (−9 ± 2%vs.−41 ± 5%) and older adults (−15 ± 2%vs.−25 ± 3%); however, the magnitude of sympatholysis was reduced in older adults (32 ± 13 vs. 74 ± 8%; P < 0.05). Similarly, α2-mediated vasoconstriction during exercise was significantly blunted in both young (−15 ± 4%vs.−44 ± 8%) and older adults (−26 ± 3%vs.−35 ± 6%), however the magnitude of sympatholysis was reduced in older adults (19 ± 8%vs. 60 ± 10%; P < 0.05). During ATP, both α1- and α2-mediated vasoconstriction was nearly abolished in young and older adults (ΔFVC ∼−5%), and the magnitude of sympatholysis was similar in both age groups (∼85–90%). Our findings indicate that the ability to modulate postjunctional α-adrenergic vasoconstriction during exercise is impaired with age, whereas the sympatholytic effect of exogenous ATP is preserved. Thus, if impairments in vascular control during exercise in older adults involve vasoactive ATP, we speculate that circulating ATP is reduced with advancing age. PMID:21486772

The Effect of Synchronized Forced Running with Chronic Stress on Short, Mid and Long- term Memory in Rats.

PubMed

Radahmadi, Maryam; Alaei, Hojjatallah; Sharifi, Mohammad-Reza; Hosseini, Nasrin

2013-03-01

Impairment of learning and memory processes has been demonstrated by many studies using different stressors. Other reports suggested that exercise has a powerful behavioral intervention to improve cognitive function and brain health. In this research, we investigated protective effects of treadmill running on chronic stress-induced memory deficit in rats. Fifty male Wistar rats were randomly divided into five groups (n=10) as follows: Control (Co), Sham (Sh), Stress (St), Exercise (Ex) and Stress and Exercise (St & Ex) groups. Chronic restraint stress was applied by 6h/day/21days and also treadmill running at a speed 20-21m/min for 1h/day/21days. Memory function was evaluated by the passive avoidance test in different intervals (1, 7 and 21 days) after foot shock. OUR RESULTS SHOWED THAT: 1) Although exercise alone showed beneficial effects especially on short and mid-term memory (P<0.05) in comparison with control group, but synchronized exercise with stress had not significantly improved short, mid and long-term memory deficit in stressed rats. 2) Short and mid-term memory deficit was significantly (P<0.05) observed in synchronized exercise with stress and stress groups with respect to normal rats. 3) Memory deficit in synchronized exercise with stress group was nearly similar to stressed rats. 4) Helpful effects of exercise were less than harmful effects of stress when they were associated together. The data correspond to the possibility that although treadmill running alone has helpful effects on learning and memory consolidation, but when it is synchronized with stress there is no significant benefit and protective effects in improvement of memory deficit induced by chronic stress. However, it is has a better effect than no training on memory deficit in stressed rats.

Preventive and therapeutic effect of treadmill running on chronic stress-induced memory deficit in rats.

PubMed

Radahmadi, Maryam; Alaei, Hojjatallah; Sharifi, Mohammad Reza; Hosseini, Nasrin

2015-04-01

Previous results indicated that stress impairs learning and memory. In this research, the effects of preventive, therapeutic and regular continually running activity on chronic stress-induced memory deficit in rats were investigated. 70 male rats were randomly divided into seven groups as follows: Control, Sham, Stress-Rest, Rest-Stress, Stress-Exercise, Exercise-Stress and Exercise-Stress & Exercise groups. Chronic restraint stress was applied 6 h/day for 21days and treadmill running 1 h/day. Memory function was evaluated by the passive avoidance test. The results revealed that running activities had therapeutic effect on mid and long-term memory deficit and preventive effects on short and mid-term memory deficit in stressed rats. Regular continually running activity improved mid and long-term memory compared to Exercise-Stress group. The beneficial effects of exercise were time-dependent in stress conditions. Finally, data corresponded to the possibility that treadmill running had a more important role on treatment rather than on prevention on memory impairment induced by stress. Copyright © 2014 Elsevier Ltd. All rights reserved.

Post-Exercise Carbohydrate-Energy Replacement Attenuates Insulin Sensitivity and Glucose Tolerance the Following Morning in Healthy Adults

PubMed Central

Taylor, Harry L.; Wu, Ching-Lin; Chen, Yung-Chih; Wang, Pin-Ging; Betts, James A.

2018-01-01

The carbohydrate deficit induced by exercise is thought to play a key role in increased post-exercise insulin action. However, the effects of replacing carbohydrate utilized during exercise on postprandial glycaemia and insulin sensitivity are yet to be determined. This study therefore isolated the extent to which the insulin-sensitizing effects of exercise are dependent on the carbohydrate deficit induced by exercise, relative to other exercise-mediated mechanisms. Fourteen healthy adults performed a 90-min run at 70% V˙O2max starting at 1600–1700 h before ingesting either a non-caloric artificially-sweetened placebo solution (CHO-DEFICIT) or a 15% carbohydrate solution (CHO-REPLACE; 221.4 ± 59.3 g maltodextrin) to precisely replace the measured quantity of carbohydrate oxidized during exercise. The alternate treatment was then applied one week later in a randomized, placebo-controlled, and double-blinded crossover design. A standardized low-carbohydrate evening meal was consumed in both trials before overnight recovery ahead of a two-hour oral glucose tolerance test (OGTT) the following morning to assess glycemic and insulinemic responses to feeding. Compared to the CHO-DEFICIT condition, CHO-REPLACE increased the incremental area under the plasma glucose curve by a mean difference of 68 mmol·L−1 (95% CI: 4 to 132 mmol·L−1; p = 0.040) and decreased the Matsuda insulin sensitivity index by a mean difference of −2 au (95% CI: −1 to −3 au; p = 0.001). This is the first study to demonstrate that post-exercise feeding to replaceme the carbohydrate expended during exercise can attenuate glucose tolerance and insulin sensitivity the following morning. The mechanism through which exercise improves insulin sensitivity is therefore (at least in part) dependent on carbohydrate availability and so the day-to-day metabolic health benefits of exercise might be best attained by maintaining a carbohydrate deficit overnight. PMID:29370143

Postmeal exercise blunts postprandial glucose excursions in people on metformin monotherapy.

PubMed

Erickson, Melissa L; Little, Jonathan P; Gay, Jennifer L; McCully, Kevin K; Jenkins, Nathan T

2017-08-01

Metformin is used clinically to reduce fasting glucose with minimal effects on postprandial glucose. Postmeal exercise reduces postprandial glucose and may offer additional glucose-lowering benefit beyond that of metformin alone, yet controversy exists surrounding exercise and metformin interactions. It is currently unknown how postmeal exercise and metformin monotherapy in combination will affect postprandial glucose. Thus, we examined the independent and combined effects of postmeal exercise and metformin monotherapy on postprandial glucose. A randomized crossover design was used to assess the influence of postmeal exercise on postprandial glucose excursions in 10 people treated with metformin monotherapy (57 ± 10 yr, HbA 1C  = 6.3 ± 0.6%). Each participant completed the following four conditions: sedentary and postmeal exercise (5 × 10-min bouts of treadmill walking at 60% V̇o 2max ) with metformin and sedentary and postmeal exercise without metformin. Peak postprandial glucose within a 2-h time window and 2-h total area under the curve was assessed after a standardized breakfast meal, using continuous glucose monitoring. Postmeal exercise significantly blunted 2-h peak ( P = 0.001) and 2-h area under the curve ( P = 0.006), with the lowest peak postprandial glucose excursion observed with postmeal exercise and metformin combined ( P < 0.05 vs. all other conditions: metformin/sedentary: 12 ± 3.4, metformin/exercise: 9.7 ± 2.3, washout/sedentary: 13.3 ± 3.2, washout/exercise: 11.1 ± 3.4 mmol/l). Postmeal exercise and metformin in combination resulted in the lowest peak postprandial glucose excursion compared with either treatment modality alone. Exercise timed to the postprandial phase may be important for optimizing glucose control during metformin monotherapy. NEW & NOTEWORTHY The interactive effects of metformin and exercise on key physiological outcomes remain an area of controversy. Findings from this study show that the combination of metformin monotherapy and moderate-intensity postmeal exercise led to beneficial reductions in postprandial glucose excursions. Postmeal exercise may be a useful strategy for the management of postprandial glucose in people on metformin. Copyright © 2017 the American Physiological Society.

Trade-offs between anti-aging dietary supplementation and exercise.

PubMed

Mendelsohn, Andrew R; Larrick, James W

2013-10-01

In otherwise healthy adults, moderate aerobic exercise extends life span and likely health span by 2-6 years. Exercise improves blood sugar regulation, and resistance exercise increases or maintains muscle mass and is associated with improved cognitive function. On the other hand, evidence for anti-oxidant supplements increasing longevity in humans is lacking. On the contrary, transient hormetic increases in reactive oxygen species (ROS), for example, associated with exercise, are actually associated with increased mammalian health span and life span. Recent studies in humans suggest that anti-oxidants such as vitamins C, E, resveratrol, and acetyl-N-cysteine blunt the beneficial effects of exercise on glucose sensitivity and blood sugar regulation, likely through direct inhibition of ROS signaling. Alternately, other studies suggest that vitamin C has beneficial effects on exercise-associated dysfunction, inhibiting exercise-induced bronchioconstriction. These data suggest that there are tradeoffs between potential benefits and harm from anti-oxidant dietary supplementation. Specific biomolecular interactions for each antioxidant also will be important. Omega-3 (n-3) polyunsaturated fattty acids (PUFAs) have anti-inflammatory activity that is not mediated through direct ROS inhibition. Although data are limited in humans, n-3 PUFAs do not seem to blunt blood sugar regulatory benefits of aerobic exercise and actually increase anabolic activity in skeletal muscle. However, another kind of tradeoff may exist with PUFAs, at least for men. A recent large clinical trial demonstrates an association of omega-3 fatty acids blood levels with increased incidence of prostate cancer, especially aggressive prostate cancer. Together these results suggest that there are significant tradeoffs in the use of dietary supplementation for prevention and treatment of diseases associated with aging. Such tradeoffs may result from underlying intertwined homeostatic mechanisms. For most individuals, moderate exercise is of significant benefit. Careful attention to individual and family medical history and personal genomic data may prove essential to make wise dietary and supplement choices to be combined with exercise.

Improved Arterial–Ventricular Coupling in Metabolic Syndrome after Exercise Training

PubMed Central

Fournier, Sara B.; Donley, David A.; Bonner, Daniel E.; DeVallance, Evan; Olfert, I. Mark; Chantler, Paul D.

2014-01-01

Purpose The metabolic syndrome (MetS) is associated with a three-fold increase risk of cardiovascular (CV) morbidity and mortality, which is in part, due to a blunted CV reserve capacity, reflected by a reduced peak exercise left ventricular contractility and aerobic capacity, and a blunted peak arterial-ventricular coupling. To date, no study has examined whether aerobic exercise training in MetS can reverse the peak exercise CV dysfunction. Further, examining how exercise training alters CV function in a group of individuals with MetS prior to the development of diabetes and/or overt CVD, can provide insights into whether some of the pathophysiological changes to the CV can be delayed/reversed, lowering their CV risk. The objective of this study was to examine the effects of 8 weeks of aerobic exercise training in individuals with MetS on resting and peak exercise CV function. Methods Twenty MetS underwent either 8 weeks of aerobic exercise training (MetS-ExT; n=10) or remained sedentary (MetS-NonT; n=10) during this time period. Resting and peak exercise CV function was characterized using Doppler echocardiography and gas exchange. Results Exercise training did not alter resting left ventricular diastolic or systolic function and arterial-ventricular coupling in MetS. In contrast, at peak exercise an increase in LV contractility (40%, p<0.01), cardiac output (28%, p<0.05) and aerobic capacity (20%, p<0.01), while a reduction in vascular resistance (30%, p<0.05) and arterial-ventricular coupling (27%, p<0.01), were noted in the MetS-ExT but not the MetS-NonT group. Further, an improvement in Lifetime Risk Score was also noted in the MetS-ExT group. Conclusions These findings have clinical importance as they provide insight that some of the pathophysiological changes associated with MetS can be improved and lower the risk of CVD. PMID:24870568

Improved arterial-ventricular coupling in metabolic syndrome after exercise training: a pilot study.

PubMed

Fournier, Sara B; Donley, David A; Bonner, Daniel E; Devallance, Evan; Olfert, I Mark; Chantler, Paul D

2015-01-01

The metabolic syndrome (MetS) is associated with threefold increased risk of cardiovascular (CV) morbidity and mortality, which is partly due to a blunted CV reserve capacity, reflected by a reduced peak exercise left ventricular (LV) contractility and aerobic capacity and a blunted peak arterial-ventricular coupling. To date, no study has examined whether aerobic exercise training in MetS can reverse peak exercise CV dysfunction. Furthermore, examining how exercise training alters CV function in a group of individuals with MetS before the development of diabetes and/or overt CV disease can provide insights into whether some of the pathophysiological CV changes can be delayed/reversed, lowering their CV risk. The objective of this study was to examine the effects of 8 wk of aerobic exercise training in individuals with MetS on resting and peak exercise CV function. Twenty participants with MetS underwent either 8 wk of aerobic exercise training (MetS-ExT, n = 10) or remained sedentary (MetS-NonT, n = 10) during this period. Resting and peak exercise CV function was characterized using Doppler echocardiography and gas exchange. Exercise training did not alter resting LV diastolic or systolic function and arterial-ventricular coupling in MetS. In contrast, at peak exercise, an increase in LV contractility (40%, P < 0.01), cardiac output (28%, P < 0.05), and aerobic capacity (20%, P < 0.01), but a reduction in vascular resistance (30%, P < 0.05) and arterial-ventricular coupling (27%, P < 0.01), were noted in the MetS-ExT but not in the MetS-NonT group. Furthermore, an improvement in lifetime risk score was also noted in the MetS-ExT group. These findings have clinical importance because they provide insight that some of the pathophysiological changes associated with MetS can be improved and can lower the risk of CV disease.

Does Sport-Drink Use During Exercise Promote an Acute Positive Energy Balance?

PubMed

Dragusin, Iulian B; Horswill, Craig A

2016-10-01

Sports drinks have been implicated in contributing to obesity and chronic diseases by providing surplus calories and excess sugars. Using existing literature we compared energy intake from sports drinks consumed during exercise with the exercise-induced calorie expenditure to determine whether sports drink use might eliminate the energy deficit and jeopardize conditions for improved metabolic fitness. We identified 11 published studies that compared sport drink consumption to placebo during exercise with a primary focused on the effect of sport drinks or total carbohydrate content on enhancing physical performance. Energy expenditure (EE) was calculated using VO 2 , RER, and exercise duration for the exercise protocol. Energy ingestion (EI) was determined using the carbohydrate dosing regimen administered before and during the exercise protocol. A two-tailed t test was used to test whether the energy balance (EI-EE) was different from zero (alpha level = 0.05). Sport drink consumption during aerobic exercise of sufficient duration (≥ 60 min) did not abolish the energy deficit (p < .001). Mean ± SD were EE, 1600 ± 639 Cal; EI, 394 ± 289 Cal; and EI-EE,-1206+594 Cal; VO 2 , 3.05 ± 0.55 L/min; RER, 0.91 ± 0.04; exercise duration 110 ± 42 min. Ingesting sports drinks to enhance performance did not abolish the caloric deficit of aerobic exercise. Sports drinks can be used in accordance with research protocols that typically provide 30-60 g of carbohydrate per hour when exercising at adequate durations for moderate to high intensity and still maintain a substantive caloric deficit.

Association Between Energy Balance and Metabolic Hormone Suppression During Ultraendurance Exercise.

PubMed

Geesmann, Bjoern; Gibbs, Jenna C; Mester, Joachim; Koehler, Karsten

2017-08-01

Ultraendurance athletes often accumulate an energy deficit when engaging in ultraendurance exercise, and on completion of the exercise, they exhibit endocrine changes that are reminiscent of starvation. However, it remains unclear whether these endocrine changes are a result of the exercise per se or secondary to the energy deficit and, more important, whether these changes can be attenuated by increased dietary intake. The goal of the study was to assess the relationship between changes in key metabolic hormones after ultraendurance exercise and measures of energy balance. Metabolic hormones, as well as energy intake and expenditure, were assessed in 14 well-trained male cyclists who completed a 1230-km ultraendurance cycling event. After completion of the event, serum testosterone (-67% ± 18%), insulin-like growth factor-1 (IGF-1) (-45% ± 8%), and leptin (-79% ± 9%) were significantly suppressed (P < .001) and remained suppressed after a 12-h recovery period (P < .001). Changes in IGF-1 were positively correlated with energy balance over the course of the event (r = .65, P = .037), which ranged from an 11,859-kcal deficit to a 3593-kcal surplus. The marked suppression of testosterone, IGF-1, and leptin after ultraendurance exercise is comparable to changes occurring during acute starvation. The suppression of IGF-1, but not that of other metabolic hormones, was strongly associated with the magnitude of the energy deficit, indicating that athletes who attained a greater energy deficit exhibited a more pronounced drop in IGF-1. Future studies are needed to determine whether increased dietary intake can attenuate the endocrine response to ultraendurance exercise.

Maximum striking velocities in strikes with steel rods-the influence of rod length, rod mass and volunteer parameters.

PubMed

Trinh, T X; Heinke, S; Rode, C; Schenkl, S; Hubig, M; Mall, G; Muggenthaler, Holger

2018-03-01

In blunt force trauma to the head caused by attacks with blunt instruments, contact forces can be estimated based on the conservation of momentum if impact velocities are known. The aims of this work were to measure maximum striking velocities and to examine the influence of rod parameters such as rod mass and length as well as volunteer parameters such as sex, age, body height, body mass, body mass index and the average amount of physical exercise. Steel rods with masses of 500, 1000 and 1500 g as well as lengths of 40, 65 and 90 cm were exemplarily tested as blunt instruments. Twenty-nine men and 22 women participated in this study. Each volunteer performed several vertical strikes with the steel rods onto a passive immobile target. Maximum striking velocities were measured by means of a Qualisys motion capture system using high-speed cameras and infrared light. Male volunteers achieved maximum striking velocities between 14.0 and 35.5 m/s whereas female volunteers achieved values between 10.4 and 28.3 m/s. Results show that maximum striking velocities increased with smaller rod masses and less consistently with higher rod lengths. Statistically significant influences were found in the volunteers' sex and average amount of physical exercise.

Oral L-arginine before resistance exercise blunts growth hormone in strength trained males.

PubMed

Forbes, Scott C; Harber, Vicki; Bell, Gordon J

2014-04-01

Acute resistance exercise and L-arginine have both been shown to independently elevate plasma growth hormone (GH) concentrations; however, their combined effect is controversial. The purpose was to investigate the combined effects of resistance exercise and L-arginine supplementation on plasma L-arginine, GH, GH secretagogues, and IGF-1 in strength trained participants. Fourteen strength trained males (age: 25 ± 4 y; body mass: 81.4 ± 9.0 kg; height: 179.4 ± 6.9 cm; and training experience: 6.3 ± 3.4 y) participated in a randomized double-blind crossover design (separated by ~7 days). Subjects reported to the laboratory at 08:00 in a fasted state, consumed L-arginine (ARG; 0.075 g·kg-1 body mass) or a placebo (PLA) before performing an acute bout of resistance exercise (3 sets of 8 exercises, 10 repetitions at ~75% 1RM). Blood samples were collected at rest, before exercise, and at 0, 15, 30, and 60 min of rest-recovery. The ARG condition significantly increased plasma L-arginine concentrations (~120%) while no change was detected in the PLA condition. There were no differences between conditions for GH, GH-releasing hormone, ghrelin, or IGF-1 at any time point. GH-inhibiting hormone was significantly lower in the ARG condition. However, integrated area under the curve for GH was blunted in the ARG condition (L-arginine = 288.4 ± 368.7 vs. placebo = 487.9± 482.0 min·ng·mL1, p < .05). L-arginine ingested before resistance exercise significantly elevated plasma L-arginine concentration but attenuated plasma GH in strength trained individuals despite a lower GHIH. Furthermore our data shows that the GH suppression was not due to a GH or IGF-1 induced autonegative feedback loop.

Cardio-embolic stroke following remote blunt chest trauma.

PubMed

Arora, Sonali; Atreya, Auras R; Penumetsa, Srikanth C; Hiser, William L

2013-03-01

A cardio-embolic stroke as a sequela of remote blunt chest trauma is a rare clinical presentation. Blunt chest trauma can cause various acute cardiac complications like arrhythmias, cardiac contusion etc. However, delayed consequences such as left ventricular thrombus resulting in thromboembolic phenomena are reported infrequently. A 30-year-old healthy man presented to an outside facility with transient neurological deficits. An MRI brain showed lesions suggestive of embolic etiology. A trans-thoracic echocardiogram (TTE) showed a 1.5 × 1.5 cm mass present in the left ventricular (LV) apex. Patient was transferred to our institution for cardiac surgery evaluation. On detailed questioning, he reported an incident of blunt chest trauma during a martial arts exhibition fight that took place 2 years back. Given this history, a cardiac catheterization was done, which showed 30% stenosis in mid-left anterior descending artery (LAD) without any other significant obstructive lesion. A trans-esophageal echocardiogram (TEE) showed akinesis of the LV apex and confirmed TTE finding of a mass, consistent with an apical thrombus. Surgery was deferred and patient was started on anticoagulation. A cardiac MRI done 2 weeks later showed evidence of apical infarction in the LAD territory. LAD is the most commonly affected coronary vessel by blunt traumatic injuries, likely due to its vulnerable anatomical position on the anterior aspect of the heart. A variety of mechanisms including intimal tear, rupture and spasm have been implicated in the pathogenesis of myocardial infarction after blunt chest trauma.

Emphysema on Thoracic CT and Exercise Ventilatory Inefficiency in Mild-to-Moderate COPD.

PubMed

Jones, Joshua H; Zelt, Joel T; Hirai, Daniel M; Diniz, Camilla V; Zaza, Aida; O'Donnell, Denis E; Neder, J Alberto

2017-04-01

There is growing evidence that emphysema on thoracic computed tomography (CT) is associated with poor exercise tolerance in COPD patients with only mild-to-moderate airflow obstruction. We hypothesized that an excessive ventilatory response to exercise (ventilatory inefficiency) would underlie these abnormalities. In a prospective study, 19 patients (FEV 1 = 82 ± 13%, 12 Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 1) and 26 controls underwent an incremental exercise test. Ventilatory inefficiency was assessed by the ventilation ([Formula: see text]E)/CO 2 output ([Formula: see text]CO 2 ) nadir. Pulmonary blood flow (PBF) in a submaximal test was calculated by inert gas rebreathing. Emphysema was quantified as % of attenuation areas below 950 HU. Patients typically presented with centrilobular emphysema (76.8 ± 10.1% of total emphysema) in the upper lobes (upper/total lung ratio = 0.82 ± 0.04). They had lower peak oxygen uptake ([Formula: see text]O 2 ), higher [Formula: see text]E/[Formula: see text]CO 2 nadir, and greater dyspnea scores than controls (p < 0.05). Lower peak [Formula: see text]O 2 and worse dyspnea were found in patients with higher [Formula: see text]E/[Formula: see text]CO 2 nadirs (≥30). Patients had blunted increases in PBF from rest to iso-[Formula: see text]O 2 exercise (p < 0.05). Higher [Formula: see text]E/[Formula: see text]CO 2 nadir in COPD was associated with emphysema severity (r = 0.63) which, in turn, was related to reduced lung diffusing capacity (r = -0.72) and blunted changes in PBF from rest to exercise (r = -0.69) (p < 0.01). Ventilation "wasted" in emphysematous areas is associated with impaired exercise ventilatory efficiency in mild-to-moderate COPD. Exercise ventilatory inefficiency links structure (emphysema) and function (D L CO) to a key clinical outcome (poor exercise tolerance) in COPD patients with only modest spirometric abnormalities.

Attenuation of exercise-induced heat shock protein 72 expression blunts improvements in whole-body insulin resistance in rats with type 2 diabetes.

PubMed

Tsuzuki, Takamasa; Kobayashi, Hiroyuki; Yoshihara, Toshinori; Kakigi, Ryo; Ichinoseki-Sekine, Noriko; Naito, Hisashi

2017-03-01

Heat shock proteins (HSPs) play an important role in insulin resistance and improve the cellular stress response via HSP induction by exercise to treat type 2 diabetes. In this study, the effects of exercise-induced HSP72 expression levels on whole-body insulin resistance in type 2 diabetic rats were investigated. Male 25-week-old Otsuka Long-Evans Tokushima Fatty rats were divided into three groups: sedentary (Sed), trained in a thermal-neutral environment (NTr: 25 °C), and trained in a cold environment (CTr: 4 °C). Exercise training was conducted 5 days/week for 10 weeks. Rectal temperature was measured following each bout of exercise. An intraperitoneal glucose tolerance test (IPGTT) was performed after the training sessions. The serum, gastrocnemius muscle, and liver were sampled 48 h after the final exercise session. HSP72 and heat shock cognate protein 73 expression levels were analyzed by Western blot, and serum total cholesterol, triglyceride (TG), and free fatty acid (FFA) levels were measured. NTr animals exhibited significantly higher body temperatures following exercise, whereas, CTr animals did not. Exercise training increased HSP72 levels in the gastrocnemius muscle and liver, whereas, HSP72 expression was significantly lower in the CTr group than that in the NTr group (p < 0.05). Glucose tolerance improved equally in both trained animals; however, insulin levels during the IPGTT were higher in CTr animals than those in NTr animals (p < 0.05). In addition, the TG and FFA levels decreased significantly only in NTr animals compared with those in Sed animals. These results suggest that attenuation of exercise-induced HSP72 expression partially blunts improvement in whole-body insulin resistance and lipid metabolism in type 2 diabetic rats.

Residual effects of combat-related mild traumatic brain injury.

PubMed

Kontos, Anthony P; Kotwal, Russ S; Elbin, R J; Lutz, Robert H; Forsten, Robert D; Benson, Peter J; Guskiewicz, Kevin M

2013-04-15

Mild traumatic brain injury (mTBI) has gained considerable notoriety during the past decade of conflict in Afghanistan and Iraq. However, the relationship between combat-related mTBI and residual mTBI symptoms, post-traumatic stress disorder (PTSD) symptoms, and neurocognitive deficits remains unclear. The purpose of the study was to compare residual mTBI and PTSD symptoms, and neurocognitive deficits among U.S. Army Special Operations Command (USASOC) personnel with diagnosed blunt, blast, and blast-blunt combination mTBIs. This study involved a retrospective medical records review of 27,169 USASOC personnel who completed a military version of the Immediate Post-Concussion Assessment Cognitive Test (ImPACT), Post-Concussion Symptom Scale (PCSS), and PTSD Checklist (PCL) between November 2009 and December 2011. Of the 22,203 personnel who met criteria for the study, 2,813 (12.7%) had a diagnosis of at least one mTBI. A total of 28% (n=410) of USASOC personnel with a history of diagnosed mTBI reported clinical levels of PTSD symptoms. Personnel with a history of diagnosed blunt (OR=3.58), blast (OR=4.23) or combination (OR=5.73) mTBI were at significantly (p=0.001) greater risk of reporting clinical levels of PTSD symptoms than those with no history of mTBI. A dose-response gradient for exposure to blast/combination mTBI on clinical levels of PTSD symptoms was also significant (p=0.001). Individuals with blast/combination mTBIs scored higher in residual mTBI (p=0.001) and PTSD symptoms (p=0.001), and performed worse on tests of visual memory (p=0.001), and reaction time (p=0.001) than those with blunt or no mTBI history. Individuals with combination mTBIs scored lower in verbal memory (p=0.02) than those with blunt mTBIs. Residual PTSD and mTBI symptoms appear to be more prevalent in personnel with blast mTBI. A dose-response gradient for blast mTBI and symptoms suggests that repeated exposures to these injuries may have lingering effects.

Duration-dependence of the effect of treadmill exercise on hyperactivity in attention deficit hyperactivity disorder rats.

PubMed

Ji, Eun-Sang; Kim, Chang-Ju; Park, Jun Heon; Bahn, Geon Ho

2014-04-01

Attention-deficit hyperactivity disorder (ADHD) is a common neurobehavioral disorder, and its symptoms are hyperactivity and deficits in learning and memory. Physical exercise increases dopamine synthesis and neuronal activity in various brain regions. In the present study, we investigate the duration-dependence of the treadmill exercise on hyperactivity in relation with dopamine expression in ADHD. Spontaneously hypertensive rats were used for the ADHD rats and Wistar-Kyoto rats were used for the control rats. The rats in the exercise groups were forced to run on a treadmill for 10 min, 30 min, and 60 min once daily for 28 consecutive days. For this experiment, open field test and immunohistochemistry for tyrosine hydroxylase were conducted. The present results revealed that ADHD rats showed hyperactivity, and tyrosine hydroxylase expression in the striatum and substantia nigra were decreased in ADHD rats. Treadmill exercise alleviated hyperactivity and also increased TH expression in ADHD rats. Treadmill exercise for 30 min per day showed most potent suppressing effect on hyperactivity, and this dose of treadmill exercise also most potently inhibited tyrosine hydroxylase expression. The present study suggests that treadmill exercise for 30 min once a day is the most effective therapeutic intervention for ADHD patients.

Impaired modulation of postjunctional α1 - but not α2 -adrenergic vasoconstriction in contracting forearm muscle of postmenopausal women.

PubMed

Kruse, Nicholas T; Hughes, William E; Ueda, Kenichi; Hanada, Satoshi; Feider, Andrew J; Iwamoto, Erika; Bock, Joshua M; Casey, Darren P

2018-04-30

Contraction-mediated blunting of postjunctional α-adrenergic vasoconstriction (functional sympatholysis) is attenuated in skeletal muscle of ageing males, brought on by altered postjunctional α 1 - and α 2 -adrenergic receptor sensitivity. The extent to which postjunctional α-adrenergic vasoconstriction occurs in the forearms at rest and during exercise in postmenopausal women remains unknown. The novel findings indicate that contraction-mediated blunting of α 1 - (via intra-arterial infusion of phenylephrine) but not α 2 -adrenergic (via intra-arterial infusion of dexmedetomidine) vasoconstriction was attenuated in postmenopausal women compared to young women. Additional important findings revealed that postjunctional α-adrenergic vasoconstrictor responsiveness at rest does not appear to be affected by age in women. Collectively, these results contribute to our understanding of local neurovascular control at rest and during exercise with age in women. Contraction-mediated blunting of postjunctional α-adrenergic vasoconstriction (functional sympatholysis) is attenuated in older males; however, direct confirmation of this effect remains unknown in postmenopausal women (PMW). The present study examined whether PMW exhibit augmented postjunctional α-adrenergic receptor vasoconstriction at rest and during forearm exercise compared to young women (YW). Eight YW (24 ± 1 years) and eight PMW (65 ± 1 years) completed a series of randomized experimental trials: (1) at rest, (2) under high flow (adenosine infusion) conditions and (3) during 6 min of forearm exercise at relative (20% of maximum) and absolute (7 kg) intensities. Phenylephrine (α 1 -agonist) or dexmedetomidine (α 2 -agonist) was administered during the last 3 min of each trial to elicit α-adrenergic vasoconstriction. Forearm vascular conductance (FVC) was calculated from blood flow and blood pressure. Vasoconstrictor responsiveness was identified as the change in FVC (%) during α-adrenergic agonist infusions from baseline (resting trial) or from steady-state conditions (high flow and exercise trials). During resting and high flow trials, the %FVC during α 1 - and α 2 -agonist stimulation was similar between YW and PMW. During exercise, α 1 -mediated vasoconstriction was blunted in YW vs. PMW at relative (-6 ± 2% vs. -15 ± 3%) and absolute (-4 ± 2% vs. -14 ± 5%) workloads, such that blood flow and FVC were lower in PMW (P < 0.05 for all). Conversely, α 2 -mediated vasoconstriction was similar between YW and PMW at relative (-22 ± 3% vs. -22 ± 4%; P > 0.05) and absolute (-19 ± 3% vs. -18 ± 4%; P > 0.05) workloads. Collectively, these findings demonstrate that despite similar α-adrenergic vasoconstrictor responsiveness at rest, PMW have a decreased ability to attenuate α 1 -adrenergic vasoconstriction in contracting skeletal muscle. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

Increased Protein Maintains Nitrogen Balance during Exercise-Induced Energy Deficit

USDA-ARS?s Scientific Manuscript database

PURPOSE: This study examined how a high-protein diet affected nitrogen balance and protein turnover during an exercise-induced energy deficit. METHODS: Twenty-two men completed a 4-d (D1-4) baseline period (BL) of an energy balance diet while maintaining usual physical activity level, followed by 7 ...

Forced running exercise attenuates hippocampal neurogenesis impairment and the neurocognitive deficits induced by whole-brain irradiation via the BDNF-mediated pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ji, Jian-feng; Ji, Sheng-jun; Sun, Rui

Highlights: •Forced exercise can ameliorate WBI induced cognitive impairment in our rat model. •Mature BDNF plays an important role in the effects of forced exercise. •Exercise may be a possible treatment of the radiation-induced cognitive impairment. -- Abstract: Cranial radiotherapy induces progressive and debilitating cognitive deficits, particularly in long-term cancer survivors, which may in part be caused by the reduction of hippocampal neurogenesis. Previous studies suggested that voluntary exercise can reduce the cognitive impairment caused by radiation therapy. However, there is no study on the effect of forced wheel exercise and little is known about the molecular mechanisms mediating themore » effect of exercise. In the present study, we investigated whether the forced running exercise after irradiation had the protective effects of the radiation-induced cognitive impairment. Sixty-four Male Sprague–Dawley rats received a single dose of 20 Gy or sham whole-brain irradiation (WBI), behavioral test was evaluated using open field test and Morris water maze at 2 months after irradiation. Half of the rats accepted a 3-week forced running exercise before the behavior detection. Immunofluorescence was used to evaluate the changes in hippocampal neurogenesis and Western blotting was used to assess changes in the levels of mature brain-derived neurotrophic factor (BDNF), phosphorylated tyrosine receptor kinase B (TrkB) receptor, protein kinase B (Akt), extracellular signal-regulated kinase (ERK), calcium-calmodulin dependent kinase (CaMKII), cAMP-calcium response element binding protein (CREB) in the BDNF–pCREB signaling. We found forced running exercise significantly prevented radiation-induced cognitive deficits, ameliorated the impairment of hippocampal neurogenesis and attenuated the down-regulation of these proteins. Moreover, exercise also increased behavioral performance, hippocampal neurogenesis and elevated BDNF–pCREB signaling in non-irradiation group. These results suggest that forced running exercise offers a potentially effective treatment for radiation-induced cognitive deficits.« less

Preliminary evidence of a blunted anti-inflammatory response to exhaustive exercise in fibromyalgia

PubMed Central

Torgrimson-Ojerio, Britta; Ross, Rebecca L.; Dieckman, Nathaniel F.; Avery, Stephanie; Bennett, Robert M.; Jones, Kim D.; Guarino, Anthony J.; Wood, Lisa J.

2014-01-01

Exercise intolerance, as evidenced by a worsening of pain, fatigue, and stiffness after novel exertion, is a key feature of fibromyalgia (FM). In this pilot study, we investigate whether; insufficient muscle repair processes and impaired anti-inflammatory mechanisms result in an exaggerated pro-inflammatory cytokine response to exhaustive exercise, and consequently a worsening of muscle pain, stiffness and fatigue in the days post-exercise. We measured changes in muscle pain and tenderness, fatigue, stiffness, and serum levels of neuroendocrine and inflammatory cytokine markers in 20 women with FM and 16 healthy controls (HCs) before and after exhaustive treadmill exercise. Compared to HCs, FM participants failed to mount the expected anti-inflammatory response to exercise and experienced a worsening of symptoms post-exercise. However, changes in post-exertional symptoms were not mediated by post-exertional changes in pro-inflammatory cytokine levels. Implications of these findings are discussed. PMID:25457842

A Study on the Gastrointestinal Hormones and the Gastric Acid Secretion during Physical Stress in Man,

DTIC Science & Technology

1983-12-15

meal and oral glucose during prolonged severe exercise, caloric deficit and sleep deprivation 43 Paper II Secretin - a new stress hormone? 49 8 Page...secretion (gastrin), and that are influenced by the amount of gastric acid produced (secretin, group I pepsinogens). Our subjects were in caloric deficit...response to a liquid meal and oral glucose during prolonged severe exercise, caloric deficit, and sleep deprivation. O Oektedalen, 0 Flaten, P K Opstad

Muscular, cardiac, ventilatory and metabolic dysfunction in patients with multiple sclerosis: Implications for screening, clinical care and endurance and resistance exercise therapy, a scoping review.

PubMed

Wens, Inez; Eijnde, Bert O; Hansen, Dominique

2016-08-15

In the treatment of multiple sclerosis (MS), exercise training is now considered a cornerstone. However, most clinicians tend to focus on neurologic deficits only, and thus prefer to prescribe rehabilitation programs specifically to counteract these deficits. However, the present comprehensive review shows that patients with MS (pwMS) also experience significant muscular, cardiac, ventilatory and metabolic dysfunction, which significantly contribute, next to neurologic deficits, to exercise intolerance. In addition, these anomalies also might increase the risk for frequent hospitalization and morbidity and can reduce life expectancy. Unfortunately, the impact of exercise intervention on these anomalies in pwMS are mostly unknown. Therefore, it is suggested that pwMS should be screened systematically for muscular, cardiac, ventilatory and metabolic function during exercise testing. The detection of such anomalies should lead to adaptations and optimisation of exercise training prescription and clinical care/medical treatment of pwMS. In addition, future studies should focus on the impact of exercise intervention on muscular, cardiac, ventilatory and metabolic (dys)function in pwMS, to contribute to improved treatment and care. Copyright © 2016. Published by Elsevier B.V.

Exogenous NO administration and alpha-adrenergic vasoconstriction in human limbs.

PubMed

Rosenmeier, Jaya B; Fritzlar, Sandy J; Dinenno, Frank A; Joyner, Michael J

2003-12-01

Nitric oxide (NO) is capable of blunting alpha-adrenergic vasoconstriction in contracting skeletal muscles of experimental animals (functional sympatholysis). We therefore tested the hypothesis that exogenous NO administration can blunt alpha-adrenergic vasoconstriction in resting human limbs by measuring forearm blood flow (FBF; Doppler ultrasound) and blood pressure in eight healthy males during brachial artery infusions of three alpha-adrenergic constrictors (tyramine, which evokes endogenous norepinephrine release; phenylephrine, an alpha1-agonist; and clonidine, an alpha2-agonist). To simulate exercise hyperemia, the vasoconstriction caused by the alpha-agonists was compared during adenosine-mediated (>50% NO independent) and sodium nitroprusside-mediated (SNP; NO donor) vasodilation of the forearm. Both adenosine and SNP increased FBF from approximately 35-40 to approximately 200-250 ml/min. All three alpha-adrenergic constrictor drugs caused marked reductions in FBF and calculated forearm vascular conductance (P < 0.05). The relative reductions in forearm vascular conductance caused by the alpha-adrenergic constrictors during SNP infusion were similar (tyramine, -74 +/- 3 vs. -65 +/- 2%; clonidine, -44 +/- 6 vs. -44 +/- 6%; P > 0.05) or slightly greater (phenylephrine, -47 +/- 6 vs. -33 +/- 6%; P < 0.05) compared with the responses during adenosine. In conclusion, these results indicate that exogenous NO sufficient to raise blood flow to levels simulating those seen during exercise does not blunt alpha-adrenergic vasoconstriction in the resting human forearm.

Top 10 Research Questions Related to Exercise Deficit Disorder (EDD) in Youth

ERIC Educational Resources Information Center

Faigenbaum, Avery D.; Best, Thomas M.; MacDonald, James; Myer, Gregory D.; Stracciolini, Andrea

2014-01-01

Exercise deficit disorder (EDD) is a pediatric medical condition characterized by reduced levels of moderate-to-vigorous physical activity (MVPA) that are below current recommendations and inconsistent with positive health outcomes. At present, a majority of children and adolescents meet the diagnostic criteria for EDD because they are not…

Exercise prescription to reverse frailty.

PubMed

Bray, Nick W; Smart, Rowan R; Jakobi, Jennifer M; Jones, Gareth R

2016-10-01

Frailty is a clinical geriatric syndrome caused by physiological deficits across multiple systems. These deficits make it challenging to sustain homeostasis required for the demands of everyday life. Exercise is likely the best therapy to reverse frailty status. Literature to date suggests that pre-frail older adults, those with 1-2 deficits on the Cardiovascular Health Study-Frailty Phenotype (CHS-frailty phenotype), should exercise 2-3 times a week, for 45-60 min. Aerobic, resistance, flexibility, and balance training components should be incorporated but resistance and balance activities should be emphasized. On the other hand, frail (CHS-frailty phenotype ≥ 3 physical deficits) older adults should exercise 3 times per week, for 30-45 min for each session with an emphasis on aerobic training. During aerobic, balance, and flexibility training, both frail and pre-frail older adults should work at an intensity equivalent to a rating of perceived exertion of 3-4 ("somewhat hard") on the Borg CR10 scale. Resistance-training intensity should be based on a percentage of 1-repetition estimated maximum (1RM). Program onset should occur at 55% of 1RM (endurance) and progress to higher intensities of 80% of 1RM (strength) to maximize functional gains. Exercise is the medicine to reverse or mitigate frailty, preserve quality of life, and restore independent functioning in older adults at risk of frailty.

The Active Classroom: Supporting Students with Attention Deficit Hyperactivity Disorder through Exercise

ERIC Educational Resources Information Center

Mulrine, Christopher F.; Prater, Mary Anne; Jenkins, Amelia

2008-01-01

Teachers face many challenges in their daily effort to meet the needs of and ensure success for a diverse group of students, including students who are inattentive and have trouble staying focused and on task. All students, especially those with attention deficit hyperactivity disorder (ADHD), need exercise; it assists them with concentration and…

Increased dietary protein attenuates C-reactive protein and creatine kinase responses to exercise-induced energy deficit

USDA-ARS?s Scientific Manuscript database

We determined if dietary protein (P) modulates responses of C-reactive protein (CRP) and creatine kinase (CK), biomarkers of inflammation and muscle damage, during exercise-induced energy deficit (DEF). Thirteen healthy men (22 +/- 1 y, VO2peak 60 +/- 2 ml.kg-1.min-1) balanced energy expenditure (EE...

Exercise-induced muscle damage and running economy in humans.

PubMed

Assumpção, Cláudio de Oliveira; Lima, Leonardo Coelho Rabello; Oliveira, Felipe Bruno Dias; Greco, Camila Coelho; Denadai, Benedito Sérgio

2013-01-01

Running economy (RE), defined as the energy demand for a given velocity of submaximal running, has been identified as a critical factor of overall distance running performance. Plyometric and resistance trainings, performed during a relatively short period of time (~15-30 days), have been successfully used to improve RE in trained athletes. However, these exercise types, particularly when they are unaccustomed activities for the individuals, may cause delayed onset muscle soreness, swelling, and reduced muscle strength. Some studies have demonstrated that exercise-induced muscle damage has a negative impact on endurance running performance. Specifically, the muscular damage induced by an acute bout of downhill running has been shown to reduce RE during subsequent moderate and high-intensity exercise (>65% VO₂max). However, strength exercise (i.e., jumps, isoinertial and isokinetic eccentric exercises) seems to impair RE only for subsequent high-intensity exercise (~90% VO₂max). Finally, a single session of resistance exercise or downhill running (i.e., repeated bout effect) attenuates changes in indirect markers of muscle damage and blunts changes in RE.

An integrated physiology model to study regional lung damage effects and the physiologic response

PubMed Central

2014-01-01

Background This work expands upon a previously developed exercise dynamic physiology model (DPM) with the addition of an anatomic pulmonary system in order to quantify the impact of lung damage on oxygen transport and physical performance decrement. Methods A pulmonary model is derived with an anatomic structure based on morphometric measurements, accounting for heterogeneous ventilation and perfusion observed experimentally. The model is incorporated into an existing exercise physiology model; the combined system is validated using human exercise data. Pulmonary damage from blast, blunt trauma, and chemical injury is quantified in the model based on lung fluid infiltration (edema) which reduces oxygen delivery to the blood. The pulmonary damage component is derived and calibrated based on published animal experiments; scaling laws are used to predict the human response to lung injury in terms of physical performance decrement. Results The augmented dynamic physiology model (DPM) accurately predicted the human response to hypoxia, altitude, and exercise observed experimentally. The pulmonary damage parameters (shunt and diffusing capacity reduction) were fit to experimental animal data obtained in blast, blunt trauma, and chemical damage studies which link lung damage to lung weight change; the model is able to predict the reduced oxygen delivery in damage conditions. The model accurately estimates physical performance reduction with pulmonary damage. Conclusions We have developed a physiologically-based mathematical model to predict performance decrement endpoints in the presence of thoracic damage; simulations can be extended to estimate human performance and escape in extreme situations. PMID:25044032

Ischemic Preconditioning Blunts Muscle Damage Responses Induced by Eccentric Exercise.

PubMed

Franz, Alexander; Behringer, Michael; Harmsen, Jan-Frieder; Mayer, Constantin; Krauspe, Rüdiger; Zilkens, Christoph; Schumann, Moritz

2018-01-01

Ischemic preconditioning (IPC) is known to reduce muscle damage induced by ischemia and reperfusion injury during surgery. Because of similarities between the pathophysiological formation of ischemia and reperfusion injury and eccentric exercise-induced muscle damage (EIMD), as characterized by an intracellular accumulation of Ca, an increased production of reactive oxygen species, and increased proinflammatory signaling, the purpose of the present study was to investigate whether IPC performed before eccentric exercise may also protect against EIMD. Nineteen healthy men were matched to an eccentric-only (ECC; n = 9) or eccentric proceeded by IPC group (IPC + ECC; n = 10). The exercise protocol consisted of bilateral biceps curls (3 × 10 repetitions at 80% of the concentric one-repetition maximum). In IPC + ECC, IPC was applied bilaterally at the upper arms by a tourniquet (200 mm Hg) immediately before the exercise (3 × 5 min of occlusion, separated by 5 min of reperfusion). Creatine kinase (CK), arm circumference, subjective pain (visual analog scale score), and radial displacement (tensiomyography, maximal radial displacement) were assessed before IPC, preexercise, postexercise, and 20 min, 2 h, 24 h, 48 h, and 72 h postexercise. CK differed from baseline only in ECC at 48 h (P < 0.001) and 72 h (P < 0.001) postexercise. After 24, 48, and 72 h, CK was increased in ECC compared with IPC + ECC (between groups: 24 h, P = 0.004; 48 h, P < 0.001; 72 h, P < 0.001). The visual analog scale score was significantly higher in ECC at 24-72 h postexercise when compared with IPC + ECC (between groups: all P values < 0.001). The maximal radial displacement was decreased on all postexercise days in ECC (all P values < 0.001) but remained statistically unchanged in IPC + ECC (between groups: P < 0.01). These findings indicate that IPC performed before a bout of eccentric exercise of the elbow flexors blunts EIMD and exercise-induced pain while maintaining the contractile properties of the muscle.

Insulin sensitivity and metabolic flexibility following exercise training among different obese insulin-resistant phenotypes.

PubMed

Malin, Steven K; Haus, Jacob M; Solomon, Thomas P J; Blaszczak, Alecia; Kashyap, Sangeeta R; Kirwan, John P

2013-11-15

Impaired fasting glucose (IFG) blunts the reversal of impaired glucose tolerance (IGT) after exercise training. Metabolic inflexibility has been implicated in the etiology of insulin resistance; however, the efficacy of exercise on peripheral and hepatic insulin sensitivity or substrate utilization in adults with IFG, IGT, or IFG + IGT is unknown. Twenty-four older (66.7 ± 0.8 yr) obese (34.2 ± 0.9 kg/m(2)) adults were categorized as IFG (n = 8), IGT (n = 8), or IFG + IGT (n = 8) according to a 75-g oral glucose tolerance test (OGTT). Subjects underwent 12-wk of exercise (60 min/day for 5 days/wk at ∼85% HRmax) and were instructed to maintain a eucaloric diet. A euglycemic hyperinsulinemic clamp (40 mU·m(2)·min(-1)) with [6,6-(2)H]glucose was used to determine peripheral and hepatic insulin sensitivity. Nonoxidative glucose disposal and metabolic flexibility [insulin-stimulated respiratory quotient (RQ) minus fasting RQ] were also assessed. Glucose incremental area under the curve (iAUCOGTT) was calculated from the OGTT. Exercise increased clamp-derived peripheral and hepatic insulin sensitivity more in adults with IFG or IGT alone than with IFG + IGT (P < 0.05). Exercise reduced glucose iAUCOGTT in IGT only (P < 0.05), and the decrease in glucose iAUCOGTT was inversely correlated with the increase in peripheral but not hepatic insulin sensitivity (P < 0.01). Increased clamp-derived peripheral insulin sensitivity was also correlated with enhanced metabolic flexibility, reduced fasting RQ, and higher nonoxidative glucose disposal (P < 0.05). Adults with IFG + IGT had smaller gains in clamp-derived peripheral insulin sensitivity and metabolic flexibility, which was related to blunted improvements in postprandial glucose. Additional work is required to assess the molecular mechanism(s) by which chronic hyperglycemia modifies insulin sensitivity following exercise training.

Diet-induced obesity attenuates endotoxin-induced cognitive deficits.

PubMed

Setti, Sharay E; Littlefield, Alyssa M; Johnson, Samantha W; Kohman, Rachel A

2015-03-15

Activation of the immune system can impair cognitive function, particularly on hippocampus dependent tasks. Several factors such as normal aging and prenatal experiences can modify the severity of these cognitive deficits. One additional factor that may modulate the behavioral response to immune activation is obesity. Prior work has shown that obesity alters the activity of the immune system. Whether diet-induced obesity (DIO) influences the cognitive deficits associated with inflammation is currently unknown. The present study explored whether DIO alters the behavioral response to the bacterial endotoxin, lipopolysaccharide (LPS). Female C57BL/6J mice were fed a high-fat (60% fat) or control diet (10% fat) for a total of five months. After consuming their respective diets for four months, mice received an LPS or saline injection and were assessed for alterations in spatial learning. One month later, mice received a second injection of LPS or saline and tissue samples were collected to assess the inflammatory response within the periphery and central nervous system. Results showed that LPS administration impaired spatial learning in the control diet mice, but had no effect in DIO mice. This lack of a cognitive deficit in the DIO female mice is likely due to a blunted inflammatory response within the brain. While cytokine production within the periphery (i.e., plasma, adipose, and spleen) was similar between the DIO and control mice, the DIO mice failed to show an increase in IL-6 and CD74 in the brain following LPS administration. Collectively, these data indicate that DIO can reduce aspects of the neuroinflammatory response as well as blunt the behavioral reaction to an immune challenge. Copyright © 2014 Elsevier Inc. All rights reserved.

Resistance Exercise Reduces Seizure Occurrence, Attenuates Memory Deficits and Restores BDNF Signaling in Rats with Chronic Epilepsy.

PubMed

de Almeida, Alexandre Aparecido; Gomes da Silva, Sérgio; Lopim, Glauber Menezes; Vannucci Campos, Diego; Fernandes, Jansen; Cabral, Francisco Romero; Arida, Ricardo Mario

2017-04-01

Epilepsy is a disease characterized by recurrent, unprovoked seizures. Cognitive impairment is an important comorbidity of chronic epilepsy. Human and animal model studies of epilepsy have shown that aerobic exercise induces beneficial structural and functional changes and reduces the number of seizures. However, little is yet understood about the effects of resistance exercise on epilepsy. We evaluated the effects of a resistance exercise program on the number of seizures, long-term memory and expression/activation of signaling proteins in rats with epilepsy. The number of seizures was quantified by video-monitoring and long-term memory was assessed by an inhibitory avoidance test. Using western blotting, multiplex and enzyme-linked immunosorbent assays, we determined the effects of a 4-week resistance exercise program on IGF-1 and BDNF levels and ERK, CREB, mTOR activation in the hippocampus of rats with epilepsy. Rats with epilepsy submitted to resistance exercise showed a decrease in the number of seizures compared to non-exercised epileptic rats. Memory deficits were attenuated by resistance exercise. Rats with epilepsy showed an increase in IGF-1 levels which were restored to control levels by resistance exercise. BDNF levels and ERK and mTOR activation were decreased in rats with epilepsy and resistance exercise restored these to control levels. In conclusion, resistance exercise reduced seizure occurrence and mitigated memory deficits in rats with epilepsy. These resistance exercise-induced beneficial effects can be related to changes in IGF-1 and BDNF levels and its signaling protein activation. Our findings indicate that the resistance exercise might be included as complementary therapeutic strategy for epilepsy treatment.

Deficits in temporal order memory induced by interferon-alpha (IFN-α) treatment are rescued by aerobic exercise.

PubMed

Barlow, Sally; Fahey, Briana; Smith, Kimberley J; Passecker, Johannes; Della-Chiesa, Andrea; Hok, Vincent; Day, Jennifer S; Callaghan, Charlotte K; O'Mara, Shane M

2018-05-18

Patients receiving cytokine immunotherapy with IFN-α frequently present with neuropsychiatric consequences and cognitive impairments, including a profound depressive-like symptomatology. While the neurobiological substrates of the dysfunction that leads to adverse events in IFN-α-treated patients remains ill-defined, dysfunctions of the hippocampus and prefrontal cortex (PFC) are strong possibilities. To date, hippocampal deficits have been well-characterised; there does however remain a lack of insight into the nature of prefrontal participation. Here, we used a PFC-supported temporal order memory paradigm to examine if IFN-α treatment induced deficits in performance; additionally, we used an object recognition task to assess the integrity of the perirhinal cortex (PRH). Finally, the utility of exercise as an ameliorative strategy to recover temporal order deficits in rats was also explored. We found that IFN-α-treatment impaired temporal order memory discriminations, whereas recognition memory remained intact, reflecting a possible dissociation between recognition and temporal order memory processing. Further characterisation of temporal order memory impairments using a longitudinal design revealed that deficits persisted for 10 weeks following cessation of IFN-α-treatment. Finally, a 6 week forced exercise regime reversed IFN-α-induced deficits in temporal order memory. These data provide further insight into the circuitry involved in cognitive impairments arising from IFN-α-treatment. Here we suggest that PFC (or the hippocampo-prefrontal pathway) may be compromised whilst the function of the PRH is preserved. Deficits may persist after cessation of IFN-α-treatment which suggests that extended patient monitoring is required. Aerobic exercise may be restorative and could prove beneficial for patients treated with IFN-α. Copyright © 2018 Elsevier Inc. All rights reserved.

Preliminary evidence of a blunted anti-inflammatory response to exhaustive exercise in fibromyalgia.

PubMed

Torgrimson-Ojerio, Britta; Ross, Rebecca L; Dieckmann, Nathan F; Avery, Stephanie; Bennett, Robert M; Jones, Kim D; Guarino, Anthony J; Wood, Lisa J

2014-12-15

Exercise intolerance, as evidenced by a worsening of pain, fatigue, and stiffness after novel exertion, is a key feature of fibromyalgia (FM). In this pilot study, we investigate whether; insufficient muscle repair processes and impaired anti-inflammatory mechanisms result in an exaggerated pro-inflammatory cytokine response to exhaustive exercise, and consequently a worsening of muscle pain, stiffness and fatigue in the days post-exercise. We measured changes in muscle pain and tenderness, fatigue, stiffness, and serum levels of neuroendocrine and inflammatory cytokine markers in 20 women with FM and 16 healthy controls (HCs) before and after exhaustive treadmill exercise. Compared to HCs, FM participants failed to mount the expected anti-inflammatory response to exercise and experienced a worsening of symptoms post-exercise. However, changes in post-exertional symptoms were not mediated by post-exertional changes in pro-inflammatory cytokine levels. Implications of these findings are discussed. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Effect of Exercise Training on Striatal Dopamine D2/D3 Receptors in Methamphetamine Users during Behavioral Treatment.

PubMed

Robertson, Chelsea L; Ishibashi, Kenji; Chudzynski, Joy; Mooney, Larissa J; Rawson, Richard A; Dolezal, Brett A; Cooper, Christopher B; Brown, Amira K; Mandelkern, Mark A; London, Edythe D

2016-05-01

Methamphetamine use disorder is associated with striatal dopaminergic deficits that have been linked to poor treatment outcomes, identifying these deficits as an important therapeutic target. Exercise attenuates methamphetamine-induced neurochemical damage in the rat brain, and a preliminary observation suggests that exercise increases striatal D2/D3 receptor availability (measured as nondisplaceable binding potential (BPND)) in patients with Parkinson's disease. The goal of this study was to evaluate whether adding an exercise training program to an inpatient behavioral intervention for methamphetamine use disorder reverses deficits in striatal D2/D3 receptors. Participants were adult men and women who met DSM-IV criteria for methamphetamine dependence and were enrolled in a residential facility, where they maintained abstinence from illicit drugs of abuse and received behavioral therapy for their addiction. They were randomized to a group that received 1 h supervised exercise training (n=10) or one that received equal-time health education training (n=9), 3 days/week for 8 weeks. They came to an academic research center for positron emission tomography (PET) using [(18)F]fallypride to determine the effects of the 8-week interventions on striatal D2/D3 receptor BPND. At baseline, striatal D2/D3 BPND did not differ between groups. However, after 8 weeks, participants in the exercise group displayed a significant increase in striatal D2/D3 BPND, whereas those in the education group did not. There were no changes in D2/D3 BPND in extrastriatal regions in either group. These findings suggest that structured exercise training can ameliorate striatal D2/D3 receptor deficits in methamphetamine users, and warrants further evaluation as an adjunctive treatment for stimulant dependence.

Effect of Exercise Training on Striatal Dopamine D2/D3 Receptors in Methamphetamine Users during Behavioral Treatment

PubMed Central

Robertson, Chelsea L; Ishibashi, Kenji; Chudzynski, Joy; Mooney, Larissa J; Rawson, Richard A; Dolezal, Brett A; Cooper, Christopher B; Brown, Amira K; Mandelkern, Mark A; London, Edythe D

2016-01-01

Methamphetamine use disorder is associated with striatal dopaminergic deficits that have been linked to poor treatment outcomes, identifying these deficits as an important therapeutic target. Exercise attenuates methamphetamine-induced neurochemical damage in the rat brain, and a preliminary observation suggests that exercise increases striatal D2/D3 receptor availability (measured as nondisplaceable binding potential (BPND)) in patients with Parkinson's disease. The goal of this study was to evaluate whether adding an exercise training program to an inpatient behavioral intervention for methamphetamine use disorder reverses deficits in striatal D2/D3 receptors. Participants were adult men and women who met DSM-IV criteria for methamphetamine dependence and were enrolled in a residential facility, where they maintained abstinence from illicit drugs of abuse and received behavioral therapy for their addiction. They were randomized to a group that received 1 h supervised exercise training (n=10) or one that received equal-time health education training (n=9), 3 days/week for 8 weeks. They came to an academic research center for positron emission tomography (PET) using [18F]fallypride to determine the effects of the 8-week interventions on striatal D2/D3 receptor BPND. At baseline, striatal D2/D3 BPND did not differ between groups. However, after 8 weeks, participants in the exercise group displayed a significant increase in striatal D2/D3 BPND, whereas those in the education group did not. There were no changes in D2/D3 BPND in extrastriatal regions in either group. These findings suggest that structured exercise training can ameliorate striatal D2/D3 receptor deficits in methamphetamine users, and warrants further evaluation as an adjunctive treatment for stimulant dependence. PMID:26503310

Nutritional compensation to exercise- vs. diet-induced acute energy deficit in adolescents with obesity.

PubMed

Thivel, David; Doucet, Eric; Julian, Valérie; Cardenoux, Charlotte; Boirie, Yves; Duclos, Martine

2017-07-01

To compare the energy and macronutrient intake responses to equivalent energy deficits induced by diet (food restriction) and exercise in adolescents with obesity. Fourteen 12-15years old obese adolescents completed three experimental conditions (08:00am to 07:30pm) in a randomized crossover design: i) control session (CON); ii) diet-induced 25% energy depletion (Def-EI), iii) and an exercise-induced 25% energy depletion (Def-EX). The sessions order was either CON/Def-EI/Def-EX or CON/Def-EX/Def-EI as the deficit corresponded to 25% of the energy ingested at lunch on the control day (CON) and was imposed either by exercise (Def-EX) or diet (Def-EI). Ad libitum EI and macronutrients preferences were assessed at dinner and appetite sensations assessed using visual analogue scales. Mean BMI was 36.6±5.0kg/m 2 (z-BMI: 2.40±0.29). The individually calibrated 25% energy deficit represented 254±92kcal. Ad libitum EI was significantly higher during both Def-EX (971±225kcal) and Def-EI (949±246kcal) compared with CON (742±297) (p<0.05). The relative energy ingested derived from fat was significantly higher on both Def-EX (36.6±10.9%) and Def-EI (36.9±13.1%) compared with CON (21.6±7.8%) (p<0.05). The energy derived from carbohydrates was significantly lower on both Def-EX (48.3±9.0%) and Def-EI (44.4±17.3%) compare with CON (61.1±10.1%) (p<0.05). Appetite sensations were not different between conditions. The induced energy deficit was negatively correlated with the ad libitum EI difference between the exercise and the control session (EI Def-EX - EI CON) (r=-0,643 p<0.05) and positively correlated with the EI difference between the dietary restriction and the control session (EI Def-EI - EI CON) (r=0,569 p<0.05). Equicaloric exercise- or diet-induced energy deficits could lead to similar EI compensation in obese adolescents but this EI compensation might be influenced by the magnitude of the deficit. Copyright © 2016 Elsevier Inc. All rights reserved.

Thromboembolic Complications Following Trauma

DTIC Science & Technology

2009-12-01

subsequent neurologic deficit from these injuries approaches an inci- dence of 20 to 30 percent, the overall rate of stroke in the total trauma...investigating stroke and neurologic outcomes in blunt cerebrovascular injuries (BCVIs). In contrast, few reports of MI or mesenteric thrombosis in the...prohemostatic agents in uncontrolled studies of severely injured patients will only confuse rather than enlighten this area of research. No single paper has

Resveratrol blunts the positive effects of exercise training on cardiovascular health in aged men

PubMed Central

Gliemann, Lasse; Schmidt, Jakob Friis; Olesen, Jesper; Biensø, Rasmus Sjørup; Peronard, Sebastian Louis; Grandjean, Simon Udsen; Mortensen, Stefan Peter; Nyberg, Michael; Bangsbo, Jens; Pilegaard, Henriette; Hellsten, Ylva

2013-01-01

Ageing is thought to be associated with decreased vascular function partly due to oxidative stress. Resveratrol is a polyphenol, which in animal studies has been shown to decrease atherosclerosis, and improve cardiovascular health and physical capacity, in part through its effects on Sirtuin 1 signalling and through an improved antioxidant capacity. We tested the hypothesis that resveratrol supplementation enhances training-induced improvements in cardiovascular health parameters in aged men. Twenty-seven healthy physically inactive aged men (age: 65 ± 1 years; body mass index: 25.4 ± 0.7 kg m−2; mean arterial pressure (MAP): 95.8 ± 2.2 mmHg; maximal oxygen uptake: 2488 ± 72 ml O2 min−1) were randomized into 8 weeks of either daily intake of either 250 mg trans-resveratrol (n= 14) or of placebo (n= 13) concomitant with high-intensity exercise training. Exercise training led to a 45% greater (P < 0.05) increase in maximal oxygen uptake in the placebo group than in the resveratrol group and to a decrease in MAP in the placebo group only (−4.8 ± 1.7 mmHg; P < 0.05). The interstitial level of vasodilator prostacyclin was lower in the resveratrol than in the placebo group after training (980 ± 90 vs. 1174 ± 121 pg ml−1; P < 0.02) and muscle thromboxane synthase was higher in the resveratrol group after training (P < 0.05). Resveratrol administration also abolished the positive effects of exercise on low-density lipoprotein, total cholesterol/high-density lipoprotein ratio and triglyceride concentrations in blood (P < 0.05). Resveratrol did not alter the effect of exercise training on the atherosclerosis marker vascular cell adhesion molecule 1 (VCAM-1). Sirtuin 1 protein levels were not affected by resveratrol supplementation. These findings indicate that, whereas exercise training effectively improves several cardiovascular health parameters in aged men, concomitant resveratrol supplementation can blunt these effects. PMID:23878368

Immune cell response to strenuous resistive breathing: comparison with whole body exercise and the effects of antioxidants

PubMed Central

Karatza, Maria-Helena; Vasileiou, Spyridoula; Katsaounou, Paraskevi; Mastora, Zafeiria

2018-01-01

Background/hypothesis Whole body exercise (WBE) changes lymphocyte subset percentages in peripheral blood. Resistive breathing, a hallmark of diseases of airway obstruction, is a form of exercise for the inspiratory muscles. Strenuous muscle contractions induce oxidative stress that may mediate immune alterations following exercise. We hypothesized that inspiratory resistive breathing (IRB) alters peripheral blood lymphocyte subsets and that oxidative stress mediates lymphocyte subpopulation alterations following both WBE and IRB. Patients and methods Six healthy nonathletes performed two WBE and two IRB sessions for 45 minutes at 70% of VO2 maximum and 70% of maximum inspiratory pressure (Pimax), respectively, before and after the administration of antioxidants (vitamins E, A, and C for 75 days, allopurinol for 30 days, and N-acetylcysteine for 3 days). Blood was drawn at baseline, at the end of each session, and 2 hours into recovery. Lymphocyte subsets were determined by flow cytometry. Results Before antioxidant supplementation at both WBE end and IRB end, the natural killer cell percentage increased, the T helper cell (CD3+ CD4+) percentage was reduced, and the CD4/CD8 ratio was depressed, a response which was abolished by antioxidants only after IRB. Furthermore, at IRB end, antioxidants promoted CD8+ CD38+ and blunted cytotoxic T-cell percentage increase. CD8+ CD45RA+ cell percentage changes were blunted after antioxidant supplementation in both WBE and IRB. Conclusion We conclude that IRB produces (as WBE) changes in peripheral blood lymphocyte subsets and that oxidative stress is a major stimulus predominantly for IRB-induced lymphocyte subset alterations. PMID:29445271

Immune cell response to strenuous resistive breathing: comparison with whole body exercise and the effects of antioxidants.

PubMed

Asimakos, Andreas; Toumpanakis, Dimitrios; Karatza, Maria-Helena; Vasileiou, Spyridoula; Katsaounou, Paraskevi; Mastora, Zafeiria; Vassilakopoulos, Theodoros

2018-01-01

Whole body exercise (WBE) changes lymphocyte subset percentages in peripheral blood. Resistive breathing, a hallmark of diseases of airway obstruction, is a form of exercise for the inspiratory muscles. Strenuous muscle contractions induce oxidative stress that may mediate immune alterations following exercise. We hypothesized that inspiratory resistive breathing (IRB) alters peripheral blood lymphocyte subsets and that oxidative stress mediates lymphocyte subpopulation alterations following both WBE and IRB. Six healthy nonathletes performed two WBE and two IRB sessions for 45 minutes at 70% of VO 2 maximum and 70% of maximum inspiratory pressure (Pi max ), respectively, before and after the administration of antioxidants (vitamins E, A, and C for 75 days, allopurinol for 30 days, and N-acetylcysteine for 3 days). Blood was drawn at baseline, at the end of each session, and 2 hours into recovery. Lymphocyte subsets were determined by flow cytometry. Before antioxidant supplementation at both WBE end and IRB end, the natural killer cell percentage increased, the T helper cell (CD3+ CD4+) percentage was reduced, and the CD4/CD8 ratio was depressed, a response which was abolished by antioxidants only after IRB. Furthermore, at IRB end, antioxidants promoted CD8+ CD38+ and blunted cytotoxic T-cell percentage increase. CD8+ CD45RA+ cell percentage changes were blunted after antioxidant supplementation in both WBE and IRB. We conclude that IRB produces (as WBE) changes in peripheral blood lymphocyte subsets and that oxidative stress is a major stimulus predominantly for IRB-induced lymphocyte subset alterations.

Blunted neural responses to reward in remitted major depression: A high-density event-related potential study

PubMed Central

Whitton, Alexis E.; Kakani, Pragya; Foti, Dan; Van’t Veer, Ashlee; Haile, Anja; Crowley, David J.; Pizzagalli, Diego A.

2015-01-01

Background Major depressive disorder (MDD) is a highly recurrent condition, and improving our understanding of the abnormalities that persist in remitted MDD (rMDD) may provide insight into mechanisms that contribute to relapse. MDD has been characterized by reward learning deficits linked to dysfunction in frontostriatal regions. Although initial behavioral evidence of reward learning deficits in rMDD has recently emerged, it is unclear whether these reflect impairments in neural reward processing that persist into remission. Methods We examined behavioral reward learning and 128-channel event-related potentials (ERP) during a well-validated probabilistic reward task in 26 rMDD individuals and 34 never-depressed controls. Temporo-spatial principal components analysis (PCA) was used to separate overlapping ERP components, and group differences in neural activity in a priori regions were examined using low-resolution electromagnetic tomography (LORETA). Results Individuals with rMDD displayed reduced behavioral reward learning, as well as blunted ERP amplitude to reward feedback. Importantly, the reduction in ERP amplitude occurred at a PCA factor that peaked during the time at which phasic reward feedback-related signaling – hypothesized to originate in the striatum and project to the anterior cingulate cortex (ACC) – are thought to modulate scalp-recorded activity. Consistent with this, LORETA analyses revealed reduced activity in the ACC in the rMDD group, and this blunting correlated with poorer reward learning. Conclusion These findings suggest that the reward learning impairment observed in acute MDD persists into full remission and that these impairments may be attributable to abnormalities in the neural processes that support reward feedback monitoring, particularly within the ACC. PMID:26858994

Exercise intolerance in Type 2 diabetes: is there a cardiovascular contribution?

PubMed

Poitras, Veronica J; Hudson, Robert W; Tschakovsky, Michael E

2018-05-01

Physical activity is critically important for Type 2 diabetes management, yet adherence levels are poor. This might be partly due to disproportionate exercise intolerance. Submaximal exercise tolerance is highly sensitive to muscle oxygenation; impairments in exercising muscle oxygen delivery may contribute to exercise intolerance in Type 2 diabetes since there is considerable evidence for the existence of both cardiac and peripheral vascular dysfunction. While uncompromised cardiac output during submaximal exercise is consistently observed in Type 2 diabetes, it remains to be determined whether an elevated cardiac sympathetic afferent reflex could sympathetically restrain exercising muscle blood flow. Furthermore, while deficits in endothelial function are common in Type 2 diabetes and are often cited as impairing exercising muscle oxygen delivery, no direct evidence in exercise exists, and there are several other vasoregulatory mechanisms whose dysfunction could contribute. Finally, while there are findings of impaired oxygen delivery, conflicting evidence also exists. A definitive conclusion that Type 2 diabetes compromises exercising muscle oxygen delivery remains premature. We review these potentially dysfunctional mechanisms in terms of how they could impair oxygen delivery in exercise, evaluate the current literature on whether an oxygen delivery deficit is actually manifest, and correspondingly identify key directions for future research.

Exercise is associated with reduction in the anxiogenic effect of mCPP on acoustic startle.

PubMed

Fox, James H; Hammack, Sayamwong E; Falls, William A

2008-08-01

Voluntary exercise has been associated with reduced anxiety across several animal models. Manipulation of central 5-HT can alter anxiety-like behaviors and administration of the 5-HT agonist metachlorophenylpiperazine (mCPP) increases anxiety in rodents and humans. To examine whether the anxiolytic effect of exercise is associated with an alteration in 5-HT systems, we examined the anxiogenic effect of mCPP in exercising and nonexercising mice. C57BL/6J mice were given 2 weeks of free access to either a functioning or nonfunctioning running wheel. Mice were then tested for acoustic startle following systemic injection of either 0, 0.1, 0.3, or 1 mg/kg of mCPP. Consistent with its anxiogenic properties, mCPP produced a dose-dependent increase in acoustic startle in nonexercising mice. However, this anxiogenic effect was blunted in exercising mice. These findings suggest that exercise may help to reduce anxiety by altering 5-HT systems, perhaps by down-regulating postsynaptic 5HT 2B/2C receptors.

Effects of voluntary and treadmill exercise on spontaneous withdrawal signs, cognitive deficits and alterations in apoptosis-associated proteins in morphine-dependent rats.

PubMed

Mokhtari-Zaer, Amin; Ghodrati-Jaldbakhan, Shahrbanoo; Vafaei, Abbas Ali; Miladi-Gorji, Hossein; Akhavan, Maziar M; Bandegi, Ahmad Reza; Rashidy-Pour, Ali

2014-09-01

Chronic exposure to morphine results in cognitive deficits and alterations of apoptotic proteins in favor of cell death in the hippocampus, a brain region critically involved in learning and memory. Physical activity has been shown to have beneficial effects on brain health. In the current work, we examined the effects of voluntary and treadmill exercise on spontaneous withdrawal signs, the associated cognitive defects, and changes of apoptotic proteins in morphine-dependent rats. Morphine dependence was induced through bi-daily administrations of morphine (10mg/kg) for 10 days. Then, the rats were trained under two different exercise protocols: mild treadmill exercise or voluntary wheel exercise for 10 days. After exercise training, their spatial learning and memory and aversive memory were examined by a water maze and by an inhibitory avoidance task, respectively. The expression of the pro-apoptotic protein Bax and the anti-apoptotic protein Bcl-2 in the hippocampus were determined by immunoblotting. We found that chronic exposure to morphine impaired spatial and aversive memory and remarkably suppressed the expression of Bcl-2, but Bax expression remained constant. Both voluntary and treadmill exercise alleviated memory impairment, increased the expression of Bcl-2 protein, and only the later suppressed the expression of Bax protein in morphine-dependent animals. Moreover, both exercise protocols diminished the occurrence of spontaneous morphine withdrawal signs. Our findings showed that exercise reduces the spontaneous morphine-withdrawal signs, blocks the associated impairment of cognitive performance, and overcomes morphine-induced alterations in apoptotic proteins in favor of cell death. Thus, exercise may be a useful therapeutic strategy for cognitive and behavioral deficits in addict individuals. Copyright © 2014 Elsevier B.V. All rights reserved.

Cardiac investigation in patients with diabetes.

PubMed

Tardif, Jean-Claude

2006-02-01

Most patients with type 2 diabetes die from heart disease. Screening for the presence of myocardial ischemia is of clinical importance in the management of this population. The pain response to ischemia can be either absent or blunted in diabetes, resulting in the absence of symptoms or an atypical presentation. Exercise electrocardiogram (ECG) should be the initial test in men who are able to exercise and have a normal resting ECG. Stress cardiac imaging should be the initial test in diabetic men with an abnormal resting ECG or who are not able to exercise. More widespread use of cardiac imaging is probably justified in diabetic women and patients with suspected coronary artery disease. Official guidelines for appropriate and cost-effective cardiac investigation should help physicians manage diabetic patients.

Effects of Different Exercise Modes on the Urinary Metabolic Fingerprint of Men with and without Metabolic Syndrome.

PubMed

Siopi, Aikaterina; Deda, Olga; Manou, Vasiliki; Kellis, Spyros; Kosmidis, Ioannis; Komninou, Despina; Raikos, Nikolaos; Christoulas, Kosmas; Theodoridis, Georgios A; Mougios, Vassilis

2017-01-26

Exercise is important in the prevention and treatment of the metabolic syndrome (MetS), a cluster of risk factors that raises morbidity. Metabolomics can facilitate the optimization of exercise prescription. This study aimed to investigate whether the response of the human urinary metabolic fingerprint to exercise depends on the presence of MetS or exercise mode. Twenty-three sedentary men (MetS, n = 9, and Healthy, n = 14) completed four trials: resting, high-intensity interval exercise (HIIE), continuous moderate-intensity exercise (CME), and resistance exercise (RE). Urine samples were collected pre-exercise and at 2, 4, and 24 h for targeted analysis by liquid chromatography-mass spectrometry. Time exerted the strongest differentiating effect, followed by exercise mode and health status. The greatest changes were observed in the first post-exercise samples, with a gradual return to baseline at 24 h. RE caused the greatest responses overall, followed by HIIE, while CME had minimal effect. The metabolic fingerprints of the two groups were separated at 2 h, after HIIE and RE; and at 4 h, after HIIE, with evidence of blunted response to exercise in MetS. Our findings show diverse responses of the urinary metabolic fingerprint to different exercise modes in men with and without metabolic syndrome.

Managing childhood and adolescent attention-deficit/hyperactivity disorder (ADHD) with exercise: A systematic review.

PubMed

Ng, Qin Xiang; Ho, Collin Yih Xian; Chan, Hwei Wuen; Yong, Bob Zheng Jie; Yeo, Wee-Song

2017-10-01

Attention deficit hyperactivity disorder (ADHD) is one of the most common neuropsychiatric disorders affecting some 8-10% of children worldwide. Increasing research has shed light on the life course of the disorder, suggesting that majority of children with ADHD will continue to have persistent symptoms into adulthood. The mainstay of ADHD management has been pharmacologic and behavioural/psychological interventions, with little attention paid to exercise as a potential management strategy. A systematic review, examining both the short-term and long-term effects of exercise on children with ADHD, is timely and necessary to guide further research in this area. Using the keywords [exercise OR physical OR activity OR sport] AND [attention deficit hyperactivity disorder OR ADHD OR ADDH], a preliminary search on the PubMed and Ovid database yielded 613 papers published in English between 1-Jan-1980 and 1-July-2016. Full articles were also reviewed for references of interest. A total of 30 studies were included in this systematic review. Both short-term and long-term studies support the clinical benefits of physical activity for individuals with ADHD. Cognitive, behavioural and physical symptoms of ADHD were alleviated in most instances, and the largest intervention effects were reported for mixed exercise programs. No adverse effects arising from physical exercise were reported in any of the studies, suggesting that exercise is a well-tolerated intervention. Physical activity, in particular moderate-to-intense aerobic exercise, is a beneficial and well-tolerated intervention for children and adolescents with ADHD. Future research should include more adequately-powered trials and investigate the ideal exercise prescription. Copyright © 2017 Elsevier Ltd. All rights reserved.

Physical activity participation by presence and type of functional deficits in older women: The Women's Health and Aging Studies.

PubMed

Jerome, Gerald J; Glass, Thomas A; Mielke, Michelle; Xue, Qian-Li; Andersen, Ross E; Fried, Linda P

2006-11-01

Physical activity is important for maintaining functional independence of older persons, especially for those with existing functional deficits. Since such deficits may pose barriers to activity, it would be instructive to examine activity patterns in relation to specific types of deficits to determine the amount and type of physical activity older women pursue. This study sought to identify categories of functional deficits associated with activity levels and evaluated the potential for older women to increase their physical activity levels. Community-dwelling women, aged 70-79 years, from the Women's Health and Aging Studies I and II (N = 710), were assessed for self-reported physical activity, functional deficits and chronic conditions, along with objective measures of muscle strength. Both type (household chores, exercise, and recreational activity) and amount of physical activity (min/wk) were examined. Meeting physical activity recommendations was defined as > or =150 minutes per week of moderate intensity physical activity, and inactivity was defined as no weekly moderate intensity physical activity. Hierarchical categories of functional deficits were based on self-reported difficulty in four functional domains (i.e., mobility/exercise tolerance, upper extremity, higher functioning, and self-care), and self-reports ranged from no difficulty to difficulty in all four domains. The prevalence of inactivity and meeting activity recommendations were 14.4% and 12.7%, respectively. Severity of functional deficits was associated with increased risk of inactivity (adjusted odds ratios [ORs(adj)] = 3.14-17.61) and reduced likelihood of meeting activity recommendations (ORs(adj) =.11-.40). Even among those with higher functioning or self-care difficulties, 30% reported walking for exercise. There was evidence that older women with functional deficits can remain physically active. However, for some of these women, meeting the recommended levels of activity may be unrealistic. Efforts to increase physical activity levels among older adults should include treatment or management of functional deficits, chronic conditions, and poor strength.

Exercise improves behavioral, neurocognitive, and scholastic performance in children with attention-deficit/hyperactivity disorder.

PubMed

Pontifex, Matthew B; Saliba, Brian J; Raine, Lauren B; Picchietti, Daniel L; Hillman, Charles H

2013-03-01

To examine the effect of a single bout of moderate-intensity aerobic exercise on preadolescent children with attention-deficit/hyperactivity disorder (ADHD) using objective measures of attention, brain neurophysiology, and academic performance. Using a within-participants design, task performance and event-related brain potentials were assessed while participants performed an attentional-control task following a bout of exercise or seated reading during 2 separate, counterbalanced sessions. Following a single 20-minute bout of exercise, both children with ADHD and healthy match control children exhibited greater response accuracy and stimulus-related processing, with the children with ADHD also exhibiting selective enhancements in regulatory processes, compared with after a similar duration of seated reading. In addition, greater performance in the areas of reading and arithmetic were observed following exercise in both groups. These findings indicate that single bouts of moderately intense aerobic exercise may have positive implications for aspects of neurocognitive function and inhibitory control in children with ADHD. Copyright © 2013 Mosby, Inc. All rights reserved.

Radiographic clearance of blunt cervical spine injury: plain radiograph or computed tomography scan?

PubMed

Griffen, Margaret M; Frykberg, Eric R; Kerwin, Andrew J; Schinco, Miren A; Tepas, Joseph J; Rowe, Kathleen; Abboud, Jennifer

2003-08-01

The purpose of this study was to evaluate the roles of cervical spine radiographs (CSR) and computed tomography of the cervical spine (CTC) in the exclusion of cervical spine injury for adult blunt trauma patients. At the authors' institution, all adult blunt trauma patients with physical findings of posterior midline neck tenderness, altered mental status, or neurologic deficit are considered at risk of cervical spine injury and undergo both CSR and CTC for evaluation of the cervical spine. The TRACS database at level 1 of the trauma center at this institution was queried for all blunt trauma patients from November 2000 to October 2001. Patient injury severity score (ISS), Glascow Coma Score (GCS), age, gender, CSR results, CTC results, and treatment data were analyzed. The review included 3,018 blunt trauma patients with appropriate data. For 1,199 of these patients (779 men and 420 women) (40%) at risk for cervical spine injury, both CSR and CTC were performed for cervical spine evaluation. The average age of these patients was 39.4 years (range, 18-89 years). The average GCS was 13 and the average ISS was 8.4 in this study population. In 116 (9.5%) of these patients, a cervical spine injury (fracture or subluxation) was detected. The injury was identified on both CSR and CTC in 75 of these patients. In the remaining 41 patients (3.2%), the CSR results were negative, but injury was detected by CTC. All these injuries missed by CSR required treatment. For this group with false-negative CSR, the average GCS was 12 and the average ISS was 14.6. There were no missed cervical spine injuries among the patients with negative CTC results. No identifiable factors predicted false-negative CSR. There does not appear to be any role for CSR screening in this setting. The data from this study add to the growing body of evidence that CTC should replace CSR for the evaluation of the cervical spine in blunt trauma.

Hippocampal and Cognitive Function, Exercise, and Ovarian Cancer: A Pilot Study

DTIC Science & Technology

2016-08-01

with   schizophrenia  (SZ)  display  substantial  cognitive  deficits  across  multiple  domains.  These  deficits  have  been...Cognition  via  Exercise  in   Schizophrenia Stress  Reactivity  in  Mitochondrial  Disease:  Physiological,  Neural,  and...the hypothesis of hippocampal hyperfunction as a pathogenic driver in schizophrenia and related disorders. P50 AG08702 (Small) 09/29/89-05/31/20

An emerging etiological factor for hand injuries in the pediatric population: public exercise equipment.

PubMed

Akşam, Berrak; Akşam, Ersin; Ceran, Candemir; Demirseren, Mustafa Erol

2016-01-01

The purpose of this study was to describe the role of public exercise equipment in pediatric hand traumas as a preventable etiological factor. Pediatric patients with hand injuries referred from the emergency department were evaluated retrospectively. Age and gender of the patients, timing, etiology, mechanism of hand trauma, localization of the injury, diagnoses of the patients, and hospitalization rates were reviewed. Amongst the 310 pediatric patients evaluated, 31 patients (10%) experienced injury related to public exercise equipment. Within this group of patients, most were between 5 to 9 years of age, and all injuries were blunt and crush type. Lacerations and fractures were the main diagnoses. Complex injuries that required inpatient care were reported in 19.3% of the patients. Public exercise equipment-related injuries are increasingly prevalent in pediatric hand traumas. Preventive actions such as shielding the moving parts should be taken to reduce these rates.

Aerobic exercise training rescues cardiac protein quality control and blunts endoplasmic reticulum stress in heart failure rats.

PubMed

Bozi, Luiz H M; Jannig, Paulo R; Rolim, Natale; Voltarelli, Vanessa A; Dourado, Paulo M M; Wisløff, Ulrik; Brum, Patricia C

2016-11-01

Cardiac endoplasmic reticulum (ER) stress through accumulation of misfolded proteins plays a pivotal role in cardiovascular diseases. In an attempt to reestablish ER homoeostasis, the unfolded protein response (UPR) is activated. However, if ER stress persists, sustained UPR activation leads to apoptosis. There is no available therapy for ER stress relief. Considering that aerobic exercise training (AET) attenuates oxidative stress, mitochondrial dysfunction and calcium imbalance, it may be a potential strategy to reestablish cardiac ER homoeostasis. We test the hypothesis that AET would attenuate impaired cardiac ER stress after myocardial infarction (MI). Wistar rats underwent to either MI or sham surgeries. Four weeks later, rats underwent to 8 weeks of moderate-intensity AET. Myocardial infarction rats displayed cardiac dysfunction and lung oedema, suggesting heart failure. Cardiac dysfunction in MI rats was paralleled by increased protein levels of UPR markers (GRP78, DERLIN-1 and CHOP), accumulation of misfolded and polyubiquitinated proteins, and reduced chymotrypsin-like proteasome activity. These results suggest an impaired cardiac protein quality control. Aerobic exercise training improved exercise capacity and cardiac function of MI animals. Interestingly, AET blunted MI-induced ER stress by reducing protein levels of UPR markers, and accumulation of both misfolded and polyubiquinated proteins, which was associated with restored proteasome activity. Taken together, our study provide evidence for AET attenuation of ER stress through the reestablishment of cardiac protein quality control, which contributes to better cardiac function in post-MI heart failure rats. These results reinforce the importance of AET as primary non-pharmacological therapy to cardiovascular disease. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Aging blunts hyperventilation-induced hypocapnia and reduction in cerebral blood flow velocity during maximal exercise.

PubMed

Marsden, K R; Haykowsky, M J; Smirl, J D; Jones, H; Nelson, M D; Altamirano-Diaz, Luis A; Gelinas, J C; Tzeng, Y C; Smith, K J; Willie, C K; Bailey, D M; Ainslie, P N

2012-06-01

Cerebral blood flow (CBF) increases from rest to ∼60% of peak oxygen uptake (VO(2peak)) and thereafter decreases towards baseline due to hyperventilation-induced hypocapnia and subsequent cerebral vasoconstriction. It is unknown what happens to CBF in older adults (OA), who experience a decline in CBF at rest coupled with a blunted ventilatory response during VO(2peak). In 14 OA (71 ± 10 year) and 21 young controls (YA; 23 ± 4 years), we hypothesized that OA would experience less hyperventilation-induced cerebral vasoconstriction and therefore an attenuated reduction in CBF at VO(2peak). Incremental exercise was performed on a cycle ergometer, whilst bilateral middle cerebral artery blood flow velocity (MCA V (mean); transcranial Doppler ultrasound), heart rate (HR; ECG) and end-tidal PCO(2) (P(ET)CO(2)) were monitored continuously. Blood pressure (BP) was monitored intermittently. From rest to 50% of VO(2peak), despite greater elevations in BP in OA, the change in MCA V(mean) was greater in YA compared to OA (28% vs. 15%, respectively; P < 0.0005). In the YA, at intensities >70% of VO(2peak), the hyperventilation-induced declines in both P(ET)CO(2) (14 mmHg (YA) vs. 4 mmHg (OA); P < 0.05) and MCA V(mean) (-21% (YA) vs. -7% (OA); P < 0.0005) were greater in YA compared to OA. Our findings show (1), from rest-to-mild intensity exercise (50% VO(2peak)), elevations in CBF are reduced in OA and (2) age-related declines in hyperventilation during maximal exercise result in less hypocapnic-induced cerebral vasoconstriction.

Exercise Preserves Lean Mass and Performance during Severe Energy Deficit: The Role of Exercise Volume and Dietary Protein Content.

PubMed

Calbet, Jose A L; Ponce-González, Jesús G; Calle-Herrero, Jaime de La; Perez-Suarez, Ismael; Martin-Rincon, Marcos; Santana, Alfredo; Morales-Alamo, David; Holmberg, Hans-Christer

2017-01-01

The loss of fat-free mass (FFM) caused by very-low-calorie diets (VLCD) can be attenuated by exercise. The aim of this study was to determine the role played by exercise and dietary protein content in preserving the lean mass and performance of exercised and non-exercised muscles, during a short period of extreme energy deficit (~23 MJ deficit/day). Fifteen overweight men underwent three consecutive experimental phases: baseline assessment (PRE), followed by 4 days of caloric restriction and exercise (CRE) and then 3 days on a control diet combined with reduced exercise (CD). During CRE, the participants ingested a VLCD and performed 45 min of one-arm cranking followed by 8 h walking each day. The VLCD consisted of 0.8 g/kg body weight/day of either whey protein (PRO, n = 8) or sucrose (SU, n = 7). FFM was reduced after CRE ( P < 0.001), with the legs and the exercised arm losing proportionally less FFM than the control arm [57% ( P < 0.05) and 29% ( P = 0.05), respectively]. Performance during leg pedaling, as reflected by the peak oxygen uptake and power output (Wpeak), was reduced after CRE by 15 and 12%, respectively ( P < 0.05), and recovered only partially after CD. The deterioration of cycling performance was more pronounced in the whey protein than sucrose group ( P < 0.05). Wpeak during arm cranking was unchanged in the control arm, but improved in the contralateral arm by arm cranking. There was a linear relationship between the reduction in whole-body FFM between PRE and CRE and the changes in the cortisol/free testosterone ratio (C/FT), serum isoleucine, leucine, tryptophan, valine, BCAA, and EAA ( r = -0.54 to -0.71, respectively, P < 0.05). C/FT tended to be higher in the PRO than the SU group following CRE ( P = 0.06). In conclusion, concomitant low-intensity exercise such as walking or arm cranking even during an extreme energy deficit results in remarkable preservation of lean mass. The intake of proteins alone may be associated with greater cortisol/free testosterone ratio and is not better than the ingestion of only carbohydrates for preserving FFM and muscle performance in interventions of short duration.

Exercise Preserves Lean Mass and Performance during Severe Energy Deficit: The Role of Exercise Volume and Dietary Protein Content

PubMed Central

Calbet, Jose A. L.; Ponce-González, Jesús G.; Calle-Herrero, Jaime de La; Perez-Suarez, Ismael; Martin-Rincon, Marcos; Santana, Alfredo; Morales-Alamo, David; Holmberg, Hans-Christer

2017-01-01

The loss of fat-free mass (FFM) caused by very-low-calorie diets (VLCD) can be attenuated by exercise. The aim of this study was to determine the role played by exercise and dietary protein content in preserving the lean mass and performance of exercised and non-exercised muscles, during a short period of extreme energy deficit (~23 MJ deficit/day). Fifteen overweight men underwent three consecutive experimental phases: baseline assessment (PRE), followed by 4 days of caloric restriction and exercise (CRE) and then 3 days on a control diet combined with reduced exercise (CD). During CRE, the participants ingested a VLCD and performed 45 min of one-arm cranking followed by 8 h walking each day. The VLCD consisted of 0.8 g/kg body weight/day of either whey protein (PRO, n = 8) or sucrose (SU, n = 7). FFM was reduced after CRE (P < 0.001), with the legs and the exercised arm losing proportionally less FFM than the control arm [57% (P < 0.05) and 29% (P = 0.05), respectively]. Performance during leg pedaling, as reflected by the peak oxygen uptake and power output (Wpeak), was reduced after CRE by 15 and 12%, respectively (P < 0.05), and recovered only partially after CD. The deterioration of cycling performance was more pronounced in the whey protein than sucrose group (P < 0.05). Wpeak during arm cranking was unchanged in the control arm, but improved in the contralateral arm by arm cranking. There was a linear relationship between the reduction in whole-body FFM between PRE and CRE and the changes in the cortisol/free testosterone ratio (C/FT), serum isoleucine, leucine, tryptophan, valine, BCAA, and EAA (r = −0.54 to −0.71, respectively, P < 0.05). C/FT tended to be higher in the PRO than the SU group following CRE (P = 0.06). In conclusion, concomitant low-intensity exercise such as walking or arm cranking even during an extreme energy deficit results in remarkable preservation of lean mass. The intake of proteins alone may be associated with greater cortisol/free testosterone ratio and is not better than the ingestion of only carbohydrates for preserving FFM and muscle performance in interventions of short duration. PMID:28790922

Restorative effect of endurance exercise on behavioral deficits in the chronic mouse model of Parkinson's disease with severe neurodegeneration

PubMed Central

Pothakos, Konstantinos; Kurz, Max J; Lau, Yuen-Sum

2009-01-01

Background Animal models of Parkinson's disease have been widely used for investigating the mechanisms of neurodegenerative process and for discovering alternative strategies for treating the disease. Following 10 injections with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 25 mg/kg) and probenecid (250 mg/kg) over 5 weeks in mice, we have established and characterized a chronic mouse model of Parkinson's disease (MPD), which displays severe long-term neurological and pathological defects resembling that of the human Parkinson's disease in the advanced stage. The behavioral manifestations in this chronic mouse model of Parkinson's syndrome remain uninvestigated. The health benefit of exercise in aging and in neurodegenerative disorders including the Parkinson's disease has been implicated; however, clinical and laboratory studies in this area are limited. In this research with the chronic MPD, we first conducted a series of behavioral tests and then investigated the impact of endurance exercise on the identified Parkinsonian behavioral deficits. Results We report here that the severe chronic MPD mice showed significant deficits in their gait pattern consistency and in learning the cued version of the Morris water maze. Their performances on the challenging beam and walking grid were considerably attenuated suggesting the lack of balance and motor coordination. Furthermore, their spontaneous and amphetamine-stimulated locomotor activities in the open field were significantly suppressed. The behavioral deficits in the chronic MPD lasted for at least 8 weeks after MPTP/probenecid treatment. When the chronic MPD mice were exercise-trained on a motorized treadmill 1 week before, 5 weeks during, and 8–12 weeks after MPTP/probenecid treatment, the behavioral deficits in gait pattern, spontaneous ambulatory movement, and balance performance were reversed; whereas neuronal loss and impairment in cognitive skill, motor coordination, and amphetamine-stimulated locomotor activity were not altered when compared to the sedentary chronic MPD animals. Conclusion This study indicates that in spite of the drastic loss of dopaminergic neurons and depletion of dopamine in the severe chronic MPD, endurance exercise training effectively reverses the Parkinson's like behavioral deficits related to regular movement, balance and gait performance. PMID:19154608

Restorative effect of endurance exercise on behavioral deficits in the chronic mouse model of Parkinson's disease with severe neurodegeneration.

PubMed

Pothakos, Konstantinos; Kurz, Max J; Lau, Yuen-Sum

2009-01-20

Animal models of Parkinson's disease have been widely used for investigating the mechanisms of neurodegenerative process and for discovering alternative strategies for treating the disease. Following 10 injections with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 25 mg/kg) and probenecid (250 mg/kg) over 5 weeks in mice, we have established and characterized a chronic mouse model of Parkinson's disease (MPD), which displays severe long-term neurological and pathological defects resembling that of the human Parkinson's disease in the advanced stage. The behavioral manifestations in this chronic mouse model of Parkinson's syndrome remain uninvestigated. The health benefit of exercise in aging and in neurodegenerative disorders including the Parkinson's disease has been implicated; however, clinical and laboratory studies in this area are limited. In this research with the chronic MPD, we first conducted a series of behavioral tests and then investigated the impact of endurance exercise on the identified Parkinsonian behavioral deficits. We report here that the severe chronic MPD mice showed significant deficits in their gait pattern consistency and in learning the cued version of the Morris water maze. Their performances on the challenging beam and walking grid were considerably attenuated suggesting the lack of balance and motor coordination. Furthermore, their spontaneous and amphetamine-stimulated locomotor activities in the open field were significantly suppressed. The behavioral deficits in the chronic MPD lasted for at least 8 weeks after MPTP/probenecid treatment. When the chronic MPD mice were exercise-trained on a motorized treadmill 1 week before, 5 weeks during, and 8-12 weeks after MPTP/probenecid treatment, the behavioral deficits in gait pattern, spontaneous ambulatory movement, and balance performance were reversed; whereas neuronal loss and impairment in cognitive skill, motor coordination, and amphetamine-stimulated locomotor activity were not altered when compared to the sedentary chronic MPD animals. This study indicates that in spite of the drastic loss of dopaminergic neurons and depletion of dopamine in the severe chronic MPD, endurance exercise training effectively reverses the Parkinson's like behavioral deficits related to regular movement, balance and gait performance.

Influence of energy drinks and alcohol on post-exercise heart rate recovery and heart rate variability.

PubMed

Wiklund, Urban; Karlsson, Marcus; Oström, Mats; Messner, Torbjörn

2009-01-01

Media have anecdotally reported that drinking energy drinks in combination with alcohol and exercise could cause sudden cardiac death. This study investigated changes in the electrocardiogram (ECG) and heart rate variability after intake of an energy drink, taken in combination with alcohol and exercise. Ten healthy volunteers (five men and five women aged 19-30) performed maximal bicycle ergometer exercise for 30 min after: (i) intake of 0.75 l of an energy drink mixed with alcohol; (ii) intake of energy drink; and, (iii) no intake of any drink. ECG was continuously recorded for analysis of heart rate variability and heart rate recovery. No subject developed any clinically significant arrhythmias. Post-exercise recovery in heart rate and heart rate variability was slower after the subjects consumed energy drink and alcohol before exercise, than after exercise alone. The healthy subjects developed blunted cardiac autonomic modulation after exercising when they had consumed energy drinks mixed with alcohol. Although they did not develop any significant arrhythmia, individuals predisposed to arrhythmia by congenital or other rhythm disorders could have an increased risk for malignant cardiac arrhythmia in similar situations.

Heart rate behavior during an exercise stress test in obese patients.

PubMed

Gondoni, L A; Titon, A M; Nibbio, F; Augello, G; Caetani, G; Liuzzi, A

2009-03-01

Heart rate (HR) response to exercise has not been fully described in the obese. We wanted to study the differences between obese and non-obese patients in HR behavior during an exercise stress test and to determine whether these differences influence exercise capacity. We studied 554 patients (318 females) who underwent a treadmill exercise test. All subjects were in sinus rhythm. Patients with ischemic heart disease, with reduced ejection fraction and patients taking drugs that interfere with HR were excluded. The population included 231 patients with BMI<30 kg/m(2) (group 1), 212 patients who were unfit and obese (group 2) and 111 patients who were trained obese (group 3). Resting HR was similar in the various groups. Peak HR, HR recovery and chronotropic index were lower in obese subjects, regardless of their fitness level. Multivariate analysis showed that HR related variables were associated with age, BMI, height, hypertension and various pharmacologic treatments, while exercise capacity was strongly dependent on HR behavior, as well as on sex, age, BMI and diabetes. Obese subjects have a marked impairment of HR behavior during exercise and in the recovery period, and the blunted increase in HR is the most important factor that influences exercise capacity.

Memantine Protects Rats Treated with Intrathecal Methotrexate from Developing Spatial Memory Deficits

PubMed Central

Cole, Peter D.; Vijayanathan, Veena; Ali, Nafeeza F.; Wagshul, Mark E.; Tanenbaum, Eric J.; Price, Jeremy; Dalal, Vidhi; Gulinello, Maria E.

2014-01-01

Purpose To test whether memantine can prevent methotrexate-induced cognitive deficits in a preclinical model. Experimental Design After noting that methotrexate exposure induces prolonged elevations of the glutamate analog homocysteic acid (HCA) within cerebrospinal fluid, we tested whether intrathecal injection of HCA would produce memory deficits similar to those observed after intrathecal methotrexate. We then tested whether memantine, an antagonist of the N-methyl-D-aspartate (NMDA) subclass of glutamate receptors, could protect animals treated with clinically relevant doses of intrathecal methotrexate against developing memory deficits. Finally, we asked whether memantine affected this pathway beyond inhibiting the NMDA receptor by altering expression of the NMDA receptor or affecting concentrations of HCA or glutamate within the central nervous system. Results Four intrathecal doses of methotrexate induced deficits in spatial memory, persisting at least one month following the final injection. Intrathecal HCA was sufficient to reproduce this deficit. Concurrent administration of memantine during the period of methotrexate exposure was protective, decreasing the incidence of methotrexate-induced spatial memory deficits from 56% to 20% (P < 0.05). Memantine neither altered expression of NMDA receptors within the hippocampus nor blunted the methotrexate-induced increases in glutamate or HCA. Conclusions Excitotoxic glutamate analogs including HCA contribute to cognitive deficits observed after intrathecal methotrexate. Memantine, an NMDA receptor antagonist, reduces the incidence of cognitive deficits in rats treated with intrathecal methotrexate, and may therefore benefit patients with cancer receiving similar treatment. PMID:23833301

Effects of harmane during treadmill exercise on spatial memory of restraint-stressed mice.

PubMed

Nasehi, Mohammad; Shahini, Faezeh; Ebrahimi-Ghiri, Mohaddeseh; Azarbayjani, MohammadAli; Zarrindast, Mohammad-Reza

2018-06-08

Chronic stress induces hippocampal-dependent memory deficits, which can be counterbalanced with prolonged exercise. On the other hand, the β-carboline alkaloid harmane exerts potential in therapies for Alzheimer's and depression diseases and modulating neuronal responses to stress. The present study investigated the effect of chronic treatment of harmane alone or during treadmill running on spatial memory deficit in restraint-stressed mice. To examine spatial memory, adult male NMRI mice were subjected to the Y-maze. Intraperitoneal administration of harmane (0.6 mg/kg, once/ 48 h for 25 days) decreased the percentage of time in the novel arm and the number of novel arm visits, indicating a spatial memory deficit. A 9-day restraint stress (3 h/day) also produced spatial learning impairment. However, a 4-week regime of treadmill running (10 m/min for 30 min/day, 5 days/week) aggravated the stress impairing effect on spatial learning of 3-day stressed mice compared to exercise/non-stressed mice. Moreover, harmane (0.3 mg/kg) associated with exercise increased the number of novel arm visits in 9-day stressed mice compared to harmane/exercise/non-stressed or 9-day stressed group. It should be noted that none of these factors alone or in combination with each other had no effect on locomotor activity. Taken together, these data suggest that there is no interaction between harmane and exercise on spatial memory in stress condition. Copyright © 2018. Published by Elsevier Inc.

Exercise ameliorates neurocognitive impairments in a translational model of pediatric radiotherapy.

PubMed

Sahnoune, Iman; Inoue, Taeko; Kesler, Shelli R; Rodgers, Shaefali P; Sabek, Omaima M; Pedersen, Steen E; Zawaski, Janice A; Nelson, Katharine H; Ris, M Douglas; Leasure, J Leigh; Gaber, M Waleed

2018-04-09

While cranial radiation therapy (CRT) is an effective treatment, healthy areas surrounding irradiation sites are negatively affected. Frontal lobe functions involving attention, processing speed, and inhibition control are impaired. These deficits appear months to years after CRT and impair quality of life. Exercise has been shown to rejuvenate the brain and aid in recovery post-injury through its effects on neurogenesis and cognition. We developed a juvenile rodent CRT model that reproduces neurocognitive deficits. Next, we utilized the model to test whether exercise ameliorates these deficits. Fischer rats (31 days old) were irradiated with a fractionated dose of 4 Gy × 5 days, trained and tested at 6, 9, and 12 months post-CRT using 5-choice serial reaction time task. After testing, fixed rat brains were imaged using diffusion tensor imaging and immunohistochemistry. CRT caused early and lasting impairments in task acquisition, accuracy, and latency to correct response, as well as causing stunting of growth and changes in brain volume and diffusion. Exercising after irradiation improved acquisition, behavioral control, and processing speed, mitigated the stunting of brain size, and increased brain fiber numbers compared with sedentary CRT values. Further, exercise partially restored global connectome organization, including assortativity and characteristic path length, and while it did not improve the specific regional connections that were lowered by CRT, it appeared to remodel these connections by increasing connectivity between alternate regional pairs. Our data strongly suggest that exercise may be useful in combination with interventions aimed at improving cognitive outcome following pediatric CRT.

Contemporary Strategies in the Management of Civilian Neck Zone II Vascular Trauma

PubMed Central

Karaolanis, Georgios; Maltezos, Konstantinos; Bakoyiannis, Chris; Georgopoulos, Sotiris

2017-01-01

Neck trauma is the leading cause of death mainly in younger persons posing to surgeons the dilemma whether to proceed with reconstruction of vascular injuries either in the presence of coma or in severe neurological deficit. Vascular injuries in zone II predominate over the other injuries located in zones I/III of the neck. Conventional open repair of carotid injuries with primary closure or interposition grafting is always recommended due to the effective long-term results for penetrating injuries or for patients unfit for endovascular intervention. In cases of blunt trauma, anticoagulation or antiplatelet therapy should be administered first in neurologically stable patients. In case of worsening of the neurological status of the patient despite adequate anticoagulation endovascular means should be considered in cases of appropriate anatomy of the arterial trauma. We provide an update on penetrating/blunt trauma in zone II of the neck, giving emphasis on the anticoagulant and endovascular treatment. PMID:29034244

Effects of N2O narcosis on the contraction and repayment of an oxygen debt

NASA Technical Reports Server (NTRS)

Schatte, C. L.; Hall, P.; Fitch, J. W.; Loader, J. E.

1974-01-01

The oxygen deficit, oxygen debt, and the difference between them were measured in five male and three female subjects during and after exercise while breathing either air or a normoxic mixture containing 33% N2O and nitrogen. With the exception of a higher respiratory quotient at rest in N2O, there were no statistically significant differences for oxygen consumption, carbon dioxide production, expired gas volume, heart rate or blood lactate while breathing N2O during rest, exercise, or recovery. An appreciably, but not statistically, greater mean oxygen deficit was found in N2O along with a significantly greater mean oxygen debt; deficit-debt difference was unaffected by N2O. It was speculated that N2O narcosis did not affect the ability to utilize oxygen but that the response to the greater oxygen need of exercise may have been slowed with perhaps a concomitant greater depletion of stored high energy compounds.

Magnitude of daily energy deficit predicts frequency but not severity of menstrual disturbances associated with exercise and caloric restriction.

PubMed

Williams, Nancy I; Leidy, Heather J; Hill, Brenna R; Lieberman, Jay L; Legro, Richard S; De Souza, Mary Jane

2015-01-01

We assessed the impact of energy deficiency on menstrual function using controlled feeding and supervised exercise over four menstrual cycles (1 baseline and 3 intervention cycles) in untrained, eumenorrheic women aged 18-30 yr. Subjects were randomized to either an exercising control (EXCON) or one of three exercising energy deficit (ED) groups, i.e., mild (ED1; -8 ± 2%), moderate (ED2; -22 ± 3%), or severe (ED3; -42 ± 3%). Menstrual cycle length and changes in urinary concentrations of estrone-1-glucuronide, pregnanediol glucuronide, and midcycle luteinizing hormone were assessed. Thirty-four subjects completed the study. Weight loss occurred in ED1 (-3.8 ± 0.2 kg), ED2 (-2.8 ± 0.6 kg), and ED3 (-2.6 ± 1.1 kg) but was minimal in EXCON (-0.9 ± 0.7 kg). The overall sum of disturbances (luteal phase defects, anovulation, and oligomenorrhea) was greater in ED2 compared with EXCON and greater in ED3 compared with EXCON AND ED1. The average percent energy deficit was the main predictor of the frequency of menstrual disturbances (f = 10.1, β = -0.48, r(2) = 0.23, P = 0.003) even when weight loss was included in the model. The estimates of the magnitude of energy deficiency associated with menstrual disturbances ranged from -22 (ED2) to -42% (ED3), reflecting an energy deficit of -470 to -810 kcal/day, respectively. This is the first study to demonstrate a dose-response relationship between the magnitude of energy deficiency and the frequency of exercise-related menstrual disturbances; however, the severity of menstrual disturbances was not dependent on the magnitude of energy deficiency. Copyright © 2015 the American Physiological Society.

Voluntary physical exercise alters attentional orienting and social behavior in a rat model of attention-deficit/hyperactivity disorder.

PubMed

Hopkins, Michael E; Sharma, Mita; Evans, Gretchen C; Bucci, David J

2009-06-01

The effects of voluntary physical exercise on attentional function and social behavior were examined in male and female spontaneously hypertensive rats (SHR), a commonly used animal model of attention-deficit/hyperactivity disorder (ADHD). Rats in the exercise groups had free access to a running wheel for 2 weeks and then all rats received nonreinforced presentations of a visual stimulus (light) during the 1st training session, followed by daily sessions in which the light was paired with food. Nonexercising male and female SHR rats exhibited more unconditioned orienting behavior than Wistar-Kyoto rats. SHRs also exhibited impaired conditioning when the light was paired with food. Exercise reduced orienting in female SHRs but not in male SHRs. In the social interaction task, nonexercising male and female SHRs interacted more with an unfamiliar rat than Wistar-Kyoto rats. Exercise reduced the number of social interactions in female SHRs but not male SHRs. There were no differences in general locomotor activity observed between the nonexercising and exercising SHRs. These data indicate that exercise may preferentially benefit female SHRs, and has implications for using exercise as an intervention for ADHD and for understanding sex differences in the effects of exercise on behavior. Copyright (c) 2009 APA, all rights reserved.

Exercise Preconditioning Protects against Spinal Cord Injury in Rats by Upregulating Neuronal and Astroglial Heat Shock Protein 72

PubMed Central

Chang, Cheng-Kuei; Chou, Willy; Lin, Hung-Jung; Huang, Yi-Ching; Tang, Ling-Yu; Lin, Mao-Tsun; Chang, Ching-Ping

2014-01-01

The heat shock protein 72 (HSP 72) is a universal marker of stress protein whose expression can be induced by physical exercise. Here we report that, in a localized model of spinal cord injury (SCI), exercised rats (given pre-SCI exercise) had significantly higher levels of neuronal and astroglial HSP 72, a lower functional deficit, fewer spinal cord contusions, and fewer apoptotic cells than did non-exercised rats. pSUPER plasmid expressing HSP 72 small interfering RNA (SiRNA-HSP 72) was injected into the injured spinal cords. In addition to reducing neuronal and astroglial HSP 72, the (SiRNA-HSP 72) significantly attenuated the beneficial effects of exercise preconditioning in reducing functional deficits as well as spinal cord contusion and apoptosis. Because exercise preconditioning induces increased neuronal and astroglial levels of HSP 72 in the gray matter of normal spinal cord tissue, exercise preconditioning promoted functional recovery in rats after SCI by upregulating neuronal and astroglial HSP 72 in the gray matter of the injured spinal cord. We reveal an important function of neuronal and astroglial HSP 72 in protecting neuronal and astroglial apoptosis in the injured spinal cord. We conclude that HSP 72-mediated exercise preconditioning is a promising strategy for facilitating functional recovery from SCI. PMID:25334068

Oxidative stress and inflammation: liver responses and adaptations to acute and regular exercise.

PubMed

Pillon Barcelos, Rômulo; Freire Royes, Luiz Fernando; Gonzalez-Gallego, Javier; Bresciani, Guilherme

2017-02-01

The liver is remarkably important during exercise outcomes due to its contribution to detoxification, synthesis, and release of biomolecules, and energy supply to the exercising muscles. Recently, liver has been also shown to play an important role in redox status and inflammatory modulation during exercise. However, while several studies have described the adaptations of skeletal muscles to acute and chronic exercise, hepatic changes are still scarcely investigated. Indeed, acute intense exercise challenges the liver with increased reactive oxygen species (ROS) and inflammation onset, whereas regular training induces hepatic antioxidant and anti-inflammatory improvements. Acute and regular exercise protocols in combination with antioxidant and anti-inflammatory supplementation have been also tested to verify hepatic adaptations to exercise. Although positive results have been reported in some acute models, several studies have shown an increased exercise-related stress upon liver. A similar trend has been observed during training: while synergistic effects of training and antioxidant/anti-inflammatory supplementations have been occasionally found, others reported a blunting of relevant adaptations to exercise, following the patterns described in skeletal muscles. This review discusses current data regarding liver responses and adaptation to acute and regular exercise protocols alone or combined with antioxidant and anti-inflammatory supplementation. The understanding of the mechanisms behind these modulations is of interest for both exercise-related health and performance outcomes.

Suppression of Oxidative Stress by Resveratrol After Isometric Contractions in Gastrocnemius Muscles of Aged Mice

PubMed Central

Ryan, Michael J.; Jackson, Janna R.; Hao, Yanlei; Williamson, Courtney L.; Dabkowski, Erinne R.; Hollander, John M.

2010-01-01

This study tested the hypothesis that resveratrol supplementation would lower oxidative stress in exercised muscles of aged mice. Young (3 months) and aged (27 months) C57BL/6 mice received a control or a 0.05% trans-resveratrol-supplemented diet for 10 days. After 7 days of dietary intervention, 20 maximal electrically evoked isometric contractions were obtained from the plantar flexors of one limb in anesthetized mice. Exercise was conducted for three consecutive days. Resveratrol supplementation blunted the exercise-induced increase in xanthine oxidase activity in muscles from young (25%) and aged (53%) mice. Resveratrol lowered H2O2 levels in control (13%) and exercised (38%) muscles from aged animals, reduced Nox4 protein in both control and exercised muscles of young (30%) and aged mice (40%), and increased the ratio of reduced glutathione to oxidized glutathione in exercised muscles from young (38%) and aged (135%) mice. Resveratrol prevented the increase in lipid oxidation, increased catalase activity, and increased MnSOD activity in exercised muscles from aged mice. These data show that dietary resveratrol suppresses muscle indicators of oxidative stress in response to isometric contractions in aged mice. PMID:20507922

Reward Responsiveness Varies by Smoking Status in Women with a History of Major Depressive Disorder

PubMed Central

Janes, Amy C; Pedrelli, Paola; Whitton, Alexis E; Pechtel, Pia; Douglas, Samuel; Martinson, Max A; Huz, Ilana; Fava, Maurizio; Pizzagalli, Diego A; Evins, A Eden

2015-01-01

Major depressive disorder (MDD) and nicotine dependence are highly comorbid, with studies showing that ~50% of individuals with MDD smoke. The link between these disorders persists even after the clinical symptoms of depression subside, as indicated by high levels of nicotine dependence among individuals with remitted depression (rMDD). Recent evidence indicates that individuals with rMDD show blunted responses to reward as measured by a probabilistic reward task (PRT), which assesses the ability to modify behavior as a function of reward history. Given nicotine's ability to enhance reward responsiveness, individuals with rMDD might smoke to address this persistent reward deficit. However, it is unclear whether smokers with rMDD show enhanced reward responsiveness relative to rMDD individuals who do not smoke. To test this hypothesis, we evaluated reward responsiveness on the PRT in four groups (N=198): individuals with and without rMDD who were or were not nicotine dependent. As hypothesized, rMDD nonsmokers had lower reward responsiveness relative to both control nonsmokers and rMDD smokers; conversely, smokers with rMDD showed behavioral patterns comparable to those without a history of depression. Given nicotine's ability to enhance reward sensitivity, it is possible that nicotine normalizes the otherwise blunted reward responsiveness in individuals with rMDD. Therapies aimed at enhancing this reward-based deficit may be beneficial in the treatment of both nicotine dependence and MDD. PMID:25662839

The Benefits of Exercise and Metabolic Interventions for the Prevention and Early Treatment of Alzheimer's Disease.

PubMed

Maliszewska-Cyna, Ewelina; Lynch, Madelaine; Oore, Jonathan Jordan; Nagy, Paul Michael; Aubert, Isabelle

2017-01-01

Alzheimer's disease (AD) is characterized by neuronal degeneration, vascular pathology and cognitive decline. Furthermore, deficits in cerebral glucose metabolism and insulin resistance are being increasingly recognized in AD. Many lifestyle-modifying approaches, including diet and exercise, have yielded promising results in modulating brain morphology and function for the prevention and early treatment of AD. This review focuses on the effects of physical exercise on rescuing cognition and limiting the progression of AD pathology. Specifically, the impact of exercise, in human and animal models of AD, on the stimulation and preservation of cognition, neurotransmission, neurogenesis, vasculature, glucose metabolism and insulin signaling is discussed. Studies have highlighted the potential of physical activity to improve overall brain health, which could delay or lessen AD-related cognitive deficits and pathology. Physical activity influences cognitive function, vascular health and brain metabolism, which taken together offers benefits for the aging population, including AD patients.

Exercise deficit disorder in youth: play now or pay later.

PubMed

Faigenbaum, Avery D; Myer, Gregory D

2012-01-01

Although the benefits of regular physical activity are widely acknowledged, recent epidemiological findings indicate that a growing number of youth are not as active as they should be. The impact of a sedentary lifestyle during childhood and adolescence on lifelong pathological processes and associated health care costs has created a need for immediate action to manage, if not prevent, unhealthy behaviors during this vulnerable period of life. The concept of identifying children with exercise deficit disorder early in life and prescribing effective exercise interventions to prevent the cascade of adverse health outcomes later in life is needed to raise public awareness, focus on primary prevention, and impact the collective behaviors of health care providers, government officials, school administrators, public health agencies, and insurance companies.

Targeted exercise therapy for voice and swallow in persons with Parkinson’s disease

PubMed Central

Russell, John A.; Ciucci, Michelle R.; Connor, Nadine P.; Schallert, Timothy

2010-01-01

Sensorimotor deficits affecting voice and swallowing ability can have a devastating impact on the quality of life of people with Parkinson disease (PD). Recent scientific findings in animal models of PD pinpoint targeted exercise therapy as a potential treatment to reduce neurochemical loss and decrease parkinsonian symptoms. Although there may be beneficial effects, targeted exercise therapy is not a standard component of therapy for the cranial sensiromotor deficits seen in PD. In this paper we review the scientific evidence for targeted training for voice and swallowing deficits. The literature search revealed 19 publications that included targeted training for voice and only one publication that included targeted training for swallowing. We summarize 3 main findings: 1) targeted training may be associated with lasting changes in voice behavior, 2) targeted training of sensorimotor actions with anatomical or functional overlap with voice and swallowing may improve voice and swallowing to some degree, but it is unknown whether these effects endure over time, and 3) evidence regarding cranial sensorimotor interventions for Parkinson disease is sparse. We concluded that targeted training for voice and swallow is a promising but under-studied intervention for cranial sensorimotor deficits associated with PD and posit that animal models can be useful in designing empirically based studies that further the science on targeted training. PMID:20233583

Short-term consumption of a high-fat diet impairs whole-body efficiency and cognitive function in sedentary men.

PubMed

Edwards, Lindsay M; Murray, Andrew J; Holloway, Cameron J; Carter, Emma E; Kemp, Graham J; Codreanu, Ion; Brooker, Helen; Tyler, Damian J; Robbins, Peter A; Clarke, Kieran

2011-03-01

We recently showed that a short-term high-fat diet blunted exercise performance in rats, accompanied by increased uncoupling protein levels and greater respiratory uncoupling. In this study, we investigated the effects of a similar diet on physical and cognitive performance in humans. Twenty sedentary men were assessed when consuming a standardized, nutritionally balanced diet (control) and after 7 d of consuming a diet comprising 74% kcal from fat. Efficiency was measured during a standardized exercise task, and cognition was assessed using a computerized assessment battery. Skeletal muscle mitochondrial function was measured using (31)P magnetic resonance spectroscopy. The diet increased mean ± se plasma free fatty acids by 44% (0.32±0.03 vs. 0.46±0.05 mM; P<0.05) and decreased whole-body efficiency by 3% (21±1 vs. 18±1%; P<0.05), although muscle uncoupling protein (UCP3) content and maximal mitochondrial function were unchanged. High-fat diet consumption also increased subjects' simple reaction times (P<0.01) and decreased power of attention (P<0.01). Thus, we have shown that a high-fat diet blunts whole-body efficiency and cognition in sedentary men. We suggest that this effect may be due to increased respiratory uncoupling.

Effects of endurance, resistance, and concurrent exercise on learning and memory after morphine withdrawal in rats.

PubMed

Zarrinkalam, Ebrahim; Heidarianpour, Ali; Salehi, Iraj; Ranjbar, Kamal; Komaki, Alireza

2016-07-15

Continuous morphine consumption contributes to the development of cognitive disorders. This work investigates the impacts of different types of exercise on learning and memory in morphine-dependent rats. Forty morphine-dependent rats were randomly divided into five groups: sedentary-dependent (Sed-D), endurance exercise-dependent (En-D), strength exercise-dependent (St-D), and combined (concurrent) exercise-dependent (Co-D). Healthy rats were used as controls (Con). After 10weeks of regular exercise (endurance, strength, and concurrent; each five days per week), spatial and aversive learning and memory were assessed using the Morris water maze and shuttle box tests. The results showed that morphine addiction contributes to deficits in spatial learning and memory. Furthermore, each form of exercise training restored spatial learning and memory performance in morphine-dependent rats to levels similar to those of healthy controls. Aversive learning and memory during the acquisition phase were not affected by morphine addiction or exercise, but were significantly decreased by morphine dependence. Only concurrent training returned the time spent in the dark compartment in the shuttle box test to control levels. These findings show that different types of exercise exert similar effects on spatial learning and memory, but show distinct effects on aversive learning and memory. Further, morphine dependence-induced deficits in cognitive function were blocked by exercise. Therefore, different exercise regimens may represent practical treatment methods for cognitive and behavioral impairments associated with morphine-related disease. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of fasted vs fed-state exercise on performance and post-exercise metabolism: A systematic review and meta-analysis.

PubMed

Aird, T P; Davies, R W; Carson, B P

2018-05-01

The effects of nutrition on exercise metabolism and performance remain an important topic among sports scientists, clinical, and athletic populations. Recently, fasted exercise has garnered interest as a beneficial stimulus which induces superior metabolic adaptations to fed exercise in key peripheral tissues. Conversely, pre-exercise feeding augments exercise performance compared with fasting conditions. Given these seemingly divergent effects on performance and metabolism, an appraisal of the literature is warranted. This review determined the effects of fasting vs pre-exercise feeding on continuous aerobic and anaerobic or intermittent exercise performance, and post-exercise metabolic adaptations. A search was performed using the MEDLINE and PubMed search engines. The literature search identified 46 studies meeting the relevant inclusion criteria. The Delphi list was used to assess study quality. A meta-analysis and meta-regression were performed where appropriate. Findings indicated that pre-exercise feeding enhanced prolonged (P = .012), but not shorter duration aerobic exercise performance (P = .687). Fasted exercise increased post-exercise circulating FFAs (P = .023) compared to fed exercise. It is evidenced that pre-exercise feeding blunted signaling in skeletal muscle and adipose tissue implicated in regulating components of metabolism, including mitochondrial adaptation and substrate utilization. This review's findings support the hypothesis that the fasted and fed conditions can divergently influence exercise metabolism and performance. Pre-exercise feeding bolsters prolonged aerobic performance, while seminal evidence highlights potential beneficial metabolic adaptations that fasted exercise may induce in peripheral tissues. However, further research is required to fully elucidate the acute and chronic physiological adaptations to fasted vs fed exercise. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparable Neutrophil Responses for Arm and Intensity-matched Leg Exercise.

PubMed

Leicht, Christof A; Goosey-Tolfrey, Victoria L; Bishop, Nicolette C

2017-08-01

Arm exercise is performed at lower absolute intensities than lower body exercise. This may impact on intensity-dependent neutrophil responses, and it is unknown whether individuals restricted to arm exercise experience the same changes in the neutrophil response as found for lower body exercise. Therefore, we aimed to investigate the importance of exercise modality and relative exercise intensity on the neutrophil response. Twelve moderately trained men performed three 45-min constant load exercise trials after determination of peak oxygen uptake for arm exercise (V˙O2peak arms) and cycling (V˙O2peak legs): 1) arm cranking exercise at 60% V˙O2peak arms, 2) moderate cycling at 60% V˙O2peak legs, and 3) easy cycling at 60% V˙O2peak arms. Neutrophil numbers in the circulation increased for all exercise trials, but were significantly lower for easy cycling when compared with arm exercise (P = 0.009), mirroring the blunted increase in HR and epinephrine during easy cycling. For all trials, exercising HR explained some of the variation of the neutrophil number 2 h postexercise (R = 0.51-0.69), epinephrine explaining less of this variation (R = 0.21-0.34). The number of neutrophils expressing CXCR2 decreased in the recovery from exercise in all trials (P < 0.05). Arm and leg exercise elicits the same neutrophil response when performed at the same relative intensity, implying that populations restricted to arm exercise might achieve a similar exercise induced neutrophil response as those performing lower body exercise. A likely explanation for this is the higher sympathetic activation and cardiac output for arm and relative intensity-matched leg exercise when compared with easy cycling, which is partly reflected in HR. This study further shows that the downregulation of CXCR2 may be implicated in exercise-induced neutrophilia.

Resistance to the beneficial effects of exercise in type 2 diabetes: are some individuals programmed to fail?

PubMed

Stephens, Natalie A; Sparks, Lauren M

2015-01-01

Exercise benefits most, but not all, individuals with type 2 diabetes (T2D). The beneficial effects are well studied, but why some individuals do not respond favorably to exercise training is largely unexplored. It is critical to treatment and prevention strategies to identify individuals with T2D that have a blunted metabolic response to exercise and investigate the underlying mechanisms that might predict this "programmed response to fail." We carried out a systematic review of classic and contemporary primary reports on clinical human and animal exercise studies. We also referenced unpublished data from our previous studies, as well those of collaborators. Genetic and epigenetic components and their associations with the exercise response were also examined. As evidence of the exercise resistance premise, we and others found that supervised exercise training results in substantial response variations in glucose homeostasis, insulin sensitivity, and muscle mitochondrial density, wherein approximately 15-20% of individuals fail to improve their metabolic health with exercise. Classic genetic studies have shown that the extent of the exercise training response is largely heritable, whereas new evidence demonstrates that DNA hypomethylation is linked to the exercise response in skeletal muscle. DNA sequence variation and/or epigenetic modifications may, therefore, dictate the exercise training response. Studies dedicated to uncovering the mechanisms of exercise resistance will advance the field of exercise and T2D, allowing interventions to be targeted to those most likely to benefit and identify novel approaches to treat those who do not experience metabolic improvements after exercise training.

Disrupted reward circuits is associated with cognitive deficits and depression severity in major depressive disorder.

PubMed

Gong, Liang; Yin, Yingying; He, Cancan; Ye, Qing; Bai, Feng; Yuan, Yonggui; Zhang, Haisan; Lv, Luxian; Zhang, Hongxing; Xie, Chunming; Zhang, Zhijun

2017-01-01

Neuroimaging studies have demonstrated that major depressive disorder (MDD) patients show blunted activity responses to reward-related tasks. However, whether abnormal reward circuits affect cognition and depression in MDD patients remains unclear. Seventy-five drug-naive MDD patients and 42 cognitively normal (CN) subjects underwent a resting-state functional magnetic resonance imaging scan. The bilateral nucleus accumbens (NAc) were selected as seeds to construct reward circuits across all subjects. A multivariate linear regression analysis was employed to investigate the neural substrates of cognitive function and depression severity on the reward circuits in MDD patients. The common pathway underlying cognitive deficits and depression was identified with conjunction analysis. Compared with CN subjects, MDD patients showed decreased reward network connectivity that was primarily located in the prefrontal-striatal regions. Importantly, distinct and common neural pathways underlying cognition and depression were identified, implying the independent and synergistic effects of cognitive deficits and depression severity on reward circuits. This study demonstrated that disrupted topological organization within reward circuits was significantly associated with cognitive deficits and depression severity in MDD patients. These findings suggest that in addition to antidepressant treatment, normalized reward circuits should be a focus and a target for improving depression and cognitive deficits in MDD patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Femoral Blood Flow and Cardiac Output During Blood Flow Restricted Leg Press Exercise

NASA Technical Reports Server (NTRS)

Everett, M. E.; Hackney, K.; Ploutz-Snyder, L.

2011-01-01

Low load blood flow restricted resistance exercise (LBFR) causes muscle hypertrophy that may be stimulated by the local ischemic environment created by the cuff pressure. However, local blood flow (BF) during such exercise is not well understood. PURPOSE: To characterize femoral artery BF and cardiac output (CO) during leg press exercise (LP) performed at a high load (HL) and low load (LL) with different levels of cuff pressure. METHODS: Eleven subjects (men/women 4/7, age 31.4+/-12.8 y, weight 68.9+/-13.2 kg, mean+/-SD) performed 3 sets of supine left LP to fatigue with 90 s of rest in 4 conditions: HL (%1-RM/cuff pressure: 80%/0); LL (20%/0); LBFR(sub DBP) (20%/1.3 x diastolic blood pressure, BP); LBFR(sub SBP) (20%/1.3 x supine systolic BP). The cuff remained inflated throughout the LBFR exercise sessions. Artery diameter, velocity time integral (VTI), and stroke volume (SV) were measured using Doppler ultrasound at rest and immediately after each set of exercise. Heart rate (HR) was monitored using a 3-lead ECG. BF was calculated as VTI x vessel cross-sectional area. CO was calculated as HR x SV. The data obtained after each set of exercise were averaged and used for analyses. Multi-level modeling was used to determine the effect of exercise condition on dependent variables. Statistical significance was set a priori at p< 0.05. RESULTS: Artery diameter did not change from baseline. BF increased (p<0.05) after exercise in each condition except LBFR(sub SBP) in the order of HL (12.73+/-1.42 cm3,mean+/-SE) > LL (9.92+/-0.82 cm3) > LBFR(sub dBP)(6.47+/-0.79 cm3) > LBFR(sub SBP) (3.51+/-0.59 cm3). Blunted exercise induced increases occurred in HR, SV, and CO after LBFR compared to HL and LL. HR increased 45% after HL and LL and 28% after LBFR (p<0.05), but SV increased (p<0.05) only after HL. Consequently, the increase (p<0.05) in CO was greater in HL and LL (approximately 3 L/min) than in LBFR (approximately 1 L/min). CONCLUSION: BF during LBFR(sub SBP) was 1/3 of that observed in LL, which supports the hypothesis that local ischemia stimulates the LBFR hypertrophic response. As the cuff did not compress the artery, the ischemia may have occurred because of the blunted rise in CO or because arterial BP cannot overcome the cuff pressure. As LBFR(sub DBP) effectively reduced BF and CO with cuff pressures less than systolic BP, future studies should investigate the hypertrophic potential of LBFR at even lower cuff pressures.

Exercising Tactically for Taming Postmeal Glucose Surges.

PubMed

Chacko, Elsamma

2016-01-01

This review seeks to synthesize data on the timing, intensity, and duration of exercise found scattered over some 39 studies spanning 3+ decades into optimal exercise conditions for controlling postmeal glucose surges. The results show that a light aerobic exercise for 60 min or moderate activity for 20-30 min starting 30 min after meal can efficiently blunt the glucose surge, with minimal risk of hypoglycemia. Exercising at other times could lead to glucose elevation caused by counterregulation. Adding a short bout of resistance exercise of moderate intensity (60%-80%  VO2max) to the aerobic activity, 2 or 3 times a week as recommended by the current guidelines, may also help with the lowering of glucose surges. On the other hand, high-intensity exercise (>80%  VO2max) causes wide glucose fluctuations and its feasibility and efficacy for glucose regulation remain to be ascertained. Promoting the kind of physical activity that best counters postmeal hyperglycemia is crucial because hundreds of millions of diabetes patients living in developing countries and in the pockets of poverty in the West must do without medicines, supplies, and special diets. Physical activity is the one tool they may readily utilize to tame postmeal glucose surges. Exercising in this manner does not violate any of the current guidelines, which encourage exercise any time.

The role of physical activity in producing and maintaining weight loss

PubMed Central

Catenacci, Victoria A; Wyatt, Holly R

2015-01-01

Summary The majority of randomized, controlled trials (RCTs) show only modest weight loss with exercise intervention alone, and slight increases in weight loss when exercise intervention is added to dietary restriction. In most RCTs, the energy deficit produced by the prescribed exercise is far smaller than that usually produced by dietary restriction. In prospective studies that prescribed high levels of exercise, enrolled individuals achieved substantially greater weight loss—comparable to that obtained after similar energy deficits were produced by caloric restriction. High levels of exercise might, however, be difficult for overweight or obese adults to achieve and sustain. RCTs examining exercise and its effect on weight-loss maintenance demonstrated mixed results; however, weight maintenance interventions were usually of limited duration and long-term adherence to exercise was problematic. Epidemiologic, cross-sectional, and prospective correlation studies suggest an essential role for physical activity in weight-loss maintenance, and post hoc analysis of prospective trials shows a clear dose–response relationship between physical activity and weight maintenance. This article reviews the role of physical activity in producing and maintaining weight loss. We focus on prospective, RCTs lasting at least 4 months; however, other prospective trials, meta-analyses and large systematic reviews are included. Limitations in the current body of literature are discussed. PMID:17581621

The role of physical activity in producing and maintaining weight loss.

PubMed

Catenacci, Victoria A; Wyatt, Holly R

2007-07-01

The majority of randomized, controlled trials (RCTs) show only modest weight loss with exercise intervention alone, and slight increases in weight loss when exercise intervention is added to dietary restriction. In most RCTs, the energy deficit produced by the prescribed exercise is far smaller than that usually produced by dietary restriction. In prospective studies that prescribed high levels of exercise, enrolled individuals achieved substantially greater weight loss-comparable to that obtained after similar energy deficits were produced by caloric restriction. High levels of exercise might, however, be difficult for overweight or obese adults to achieve and sustain. RCTs examining exercise and its effect on weight-loss maintenance demonstrated mixed results; however, weight maintenance interventions were usually of limited duration and long-term adherence to exercise was problematic. Epidemiologic, cross-sectional, and prospective correlation studies suggest an essential role for physical activity in weight-loss maintenance, and post hoc analysis of prospective trials shows a clear dose-response relationship between physical activity and weight maintenance. This article reviews the role of physical activity in producing and maintaining weight loss. We focus on prospective, RCTs lasting at least 4 months; however, other prospective trials, meta-analyses and large systematic reviews are included. Limitations in the current body of literature are discussed.

Appetite and gut peptide responses to exercise and calorie restriction. The effect of modest energy deficits.

PubMed

Deighton, Kevin; Batterham, Rachel L; Stensel, David J

2014-10-01

Weight loss is the result of a sustained negative energy balance, which is typically achieved by decreasing food intake and/or increasing physical activity. Current evidence suggests that acute energy deficits of ~4820 kJ elicit contrasting homeostatic responses when induced by exercise and food restriction but the response to government-recommended energy deficits is unknown. Twelve healthy men (mean(SD): age 24(5) years, body mass index 23.8(2.7) kg⋅m(-2), maximum oxygen uptake 55.4(9.1) mL⋅kg(-1)⋅min(-1)) completed three 8 h trials (control (Con), exercise-induced energy deficit (Ex-Def) and food restriction (Food-Def)) separated by 1 week. Thirty minutes of cycling at 64.5(3.2)% of maximum oxygen uptake was performed in Ex-Def from 0 to 0.5 h, which induced an energy deficit of 1469(256) kJ. An equivalent energy deficit was induced in Food-Def (1478(275) kJ) by reducing the energy content of standardised test meals at 1 h and 4 h. Appetite ratings, acylated ghrelin and peptide YY3-36 concentrations were measured throughout each trial. An ad libitum meal was provided at 7 h. Appetite was higher in Food-Def than Ex-Def from 4 to 8 h (P = 0.033) and tended to be higher across the entire 8 h trial (P = 0.059). However, energy intake at the ad libitum meal did not differ between trials (P = 0.634; Con 4376 (1634); Food-Def 4481 (1846); Ex-Def 4217 (1850) kJ). Acylated ghrelin was not related to changes in appetite but plasma PYY3-36 concentrations were higher in Ex-Def than Food-Def (P < 0.05) and negatively correlated with changes in appetite across the entire 8 h trial (P = 0.037). An energy deficit of ~1475 kJ stimulated compensatory increases in appetite when induced via calorie restriction but not when achieved by an acute bout of exercise. Appetite responses were associated with changes in plasma PYY3-36 but not acylated ghrelin concentrations and did not influence subsequent energy intake. Copyright © 2014 Elsevier Ltd. All rights reserved.

Obesity and Prader-Willi Syndrome Affect Heart Rate Recovery from Dynamic Resistance Exercise in Youth.

PubMed

Castner, Diobel M; Clark, Susan J; Judelson, Daniel A; Rubin, Daniela A

2016-01-15

Following exercise, heart rate decline is initially driven by parasympathetic reactivation and later by sympathetic withdrawal. Obesity delays endurance exercise heart rate recovery (HRR) in both children and adults. Young people with Prader-Willi Syndrome (PWS), a congenital cause for obesity, have shown a slower 60-s endurance exercise HRR compared to lean and obese children, suggesting compromised regulation. This study further evaluated effects of obesity and PWS on resistance exercise HRR at 30 and 60 s in children. PWS (8-18 years) and lean and obese controls (8-11 years) completed a weighted step-up protocol (six sets x 10 reps per leg, separated by one-minute rest), standardized using participant stature and lean body mass. HRR was evaluated by calculated HRR value (HRRV = difference between HR at test termination and 30 (HRRV30) and 60 (HRRV60) s post-exercise). PWS and obese had a smaller HRRV30 than lean ( p < 0.01 for both). Additionally, PWS had a smaller HRRV60 than lean and obese ( p = 0.01 for both). Obesity appears to delay early parasympathetic reactivation, which occurs within 30 s following resistance exercise. However, the continued HRR delay at 60 s in PWS may be explained by either blunted parasympathetic nervous system reactivation, delayed sympathetic withdrawal and/or poor cardiovascular fitness.

Aerobic physical exercise as a possible treatment for neurocognitive dysfunction in bipolar disorder.

PubMed

Kucyi, Aaron; Alsuwaidan, Mohammad T; Liauw, Samantha S; McIntyre, Roger S

2010-11-01

Neurocognitive dysfunction associated with bipolar disorder (BD) is pervasive, persistent across illness phases, and is demonstrated to predispose and portend psychosocial impairment. Moreover, no approved therapies for various phases of BD have been shown to reliably improve any dimension of neurocognitive performance. In this article, we emphasize that aerobic physical exercise is a viable neurocognitive-enhancing adjunctive treatment for patients with BD. The overarching aim of this review is to emphasize that aerobic physical exercise is a viable neurocognitive-enhancing adjunctive treatment for patients with BD. We conducted PubMed and Google Scholar searches of all English-language articles published between January 1966 and February 2010 using the search terms bipolar disorder, major depressive disorder, depression, exercise, and physical activity cross-referenced with each other and the following terms: cognition, executive function, learning, memory, attention, emotion, and behavior. Articles selected for review were based on adequacy of sample size, use of standardized experimental procedures, validated assessment measures, and overall quality. Available studies have documented an array of persisting neurocognitive deficits across disparate bipolar populations. Abnormalities in verbal working memory are highly replicated; deficits in executive function, learning, attention, and processing speed are also a consistent abnormality. The effect sizes of neurocognitive deficits in BD are intermediate between those reported in schizophrenia and major depressive disorder. Several original reports and reviews have documented the neurocognitive-enhancing effects of aerobic exercise in the general population as well as across diverse medical populations and ages. Proposed mechanisms involve nonexclusive effects on neurogenesis, neurotrophism, immunoinflammatory systems, insulin sensitivity, and neurotransmitter systems. Each of these effector systems are implicated in both normal and abnormal neurocognitive processes in BD. Available evidence provides a rationale for empirically evaluating the neurocognitive benefits of aerobic exercise in BD.

Magnitude of daily energy deficit predicts frequency but not severity of menstrual disturbances associated with exercise and caloric restriction

PubMed Central

Leidy, Heather J.; Hill, Brenna R.; Lieberman, Jay L.; Legro, Richard S.; Souza, Mary Jane De

2014-01-01

We assessed the impact of energy deficiency on menstrual function using controlled feeding and supervised exercise over four menstrual cycles (1 baseline and 3 intervention cycles) in untrained, eumenorrheic women aged 18–30 yr. Subjects were randomized to either an exercising control (EXCON) or one of three exercising energy deficit (ED) groups, i.e., mild (ED1; −8 ± 2%), moderate (ED2; −22 ± 3%), or severe (ED3; −42 ± 3%). Menstrual cycle length and changes in urinary concentrations of estrone-1-glucuronide, pregnanediol glucuronide, and midcycle luteinizing hormone were assessed. Thirty-four subjects completed the study. Weight loss occurred in ED1 (−3.8 ± 0.2 kg), ED2 (−2.8 ± 0.6 kg), and ED3 (−2.6 ± 1.1 kg) but was minimal in EXCON (−0.9 ± 0.7 kg). The overall sum of disturbances (luteal phase defects, anovulation, and oligomenorrhea) was greater in ED2 compared with EXCON and greater in ED3 compared with EXCON AND ED1. The average percent energy deficit was the main predictor of the frequency of menstrual disturbances (f = 10.1, β = −0.48, r2 = 0.23, P = 0.003) even when weight loss was included in the model. The estimates of the magnitude of energy deficiency associated with menstrual disturbances ranged from −22 (ED2) to −42% (ED3), reflecting an energy deficit of −470 to −810 kcal/day, respectively. This is the first study to demonstrate a dose-response relationship between the magnitude of energy deficiency and the frequency of exercise-related menstrual disturbances; however, the severity of menstrual disturbances was not dependent on the magnitude of energy deficiency. PMID:25352438

Exercise-induced rescue of tongue function without striatal dopamine sparing in a rat neurotoxin model of Parkinson disease.

PubMed

Ciucci, Michelle R; Schaser, Allison J; Russell, John A

2013-09-01

Unilateral lesions to the medial forebrain bundle with 6-hydroxydopamine (6-OHDA) lead to force and timing deficits during a complex licking task. We hypothesized that training targeting tongue force generation during licking would improve timing and force measures and also lead to striatal dopamine sparing. Nine month-old male Fisher344/Brown Norway rats were used in this experiment. Sixteen rats were in the control condition and received tongue exercise (n=8) or no exercise (n=8). Fourteen rats were in the 6-OHDA lesion condition and underwent tongue exercise (n=7) and or no exercise (n=7). Following 4 weeks of training and post-training measures, all animals underwent bilateral stimulation of the hypoglossal nerves to measure muscle contractile properties and were then transcardially perfused and brain tissues collected for immunohistochemistry to examine striatal dopamine content. Results demonstrated that exercise animals performed better for maximal force, average force, and press rate than their no-exercise counterparts, and the 6-OHDA animals that underwent exercise performed as well as the Control No Exercise group. Interestingly, there were no group differences for tetanic muscle force, despite behavioral recovery of forces. Additionally, behavioral and neurochemical analyses indicate that there were no differences in striatal dopamine. Thus, targeted exercise can improve tongue force and timing deficits related to 6-OHDA lesions and this exercise likely has a central, versus peripheral (muscle strength) mechanism. However, this mechanism is not related to sparing of striatal dopamine content. Copyright © 2013 Elsevier B.V. All rights reserved.

Strength deficits of the shoulder complex during isokinetic testing in people with chronic stroke

PubMed Central

Nascimento, Lucas R.; Teixeira-Salmela, Luci F.; Polese, Janaine C.; Ada, Louise; Faria, Christina D. C. M.; Laurentino, Glória E. C.

2014-01-01

OBJECTIVES: To examine the strength deficits of the shoulder complex after stroke and to characterize the pattern of weakness according to type of movement and type of isokinetic parameter. METHOD: Twelve chronic stroke survivors and 12 age-matched healthy controls had their shoulder strength measured using a Biodex isokinetic dynamometer. Concentric measures of peak torque and work during shoulder movements were obtained in random order at speeds of 60°/s for both groups and sides. Type of movement was defined as scapulothoracic (protraction and retraction), glenohumeral (shoulder internal and external rotation) or combined (shoulder flexion and extension). Type of isokinetic parameter was defined as maximum (peak torque) or sustained (work). Strength deficits were calculated using the control group as reference. RESULTS: The average strength deficit for the paretic upper limb was 52% for peak torque and 56% for work. Decreases observed in the non-paretic shoulder were 21% and 22%, respectively. Strength deficit of the scapulothoracic muscles was similar to the glenohumeral muscles, with a mean difference of 6% (95% CI -5 to 17). Ability to sustain torque throughout a given range of motion was decreased as much as the peak torque, with a mean difference of 4% (95% CI -2 to 10). CONCLUSIONS: The findings suggest that people after stroke might benefit from strengthening exercises directed at the paretic scapulothoracic muscles in addition to exercises of arm elevation. Clinicians should also prescribe different exercises to improve the ability to generate force and the ability to sustain the torque during a specific range of motion. PMID:25003280

Environmental enrichment and exercise are better than social enrichment to reduce memory deficits in amyloid beta neurotoxicity.

PubMed

Prado Lima, Mariza G; Schimidt, Helen L; Garcia, Alexandre; Daré, Letícia R; Carpes, Felipe P; Izquierdo, Ivan; Mello-Carpes, Pâmela B

2018-03-06

Recently, nongenetic animal models to study the onset and development of Alzheimer's disease (AD) have appeared, such as the intrahippocampal infusion of peptides present in Alzheimer amyloid plaques [i.e., amyloid-β (Aβ)]. Nonpharmacological approaches to AD treatment also have been advanced recently, which involve combinations of behavioral interventions whose specific effects are often difficult to determine. Here we isolate the neuroprotective effects of three of these interventions-environmental enrichment (EE), anaerobic physical exercise (AnPE), and social enrichment (SE)-on Aβ-induced oxidative stress and on impairments in learning and memory induced by Aβ. Wistar rats were submitted to 8 wk of EE, AnPE, or SE, followed by Aβ infusion in the dorsal hippocampus. Short-term memory (STM) and long-term memory (LTM) of object recognition (OR) and social recognition (SR) were evaluated. Biochemical assays determined hippocampal oxidative status: reactive oxygen species, lipid peroxidation by thiobarbituric acid reactive substance (TBARS) test, and total antioxidant capacity by ferric reducing/antioxidant power (FRAP), as well as acetylcholinesterase activity. Aβ infusion resulted in memory deficits and hippocampal oxidative damage. EE and AnPE prevented all memory deficits (STM and LTM of OR and SR) and lipid peroxidation (i.e., TBARS). SE prevented only the SR memory deficits and the decrease of total antioxidant capacity decrease (i.e., FRAP). Traditionally, findings obtained with EE protocols do not allow discrimination of the roles of the three individual factors involved. Here we demonstrate that EE and physical exercise have better neuroprotective effects than SE in memory deficits related to Aβ neurotoxicity in the AD model tested.

Effects of Acute Exercise on Resting EEG in Children with Attention-Deficit/Hyperactivity Disorder.

PubMed

Huang, Chung-Ju; Huang, Ching-Wen; Hung, Chiao-Ling; Tsai, Yu-Jung; Chang, Yu-Kai; Wu, Chien-Ting; Hung, Tsung-Min

2018-06-05

This two stage study examined the effects of acute exercise on resting electroencephalographic (EEG) patterns of children with attention-deficit hyperactivity disorder (ADHD). The first stage compared the neural oscillatory patterns of children with and without ADHD. Resting EEGs were recorded under an open-eyes condition from 24 boys with ADHD and 28 matched controls. The second stage of the study employed a randomized cross-over trial design. The 24 boys with ADHD engaged in a 30-min intervention that consisted of either running on a treadmill or watching a video on alternative days, with resting EEGs recorded before and after treatment. The first stage found that children with ADHD exhibited significantly higher theta/beta ratios over the midline electrodes sites than controls. The second stage further indicated that children with ADHD displayed smaller theta/beta ratios following the exercise condition compared with the video-watching condition. This finding suggests that acute exercise normalizes arousal and alertness of children with ADHD, as reflected in resting EEG readings.

Attention Deficit Syndrome: Educational Bugaboo of the 90s.

ERIC Educational Resources Information Center

Gold, Svea J.

The increase in the diagnosis of attention deficit disorder (ADD) and the characteristics and treatment of ADD using sensory motor exercises are discussed. Reasons for the disability are explored, including neurological differences and difficulties in interpreting sensory input. Problems with focusing and hearing as well as hypersensitivity to…

Continuation of Exercise Is Necessary to Inhibit High Fat Diet-Induced β-Amyloid Deposition and Memory Deficit in Amyloid Precursor Protein Transgenic Mice

PubMed Central

Maesako, Masato; Uemura, Kengo; Iwata, Ayana; Kubota, Masakazu; Watanabe, Kiwamu; Uemura, Maiko; Noda, Yasuha; Asada-Utsugi, Megumi; Kihara, Takeshi; Takahashi, Ryosuke; Shimohama, Shun; Kinoshita, Ayae

2013-01-01

High fat diet (HFD) is prevalent in many modern societies and HFD-induced metabolic condition is a growing concern worldwide. It has been previously reported that HFD clearly worsens cognitive function in amyloid precursor protein (APP) transgenic mice. On the other hand, we have demonstrated that voluntary exercise in an enriched environment is an effective intervention to rescue HFD-induced β-amyloid (Aβ) deposition and memory deficit. However, it had been unclear whether consumption of HFD after exercising abolished the beneficial effect of exercise on the inhibition of Alzheimer's disease (AD) pathology. To examine this question, we exposed wild type (WT) and APP mice fed with HFD to exercise conditions at different time periods. In our previous experiment, we gave HFD to mice for 20 weeks and subjected them to exercise during weeks 10–20. In the present study, mice were subjected to exercise conditions during weeks 0–10 or weeks 5–15 while being on HFD. Interestingly, we found that the effect of exercise during weeks 0–10 or weeks 5–15 on memory function was not abolished in WT mice even if they kept having HFD after finishing exercise. However, in APP transgenic mice, HFD clearly disrupted the effect of exercise during weeks 0–10 or weeks 5–15 on memory function. Importantly, we observed that the level of Aβ oligomer was significantly elevated in the APP mice that exercised during weeks 0–10: this might have been caused by the up-regulation of Aβ production. These results provide solid evidence that continuation of exercise is necessary to rescue HFD-induced aggravation of cognitive decline in the pathological setting of AD. PMID:24023774

Effect of acute exercise on AMPK signaling in skeletal muscle of subjects with type 2 diabetes: a time-course and dose-response study.

PubMed

Sriwijitkamol, Apiradee; Coletta, Dawn K; Wajcberg, Estela; Balbontin, Gabriela B; Reyna, Sara M; Barrientes, John; Eagan, Phyllis A; Jenkinson, Christopher P; Cersosimo, Eugenio; DeFronzo, Ralph A; Sakamoto, Kei; Musi, Nicolas

2007-03-01

Activation of AMP-activated protein kinase (AMPK) by exercise induces several cellular processes in muscle. Exercise activation of AMPK is unaffected in lean (BMI approximately 25 kg/m(2)) subjects with type 2 diabetes. However, most type 2 diabetic subjects are obese (BMI >30 kg/m(2)), and exercise stimulation of AMPK is blunted in obese rodents. We examined whether obese type 2 diabetic subjects have impaired exercise stimulation of AMPK, at different signaling levels, spanning from the upstream kinase, LKB1, to the putative AMPK targets, AS160 and peroxisome proliferator-activated receptor coactivator (PGC)-1alpha, involved in glucose transport regulation and mitochondrial biogenesis, respectively. Twelve type 2 diabetic, eight obese, and eight lean subjects exercised on a cycle ergometer for 40 min. Muscle biopsies were done before, during, and after exercise. Subjects underwent this protocol on two occasions, at low (50% Vo(2max)) and moderate (70% Vo(2max)) intensities, with a 4-6 week interval. Exercise had no effect on LKB1 activity. Exercise had a time- and intensity-dependent effect to increase AMPK activity and AS160 phosphorylation. Obese and type 2 diabetic subjects had attenuated exercise-stimulated AMPK activity and AS160 phosphorylation. Type 2 diabetic subjects had reduced basal PGC-1 gene expression but normal exercise-induced increases in PGC-1 expression. Our findings suggest that obese type 2 diabetic subjects may need to exercise at higher intensity to stimulate the AMPK-AS160 axis to the same level as lean subjects.

Effect of Acute Exercise on AMPK Signaling in Skeletal Muscle of Subjects With Type 2 Diabetes

PubMed Central

Sriwijitkamol, Apiradee; Coletta, Dawn K.; Wajcberg, Estela; Balbontin, Gabriela B.; Reyna, Sara M.; Barrientes, John; Eagan, Phyllis A.; Jenkinson, Christopher P.; Cersosimo, Eugenio; DeFronzo, Ralph A.; Sakamoto, Kei; Musi, Nicolas

2010-01-01

Activation of AMP-activated protein kinase (AMPK) by exercise induces several cellular processes in muscle. Exercise activation of AMPK is unaffected in lean (BMI ~25 kg/m2) subjects with type 2 diabetes. However, most type 2 diabetic subjects are obese (BMI >30 kg/m2), and exercise stimulation of AMPK is blunted in obese rodents. We examined whether obese type 2 diabetic subjects have impaired exercise stimulation of AMPK, at different signaling levels, spanning from the upstream kinase, LKB1, to the putative AMPK targets, AS160 and peroxisome proliferator–activated receptor coactivator (PGC)-1α, involved in glucose transport regulation and mitochondrial biogenesis, respectively. Twelve type 2 diabetic, eight obese, and eight lean subjects exercised on a cycle ergometer for 40 min. Muscle biopsies were done before, during, and after exercise. Subjects underwent this protocol on two occasions, at low (50% VO2max) and moderate (70% VO2max) intensities, with a 4–6 week interval. Exercise had no effect on LKB1 activity. Exercise had a time- and intensity-dependent effect to increase AMPK activity and AS160 phosphorylation. Obese and type 2 diabetic subjects had attenuated exercise-stimulated AMPK activity and AS160 phosphorylation. Type 2 diabetic subjects had reduced basal PGC-1 gene expression but normal exercise-induced increases in PGC-1 expression. Our findings suggest that obese type 2 diabetic subjects may need to exercise at higher intensity to stimulate the AMPK-AS160 axis to the same level as lean subjects. PMID:17327455

Effects of exercise on capillaries in the white matter of transgenic AD mice

PubMed Central

Zhang, Yi; Chao, Feng-Lei; Zhou, Chun-Ni; Jiang, Lin; Zhang, Lei; Chen, Lin-Mu; Luo, Yan-Min; Xiao, Qian; Tang, Yong

2017-01-01

Previous studies have shown that exercise can prevent white matter atrophy in APP/PS1 transgenic Alzheimer’s disease (AD) mice. However, the mechanism of this protective effect remains unknown. To further understand this issue, we investigated the effects of exercise on the blood supply of white matter in transgenic AD mice. Six-month-old male APP/PS1 mice were randomly divided into a control group and a running group, and age-matched non-transgenic littermates were used as a wild-type control group. Mice in the running group ran on a treadmill at low intensity for four months. Then, spatial learning and memory abilities, white matter and white matter capillaries were examined in all mice. The 10-month-old AD mice exhibited deficits in cognitive function, and 4 months of exercise improved these deficits. The white matter volume and the total length, total volume and total surface area of the white matter capillaries were decreased in the 10-month-old AD mice, and 4 months of exercise dramatically delayed the changes in these parameters in the AD mice. Our results demonstrate that even low-intensity running exercise can improve spatial learning and memory abilities, delay white matter atrophy and protect white matter capillaries in early-stage AD mice. Protecting capillaries might be an important structural basis for the exercise-induced protection of the structural integrity of white matter in AD. PMID:29029478

Effects of exercise on capillaries in the white matter of transgenic AD mice.

PubMed

Zhang, Yi; Chao, Feng-Lei; Zhou, Chun-Ni; Jiang, Lin; Zhang, Lei; Chen, Lin-Mu; Luo, Yan-Min; Xiao, Qian; Tang, Yong

2017-09-12

Previous studies have shown that exercise can prevent white matter atrophy in APP/PS1 transgenic Alzheimer's disease (AD) mice. However, the mechanism of this protective effect remains unknown. To further understand this issue, we investigated the effects of exercise on the blood supply of white matter in transgenic AD mice. Six-month-old male APP/PS1 mice were randomly divided into a control group and a running group, and age-matched non-transgenic littermates were used as a wild-type control group. Mice in the running group ran on a treadmill at low intensity for four months. Then, spatial learning and memory abilities, white matter and white matter capillaries were examined in all mice. The 10-month-old AD mice exhibited deficits in cognitive function, and 4 months of exercise improved these deficits. The white matter volume and the total length, total volume and total surface area of the white matter capillaries were decreased in the 10-month-old AD mice, and 4 months of exercise dramatically delayed the changes in these parameters in the AD mice. Our results demonstrate that even low-intensity running exercise can improve spatial learning and memory abilities, delay white matter atrophy and protect white matter capillaries in early-stage AD mice. Protecting capillaries might be an important structural basis for the exercise-induced protection of the structural integrity of white matter in AD.

Behavioral and Neural Sustained Attention Deficits in Disruptive Mood Dysregulation Disorder and Attention-Deficit/Hyperactivity Disorder

PubMed Central

Pagliaccio, David; Wiggins, Jillian Lee; Adleman, Nancy E.; Curhan, Alexa; Zhang, Susan; Towbin, Kenneth E.; Brotman, Melissa A.; Pine, Daniel S.; Leibenluft, Ellen

2017-01-01

Objective Disruptive mood dysregulation disorder (DMDD), characterized by severe irritability, and attention-deficit/hyperactivity disorder (ADHD) are highly comorbid. This is the first study to characterize neural and behavioral similarities and differences in attentional functioning across these disorders. Method Twenty-seven healthy volunteers, 31 patients with DMDD, and 25 patients with ADHD (8–18-year-olds) completed a functional magnetic resonance imaging (fMRI) attention task. Group differences in intra-subject variability in reaction time (ISVRT) were examined. The current fMRI analytic approach precisely quantified trial-wise associations between reaction time and brain activity. Results Group differences manifested in the relationship between reaction time and brain activity (all regions: p<.01, F>2.54, ηp2>0.06). Patients with DMDD showed specific alterations in the right paracentral lobule, superior parietal lobule, fusiform gyrus, and cerebellar culmen. In contrast, both patients with DMDD and ADHD exhibited blunted compensatory increases in activity on long reaction time trials. Additionally, youth with DMDD exhibited increased activity in the postcentral gyrus, medial frontal gyrus, and cerebellar tonsil and declive (all regions: p<.05, F>2.46, ηp2>0.06). The groups in the imaging sample did not differ significantly in ISVRT (F[2,79]=2.664, p=.076, ηp2=0.063), though ISVRT was significantly elevated among youth with DMDD and ADHD when including those not meeting strict motion and accuracy criteria for the imaging analysis (F[2,96]=4.283, p=.017, ηp2=0.083). Conclusion Patients with DMDD exhibited specific alterations in the relationship between pre-stimulus brain activity and reaction time. Both patients with DMDD and ADHD exhibited similar blunting of compensatory neural activity in frontal, parietal, and other regions. Additionally, patients with DMDD demonstrated elevated reaction time variability relative to healthy youth. This work is the first to identify common and unique behavioral and neural signatures of DMDD and ADHD. PMID:28433092

Effects of acute aerobic exercise on neural correlates of attention and inhibition in adolescents with bipolar disorder

PubMed Central

Metcalfe, A W S; MacIntosh, B J; Scavone, A; Ou, X; Korczak, D; Goldstein, B I

2016-01-01

Executive dysfunction is common during and between mood episodes in bipolar disorder (BD), causing social and functional impairment. This study investigated the effect of acute exercise on adolescents with BD and healthy control subjects (HC) to test for positive or negative consequences on neural response during an executive task. Fifty adolescents (mean age 16.54±1.47 years, 56% female, 30 with BD) completed an attention and response inhibition task before and after 20 min of recumbent cycling at ~70% of age-predicted maximum heart rate. 3 T functional magnetic resonance imaging data were analyzed in a whole brain voxel-wise analysis and as regions of interest (ROI), examining Go and NoGo response events. In the whole brain analysis of Go trials, exercise had larger effect in BD vs HC throughout ventral prefrontal cortex, amygdala and hippocampus; the profile of these effects was of greater disengagement after exercise. Pre-exercise ROI analysis confirmed this 'deficit in deactivation' for BDs in rostral ACC and found an activation deficit on NoGo errors in accumbens. Pre-exercise accumbens NoGo error activity correlated with depression symptoms and Go activity with mania symptoms; no correlations were present after exercise. Performance was matched to controls and results survived a series of covariate analyses. This study provides evidence that acute aerobic exercise transiently changes neural response during an executive task among adolescents with BD, and that pre-exercise relationships between symptoms and neural response are absent after exercise. Acute aerobic exercise constitutes a biological probe that may provide insights regarding pathophysiology and treatment of BD. PMID:27187236

Effects of acute aerobic exercise on neural correlates of attention and inhibition in adolescents with bipolar disorder.

PubMed

Metcalfe, A W S; MacIntosh, B J; Scavone, A; Ou, X; Korczak, D; Goldstein, B I

2016-05-17

Executive dysfunction is common during and between mood episodes in bipolar disorder (BD), causing social and functional impairment. This study investigated the effect of acute exercise on adolescents with BD and healthy control subjects (HC) to test for positive or negative consequences on neural response during an executive task. Fifty adolescents (mean age 16.54±1.47 years, 56% female, 30 with BD) completed an attention and response inhibition task before and after 20 min of recumbent cycling at ~70% of age-predicted maximum heart rate. 3 T functional magnetic resonance imaging data were analyzed in a whole brain voxel-wise analysis and as regions of interest (ROI), examining Go and NoGo response events. In the whole brain analysis of Go trials, exercise had larger effect in BD vs HC throughout ventral prefrontal cortex, amygdala and hippocampus; the profile of these effects was of greater disengagement after exercise. Pre-exercise ROI analysis confirmed this 'deficit in deactivation' for BDs in rostral ACC and found an activation deficit on NoGo errors in accumbens. Pre-exercise accumbens NoGo error activity correlated with depression symptoms and Go activity with mania symptoms; no correlations were present after exercise. Performance was matched to controls and results survived a series of covariate analyses. This study provides evidence that acute aerobic exercise transiently changes neural response during an executive task among adolescents with BD, and that pre-exercise relationships between symptoms and neural response are absent after exercise. Acute aerobic exercise constitutes a biological probe that may provide insights regarding pathophysiology and treatment of BD.

The effect of different water immersion temperatures on post-exercise parasympathetic reactivation.

PubMed

de Oliveira Ottone, Vinícius; de Castro Magalhães, Flávio; de Paula, Fabrício; Avelar, Núbia Carelli Pereira; Aguiar, Paula Fernandes; da Matta Sampaio, Pâmela Fiche; Duarte, Tamiris Campos; Costa, Karine Beatriz; Araújo, Tatiane Líliam; Coimbra, Cândido Celso; Nakamura, Fábio Yuzo; Amorim, Fabiano Trigueiro; Rocha-Vieira, Etel

2014-01-01

We evaluated the effect of different water immersion (WI) temperatures on post-exercise cardiac parasympathetic reactivation. Eight young, physically active men participated in four experimental conditions composed of resting (REST), exercise session (resistance and endurance exercises), post-exercise recovery strategies, including 15 min of WI at 15°C (CWI), 28°C (TWI), 38°C (HWI) or control (CTRL, seated at room temperature), followed by passive resting. The following indices were assessed before and during WI, 30 min post-WI and 4 hours post-exercise: mean R-R (mR-R), the natural logarithm (ln) of the square root of the mean of the sum of the squares of differences between adjacent normal R-R (ln rMSSD) and the ln of instantaneous beat-to-beat variability (ln SD1). The results showed that during WI mRR was reduced for CTRL, TWI and HWI versus REST, and ln rMSSD and ln SD1 were reduced for TWI and HWI versus REST. During post-WI, mRR, ln rMSSD and ln SD1 were reduced for HWI versus REST, and mRR values for CWI were higher versus CTRL. Four hours post exercise, mRR was reduced for HWI versus REST, although no difference was observed among conditions. We conclude that CWI accelerates, while HWI blunts post-exercise parasympathetic reactivation, but these recovery strategies are short-lasting and not evident 4 hours after the exercise session.

The Effect of Different Water Immersion Temperatures on Post-Exercise Parasympathetic Reactivation

PubMed Central

de Oliveira Ottone, Vinícius; de Castro Magalhães, Flávio; de Paula, Fabrício; Avelar, Núbia Carelli Pereira; Aguiar, Paula Fernandes; da Matta Sampaio, Pâmela Fiche; Duarte, Tamiris Campos; Costa, Karine Beatriz; Araújo, Tatiane Líliam; Coimbra, Cândido Celso; Nakamura, Fábio Yuzo; Amorim, Fabiano Trigueiro; Rocha-Vieira, Etel

2014-01-01

Purpose We evaluated the effect of different water immersion (WI) temperatures on post-exercise cardiac parasympathetic reactivation. Methods Eight young, physically active men participated in four experimental conditions composed of resting (REST), exercise session (resistance and endurance exercises), post-exercise recovery strategies, including 15 min of WI at 15°C (CWI), 28°C (TWI), 38°C (HWI) or control (CTRL, seated at room temperature), followed by passive resting. The following indices were assessed before and during WI, 30 min post-WI and 4 hours post-exercise: mean R-R (mR-R), the natural logarithm (ln) of the square root of the mean of the sum of the squares of differences between adjacent normal R–R (ln rMSSD) and the ln of instantaneous beat-to-beat variability (ln SD1). Results The results showed that during WI mRR was reduced for CTRL, TWI and HWI versus REST, and ln rMSSD and ln SD1 were reduced for TWI and HWI versus REST. During post-WI, mRR, ln rMSSD and ln SD1 were reduced for HWI versus REST, and mRR values for CWI were higher versus CTRL. Four hours post exercise, mRR was reduced for HWI versus REST, although no difference was observed among conditions. Conclusions We conclude that CWI accelerates, while HWI blunts post-exercise parasympathetic reactivation, but these recovery strategies are short-lasting and not evident 4 hours after the exercise session. PMID:25437181

Redox modulation of mitochondriogenesis in exercise. Does antioxidant supplementation blunt the benefits of exercise training?

PubMed

Gomez-Cabrera, Mari Carmen; Salvador-Pascual, Andrea; Cabo, Helena; Ferrando, Beatriz; Viña, Jose

2015-09-01

Physical exercise increases the cellular production of reactive oxygen species (ROS) in muscle, liver, and other organs. This is unlikely due to increased mitochondrial production but rather to extramitochondrial sources such as NADPH oxidase or xanthine oxidase. We have reported a xanthine oxidase-mediated increase in ROS production in many experimental models from isolated cells to humans. Originally, ROS were considered as detrimental and thus as a likely cause of cell damage associated with exhaustion. In the past decade, evidence showing that ROS act as signals has been gathered and thus the idea that antioxidant supplementation in exercise is always recommendable has proved incorrect. In fact, we proposed that exercise itself can be considered as an antioxidant because training increases the expression of classical antioxidant enzymes such as superoxide dismutase and glutathione peroxidase and, in general, lowering the endogenous antioxidant enzymes by administration of antioxidant supplements may not be a good strategy when training. Antioxidant enzymes are not the only ones to be activated by training. Mitochondriogenesis is an important process activated in exercise. Many redox-sensitive enzymes are involved in this process. Important signaling molecules like MAP kinases, NF-κB, PGC-1α, p53, heat shock factor, and others modulate muscle adaptation to exercise. Interventions aimed at modifying the production of ROS in exercise must be performed with care as they may be detrimental in that they may lower useful adaptations to exercise. Copyright © 2015 Elsevier Inc. All rights reserved.

A randomized controlled trial of aspirin and exertional heat stress activation of platelets in firefighters during exertion in thermal protective clothing.

PubMed

Hostler, David; Suyama, Joe; Guyette, Francis X; Moore, Charity G; Pryor, Riana R; Khorana, Priya; McEntire, Serina J; Comer, Diane; Reis, Steven E

2014-01-01

Platelet aggregation is enhanced in firefighters following short bouts of work in thermal protective clothing (TPC). We sought to determine if aspirin therapy before and/or following exertion in TPC prevents platelet activation. In a double-blind, placebo-controlled study, 102 firefighters were randomized to receive daily therapy (81 mg aspirin or placebo) for 14 days before and a single dose (325 mg aspirin or placebo) following exercise in TPC resulting in four potential assignments: aspirin before and after exercise (AA), placebo before and after exercise (PP), aspirin before and placebo after exercise (AP), and placebo before and aspirin after exercise (PA). Platelet closure time (PCT) was measured with a platelet function analyzer before the 2-week treatment, after the 2 week treatment period, immediately after exercise, and 30, 60, and 90 minutes later. Baseline PCT did not differ between groups. PCT changed over time in all four groups (p < 0.001) rising to a median of >300 seconds [IQR 99, 300] in AA and >300 [92, 300] in AP prior to exercise. Following exercise, median PCT decreased to in all groups. Median PCT returned to >300 seconds 30 minutes later in AA and AP and rose to 300 seconds in PA 60 minutes after exercise. Daily aspirin therapy blunts platelet activation during exertional heat stress and single-dose aspirin therapy following exertional heat stress reduces platelet activation within 60 minutes.

Effect of beta-adrenergic blockade with timolol on myocardial blood flow during exercise after myocardial infarction in the dog.

PubMed

Herzog, C A; Aeppli, D P; Bache, R J

1984-12-01

The effect of beta-adrenergic blockade with timolol (40 micrograms/kg) on myocardial blood flow during rest and graded treadmill exercise was assessed in 12 chronically instrumented dogs 10 to 14 days after myocardial infarction was produced by acute left circumflex coronary artery occlusion. During exercise at comparable external work loads, the heart rate-systolic blood pressure product was significantly decreased after timilol, with concomitant reductions of myocardial blood flow in normal, border and central ischemic areas (p less than 0.001) and increases in subendocardial/subepicardial blood flow ratios (p less than 0.05). In addition to the blunted chronotropic response to exercise, timolol exerted an effect on myocardial blood flow that was not explained by changes in heart rate or blood pressure. At comparable rate-pressure products during exercise, total myocardial blood flow was 24% lower after timolol (p less than 0.02) and flow was redistributed from subepicardium to subendocardium in all myocardial regions. Thus, timolol altered myocardial blood flow during exercise by two separate mechanisms: a negative chronotropic effect, and a significant selective reduction of subepicardial perfusion independent of changes in heart rate or blood pressure with transmural redistribution of flow toward the subendocardium.

Chronic Exercise Reduces CETP and Mesterolone Treatment Counteracts Exercise Benefits on Plasma Lipoproteins Profile: Studies in Transgenic Mice.

PubMed

Casquero, Andrea Camargo; Berti, Jairo Augusto; Teixeira, Laura Lauand Sampaio; de Oliveira, Helena Coutinho Franco

2017-12-01

Regular exercise and anabolic androgenic steroids have opposing effects on the plasma lipoprotein profile and risk of cardio-metabolic diseases in humans. Studies in humans and animal models show conflicting results. Here, we used a mice model genetically modified to mimic human lipoprotein profile and metabolism. They under-express the endogenous LDL receptor gene (R1) and express a human transgene encoding the cholesteryl ester transfer protein (CETP), normally absent in mice. The present study was designed to evaluate the independent and interactive effects of testosterone supplementation, exercise training and CETP expression on the plasma lipoprotein profile and CETP activity. CETP/R1 and R1 mice were submitted to a 6-week swimming training and mesterolone (MEST) supplementation in the last 3 weeks. MEST treatment increased markedly LDL levels (40%) in sedentary CETP/R1 mice and reduced HDL levels in exercised R1 mice (18%). A multifactorial ANOVA revealed the independent effects of each factor, as follows. CETP expression reduced HDL (21%) and increased non-HDL (15%) fractions. MEST treatment increased the VLDL concentrations (42%) regardless of other interventions. Exercise training reduced triacylglycerol (25%) and free fatty acids (20%), increased both LDL and HDL (25-33%), and reduced CETP (19%) plasma levels. Significant factor interactions showed that the increase in HDL induced by exercise is explained by reducing CETP activity and that MEST blunted the exercise-induced elevation of HDL-cholesterol. These results reinforce the positive metabolic effects of exercise, resolved a controversy about CETP response to exercise and evidenced MEST potency to counteract specific exercise benefits.

Challenges in Determining the Role of Rest and Exercise in the Management of Mild Traumatic Brain Injury.

PubMed

Wells, Elizabeth M; Goodkin, Howard P; Griesbach, Grace S

2016-01-01

Current consensus guidelines recommending physical and cognitive rest until a patient is asymptomatic after a sports concussion (ie, a mild traumatic brain injury) are being called into question, particularly for patients who are slower to recover and in light of preclinical and clinical research demonstrating that exercise aids neurorehabilitation. The pathophysiological response to mild traumatic brain injury includes a complex neurometabolic cascade of events resulting in a neurologic energy deficit. It has been proposed that this energy deficit leads to a period of vulnerability during which the brain is at risk for additional injury, explains why early postconcussive symptoms are exacerbated by cognitive and physical exertion, and is used to rationalize absolute rest until all symptoms have resolved. However, at some point, rest might no longer be beneficial and exercise might need to be introduced. At both extremes, excessive exertion and prolonged avoidance of exercise (physical and mental) have negative consequences. Individuals who have experienced a concussion need guidance for avoidance of triggers of severe symptoms and a plan for graduated exercise to promote recovery as well as optimal functioning (physical, educational, and social) during the postconcussion period. © The Author(s) 2015.

Endurance exercise rescues progeroid aging and induces systemic mitochondrial rejuvenation in mtDNA mutator mice

PubMed Central

Safdar, Adeel; Bourgeois, Jacqueline M.; Ogborn, Daniel I.; Little, Jonathan P.; Hettinga, Bart P.; Akhtar, Mahmood; Thompson, James E.; Melov, Simon; Mocellin, Nicholas J.; Kujoth, Gregory C.; Prolla, Tomas A.; Tarnopolsky, Mark A.

2011-01-01

A causal role for mitochondrial DNA (mtDNA) mutagenesis in mammalian aging is supported by recent studies demonstrating that the mtDNA mutator mouse, harboring a defect in the proofreading-exonuclease activity of mitochondrial polymerase gamma, exhibits accelerated aging phenotypes characteristic of human aging, systemic mitochondrial dysfunction, multisystem pathology, and reduced lifespan. Epidemiologic studies in humans have demonstrated that endurance training reduces the risk of chronic diseases and extends life expectancy. Whether endurance exercise can attenuate the cumulative systemic decline observed in aging remains elusive. Here we show that 5 mo of endurance exercise induced systemic mitochondrial biogenesis, prevented mtDNA depletion and mutations, increased mitochondrial oxidative capacity and respiratory chain assembly, restored mitochondrial morphology, and blunted pathological levels of apoptosis in multiple tissues of mtDNA mutator mice. These adaptations conferred complete phenotypic protection, reduced multisystem pathology, and prevented premature mortality in these mice. The systemic mitochondrial rejuvenation through endurance exercise promises to be an effective therapeutic approach to mitigating mitochondrial dysfunction in aging and related comorbidities. PMID:21368114

Do reward-processing deficits in schizophrenia-spectrum disorders promote cannabis use? An investigation of physiological response to natural rewards and drug cues

PubMed Central

Cassidy, Clifford M.; Brodeur, Mathieu B.; Lepage, Martin; Malla, Ashok

2014-01-01

Background Dysfunctional reward processing is present in individuals with schizophrenia-spectrum disorders (SSD) and may confer vulnerability to addiction. Our objective was to identify a deficit in patients with SSD on response to rewarding stimuli and determine whether this deficit predicts cannabis use. Methods We divided a group of patients with SSD and nonpsychotic controls into cannabis users and nonusers. Response to emotional and cannabis-associated visual stimuli was assessed using self-report, event-related potentials (using the late positive potential [LPP]), facial electromyography and skin-conductance response. Results Our sample comprised 35 patients with SSD and 35 nonpsychotic controls. Compared with controls, the patients with SSD showed blunted LPP response to pleasant stimuli (p = 0.003). Across measures, cannabis-using controls showed greater response to pleasant stimuli than to cannabis stimuli whereas cannabis-using patients showed little bias toward pleasant stimuli. Reduced LPP response to pleasant stimuli was predictive of more frequent subsequent cannabis use (β = −0.24, p = 0.034). Limitations It is not clear if the deficit associated with cannabis use is specific to rewarding stimuli or nonspecific to any kind of emotionally salient stimuli. Conclusion The LPP captures a reward-processing deficit in patients with SSD and shows potential as a biomarker for identifying patients at risk of heavy cannabis use. PMID:24913137

Do reward-processing deficits in schizophrenia-spectrum disorders promote cannabis use? An investigation of physiological response to natural rewards and drug cues.

PubMed

Cassidy, Clifford M; Brodeur, Mathieu B; Lepage, Martin; Malla, Ashok

2014-09-01

Dysfunctional reward processing is present in individuals with schizophrenia-spectrum disorders (SSD) and may confer vulnerability to addiction. Our objective was to identify a deficit in patients with SSD on response to rewarding stimuli and determine whether this deficit predicts cannabis use. We divided a group of patients with SSD and nonpsychotic controls into cannabis users and nonusers. Response to emotional and cannabis-associated visual stimuli was assessed using self-report, event-related potentials (using the late positive potential [LPP]), facial electromyography and skin-conductance response. Our sample comprised 35 patients with SSD and 35 nonpsychotic controls. Compared with controls, the patients with SSD showed blunted LPP response to pleasant stimuli (p = 0.003). Across measures, cannabis-using controls showed greater response to pleasant stimuli than to cannabis stimuli whereas cannabis-using patients showed little bias toward pleasant stimuli. Reduced LPP response to pleasant stimuli was predictive of more frequent subsequent cannabis use (β = -0.24, p = 0.034). It is not clear if the deficit associated with cannabis use is specific to rewarding stimuli or nonspecific to any kind of emotionally salient stimuli. The LPP captures a reward-processing deficit in patients with SSD and shows potential as a biomarker for identifying patients at risk of heavy cannabis use.

Prolonged running, not fluoxetine treatment, increases neurogenesis, but does not alter neuropathology, in the 3xTg mouse model of Alzheimer's disease.

PubMed

Marlatt, Michael W; Potter, Michelle C; Bayer, Thomas A; van Praag, Henriette; Lucassen, Paul J

2013-01-01

Reductions in adult neurogenesis have been documented in the original 3xTg mouse model of Alzheimer's disease (AD), notably occurring at the same age when spatial memory deficits and amyloid plaque pathology appeared. As this suggested reduced neurogenesis was associated with behavioral deficits, we tested whether activity and pharmacological stimulation could prevent memory deficits and modify neurogenesis and/or neuropathology in the 3xTg model backcrossed to the C57Bl/6 strain. We chronically administered the antidepressant fluoxetine to one group of mice, allowed access to a running wheel in another, and combined both treatments in a third cohort. All treatments lasted for 11 months. The female 3xTg mice failed to exhibit any deficits in spatial learning and memory as measured in the Morris water maze, indicating that when backcrossed to the C57Bl/6 strain, the 3xTg mice lost the behavioral phenotype that was present in the original 3xTg mouse maintained on a hybrid background. Despite this, the backcrossed 3xTg mice expressed prominent intraneuronal amyloid beta (Aβ) levels in the cortex and amygdala, with lower levels in the CA1 area of the hippocampus. In the combined cohort, fluoxetine treatment interfered with exercise and reduced the total distance run. The extent of Aβ neuropathology, the tau accumulations, or BDNF levels, were not altered by prolonged exercise. Thus, neuropathology was present but not paralleled by spatial memory deficits in the backcrossed 3xTg mouse model of AD. Prolonged exercise for 11 months did improve the long-term survival of newborn neurons generated during middle-age, whereas fluoxetine had no effect. We further review and discuss the relevant literature in this respect.

Cold-water immersion decreases cerebral oxygenation but improves recovery after intermittent-sprint exercise in the heat.

PubMed

Minett, G M; Duffield, R; Billaut, F; Cannon, J; Portus, M R; Marino, F E

2014-08-01

This study examined the effects of post-exercise cooling on recovery of neuromuscular, physiological, and cerebral hemodynamic responses after intermittent-sprint exercise in the heat. Nine participants underwent three post-exercise recovery trials, including a control (CONT), mixed-method cooling (MIX), and cold-water immersion (10 °C; CWI). Voluntary force and activation were assessed simultaneously with cerebral oxygenation (near-infrared spectroscopy) pre- and post-exercise, post-intervention, and 1-h and 24-h post-exercise. Measures of heart rate, core temperature, skin temperature, muscle damage, and inflammation were also collected. Both cooling interventions reduced heart rate, core, and skin temperature post-intervention (P < 0.05). CWI hastened the recovery of voluntary force by 12.7 ± 11.7% (mean ± SD) and 16.3 ± 10.5% 1-h post-exercise compared to MIX and CONT, respectively (P < 0.01). Voluntary force remained elevated by 16.1 ± 20.5% 24-h post-exercise after CWI compared to CONT (P < 0.05). Central activation was increased post-intervention and 1-h post-exercise with CWI compared to CONT (P < 0.05), without differences between conditions 24-h post-exercise (P > 0.05). CWI reduced cerebral oxygenation compared to MIX and CONT post-intervention (P < 0.01). Furthermore, cooling interventions reduced cortisol 1-h post-exercise (P < 0.01), although only CWI blunted creatine kinase 24-h post-exercise compared to CONT (P < 0.05). Accordingly, improvements in neuromuscular recovery after post-exercise cooling appear to be disassociated with cerebral oxygenation, rather reflecting reductions in thermoregulatory demands to sustain force production. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Energy and nutrient status of amenorrheic athletes participating in a diet and exercise training intervention program.

PubMed

Kopp-Woodroffe, S A; Manore, M M; Dueck, C A; Skinner, J S; Matt, K S

1999-03-01

Chronic energy deficit is one of the strongest factors contributors to exercise-induced menstrual dysfunction. In such cases, macro- and micronutrient intakes may also be low. This study presents the results of a diet and exercise training intervention program. designed to reverse athletic amenorrhea, on improving energy balance and nutritional status in 4 amenorrheic athletes. The 20-week program provided a daily sport nutrition supplement and 1 day of rest/week. The program increased protein intakes for the 3 athletes with a protein deficit to within the recommended levels for active individuals. Micronutrient intakes increased, as did serum concentrations of vitamin B12, folate, zinc, iron, and ferritin. These results indicate that some amenorrheic athletes have poor nutritional status due to restricted EIs and poor food selections. A sport nutrition supplement may improve energy balance and nutritional status in active amenorrheic women.

Exercise deficit disorder in youth: an emergent health concern for school nurses.

PubMed

Faigenbaum, Avery D; Gipson-Jones, Trina L; Myer, Gregory D

2012-08-01

Although the benefits of regular physical activity are widely acknowledged, recent findings indicate that a growing number of youth are not as active as they should be. The impact of a sedentary lifestyle during childhood on lifelong pathological processes and associated health care costs have created a need for immediate action to manage, if not prevent, unhealthy behaviors during this vulnerable period of life. The concept of identifying children with exercise deficit disorder early in life and prescribing effective interventions to prevent the cascade of adverse health outcomes later in life is needed to raise public awareness, focus on primary prevention, and impact the collective behaviors of health care providers and public health agencies. School nurses are in a unique position to take advantage of well-child visits as an ideal opportunity to assess physical activity habits and encourage daily participation in play, recess, sports, planned exercise, and physical education.

Interstitial glucose concentrations and hypoglycemia during 2 days of caloric deficit and sustained exercise: a double-blind, placebo-controlled trial.

PubMed

Smith, Tracey J; Wilson, Marques A; Karl, J Philip; Austin, Krista; Bukhari, Asma; Pasiakos, Stefan M; O'Connor, Kristie L; Lieberman, Harris R

2016-11-01

Military personnel and some athlete populations endure short-term energy deficits from reduced energy intake and/or increased energy expenditure (EE) that may degrade physical and cognitive performance due to severe hypoglycemia (<3.1 mmol/l). The extent to which energy deficits alter normoglycemia (3.9-7.8 mmol/l) in healthy individuals is not known, since prior studies measured glucose infrequently, not continuously. The purpose of this study was to characterize the glycemic response to acute, severe energy deficit compared with fully fed control condition, using continuous glucose monitoring (CGM). For 2 days during a double-blind, placebo-controlled, crossover study, 23 volunteers (17 men/6 women; age: 21.3 ± 3.0 yr; body mass index: 25 ± 3 kg/m) increased habitual daily EE [2,300 ± 450 kcal/day [means ± SD)] by 1,647 ± 345 kcal/day through prescribed exercise (~3 h/day; 40-65% peak O 2 consumption), and consumed diets designed to maintain energy balance (FED) or induce 93% energy deficit (DEF). Interstitial glucose concentrations were measured continuously by CGM (Medtronic Minimed). Interstitial glucose concentrations were 1.0 ± 0.9 mmol/l lower during DEF vs. FED (P < 0.0001). The percentage of time spent in mild (3.1-3.8 mmol/l) hypoglycemia was higher during DEF compared with FED [mean difference = 20.5%; 95% confidence interval (CI): 13.1%, 27.9%; P = 0.04], while time spent in severe (<3.1 mmol/l) hypoglycemia was not different between interventions (mean difference = 4.6%; 95% CI: -0.6%, 9.8%; P = 0.10). Three of 23 participants spontaneously reported symptoms (e.g., nausea) potentially related to hypoglycemia during DEF, and an additional participant reported symptoms during both interventions. These findings suggest that severe hypoglycemia rarely occurs in healthy individuals enduring severe, short-term energy deficit secondary to heavy exercise and inadequate energy intake. Copyright © 2016 the American Physiological Society.

Behavioral deficits induced by third-trimester equivalent alcohol exposure in male C57BL/6J mice are not associated with reduced adult hippocampal neurogenesis but are still rescued with voluntary exercise.

PubMed

Hamilton, G F; Bucko, P J; Miller, D S; DeAngelis, R S; Krebs, C P; Rhodes, J S

2016-11-01

Prenatal alcohol exposure can produce permanent alterations in brain structure and profound behavioral deficits. Mouse models can help discover mechanisms and identify potentially useful interventions. This study examined long-term influences of either a single or repeated alcohol exposure during the third-trimester equivalent on survival of new neurons in the hippocampus, behavioral performance on the Passive avoidance and Rotarod tasks, and the potential role of exercise as a therapeutic intervention. C57BL/6J male mice received either saline or 5g/kg ethanol split into two s.c. injections, two hours apart, on postnatal day (PD)7 (Experiment 1) or on PD5, 7 and 9 (Experiment 2). All mice were weaned on PD21 and received either a running wheel or remained sedentary from PD35-PD80/81. From PD36-45, mice received i.p. injections of 50mg/kg bromodeoxyuridine (BrdU) to label dividing cells. Behavioral testing occurred between PD72-79. Number of surviving BrdU+ cells and immature neurons (doublecortin; DCX+) was measured at PD80-81. Alcohol did not affect number of BrdU+ or DCX+ cells in either experiment. Running significantly increased number of BrdU+ and DCX+ cells in both treatment groups. Alcohol-induced deficits on Rotarod performance and acquisition of the Passive avoidance task (Day 1) were evident only in Experiment 2 and running rescued these deficits. These data suggest neonatal alcohol exposure does not result in long-term impairments in adult hippocampal neurogenesis in the mouse model. Three doses of ethanol were necessary to induce behavioral deficits. Finally, the mechanisms by which exercise ameliorated the neonatal alcohol induced behavioral deficits remain unknown. Copyright © 2016 Elsevier B.V. All rights reserved.

Obesity and Prader-Willi Syndrome Affect Heart Rate Recovery from Dynamic Resistance Exercise in Youth

PubMed Central

Castner, Diobel M.; Clark, Susan J.; Judelson, Daniel A.; Rubin, Daniela A.

2016-01-01

Following exercise, heart rate decline is initially driven by parasympathetic reactivation and later by sympathetic withdrawal. Obesity delays endurance exercise heart rate recovery (HRR) in both children and adults. Young people with Prader-Willi Syndrome (PWS), a congenital cause for obesity, have shown a slower 60-s endurance exercise HRR compared to lean and obese children, suggesting compromised regulation. This study further evaluated effects of obesity and PWS on resistance exercise HRR at 30 and 60 s in children. PWS (8–18 years) and lean and obese controls (8–11 years) completed a weighted step-up protocol (six sets x 10 reps per leg, separated by one-minute rest), standardized using participant stature and lean body mass. HRR was evaluated by calculated HRR value (HRRV = difference between HR at test termination and 30 (HRRV30) and 60 (HRRV60) s post-exercise). PWS and obese had a smaller HRRV30 than lean (p < 0.01 for both). Additionally, PWS had a smaller HRRV60 than lean and obese (p = 0.01 for both). Obesity appears to delay early parasympathetic reactivation, which occurs within 30 s following resistance exercise. However, the continued HRR delay at 60 s in PWS may be explained by either blunted parasympathetic nervous system reactivation, delayed sympathetic withdrawal and/or poor cardiovascular fitness. PMID:28933384

Age-related differences in lean mass, protein synthesis and skeletal muscle markers of proteolysis after bed rest and exercise rehabilitation.

PubMed

Tanner, Ruth E; Brunker, Lucille B; Agergaard, Jakob; Barrows, Katherine M; Briggs, Robert A; Kwon, Oh Sung; Young, Laura M; Hopkins, Paul N; Volpi, Elena; Marcus, Robin L; LaStayo, Paul C; Drummond, Micah J

2015-09-15

Bed rest-induced muscle loss and impaired muscle recovery may contribute to age-related sarcopenia. It is unknown if there are age-related differences in muscle mass and muscle anabolic and catabolic responses to bed rest. A secondary objective was to determine if rehabilitation could reverse bed rest responses. Nine older and fourteen young adults participated in a 5-day bed rest challenge (BED REST). This was followed by 8 weeks of high intensity resistance exercise (REHAB). Leg lean mass (via dual-energy X-ray absorptiometry; DXA) and strength were determined. Muscle biopsies were collected during a constant stable isotope infusion in the postabsorptive state and after essential amino acid (EAA) ingestion on three occasions: before (PRE), after bed rest and after rehabilitation. Samples were assessed for protein synthesis, mTORC1 signalling, REDD1/2 expression and molecular markers related to muscle proteolysis (MURF1, MAFBX, AMPKα, LC3II/I, Beclin1). We found that leg lean mass and strength decreased in older but not younger adults after bedrest (P < 0.05) and was restored after rehabilitation. EAA-induced mTORC1 signalling and protein synthesis increased before bed rest in both age groups (P < 0.05). Although both groups had blunted mTORC1 signalling, increased REDD2 and MURF1 mRNA after bedrest, only older adults had reduced EAA-induced protein synthesis rates and increased MAFBX mRNA, p-AMPKα and the LC3II/I ratio (P < 0.05). We conclude that older adults are more susceptible than young persons to muscle loss after short-term bed rest. This may be partially explained by a combined suppression of protein synthesis and a marginal increase in proteolytic markers. Finally, rehabilitation restored bed rest-induced deficits in lean mass and strength in older adults. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

Exercise Increases 24-h Fat Oxidation Only When It Is Performed Before Breakfast

PubMed Central

Iwayama, Kaito; Kurihara, Reiko; Nabekura, Yoshiharu; Kawabuchi, Ryosuke; Park, Insung; Kobayashi, Masashi; Ogata, Hitomi; Kayaba, Momoko; Satoh, Makoto; Tokuyama, Kumpei

2015-01-01

Background As part of the growing lifestyle diversity in modern society, there is wide variation in the time of day individuals choose to exercise. Recent surveys in the US and Japan have reported that on weekdays, more people exercise in the evening, with fewer individuals exercising in the morning or afternoon. Exercise performed in the post-prandial state has little effect on accumulated fat oxidation over 24 h (24-h fat oxidation) when energy intake is matched to energy expenditure (energy-balanced condition). The present study explored the possibility that exercise increases 24-h fat oxidation only when performed in a post-absorptive state, i.e. before breakfast. Methods Indirect calorimetry using a metabolic chamber was performed in 10 young, non-obese men over 24 h. Subjects remained sedentary (control) or performed 60-min exercise before breakfast (morning), after lunch (afternoon), or after dinner (evening) at 50% of VO2max. All trials were designed to be energy balanced over 24 h. Time course of energy and substrate balance relative to the start of calorimetry were estimated from the differences between input (meal consumption) and output (oxidation). Findings Fat oxidation over 24 h was increased only when exercise was performed before breakfast (control, 456 ± 61; morning, 717 ± 64; afternoon, 446 ± 57; and evening, 432 ± 44 kcal/day). Fat oxidation over 24 h was negatively correlated with the magnitude of the transient deficit in energy and carbohydrate. Interpretation Under energy-balanced conditions, 24-h fat oxidation was increased by exercise only when performed before breakfast. Transient carbohydrate deficits, i.e., glycogen depletion, observed after morning exercise may have contributed to increased 24-h fat oxidation. PMID:26844280

TrkB signalling pathway mediates the protective effects of exercise in the diabetic rat retina.

PubMed

Allen, Rachael S; Hanif, Adam M; Gogniat, Marissa A; Prall, Brian C; Haider, Raza; Aung, Moe H; Prunty, Megan C; Mees, Lukas M; Coulter, Monica M; Motz, Cara T; Boatright, Jeffrey H; Pardue, Machelle T

2018-05-01

Diabetic retinopathy is a leading cause of vision loss. Treatment options for early retinopathy are sparse. Exercise protects dying photoreceptors in models of retinal degeneration, thereby preserving vision. We tested the protective effects of exercise on retinal and cognitive deficits in a type 1 diabetes model and determined whether the TrkB pathway mediates this effect. Hyperglycaemia was induced in Long Evans rats via streptozotocin injection (STZ; 100 mg/kg). Following confirmed hyperglycaemia, both control and diabetic rats underwent treadmill exercise for 30 min, 5 days/week at 0 m/min (inactive groups) or 15 m/min (active groups) for 8 weeks. A TrkB receptor antagonist (ANA-12), or vehicle, was injected 2.5 h before exercise training. We measured spatial frequency and contrast sensitivity using optokinetic tracking biweekly post-STZ; retinal function using electroretinography at 4 and 8 weeks; and cognitive function and exploratory behaviour using Y-maze at 8 weeks. Retinal neurotrophin-4 was measured using ELISA. Compared with non-diabetic controls, diabetic rats showed significantly reduced spatial frequency and contrast sensitivity, delayed electroretinogram oscillatory potential and flicker implicit times and reduced cognitive function and exploratory behaviour. Exercise interventions significantly delayed the appearance of all deficits, except for exploratory behaviour. Treatment with ANA-12 significantly reduced this protection, suggesting a TrkB-mediated mechanism. Despite this, no changes in retinal neurotrohin-4 were observed with diabetes or exercise. Exercise protected against early visual and cognitive dysfunction in diabetic rats, suggesting that exercise interventions started after hyperglycaemia diagnosis may be a beneficial treatment. The translational potential is high, given that exercise treatment is non-invasive, patient controlled and inexpensive. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Voluntary Physical Exercise Improves Subsequent Motor and Cognitive Impairments in a Rat Model of Parkinson’s Disease

PubMed Central

Hsueh, Shih-Chang; Lai, Jing-Huei; Wu, Chung-Che; Yu, Yu-Wen; Luo, Yu; Hsieh, Tsung-Hsun; Chiang, Yung-Hsiao

2018-01-01

Background: Parkinson’s disease (PD) is typically characterized by impairment of motor function. Gait disturbances similar to those observed in patients with PD can be observed in animals after injection of neurotoxin 6-hydroxydopamine (6-OHDA) to induce unilateral nigrostriatal dopamine depletion. Exercise has been shown to be a promising non-pharmacological approach to reduce the risk of neurodegenerative disease. Methods: In this study, we investigated the long-term effects of voluntary running wheel exercise on gait phenotypes, depression, cognitive, rotational behaviors as well as histology in a 6-OHDA-lesioned rat model of PD. Results: We observed that, when compared with the non-exercise controls, five-week voluntary exercise alleviated and postponed the 6-OHDA-induced gait deficits, including a significantly improved walking speed, step/stride length, base of support and print length. In addition, we found that the non-motor functions, such as novel object recognition and forced swim test, were also ameliorated by voluntary exercise. However, the rotational behavior of the exercise group did not show significant differences when compared with the non-exercise group. Conclusions: We first analyzed the detailed spatiotemporal changes of gait pattern to investigate the potential benefits after long-term exercise in the rat model of PD, which could be useful for future objective assessment of locomotor function in PD or other neurological animal models. Furthermore, these results suggest that short-term voluntary exercise is sufficient to alleviate cognition deficits and depressive behavior in 6-OHDA lesioned rats and long-term treatment reduces the progression of motor symptoms and elevates tyrosine hydroxylase (TH), Brain-derived neurotrophic factor (BDNF), bone marrow tyrosine kinase in chromosome X (BMX) protein expression level without affecting dopaminergic (DA) neuron loss in this PD rat model. PMID:29419747

The Role of Eye Movement Driven Attention in Functional Strabismic Amblyopia

PubMed Central

2015-01-01

Strabismic amblyopia “blunt vision” is a developmental anomaly that affects binocular vision and results in lowered visual acuity. Strabismus is a term for a misalignment of the visual axes and is usually characterized by impaired ability of the strabismic eye to take up fixation. Such impaired fixation is usually a function of the temporally and spatially impaired binocular eye movements that normally underlie binocular shifts in visual attention. In this review, we discuss how abnormal eye movement function in children with misaligned eyes influences the development of normal binocular visual attention and results in deficits in visual function such as depth perception. We also discuss how eye movement function deficits in adult amblyopia patients can also lead to other abnormalities in visual perception. Finally, we examine how the nonamblyopic eye of an amblyope is also affected in strabismic amblyopia. PMID:25838941

Treadmill Exercise Ameliorates Spatial Learning and Memory Deficits Through Improving the Clearance of Peripheral and Central Amyloid-Beta Levels.

PubMed

Khodadadi, Davar; Gharakhanlou, Reza; Naghdi, Naser; Salimi, Mona; Azimi, Mohammad; Shahed, Atabak; Heysieattalab, Soomaayeh

2018-06-11

Aggregated amyloid beta (Aβ) peptides are believed to play a decisive role in the pathology of Alzheimer's disease (AD). Previous evidence suggested that exercise contributes to the improvement of cognitive decline and slows down pathogenesis of AD; however, the exact mechanisms for this have not been fully understood. Here, we evaluated the effect of a 4-week moderate treadmill exercise on spatial memory via central and peripheral Aβ clearance mechanisms following developed AD-like neuropathology induced by intra-hippocampal Aβ 1-42 injection in male Wistar rats. We found Aβ 1-42 -treated animals showed spatial learning and memory impairment which was accompanied by increased levels of amyloid plaque load and soluble Aβ 1-42 (sAβ 1-42 ), decreased mRNA and protein expression of neprilysin (NEP), insulin degrading enzyme (IDE) and low-density lipoprotein receptor-related protein-1 (LRP-1) in the hippocampus. Aβ 1-42 -treated animals also exhibited a higher level of sAβ 1-42 and a lower level of soluble LRP-1 (sLRP-1) in plasma, as well as a decreased level of LRP-1 mRNA and protein content in the liver. However, exercise training improved the spatial learning and memory deficits, reduced both plaque load and sAβ 1-42 levels, and up-regulated expression of NEP, IDE, and LRP-1 in the hippocampus of Aβ 1-42 -treated animals. Aβ 1-42 -treated animals subjected to treadmill exercise also revealed decreased levels of sAβ 1-42 and increased levels of sLRP-1 in plasma, as well as increased levels of LRP-1 mRNA and protein in the liver. In conclusion, our findings suggest that exercise-induced improvement in both of central and peripheral Aβ clearance are likely involved in ameliorating spatial learning and memory deficits in an animal model of AD. Future studies need to determine their relative contribution.

Treadmill exercise delays the onset of non-motor behaviors and striatal pathology in the CAG140 knock-in mouse model of Huntington's disease.

PubMed

Stefanko, D P; Shah, V D; Yamasaki, W K; Petzinger, G M; Jakowec, M W

2017-09-01

Depression, cognitive impairments, and other neuropsychiatric disturbances are common during the prodromal phase of Huntington's disease (HD) well before the onset of classical motor symptoms of this degenerative disorder. The purpose of this study was to examine the potential impact of physical activity in the form of exercise on a motorized treadmill on non-motor behavioral features including depression-like behavior and cognition in the CAG 140 knock-in (KI) mouse model of HD. The CAG 140 KI mouse model has a long lifespan compared to other HD rodent models with HD motor deficits emerging after 12months of age and thus provides the opportunity to investigate early life interventions such as exercise on disease progression. Motorized treadmill running was initiated at 4weeks of age (1h per session, 3 times per week) and continued for 6months. Non-motor behaviors were assessed up to 6months of age and included analysis of depression-like behavior (using the tail-suspension and forced-swim tests) and cognition (using the T-maze and object recognition tests). At both 4 and 6months of age, CAG 140 KI mice displayed significant depression-like behavior in the forced swim and tail suspension tests and cognitive impairment by deficits in reversal relearning in the T-maze test. These deficits were not evident in mice engaged in treadmill running. In addition, exercise restored striatal dopamine D2 receptor expression and dopamine neurotransmitter levels both reduced in sedentary HD mice. Finally, we examined the pattern of striatal expression of mutant huntingtin (mHTT) protein and showed that the number and intensity of immunohistochemical staining patterns of intranuclear aggregates were significantly reduced with exercise. Altogether these findings begin to address the potential impact of lifestyle and early intervention such as exercise on modifying HD progression. Copyright © 2017 Elsevier Inc. All rights reserved.

Towards the development of improved tests for negative symptoms of schizophrenia in a validated animal model.

PubMed

Sahin, Ceren; Doostdar, Nazanin; Neill, Joanna C

2016-10-01

Negative symptoms in schizophrenia remain an unmet clinical need. There is no licensed treatment specifically for this debilitating aspect of the disorder and effect sizes of new therapies are too small to make an impact on quality of life and function. Negative symptoms are multifactorial but often considered in terms of two domains, expressive deficit incorporating blunted affect and poverty of speech and avolition incorporating asociality and lack of drive. There is a clear need for improved understanding of the neurobiology of negative symptoms which can be enabled through the use of carefully validated animal models. While there are several tests for assessing sociability in animals, tests for blunted affect in schizophrenia are currently lacking. Two paradigms have recently been developed for assessing negative affect of relevance to depression in rats. Here we assess their utility for studying negative symptoms in schizophrenia using our well validated model for schizophrenia of sub-chronic (sc) treatment with Phencyclidine (PCP) in adult female rats. Results demonstrate that sc PCP treatment produces a significant negative affect bias in response to a high value reward in the optimistic and affective bias tests. Our results are not easily explained by the known cognitive deficits induced by sc PCP and support the hypothesis of a negative affective bias in this model. We suggest that further refinement of these two tests will provide a means to investigate the neurobiological basis of negative affect in schizophrenia, thus supporting the assessment of efficacy of new targets for this currently untreated symptom domain. Copyright © 2016 Elsevier B.V. All rights reserved.

Functional changes of the reward system underlie blunted response to social gaze in cocaine users

PubMed Central

Preller, Katrin H.; Herdener, Marcus; Schilbach, Leonhard; Stämpfli, Philipp; Hulka, Lea M.; Vonmoos, Matthias; Ingold, Nina; Vogeley, Kai; Tobler, Philippe N.; Seifritz, Erich; Quednow, Boris B.

2014-01-01

Social interaction deficits in drug users likely impede treatment, increase the burden of the affected families, and consequently contribute to the high costs for society associated with addiction. Despite its significance, the neural basis of altered social interaction in drug users is currently unknown. Therefore, we investigated basal social gaze behavior in cocaine users by applying behavioral, psychophysiological, and functional brain-imaging methods. In study I, 80 regular cocaine users and 63 healthy controls completed an interactive paradigm in which the participants’ gaze was recorded by an eye-tracking device that controlled the gaze of an anthropomorphic virtual character. Valence ratings of different eye-contact conditions revealed that cocaine users show diminished emotional engagement in social interaction, which was also supported by reduced pupil responses. Study II investigated the neural underpinnings of changes in social reward processing observed in study I. Sixteen cocaine users and 16 controls completed a similar interaction paradigm as used in study I while undergoing functional magnetic resonance imaging. In response to social interaction, cocaine users displayed decreased activation of the medial orbitofrontal cortex, a key region of reward processing. Moreover, blunted activation of the medial orbitofrontal cortex was significantly correlated with a decreased social network size, reflecting problems in real-life social behavior because of reduced social reward. In conclusion, basic social interaction deficits in cocaine users as observed here may arise from altered social reward processing. Consequently, these results point to the importance of reinstatement of social reward in the treatment of stimulant addiction. PMID:24449854

Influence of physical exercise on traumatic brain injury deficits: scaffolding effect.

PubMed

Archer, Trevor

2012-05-01

Traumatic brain injury (TBI) may be due to a bump, blow, or jolt to the head or a penetrating head injury that disrupts normal brain function; it presents an ever-growing, serious public health problem that causes a considerable number of fatalities and cases of permanent disability annually. Physical exercise restores the healthy homeostatic regulation of stress, affect and the regulation of hypothalamic-pituitary-adrenal axis. Physical activity attenuates or reverses the performance deficits observed in neurocognitive tasks. It induces anti-apoptotic effects and buttresses blood-brain barrier intactness. Exercise offers a unique non-pharmacologic, non-invasive intervention that incorporates different regimes, whether dynamic or static, endurance, or resistance. Exercise intervention protects against vascular risk factors that include hypertension, diabetes, cellular inflammation, and aortic rigidity. It induces direct changes in cerebrovasculature that produce beneficial changes in cerebral blood flow, angiogenesis and vascular disease improvement. The improvements induced by physical exercise regimes in brain plasticity and neurocognitive performance are evident both in healthy individuals and in those afflicted by TBI. The overlap and inter-relations between TBI effects on brain and cognition as related to physical exercise and cognition may provide lasting therapeutic benefits for recovery from TBI. It seems likely that some modification of the notion of scaffolding would postulate that physical exercise reinforces the adaptive processes of the brain that has undergone TBI thereby facilitating the development of existing networks, albeit possibly less efficient, that compensate for those lost through damage. © Springer Science+Business Media, LLC 2011

Acute fatal coronary artery dissection following exercise-related blunt chest trauma.

PubMed

Barbesier, Marie; Boval, Catherine; Desfeux, Jacques; Lebreton, Catherine; Léonetti, Georges; Piercecchi, Marie-Dominique

2015-01-01

Coronary artery injury such as acute coronary dissection is an uncommon and potentially life-threatening complication after blunt chest trauma. The authors report an unusual autopsy case of a 43-year-old healthy man who suddenly collapsed after receiving a punch to the chest during the practice of kung fu. The occurrence of the punch was supported by the presence of one recent contusion on the left lateral chest area at the external examination and by areas of hemorrhage next to the left lateral intercostal spaces at the internal examination. The histological examination revealed the presence of an acute dissection of the proximal segment of the left anterior descending coronary artery. Only few cases of coronary artery dissection have been reported due to trauma during sports activities such as rugby and soccer games, but never during the practice of martial arts, sports usually considered as safe and responsible for only minor trauma. © 2014 American Academy of Forensic Sciences.

Autonomic Recovery Is Delayed in Chinese Compared with Caucasian following Treadmill Exercise.

PubMed

Sun, Peng; Yan, Huimin; Ranadive, Sushant M; Lane, Abbi D; Kappus, Rebecca M; Bunsawat, Kanokwan; Baynard, Tracy; Hu, Min; Li, Shichang; Fernhall, Bo

2016-01-01

Caucasian populations have a higher prevalence of cardiovascular disease (CVD) when compared with their Chinese counterparts and CVD is associated with autonomic function. It is unknown whether autonomic function during exercise recovery differs between Caucasians and Chinese. The present study investigated autonomic recovery following an acute bout of treadmill exercise in healthy Caucasians and Chinese. Sixty-two participants (30 Caucasian and 32 Chinese, 50% male) performed an acute bout of treadmill exercise at 70% of heart rate reserve. Heart rate variability (HRV) and baroreflex sensitivity (BRS) were obtained during 5-min epochs at pre-exercise, 30-min, and 60-min post-exercise. HRV was assessed using frequency [natural logarithm of high (LnHF) and low frequency (LnLF) powers, normalized high (nHF) and low frequency (nLF) powers, and LF/HF ratio] and time domains [Root mean square of successive differences (RMSSD), natural logarithm of RMSSD (LnRMSSD) and R-R interval (RRI)]. Spontaneous BRS included both up-up and down-down sequences. At pre-exercise, no group differences were observed for any HR, HRV and BRS parameters. During exercise recovery, significant race-by-time interactions were observed for LnHF, nHF, nLF, LF/HF, LnRMSSD, RRI, HR, and BRS (up-up). The declines in LnHF, nHF, RMSSD, RRI and BRS (up-up) and the increases in LF/HF, nLF and HR were blunted in Chinese when compared to Caucasians from pre-exercise to 30-min to 60-min post-exercise. Chinese exhibited delayed autonomic recovery following an acute bout of treadmill exercise. This delayed autonomic recovery may result from greater sympathetic dominance and extended vagal withdrawal in Chinese. Chinese Clinical Trial Register ChiCTR-IPR-15006684.

Autonomic Recovery Is Delayed in Chinese Compared with Caucasian following Treadmill Exercise

PubMed Central

Sun, Peng; Yan, Huimin; Ranadive, Sushant M.; Lane, Abbi D.; Kappus, Rebecca M.; Bunsawat, Kanokwan; Baynard, Tracy; Hu, Min; Li, Shichang; Fernhall, Bo

2016-01-01

Caucasian populations have a higher prevalence of cardiovascular disease (CVD) when compared with their Chinese counterparts and CVD is associated with autonomic function. It is unknown whether autonomic function during exercise recovery differs between Caucasians and Chinese. The present study investigated autonomic recovery following an acute bout of treadmill exercise in healthy Caucasians and Chinese. Sixty-two participants (30 Caucasian and 32 Chinese, 50% male) performed an acute bout of treadmill exercise at 70% of heart rate reserve. Heart rate variability (HRV) and baroreflex sensitivity (BRS) were obtained during 5-min epochs at pre-exercise, 30-min, and 60-min post-exercise. HRV was assessed using frequency [natural logarithm of high (LnHF) and low frequency (LnLF) powers, normalized high (nHF) and low frequency (nLF) powers, and LF/HF ratio] and time domains [Root mean square of successive differences (RMSSD), natural logarithm of RMSSD (LnRMSSD) and R–R interval (RRI)]. Spontaneous BRS included both up-up and down-down sequences. At pre-exercise, no group differences were observed for any HR, HRV and BRS parameters. During exercise recovery, significant race-by-time interactions were observed for LnHF, nHF, nLF, LF/HF, LnRMSSD, RRI, HR, and BRS (up-up). The declines in LnHF, nHF, RMSSD, RRI and BRS (up-up) and the increases in LF/HF, nLF and HR were blunted in Chinese when compared to Caucasians from pre-exercise to 30-min to 60-min post-exercise. Chinese exhibited delayed autonomic recovery following an acute bout of treadmill exercise. This delayed autonomic recovery may result from greater sympathetic dominance and extended vagal withdrawal in Chinese. Trial Registration: Chinese Clinical Trial Register ChiCTR-IPR-15006684 PMID:26784109

The impact of age on cerebral perfusion, oxygenation and metabolism during exercise in humans

PubMed Central

Braz, Igor D.

2015-01-01

Abstract Age is one of the most important risk factors for dementia and stroke. Examination of the cerebral circulatory responses to acute exercise in the elderly may help to pinpoint the mechanisms by which exercise training can reduce the risk of brain diseases, inform the optimization of exercise training programmes and assist with the identification of age‐related alterations in cerebral vascular function. During low‐to‐moderate intensity dynamic exercise, enhanced neuronal activity is accompanied by cerebral perfusion increases of ∼10–30%. Beyond ∼60–70% maximal oxygen uptake, cerebral metabolism remains elevated but perfusion in the anterior portion of the circulation returns towards baseline, substantively because of a hyperventilation‐mediated reduction in the partial pressure of arterial carbon dioxide (P aC O2) and cerebral vasoconstriction. Cerebral perfusion is lower in older individuals, both at rest and during incremental dynamic exercise. Nevertheless, the increase in the estimated cerebral metabolic rate for oxygen and the arterial–internal jugular venous differences for glucose and lactate are similar in young and older individuals exercising at the same relative exercise intensities. Correction for the age‐related reduction in P aC O2 during exercise by the provision of supplementary CO2 is suggested to remove ∼50% of the difference in cerebral perfusion between young and older individuals. A multitude of candidates could account for the remaining difference, including cerebral atrophy, and enhanced vasoconstrictor and blunted vasodilatory pathways. In summary, age‐related reductions in cerebral perfusion during exercise are partly associated with a lower P aC O2 in exercising older individuals; nevertheless the cerebral extraction of glucose, lactate and oxygen appear to be preserved. PMID:26435295

Regulation of coronary resistance vessel tone in response to exercise.

PubMed

Duncker, Dirk J; Bache, Robert J; Merkus, Daphne

2012-04-01

Exercise is a primary stimulus for increased myocardial oxygen demand. The ~6-fold increase in oxygen demand of the left ventricle during heavy exercise is met principally by augmenting coronary blood flow (~5-fold), as hemoglobin concentration and oxygen extraction (which is already ~70% at rest) increase only modestly in most species. As a result, coronary blood flow is tightly coupled to myocardial oxygen consumption over a wide range of physical activity. This tight coupling has been proposed to depend on periarteriolar oxygen tension, signals released from cardiomyocytes and the endothelium as well as neurohumoral influences, but the contribution of each of these regulatory pathways, and their interactions, to exercise hyperemia in the heart remain incompletely understood. In humans, nitric oxide, adenosine and K(ATP) channels each appear to contribute to resting coronary resistance vessel tone, but evidence for a critical contribution to exercise hyperemia is lacking. In dogs K(ATP)-channel activation together with adenosine and nitric oxide contribute to exercise hyperemia in a non-linear redundant fashion. In contrast, in swine nitric oxide, adenosine and K(ATP) channels contribute to resting coronary resistance vessel tone control in a linear additive manner, but do not appear to be mandatory for exercise hyperemia. Rather, exercise hyperemia in swine appears to involve β-adrenergic activation in conjunction with exercise-induced blunting of an endothelin-mediated vasoconstrictor influence. In view of these remarkable species differences in coronary vasomotor control during exercise, future studies are required to determine the system of vasodilator components that mediate exercise hyperemia in humans. This article is part of a Special Issue entitled "Coronary Blood Flow". Copyright © 2011 Elsevier Ltd. All rights reserved.

Acetylsalicylic acid inhibits the pituitary response to exercise-related stress in humans.

PubMed

Di Luigi, L; Guidetti, L; Romanelli, F; Baldari, C; Conte, D

2001-12-01

Prostaglandins (PGs) modulate the activity of the hypothalamus-pituitary axis, and pituitary hormones are largely involved in the physiological responses to exercise. The purpose of this study was to analyze the effects of acetylsalicylic acid (ASA), an inhibitor of PGs synthesis, in the pituitary responses to physical stress in humans. Adrenocorticotropin (ACTH), beta-endorphin, cortisol, growth hormone (GH), and prolactin (PRL) responses to exercise were evaluated after administration of either placebo or ASA. Blood samples for hormone evaluations before (-30, -15, and 0 pre) and after (0 post, +15, +30, +45, +60, and +90 min) a 30-min treadmill exercise (75% of .VO(2max)) were taken from 12 male athletes during two exercise trials. One tablet of ASA (800 mg), or placebo, was administered two times daily for 3 d before and on the morning of each exercise-test. The results clearly show that, compared with placebo, ASA ingestion significantly blunted the increased serum ACTH, beta-endorphin, cortisol, and GH levels before exercise (anticipatory response) and was associated with reduced cortisol concentrations after exercise. Furthermore, although no differences in the GH response to exercise were shown, a significantly reduced total PRL response to stress condition was observed after ASA. ASA influences ACTH, beta-endorphin, cortisol, GH, and PRL responses to exercise-related stress in humans (preexercise activation/exercise-linked response). Even though it is not possible to exclude direct action for ASA, our data indirectly confirm a role of PGs in these responses. We have to further evaluate the nature of the preexercise endocrine activation and, because of the large use of anti-inflammatory drugs in athletes, whether the interaction between ASA and hormones might positively or negatively influence health status, performance, and/or recovery.

Home exercise programmes supported by video and automated reminders compared with standard paper-based home exercise programmes in patients with stroke: a randomized controlled trial.

PubMed

Emmerson, Kellie B; Harding, Katherine E; Taylor, Nicholas F

2017-08-01

To determine whether patients with stroke receiving rehabilitation for upper limb deficits using smart technology (video and reminder functions) demonstrate greater adherence to prescribed home exercise programmes and better functional outcomes when compared with traditional paper-based exercise prescription. Randomized controlled trial comparing upper limb home exercise programmes supported by video and automated reminders on smart technology, with standard paper-based home exercise programmes. A community rehabilitation programme within a large metropolitan health service. Patients with stroke with upper limb deficits, referred for outpatient rehabilitation. Participants were randomly assigned to the control (paper-based home exercise programme) or intervention group (home exercise programme filmed on an electronic tablet, with an automated reminder). Both groups completed their prescribed home exercise programme for four weeks. The primary outcome was adherence using a self-reported log book. Secondary outcomes were change in upper limb function and patient satisfaction. A total of 62 participants were allocated to the intervention ( n = 30) and control groups ( n = 32). There were no differences between the groups for measures of adherence (mean difference 2%, 95% CI -12 to 17) or change in the Wolf Motor Function Test log transformed time (mean difference 0.02 seconds, 95% CI -0.1 to 0.1). There were no between-group differences in how participants found instructions ( p = 0.452), whether they remembered to do their exercises ( p = 0.485), or whether they enjoyed doing their exercises ( p = 0.864). The use of smart technology was not superior to standard paper-based home exercise programmes for patients recovering from stroke. This trial design was registered prospectively with the Australian and New Zealand Clinical Trials Register, ID: ACTRN 12613000786796. http://www.anzctr.org.au/trialSearch.aspx.

Aerobic exercise and a BDNF-mimetic therapy rescue learning and memory in a mouse model of Down syndrome.

PubMed

Parrini, Martina; Ghezzi, Diego; Deidda, Gabriele; Medrihan, Lucian; Castroflorio, Enrico; Alberti, Micol; Baldelli, Pietro; Cancedda, Laura; Contestabile, Andrea

2017-12-04

Down syndrome (DS) is caused by the triplication of human chromosome 21 and represents the most frequent genetic cause of intellectual disability. The trisomic Ts65Dn mouse model of DS shows synaptic deficits and reproduces the essential cognitive disabilities of the human syndrome. Aerobic exercise improved various neurophysiological dysfunctions in Ts65Dn mice, including hippocampal synaptic deficits, by promoting synaptogenesis and neurotransmission at glutamatergic terminals. Most importantly, the same intervention also prompted the recovery of hippocampal adult neurogenesis and synaptic plasticity and restored cognitive performance in trisomic mice. Additionally, the expression of brain-derived neurotrophic factor (BDNF) was markedly decreased in the hippocampus of patients with DS. Since the positive effect of exercise was paralleled by increased BDNF expression in trisomic mice, we investigated the effectiveness of a BDNF-mimetic treatment with 7,8-dihydroxyflavone at alleviating intellectual disabilities in the DS model. Pharmacological stimulation of BDNF signaling rescued synaptic plasticity and memory deficits in Ts65Dn mice. Based on our findings, Ts65Dn mice benefit from interventions aimed at promoting brain plasticity, and we provide evidence that BDNF signaling represents a potentially new pharmacological target for treatments aimed at rescuing cognitive disabilities in patients with DS.

Exercise and the Regulation of Immune Functions.

PubMed

Simpson, Richard J; Kunz, Hawley; Agha, Nadia; Graff, Rachel

2015-01-01

Exercise has a profound effect on the normal functioning of the immune system. It is generally accepted that prolonged periods of intensive exercise training can depress immunity, while regular moderate intensity exercise is beneficial. Single bouts of exercise evoke a striking leukocytosis and a redistribution of effector cells between the blood compartment and the lymphoid and peripheral tissues, a response that is mediated by increased hemodynamics and the release of catecholamines and glucocorticoids following the activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis. Single bouts of prolonged exercise may impair T-cell, NK-cell, and neutrophil function, alter the Type I and Type II cytokine balance, and blunt immune responses to primary and recall antigens in vivo. Elite athletes frequently report symptoms associated with upper respiratory tract infections (URTI) during periods of heavy training and competition that may be due to alterations in mucosal immunity, particularly reductions in secretory immunoglobulin A. In contrast, single bouts of moderate intensity exercise are "immuno-enhancing" and have been used to effectively increase vaccine responses in "at-risk" patients. Improvements in immunity due to regular exercise of moderate intensity may be due to reductions in inflammation, maintenance of thymic mass, alterations in the composition of "older" and "younger" immune cells, enhanced immunosurveillance, and/or the amelioration of psychological stress. Indeed, exercise is a powerful behavioral intervention that has the potential to improve immune and health outcomes in the elderly, the obese, and patients living with cancer and chronic viral infections such as HIV. © 2015 Elsevier Inc. All rights reserved.

Diclofenac pretreatment modulates exercise-induced inflammation in skeletal muscle of rats through the TLR4/NF-κB pathway.

PubMed

Barcelos, Rômulo Pillon; Bresciani, Guilherme; Cuevas, Maria José; Martínez-Flórez, Susana; Soares, Félix Alexandre Antunes; González-Gallego, Javier

2017-07-01

Nonsteroidal anti-inflammatory drugs, such as diclofenac, are widely used to treat inflammation and pain in several conditions, including sports injuries. This study analyzes the influence of diclofenac on the toll-like receptor-nuclear factor kappa B (TLR-NF-κB) pathway in skeletal muscle of rats submitted to acute eccentric exercise. Twenty male Wistar rats were divided into 4 groups: control-saline, control-diclofenac, exercise-saline, and exercise-diclofenac. Diclofenac or saline were administered for 7 days prior to an acute eccentric exercise bout. The inflammatory status was evaluated through mRNA levels of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), IL-1β, and tumor necrosis factor alpha (TNF-α), and protein content of COX-2, IL-6, and TNF-α in vastus lateralis muscle. Data obtained showed that a single bout of eccentric exercise significantly increased COX-2 gene expression. Similarly, mRNA expression and protein content of other inflammation-related genes also increased after the acute exercise. However, these effects were attenuated in the exercise + diclofenac group. TLR4, myeloid differentiation primary response gene 88 (MyD88), and p65 were also upregulated after the acute eccentric bout and the effect was blunted by the anti-inflammatory drug. These findings suggest that pretreatment with diclofenac may represent an effective tool to ameliorate the pro-inflammatory status induced by acute exercise in rat skeletal muscle possibly through an attenuation of the TLR4-NF-κB signaling pathway.

Holistic Treatment Approaches to ADHD: Nutrition, Sleep,and Exercise, Part 7

ERIC Educational Resources Information Center

Lavoie, Theresa

2009-01-01

This article is part of a series exploring Attention Deficit Hyperactivity Disorder (ADHD). In this seventh installment, the author discusses three holistic treatments for children and adults with ADHD: diet and nutrition, sleep, and exercise. These approaches focus and improve the overall health of ADHD patients. (For Part 6 of this series, see…

Beneficial effects of dietary EGCG and voluntary exercise on behavior in an Alzheimer's disease mouse model.

PubMed

Walker, Jennifer M; Klakotskaia, Diana; Ajit, Deepa; Weisman, Gary A; Wood, W Gibson; Sun, Grace Y; Serfozo, Peter; Simonyi, Agnes; Schachtman, Todd R

2015-01-01

Alzheimer's disease (AD) is a progressive, age-dependent neurodegenerative disorder affecting specific brain regions that control memory and cognitive functions. Epidemiological studies suggest that exercise and dietary antioxidants are beneficial in reducing AD risk. To date, botanical flavonoids are consistently associated with the prevention of age-related diseases. The present study investigated the effects of 4 months of wheel-running exercise, initiated at 2-months of age, in conjunction with the effects of the green tea catechin (-)-epigallocatechin-3-gallate (EGCG) administered orally in the drinking water (50 mg/kg daily) on: (1) behavioral measures: learning and memory performance in the Barnes maze, nest building, open-field, anxiety in the light-dark box; and (2) soluble amyloid-β (Aβ) levels in the cortex and hippocampus in TgCRND8 (Tg) mice. Untreated Tg mice showed hyperactivity, relatively poor nest building behaviors, and deficits in spatial learning in the Barnes maze. Both EGCG and voluntary exercise, separately and in combination, were able to attenuate nest building and Barnes maze performance deficits. Additionally, these interventions lowered soluble Aβ1-42 levels in the cortex and hippocampus. These results, together with epidemiological and clinical studies in humans, suggest that dietary polyphenols and exercise may have beneficial effects on brain health and slow the progression of AD.

Fat oxidation, hormonal and plasma metabolite kinetics during a submaximal incremental test in lean and obese adults.

PubMed

Lanzi, Stefano; Codecasa, Franco; Cornacchia, Mauro; Maestrini, Sabrina; Salvadori, Alberto; Brunani, Amelia; Malatesta, Davide

2014-01-01

This study aimed to compare fat oxidation, hormonal and plasma metabolite kinetics during exercise in lean (L) and obese (O) men. Sixteen L and 16 O men [Body Mass Index (BMI): 22.9 ± 0.3 and 39.0 ± 1.4 kg · m(-2)] performed a submaximal incremental test (Incr) on a cycle-ergometer. Fat oxidation rates (FORs) were determined using indirect calorimetry. A sinusoidal model, including 3 independent variables (dilatation, symmetry, translation), was used to describe fat oxidation kinetics and determine the intensity (Fat(max)) eliciting maximal fat oxidation. Blood samples were drawn for the hormonal and plasma metabolite determination at each step of Incr. FORs (mg · FFM(-1) · min(-1)) were significantly higher from 20 to 30% of peak oxygen uptake (VO2peak) in O than in L and from 65 to 85% VO2peak in L than in O (p ≤ 0.05). FORs were similar in O and in L from 35 to 60% VO2peak. Fat max was 17% significantly lower in O than in L (p<0.01). Fat oxidation kinetics were characterized by similar translation, significantly lower dilatation and left-shift symmetry in O compared with L (p<0.05). During whole exercise, a blunted lipolysis was found in O [lower glycerol/fat mass (FM) in O than in L (p ≤ 0.001)], likely associated with higher insulin concentrations in O than in L (p<0.01). Non-esterified fatty acids (NEFA) were significantly higher in O compared with L (p<0.05). Despite the blunted lipolysis, O presented higher NEFA availability, likely due to larger amounts of FM. Therefore, a lower Fat(max), a left-shifted and less dilated curve and a lower reliance on fat oxidation at high exercise intensities suggest that the difference in the fat oxidation kinetics is likely linked to impaired muscular capacity to oxidize NEFA in O. These results may have important implications for the appropriate exercise intensity prescription in training programs designed to optimize fat oxidation in O.

Disordered eating behaviour is associated with blunted cortisol and cardiovascular reactions to acute psychological stress.

PubMed

Ginty, Annie T; Phillips, Anna C; Higgs, Suzanne; Heaney, Jennifer L J; Carroll, Douglas

2012-05-01

Research suggests a potential dysregulation of the stress response in individuals with bulimia nervosa. This study measured both cardiovascular and cortisol reactions to a standardised laboratory stress task in individuals identified as showing disordered eating behaviour to determine whether dysregulation of the stress response is characteristic of the two branches of the stress response system. Female students (N=455) were screened using two validated eating disorder questionnaires. Twelve women with disordered eating, including self-induced vomiting, and 12 healthy controls were selected for laboratory stress testing. Salivary cortisol and cardiovascular activity, via Doppler imaging and semi-automatic blood pressure monitoring, were measured at resting baseline and during and after exposure to a 10-min mental arithmetic stress task. Compared to controls the disordered eating group showed blunted cortisol, cardiac output, heart rate, and stroke volume reactions to the acute stress, as well as an attenuated vasodilatory reaction. These effects could not be accounted for in terms of group differences in stress task performance, subjective task impact/engagement, age, BMI, neuroticism, cardio-respiratory fitness, or co-morbid exercise dependence. Our findings suggest that disordered eating is characterised by a dysregulation of the autonomic stress-response system. As such, they add further weight to the general contention that blunted stress reactivity is characteristic of a number of maladaptive behaviours and states. Copyright © 2011 Elsevier Ltd. All rights reserved.

Attention Deficit Hyperactivity Disorder in Preschool-Age Children.

PubMed

Tandon, Mini; Pergjika, Alba

2017-07-01

Attention deficit hyperactivity disorder is a neurodevelopmental disorder marked by age-inappropriate deficits in attention or hyperactivity/impulsivity that interfere with functioning or development. It is highly correlated with other disorders, such as oppositional defiant disorder, conduct disorder, and mood symptoms. The etiology is multifactorial, and neuroimaging findings are nonspecific. Although assessment tools exist, there is variability among them, and historically, parent-teacher agreement has not been consistent. Treatment algorithm for attention deficit hyperactivity disorder in preschoolers includes behavioral interventions first followed by psychopharmacologic treatment when behavioral therapies fail. Other nonpharmacologic and nonbehavioral interventions are discussed including the role of exercise and nutrition. Copyright © 2017 Elsevier Inc. All rights reserved.

Cardiopulmonary Exercise Testing in Adult Congenital Heart Disease.

PubMed

Mantegazza, Valentina; Apostolo, Anna; Hager, Alfred

2017-07-01

Recently, the number of patients with congenital heart diseases reaching adulthood has been progressively increasing in developed countries, and new issues are emerging: the evaluation of their capacity to cope with physical activity and whether this knowledge can be used to optimize medical management. A symptom-limited cardiopulmonary exercise test has proven to be an essential tool, because it can objectively evaluate the functional cardiovascular capacity of these patients, identify the pathological mechanisms of the defect (circulatory failure, shunts, and/or pulmonary hypertension), and help prescribe an individualized rehabilitation program when needed. The common findings on cardiopulmonary exercise testing in patients with congenital heart diseases are a reduced peak [Formula: see text]o 2 , an early anaerobic threshold, a blunted heart rate response, a reduced increase of Vt, and an increased [Formula: see text]e/[Formula: see text]co 2 . All these measures suggest common pathophysiological abnormalities: (1) a compromised exercise capacity from anomalies affecting the heart, vessels, lungs, or muscles; (2) chronotropic incompetence secondary to cardiac autonomic dysfunction or β-blockers and antiarrhythmic therapy; and (3) ventilatory inefficiency caused by left-heart failure with pulmonary congestion, pulmonary hypertension, pulmonary obstructive vascular disease, or cachexia. Most of these variables also have prognostic significance. For these patients, cardiopulmonary exercise testing allows evaluation and decisions affecting lifestyle and therapeutic interventions.

Redox interventions to increase exercise performance

PubMed Central

2015-01-01

Abstract Skeletal muscle continually produces reactive oxygen species (ROS) and nitric oxide (NO) derivatives. Both oxidant cascades have complex effects on muscle contraction, metabolic function and tissue perfusion. Strenuous exercise increases oxidant production by muscle, limiting performance during endurance exercise tasks. Conversely, redox interventions that modulate ROS or NO activity have the potential to improve performance. Antioxidants have long been known to buffer ROS activity and lessen oxidative perturbations during exercise. The capacity to enhance human performance varies among antioxidant categories. Vitamins, provitamins and nutriceuticals often blunt oxidative changes at the biochemical level but do not enhance performance. In contrast, reduced thiol donors have been shown to delay fatigue or increase endurance under a variety of experimental conditions. Dietary nitrate supplementation has recently emerged as a second redox strategy for increasing endurance. Purified nitrate salts and nitrate‐rich foods, notably beetroot and beetroot juice, are reported to lessen the oxygen cost of exercise, increase efficiency, and enhance performance during endurance tasks. These findings are exciting but enigmatic since nitrate per se has little bioactivity and cannot be converted to NO by mammalian cells. Overall, the available data suggest exercise endurance can be augmented by redox‐active supplements, either reduced thiol donors or dietary nitrates. These findings have clear implications for athletes seeking a competitive edge. More importantly, interventions that increase endurance may benefit individuals whose physical activity is limited by illness, ageing, or frailty. PMID:26584644

Reduced wheel running and blunted effects of voluntary exercise in LPA1-null mice: The importance of assessing the amount of running in transgenic mice studies

PubMed Central

Castilla-Ortega, Estela; Rosell-Valle, Cristina; Blanco, Eduardo; Pedraza, Carmen; Chun, Jerold; de Fonseca, Fernando Rodríguez; Estivill-Torrús, Guillermo; Santín, Luis J.

2014-01-01

This work was aimed to assess whether voluntary exercise rescued behavioral and hippocampal alterations in mice lacking the lysophosphatidic acid LPA1 receptor (LPA1-null mice), studying the potential relationship between the amount of exercise performed and its effects. Normal and LPA1-null mice underwent 23 days of free wheel running and were tested for open-field behavior and adult hippocampal neurogenesis (cell proliferation, immature neurons, cell survival). Running decreased anxiety-like behavior in both genotypes but increased exploration only in the normal mice. While running affected all neurogenesis-related measures in normal mice (especially in the suprapyramidal blade of the dentate gyrus), only a moderate increase in cell survival was found in the mutants. Importantly, the LPA1-nulls showed notably reduced running. Analysis suggested that defective running in the LPA1-null mice could contribute to explain the scarce benefit of the voluntary exercise treatment. On the other hand, a literature review revealed that voluntary exercise is frequently used to modulate behavior and the hippocampus in transgenic mice, but half of the studies did not assess the quantity of running, overlooking any potential running impairments. This study adds evidence to the relevance of the quantity of exercise performed, emphasizing the importance of its assessment in transgenic mice research. PMID:24055600

Use of atropine in patients with submaximal heart rate during exercise myocardial perfusion SPECT.

PubMed

De Lorenzo, Andrea; Foerster, James; Sciammarella, Maria G; Suey, Cathy; Hayes, Sean W; Friedman, John D; Berman, Daniel S

2003-01-01

Failure to reach 85% of maximal predicted heart rate (MPHR) during exercise may render a myocardial perfusion single photon emission computed tomography (MPS) study nondiagnostic for ischemia detection. Although commonly used to increase heart rate (HR) during dobutamine stress, the administration of atropine for patients failing to achieve 85% of MPHR during exercise performed for MPS is still infrequent. Patients undergoing dual-isotope MPS were considered candidates for the study when, during exercise treadmill testing, they had less than 85% of MPHR and were unable to continue because of fatigue, without an ischemic response. Forty-seven patients (aged 65.3 +/- 12.5 years, 78.7% men) received atropine (0.6-1.2 mg). Maximal HR achieved before and after atropine was 118.0 +/- 14.8 beats/min (76.3% +/- 6.2% of MPHR) and 146.4 +/- 12.6 beats/min (94.4% +/- 8.1% of MPHR), respectively (P < .001). Of patients, 44 (93.6%) reached at least 85% of MPHR after atropine and had diagnostic MPS studies. After atropine, arrhythmias occurred in 14 patients (29.8%) and other minor side effects in 1 (2.1%). Atropine allows patients initially failing to achieve 85% of MPHR during exercise to increase HR and have a diagnostic MPS study, without major complications. It may provide an alternative to pharmacologic stress for patients with a blunted HR response to exercise.

Effects of Moderate Aerobic Exercise Combined With Calorie Restriction on Circulating Estrogens and IGF-I in Premenopausal Women

DTIC Science & Technology

2004-10-01

significantly either, indicating that chronic exercise and dieting do not result in favorable changes in two hormonal biomarkers for breast cancer. 14...physical activity and or diet in the risk of breast cancer, the battery of metabolic hormones that comprise the proposed method must be amenable to...new and important information regarding the degree to which an exercise and diet program that results in an energy deficit will reduce the risk of

Effects of γ-Aminobutyric Acid A Receptor Activation on Counterregulatory Responses to Subsequent Exercise in Individuals With Type 1 Diabetes

PubMed Central

Hedrington, Maka S.; Mikeladze, Maia; Tate, Donna B.; Younk, Lisa M.; Davis, Ian

2016-01-01

The effects of γ-aminobutyric acid (GABA) A receptor activation on physiologic responses during next-day exercise in type 1 diabetes are unknown. To test the hypothesis that GABA A activation with the benzodiazepine alprazolam would blunt counterregulatory responses during subsequent exercise, 29 (15 male, 14 female) individuals with type 1 diabetes (HbA1c 7.8 ± 1%) were studied during separate 2-day protocols. Day 1 consisted of morning and afternoon 2-h euglycemic or 2.9 mmol/L hypoglycemic clamps with or without 1 mg alprazolam given 30 min before each clamp. Day 2 consisted of a 90-min euglycemic cycling exercise at 50% VO2max. Tritiated glucose was used to measure glucose kinetics. Despite equivalent day 2 insulin (93 ± 6 pmol/L) and glucose levels (5.3 ± 0.1 mmol/L), plasma epinephrine, norepinephrine, glucagon, cortisol, and growth hormone responses were similarly reduced after alprazolam or day 1 hypoglycemia compared with euglycemic control. Endogenous glucose production, lipolysis (glycerol, nonesterified fatty acid), and glycogenolysis (lactate) were also reduced during day 2 exercise after day 1 GABA A activation. We conclude that activation of GABA A receptors with alprazolam can result in widespread neuroendocrine, autonomic nervous system, and metabolic counterregulatory failure during subsequent submaximal exercise and may increase the risk of exercise-associated hypoglycemia in individuals with type 1 diabetes. PMID:27217489

Preliminary evidence of altered biomechanics in adolescents with Juvenile Fibromyalgia

PubMed Central

Sil, Soumitri; Thomas, Staci; DiCesare, Christopher; Strotman, Daniel; Ting, Tracy V; Myer, Gregory; Kashikar-Zuck, Susmita

2014-01-01

Objective Juvenile Fibromyalgia (JFM) is characterized by chronic musculoskeletal pain and marked reduction in physical activity. Despite recommendations for exercise to manage JFM pain, exercise adherence is poor. Due to pain and activity avoidance, adolescents with JFM are at risk for altered joint mechanics that may make them susceptible to increased pain and reduced tolerance for exercise. The primary aim of this study was to assess functional deficits in patients with JFM compared to healthy controls using objective biomechanical assessment. Methods Female adolescent patients with JFM (n=17) and healthy controls (n=14) completed biomechanical assessments including gait analysis and tests of lower extremity strength (isokinetic knee extension/flexion, hip abduction) and functional performance (Drop Vertical Jump) along with self-report measures of disability (Functional Disability Inventory), pain intensity, depressive symptoms (Children’s Depression Inventory), and fear of movement (Tampa Scale of Kinesiophobia). Results Patients with JFM demonstrated mild deficiencies in walking gait and functional performance (p’s <. 05), significantly lower left knee extension and flexion strength (19–26% deficit) and bilateral hip abduction strength (33–37%) compared to healthy controls (p’s < .008). Patients with JFM reported significantly higher functional disability, pain intensity, depressive symptoms, and fear of movement relative to controls (p’s < 0.01). Conclusions This study showed that adolescents with JFM exhibited objective alterations in biomechanics, and self-reported fear of movement which may reinforce their activity avoidance. Interventions for JFM should include a focus on correcting functional deficits and instilling greater confidence in adolescents with JFM to engage in exercise to improve functional outcomes. PMID:25156509

Size, shape, and stamina: the impact of left ventricular geometry on exercise capacity.

PubMed

Lam, Carolyn S P; Grewal, Jasmine; Borlaug, Barry A; Ommen, Steve R; Kane, Garvan C; McCully, Robert B; Pellikka, Patricia A

2010-05-01

Although several studies have examined the cardiac functional determinants of exercise capacity, few have investigated the effects of structural remodeling. The current study evaluated the association between cardiac geometry and exercise capacity. Subjects with ejection fraction > or = 50% and no valvular disease, myocardial ischemia, or arrhythmias were identified from a large prospective exercise echocardiography database. Left ventricular mass index and relative wall thickness were used to classify geometry into normal, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. All of the subjects underwent symptom-limited treadmill exercise according to standard Bruce protocol. Maximal exercise tolerance was measured in metabolic equivalents. Of 366 (60+/-14 years; 57% male) subjects, 166 (45%) had normal geometry, 106 (29%) had concentric remodeling, 40 (11%) had eccentric hypertrophy, and 54 (15%) had concentric hypertrophy. Geometry was related to exercise capacity: in descending order, the maximum achieved metabolic equivalents were 9.9+/-2.8 in normal, 8.9+/-2.6 in concentric remodeling, 8.6+/-3.1 in eccentric hypertrophy, and 8.0+/-2.7 in concentric hypertrophy (all P<0.02 versus normal). Left ventricular mass index and relative wall thickness were negatively correlated with exercise tolerance in metabolic equivalents (r=-0.14; P=0.009 and r=-0.21; P<0.001, respectively). Augmentation of heart rate and ejection fraction with exercise were blunted in concentric hypertrophy compared with normal, even after adjusting for medications. In conclusion, the pattern of ventricular remodeling is related to exercise capacity among low-risk adults. Subjects with concentric hypertrophy display the greatest limitation, and this is related to reduced systolic and chronotropic reserve. Reverse remodeling strategies may prevent or treat functional decline in patients with structural heart disease.

Size, Shape and Stamina: The Impact of Left Ventricular Geometry on Exercise Capacity

PubMed Central

Lam, Carolyn S.P.; Grewal, Jasmine; Borlaug, Barry A.; Ommen, Steve R.; Kane, Garvan C.; McCully, Robert B.; Pellikka, Patricia A.

2010-01-01

While several studies have examined the cardiac functional determinants of exercise capacity, few have investigated the effects of structural remodeling. The current study evaluated the association between cardiac geometry and exercise capacity. Subjects with ejection fraction ≥ 50% and no valvular disease, myocardial ischemia or arrhythmias were identified from a large prospective exercise echocardiography database. Left ventricular mass index and relative wall thickness were used to classify geometry into normal, concentric remodeling, eccentric hypertrophy and concentric hypertrophy. All subjects underwent symptom-limited treadmill exercise according to standard Bruce protocol. Maximal exercise tolerance was measured in metabolic equivalents. Of 366 (60±14 years; 57% male) subjects, 166(45%) had normal geometry, 106(29%) had concentric remodeling, 40(11%) had eccentric hypertrophy and 54(15%) had concentric hypertrophy. Geometry was related to exercise capacity: in descending order, the maximum achieved metabolic equivalents was 9.9±2.8 in normal, 8.9±2.6 in concentric remodeling, 8.6±3.1 in eccentric hypertrophy and 8.0±2.7 in concentric hypertrophy (all p<0.02 vs normal). Left ventricular mass index and relative wall thickness were negatively correlated with exercise tolerance in metabolic equivalents (r= -0.14; p=0.009 and r= -0.21; p<0.001, respectively). Augmentation of heart rate and ejection fraction with exercise were blunted in concentric hypertrophy compared to normal, even after adjusting for medications. In conclusion, the pattern of ventricular remodeling is related to exercise capacity among low-risk adults. Subjects with concentric hypertrophy display the greatest limitation and this is related to reduced systolic and chronotropic reserve. Reverse remodeling strategies may prevent or treat functional decline in patients with structural heart disease. PMID:20215563

Activity and immobilization after eccentric exercise: II. Serum CK.

PubMed

Sayers, S P; Clarkson, P M; Lee, J

2000-09-01

The purpose of the present study was to examine the effect of muscle activity level on serum creatine kinase (CK) activity after high-force eccentric exercise of the elbow flexors. Twenty-six male volunteers were randomly assigned to one of three groups for a 4-d treatment period after exercise: immobilization (N = 9), control (N = 8), and light exercise (N = 9). During the treatment period, the immobilization group had their arm casted and supported in a sling at 90 degrees. The control group had no restriction of their arm activity. The light exercise group performed a daily exercise regimen of 50 biceps curls with a 5-lb dumbbell. Serum CK activity was obtained by venipuncture for three consecutive days before eccentric exercise and during the 4-d treatment period. To quantify activity of the arm, CSA (Computer Science and Applications, Inc.) activity-monitoring devices were worn. Serum CK measurements revealed that there was a significant group by time interaction in the analysis of variance (P < 0.05). Peak serum CK activity of the immobilized group (668 IU) was lower than either the control (4230 IU) or light exercise (2740 IU) group. During the treatment period, activity level among the three groups was significantly different from each other (P < 0.001): 529 counts x min(-1) for the immobilization group, 944 counts x min(-1) for the control group, and 1334 counts x min(-1) for the light exercise group. These results suggest that immobilization of exercised damaged muscle during recovery significantly blunted serum CK activity, which may be due to attenuated removal of CK from the muscle and/or decrease lymphatic transport.

Prevention of bedrest-induced physical deconditioning by daily dobutamine infusions. Implications for drug-induced physical conditioning.

PubMed Central

Sullivan, M J; Binkley, P F; Unverferth, D V; Ren, J H; Boudoulas, H; Bashore, T M; Merola, A J; Leier, C V

1985-01-01

The effects of intermittent infusions of dobutamine were studied in young normal male subjects during a period of bedrest deconditioning to determine whether this synthetic catechol affects physical conditioning processes in humans. 24 volunteers were placed at bedrest and randomized to daily 2-h treatments of saline infusions (control), dobutamine infusions, or maintenance exercise (control). Exercise, hemodynamic, and metabolic studies were performed at base line and at the termination of the 3-wk treatment period. Maximal exercise (duration, oxygen consumption, and workload) fell for the saline group and remained unchanged for the dobutamine and exercise groups. Hemodynamics during exercise were maintained the same as pretreatment base line for the dobutamine and exercise groups, whereas stroke volume and cardiac output dropped and heart rate rose for the saline group. The metabolic profile showed an increased blood lactate response at rest and during submaximal exercise after 3 wk of bedrest for the saline group, and essentially no change for the exercise and the dobutamine groups. Extraction of oxygen across the exercising lower limb rose for the dobutamine group, as did the activity of the skeletal muscle oxidative enzymes, citrate synthetase, and succinate dehydrogenase. In contrast to the exercise control group, the saline and dobutamine groups developed orthostatic hypotension, tachycardia, and accentuation of the renin-aldosterone response over the 3-wk treatment period; for the saline group, this is best explained by the observed fall in blood volume and for the dobutamine group, by the blunting of vascular vasoconstrictive responses. During a period of bedrest deconditioning in humans, infusions of dobutamine maintain many of the physiologic expressions of physical conditioning. PMID:3932470

Ventricular-Arterial Coupling and Exercise-Induced Pulmonary Hypertension During Low-Level Exercise in Heart Failure With Preserved or Reduced Ejection Fraction.

PubMed

Obokata, Masaru; Nagata, Yasufumi; Kado, Yuichiro; Kurabayashi, Masahiko; Otsuji, Yutaka; Takeuchi, Masaaki

2017-03-01

Exercise-induced pulmonary hypertension (EIPH) may develop even at low workloads in heart failure (HF) patients. Ventricular-arterial stiffening plays an important role in the pathophysiology of HF with preserved ejection fraction (HFpEF). This study aimed to compare the response of ventricular-arterial coupling and PH during low-level exercise between HFpEF and HF with reduced EF (HFrEF). Echocardiography was performed at rest and during 10 W of bicycle exercise in HFpEF (n = 37) and HFrEF (n = 43). Load-independent contractility (end-systolic elastance [Ees], preload recruitable stroke work [PRSW], and peak power index [PWRI]), arterial afterload (arterial elastance [Ea]), and ventricular-arterial interaction (Ea/Ees) were measured with the use of a noninvasive single-beat technique. EIPH was defined as an estimated pulmonary arterial systolic pressure (PASP) of ≥50 mm Hg at 10 W of exercise. PASP was significantly increased during 10 W of exercise in both HF types, and ~50% of HFpEF patients developed EIPH. Arterial afterload was increased significantly during exercise in both groups. HFrEF and HFpEF patients showed a significant increase in LV contractility assessed by Ees, PRSW, and PWRI during exercise. Although Ea/Ees ratio decreased significantly in HFrEF, reduction in Ea/Ees was attenuated because of blunted Ees increases in patients with HFpEF compared with HFrEF. Even at low-level exercise, ~50% of HFpEF patients developed EIPH. Reduction in Ea/Ees was attenuated owing to less Ees increase in HFpEF compared with HFrEF. Further studies are needed to elucidate the association between ventricular-arterial coupling and EIPH in HFpEF. Copyright © 2016 Elsevier Inc. All rights reserved.

Use of the Frank-Starling mechanism during exercise is linked to exercise-induced changes in arterial load

PubMed Central

Chantler, Paul D.; Melenovsky, Vojtech; Schulman, Steven P.; Gerstenblith, Gary; Becker, Lewis C.; Ferrucci, Luigi; Fleg, Jerome L.; Najjar, Samer S.

2012-01-01

Effective arterial elastance(EA) is a measure of the net arterial load imposed on the heart that integrates the effects of heart rate(HR), peripheral vascular resistance(PVR), and total arterial compliance(TAC) and is a modulator of cardiac performance. To what extent the change in EA during exercise impacts on cardiac performance and aerobic capacity is unknown. We examined EA and its relationship with cardiovascular performance in 352 healthy subjects. Subjects underwent rest and exercise gated scans to measure cardiac volumes and to derive EA[end-systolic pressure/stroke volume index(SV)], PVR[MAP/(SV*HR)], and TAC(SV/pulse pressure). EA varied with exercise intensity: the ΔEA between rest and peak exercise along with its determinants, differed among individuals and ranged from −44% to +149%, and was independent of age and sex. Individuals were separated into 3 groups based on their ΔEAI. Individuals with the largest increase in ΔEA(group 3;ΔEA≥0.98 mmHg.m2/ml) had the smallest reduction in PVR, the greatest reduction in TAC and a similar increase in HR vs. group 1(ΔEA<0.22 mmHg.m2/ml). Furthermore, group 3 had a reduction in end-diastolic volume, and a blunted increase in SV(80%), and cardiac output(27%), during exercise vs. group 1. Despite limitations in the Frank-Starling mechanism and cardiac function, peak aerobic capacity did not differ by group because arterial-venous oxygen difference was greater in group 3 vs. 1. Thus the change in arterial load during exercise has important effects on the Frank-Starling mechanism and cardiac performance but not on exercise capacity. These findings provide interesting insights into the dynamic cardiovascular alterations during exercise. PMID:22003052

A Meta-Analytic Review of the Efficacy of Physical Exercise Interventions on Cognition in Individuals with Autism Spectrum Disorder and ADHD

ERIC Educational Resources Information Center

Tan, Beron W. Z.; Pooley, Julie A.; Speelman, Craig P.

2016-01-01

This review evaluates the efficacy of using physical exercise interventions on improving cognitive functions in individuals with autism spectrum disorder (ASD) and/or attention deficit hyperactivity disorder (ADHD). This review includes a meta-analysis based on a random-effects model of data reported in 22 studies with 579 participants aged…

Age-specific effects of voluntary exercise on memory and the older brain.

PubMed

Siette, Joyce; Westbrook, R Frederick; Cotman, Carl; Sidhu, Kuldip; Zhu, Wanlin; Sachdev, Perminder; Valenzuela, Michael J

2013-03-01

Physical exercise in early adulthood and mid-life improves cognitive function and enhances brain plasticity, but the effects of commencing exercise in late adulthood are not well-understood. We investigated the effects of voluntary exercise in the restoration of place recognition memory in aged rats and examined hippocampal changes of synaptic density and neurogenesis. We found a highly selective age-related deficit in place recognition memory that is stable across retest sessions and correlates strongly with loss of hippocampal synapses. Additionally, 12 weeks of voluntary running at 20 months of age removed the deficit in the hippocampally dependent place recognition memory. Voluntary running restored presynaptic density in the dentate gyrus and CA3 hippocampal subregions in aged rats to levels beyond those observed in younger animals, in which exercise had no functional or synaptic effects. By contrast, hippocampal neurogenesis, a possible memory-related mechanism, increased in both young and aged rats after physical exercise but was not linked with performance in the place recognition task. We used graph-based network analysis based on synaptic covariance patterns to characterize efficient intrahippocampal connectivity. This analysis revealed that voluntary running completely reverses the profound degradation of hippocampal network efficiency that accompanies sedentary aging. Furthermore, at an individual animal level, both overall hippocampal presynaptic density and subregional connectivity independently contribute to prediction of successful place recognition memory performance. Our findings emphasize the unique synaptic effects of exercise on the aged brain and their specific relevance to a hippocampally based memory system for place recognition. Copyright © 2013 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Do antioxidant supplements interfere with skeletal muscle adaptation to exercise training?

PubMed Central

Ristow, Michael

2016-01-01

Abstract A popular belief is that reactive oxygen species (ROS) and reactive nitrogen species (RNS) produced during exercise by the mitochondria and other subcellular compartments ubiquitously cause skeletal muscle damage, fatigue and impair recovery. However, the importance of ROS and RNS as signals in the cellular adaptation process to stress is now evident. In an effort to combat the perceived deleterious effects of ROS and RNS it has become common practice for active individuals to ingest supplements with antioxidant properties, but interfering with ROS/RNS signalling in skeletal muscle during acute exercise may blunt favourable adaptation. There is building evidence that antioxidant supplementation can attenuate endurance training‐induced and ROS/RNS‐mediated enhancements in antioxidant capacity, mitochondrial biogenesis, cellular defence mechanisms and insulin sensitivity. However, this is not a universal finding, potentially indicating that there is redundancy in the mechanisms controlling skeletal muscle adaptation to exercise, meaning that in some circumstances the negative impact of antioxidants on acute exercise response can be overcome by training. Antioxidant supplementation has been more consistently reported to have deleterious effects on the response to overload stress and high‐intensity training, suggesting that remodelling of skeletal muscle following resistance and high‐intensity exercise is more dependent on ROS/RNS signalling. Importantly there is no convincing evidence to suggest that antioxidant supplementation enhances exercise‐training adaptions. Overall, ROS/RNS are likely to exhibit a non‐linear (hormetic) pattern on exercise adaptations, where physiological doses are beneficial and high exposure (which would seldom be achieved during normal exercise training) may be detrimental. PMID:26638792

SMA statement the benefits and risks of exercise during pregnancy. Sport Medicine Australia.

PubMed

2002-03-01

There are numerous benefits to pregnant women of remaining active during pregnancy. These include improved weight control and maintenance of fitness. There may also be benefits in terms of reduced risk of development of gestational diabetes meilitus and improved psychological functioning. Moderate intensity aerobic exercise has been shown to be safe in pregnancy, with a number of studies now indicating that for trained athletes it may be possible to exercise at a higher level than is currently recommended by the American College of Obstetricians and Gynecologists. Studies of resistance training, incorporating moderate weights and avoiding maximal isometnc contractions, have shown no adverse outcomes. There may be benefits of increased strength and flexibility. The risk of neural tube defects due to exercise-induced hyperthermia that is suggested by animal studies is less likely in women, because of more effective mechanisms of heat dissipation in humans. There is accumulating evidence to suggest that participation in moderate intensity exercise throughout pregnancy may enhance birth weight, while more severe or frequent exercise, maintained for longer into the pregnancy: may result in lighter babies. There have been no reports of foetal injury or death in relation to trauma or contact during sporting activities. Despite this, a risk of severe blunt trauma is present in some sporting situations as pregnancy progresses. Exercise and lactation are compatible in the post-partum period, providing adequate calories are consumed. Considerations of pelvic floor function and type of delivery are relevant in planning a return to certain types of exercise at this time.

Muscle glycogen depletion and subsequent replenishment affect anaerobic capacity of horses.

PubMed

Lacombe, V A; Hinchcliff, K W; Geor, R J; Baskin, C R

2001-10-01

The purpose of this study was to determine the effect of muscle glycogen depletion and subsequent replenishment on anaerobic capacity of horses. In a blinded crossover study, seven fit horses performed glycogen-depleting exercise on two occasions. Horses were infused after glycogen-depleting exercise with either 6 g/kg body wt of glucose as a 13.5% solution in 0.9% NaCl (Glu) or with 0.9% NaCl (Sal) of equivalent volume. Subsequently, horses performed a high-speed exercise test (120% of maximal rate of oxygen consumption) to estimate maximum accumulated oxygen deficit. Replenishment of muscle glycogen was greater (P < 0.05) in Glu [from 24.7 +/- 7.2 (SE) to 116.5 +/- 7 mmol/kg wet wt before and after infusion, respectively] than in Sal (from 23.4 +/- 7.2 to 47.8 +/- 5.7 mmol/kg wet wt before and after infusion, respectively). Run time to fatigue during the high-speed exercise test (97.3 +/- 8.2 and 70.8 +/- 8.3 s, P < 0.05), maximal accumulated oxygen deficit (105.7 +/- 9.3 and 82.4 +/- 10.3 ml O(2) equivalent/kg, P < 0.05), and blood lactate concentration at the end of the high-speed exercise test (11.1 +/- 1.4 and 9.2 +/- 3.7 mmol/l, P < 0.05) were greater for Glu than for Sal, respectively. We concluded that decreased availability of skeletal muscle glycogen stores diminishes anaerobic power generation and capacity for high-intensity exercise in horses.

The BIG Score and Prediction of Mortality in Pediatric Blunt Trauma.

PubMed

Davis, Adrienne L; Wales, Paul W; Malik, Tahira; Stephens, Derek; Razik, Fathima; Schuh, Suzanne

2015-09-01

To examine the association between in-hospital mortality and the BIG (composed of the base deficit [B], International normalized ratio [I], Glasgow Coma Scale [G]) score measured on arrival to the emergency department in pediatric blunt trauma patients, adjusted for pre-hospital intubation, volume administration, and presence of hypotension and head injury. We also examined the association between the BIG score and mortality in patients requiring admission to the intensive care unit (ICU). A retrospective 2001-2012 trauma database review of patients with blunt trauma ≤ 17 years old with an Injury Severity score ≥ 12. Charts were reviewed for in-hospital mortality, components of the BIG score upon arrival to the emergency department, prehospital intubation, crystalloids ≥ 20 mL/kg, presence of hypotension, head injury, and disposition. 50/621 (8%) of the study patients died. Independent mortality predictors were the BIG score (OR 11, 95% CI 6-25), prior fluid bolus (OR 3, 95% CI 1.3-9), and prior intubation (OR 8, 95% CI 2-40). The area under the receiver operating characteristic curve was 0.95 (CI 0.93-0.98), with the optimal BIG cutoff of 16. With BIG <16, death rate was 3/496 (0.006, 95% CI 0.001-0.007) vs 47/125 (0.38, 95% CI 0.15-0.7) with BIG ≥ 16, (P < .0001). In patients requiring admission to the ICU, the BIG score remained predictive of mortality (OR 14.3, 95% CI 7.3-32, P < .0001). The BIG score accurately predicts mortality in a population of North American pediatric patients with blunt trauma independent of pre-hospital interventions, presence of head injury, and hypotension, and identifies children with a high probability of survival (BIG <16). The BIG score is also associated with mortality in pediatric patients with trauma requiring admission to the ICU. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of macro- and micronutrients on exercise-induced hepcidin response in highly trained endurance athletes.

PubMed

Dahlquist, Dylan T; Stellingwerff, Trent; Dieter, Brad P; McKenzie, Donald C; Koehle, Michael S

2017-10-01

Iron deficiency has ergolytic effects on athletic performance. Exercise-induced inflammation impedes iron absorption in the digestive tract by upregulating the expression of the iron regulatory protein, hepcidin. Limited research indicates the potential of specific macro- and micronutrients on blunting exercise-induced hepcidin. Therefore, we investigated the effects of postexercise supplementation with protein and carbohydrate (CHO) and vitamins D 3 and K 2 on the postexercise hepcidin response. Ten highly trained male cyclists (age: 26.9 ± 6.4 years; maximal oxygen uptake: 67.4 ± 4.4 mL·kg -1 ·min -1 completed 4 cycling sessions in a randomized, placebo-controlled, single-blinded, triple-crossover study. Experimental days consisted of an 8-min warm-up at 50% power output at maximal oxygen uptake, followed by 8 × 3-min intervals at 85% power output at maximal oxygen uptake with 1.5 min at 60% power output at maximal oxygen uptake between each interval. Blood samples were collected pre- and postexercise, and at 3 h postexercise. Three different drinks consisting of CHO (75 g) and protein (25 g) with (VPRO) or without (PRO) vitamins D 3 (5000 IU) and K 2 (1000 μg), or a zero-calorie control drink (PLA) were consumed immediately after the postexercise blood sample. Results showed that the postexercise drinks had no significant (p ≥ 0.05) effect on any biomarker measured. There was a significant (p < 0.05) increase in hepcidin and interleukin-6 following intense cycling intervals in the participants. Hepcidin increased significantly (p < 0.05) from baseline (nmol·L -1 : 9.94 ± 8.93, 14.18 ± 14.90, 10.44 ± 14.62) to 3 h postexercise (nmol·L -1 : 22.27 ± 13.41, 25.44 ± 11.91, 22.57 ± 15.57) in VPRO, PRO, and PLA, respectively. Contrary to our hypothesis, the drink compositions used did not blunt the postexercise hepcidin response in highly trained athletes.

Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial.

PubMed

Longland, Thomas M; Oikawa, Sara Y; Mitchell, Cameron J; Devries, Michaela C; Phillips, Stuart M

2016-03-01

A dietary protein intake higher than the Recommended Dietary Allowance during an energy deficit helps to preserve lean body mass (LBM), particularly when combined with exercise. The purpose of this study was to conduct a proof-of-principle trial to test whether manipulation of dietary protein intake during a marked energy deficit in addition to intense exercise training would affect changes in body composition. We used a single-blind, randomized, parallel-group prospective trial. During a 4-wk period, we provided hypoenergetic (~40% reduction compared with requirements) diets providing 33 ± 1 kcal/kg LBM to young men who were randomly assigned (n = 20/group) to consume either a lower-protein (1.2 g · kg(-1) · d(-1)) control diet (CON) or a higher-protein (2.4 g · kg(-1) · d(-1)) diet (PRO). All subjects performed resistance exercise training combined with high-intensity interval training for 6 d/wk. A 4-compartment model assessment of body composition was made pre- and postintervention. As a result of the intervention, LBM increased (P < 0.05) in the PRO group (1.2 ± 1.0 kg) and to a greater extent (P < 0.05) compared with the CON group (0.1 ± 1.0 kg). The PRO group had a greater loss of fat mass than did the CON group (PRO: -4.8 ± 1.6 kg; CON: -3.5 ± 1.4kg; P < 0.05). All measures of exercise performance improved similarly in the PRO and CON groups as a result of the intervention with no effect of protein supplementation. Changes in serum cortisol during the intervention were associated with changes in body fat (r = 0.39, P = 0.01) and LBM (r = -0.34, P = 0.03). Our results showed that, during a marked energy deficit, consumption of a diet containing 2.4 g protein · kg(-1) · d(-1) was more effective than consumption of a diet containing 1.2 g protein · kg(-1) · d(-1) in promoting increases in LBM and losses of fat mass when combined with a high volume of resistance and anaerobic exercise. Changes in serum cortisol were associated with changes in body fat and LBM, but did not explain much variance in either measure. This trial was registered at clinicaltrials.gov as NCT01776359. © 2016 American Society for Nutrition.

Functional Reorganization of Motor and Limbic Circuits after Exercise Training in a Rat Model of Bilateral Parkinsonism

PubMed Central

Wang, Zhuo; Myers, Kalisa G.; Guo, Yumei; Ocampo, Marco A.; Pang, Raina D.; Jakowec, Michael W.; Holschneider, Daniel P.

2013-01-01

Exercise training is widely used for neurorehabilitation of Parkinson’s disease (PD). However, little is known about the functional reorganization of the injured brain after long-term aerobic exercise. We examined the effects of 4 weeks of forced running wheel exercise in a rat model of dopaminergic deafferentation (bilateral, dorsal striatal 6-hydroxydopamine lesions). One week after training, cerebral perfusion was mapped during treadmill walking or at rest using [14C]-iodoantipyrine autoradiography. Regional cerebral blood flow-related tissue radioactivity (rCBF) was analyzed in three-dimensionally reconstructed brains by statistical parametric mapping. In non-exercised rats, lesions resulted in persistent motor deficits. Compared to sham-lesioned rats, lesioned rats showed altered functional brain activation during walking, including: 1. hypoactivation of the striatum and motor cortex; 2. hyperactivation of non-lesioned areas in the basal ganglia-thalamocortical circuit; 3. functional recruitment of the red nucleus, superior colliculus and somatosensory cortex; 4. hyperactivation of the ventrolateral thalamus, cerebellar vermis and deep nuclei, suggesting recruitment of the cerebellar-thalamocortical circuit; 5. hyperactivation of limbic areas (amygdala, hippocampus, ventral striatum, septum, raphe, insula). These findings show remarkable similarities to imaging findings reported in PD patients. Exercise progressively improved motor deficits in lesioned rats, while increasing activation in dorsal striatum and rostral secondary motor cortex, attenuating a hyperemia of the zona incerta and eliciting a functional reorganization of regions participating in the cerebellar-thalamocortical circuit. Both lesions and exercise increased activation in mesolimbic areas (amygdala, hippocampus, ventral striatum, laterodorsal tegmental n., ventral pallidum), as well as in related paralimbic regions (septum, raphe, insula). Exercise, but not lesioning, resulted in decreases in rCBF in the medial prefrontal cortex (cingulate, prelimbic, infralimbic). Our results in this PD rat model uniquely highlight the breadth of functional reorganizations in motor and limbic circuits following lesion and long-term, aerobic exercise, and provide a framework for understanding the neural substrates underlying exercise-based neurorehabilitation. PMID:24278239

[Sports and pregnancy].

PubMed

Kagan, Karl Oliver; Kuhn, Ulrich

2004-06-01

MATERNAL ASPECTS: Cardiorespiratory responses to exercise in pregnant women generally don't differ from those in nonpregnant women. Impairment of the cabability of the uteroplacental unit to maintain a sufficient oxygen and substrate supply to the fetus should be avoided by performing exercise in a submaximal range. Increase in body weight, a shift of the center of gravidity, and the ligamentous laxity in pregnancy lead to a certain joint instability and consecutively to an increased risk of injury. Therefore contact sports and sports with a high potential of injury are not suitable in pregnancy. Furthermore the beneficial effects of exercise on glucose metabolism especially in pregnant women with an impaired glusose tolerance, psychological well-being, delivery, and lactation are discussed. Exercise results in an elevation of the fetal heart rate. So far no pathological heart rate alterations could be observed. There are controversial findings concerning the influence of exercise on birth weight. Actually no retardation below the 10th percentile could be demonstrated. To prevent pregnancy complications like preterm labour or placental abruption exercises with a risk of blunt abdominal trauma are not recommended in the 2nd and 3rd trimester. Additionally the effects of exercise on embryogenesis and the possible implications of hyperthermia are presented. In general, pregnant women should practise exercise in a moderate, i. e. submaximal aerobic range. Preexisting cardiopulmonary diseases and pregnancy pathologies have to be considered as contraindications. Thus gestational age adapted exercise represents a safe and effective support for mother and fetus. Recommendations concerning exercise in pregnancy underwent significant changes during the past three decades. Today there is a lot of evidence for the beneficial effects of moderate exercise in pregnancy even in formerly inactive women. This review first presents aspects of maternal and fetal physiology with special respect to exercise in pregnancy. Subsequently, risks and contraindications as well as the suitability of different kinds of exercise for pregnant woman are discussed.

Vitamin D Deficiency and a Blunted Parathyroid Hormone Response in Children with Attention-Deficit/Hyperactivity Disorder.

PubMed

Avcil, Sibelnur; Uysal, Pinar; Yilmaz, Mustafa; Erge, Duygu; Demirkaya, Sevcan K; Eren, Esra

2017-03-01

Attention-deficit/hyperactivity disorder (ADHD) is the most frequently diagnosed neuropsychiatric disorder of childhood. The etiopathogenesis of ADHD has not been fully defined. Recent evidence has suggested a pathophysiological role of vitamin D deficiency in ADHD. In this study, we evaluated the serum levels of 25-hydroxy vitamin D (25(OH)D), parathyroid hormone (PTH), calcium (Ca), phosphate (P), and alkaline phosphatase (ALP) in children with ADHD. The study group consisted of 105 children diagnosed with ADHD according to DSM-IV-TR criteria. A control group, matched for age and gender, was composed of 95 healthy children. Venous blood samples were collected, and 25(OH)D, PTH, Ca, P, and ALP levels were measured. The mean serum 25(OH)D, Ca, and P levels of the children with ADHD were significantly lower than those of the healthy controls. There were no significant differences between the groups regarding PTH and ALP. Serum PTH levels were found to be normal, but vitamin D deficiency, hypocalcemia, and hypophosphatemia were observed in children with ADHD. There was no correlation between serum PTH and Ca levels in children with ADHD, whereas, there was a negative correlation between serum PTH and Ca levels in healthy controls. There was no correlation between serum 25(OH)D and PTH levels in children with ADHD, whereas, there was a negative correlation between serum 25(OH)D and PTH levels in healthy controls. There were no significant differences in all parameters' levels among the subtypes of ADHD. The findings suggest that ADHD is associated with vitamin D deficiency, blunted PTH response, and impaired Ca homeostasis in children.

Familial Risk for Insomnia Is Associated With Abnormal Cortisol Response to Stress.

PubMed

Drake, Christopher L; Cheng, Philip; Almeida, David M; Roth, Thomas

2017-10-01

Abnormalities in the stress system have been implicated in insomnia. However, studies examining physiological stress regulation in insomnia have not consistently detected differences in the hypothalamic-pituitary-adrenal (HPA)-axis response to stress. One explanation may be that deficits in the stress system are associated specifically with a biological vulnerability to insomnia rather than the phenotypic expression of insomnia. To examine stress response as a function of vulnerability to insomnia, this study tested response to the Trier Social Stress Test in a sample of healthy sleepers with varying familial risks for insomnia. Thirty-five healthy individuals with and without familial risk for insomnia were recruited to complete a laboratory stressor. Participants with one or both biological parents with insomnia were categorized as positive for familial risk, whereas those without biological parents with insomnia were categorized as negative for familial risk. Participants completed the Trier Social Stress Test in the laboratory, and psychological and physiological (autonomic and HPA-axis) responses were compared. Despite self-reported increases in anxiety, those positive for familial risk exhibited a blunted cortisol response relative to those without familial risk for insomnia. Individuals with blunted cortisol also reported heightened reactivity to personal life stressors, including increased sleep disturbances, elevated cognitive intrusions, and more behavioral avoidance. Findings from this study provide initial evidence that abnormal stress regulation may be a biological predisposing factor conferred via familial risk for insomnia. This deficit may also predict negative consequences over time, including insomnia and the associated psychiatric comorbidities. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Motor deficits, impaired response inhibition, and blunted response to methylphenidate following neonatal exposure to decabromodiphenyl ether.

PubMed

Markowski, Vincent P; Miller-Rhodes, Patrick; Cheung, Randy; Goeke, Calla; Pecoraro, Vincent; Cohen, Gideon; Small, Deena J

2017-09-01

Decabromodiphenyl ether (decaBDE) is an applied brominated flame retardant that is widely-used in electronic equipment. After decades of use, decaBDE and other members of its polybrominated diphenyl ether class have become globally-distributed environmental contaminants that can be measured in the atmosphere, water bodies, wildlife, food staples and human breastmilk. Although it has been banned in Europe and voluntarily withdrawn from the U.S. market, it is still used in Asian countries. Evidence from epidemiological and animal studies indicate that decaBDE exposure targets brain development and produces behavioral impairments. The current study examined an array of motor and learning behaviors in a C57BL6/J mouse model to determine the breadth of the developmental neurotoxicity produced by decaBDE. Mouse pups were given a single daily oral dose of 0 or 20mg/kg decaBDE from postnatal day 1 to 21 and were tested in adulthood. Exposed male mice had impaired forelimb grip strength, altered motor output in a circadian wheel-running procedure, increased response errors during an operant differential reinforcement of low rates (DRL) procedure and a blunted response to an acute methylphenidate challenge administered before DRL testing. With the exception of altered wheel-running output, exposed females were not affected. Neither sex had altered somatic growth, motor coordination impairments on the Rotarod, gross learning deficits during operant lever-press acquisition, or impaired food motivation. The overall pattern of effects suggests that males are more sensitive to developmental decaBDE exposure, especially when performing behaviors that require effortful motor output or when learning tasks that require sufficient response inhibition for their successful completion. Copyright © 2017 Elsevier Inc. All rights reserved.

SMG-1 kinase attenuates mitochondrial ROS production but not cell respiration deficits during hyperoxia.

PubMed

Resseguie, Emily A; Brookes, Paul S; O'Reilly, Michael A

Supplemental oxygen (hyperoxia) used to treat individuals in respiratory distress causes cell injury by enhancing the production of toxic reactive oxygen species (ROS) and inhibiting mitochondrial respiration. The suppressor of morphogenesis of genitalia (SMG-1) kinase is activated during hyperoxia and promotes cell survival by phosphorylating the tumor suppressor p53 on serine 15. Here, we investigate whether SMG-1 and p53 blunt this vicious cycle of progressive ROS production and decline in mitochondrial respiration seen during hyperoxia. Human lung adenocarcinoma A549 and H1299 or colon carcinoma HCT116 cells were depleted of SMG-1, UPF-1, or p53 using RNA interference, and then exposed to room air (21% oxygen) or hyperoxia (95% oxygen). Immunoblotting was used to evaluate protein expression; a Seahorse Bioanalyzer was used to assess cellular respiration; and flow cytometry was used to evaluate fluorescence intensity of cells stained with mitochondrial or redox sensitive dyes. Hyperoxia increased mitochondrial and cytoplasmic ROS and suppressed mitochondrial respiration without changing mitochondrial mass or membrane potential. Depletion of SMG-1 or its cofactor, UPF1, significantly enhanced hyperoxia-induced mitochondrial but not cytosolic ROS abundance. They did not affect mitochondrial mass, membrane potential, or hyperoxia-induced deficits in mitochondrial respiration. Genetic depletion of p53 in A549 cells and ablation of the p53 gene in H1299 or HCT116 cells revealed that SMG-1 influences mitochondrial ROS through activation of p53. Our findings show that hyperoxia does not promote a vicious cycle of progressive mitochondrial ROS and dysfunction because SMG-1-p53 signaling attenuates production of mitochondrial ROS without preserving respiration. This suggests antioxidant therapies that blunt ROS production during hyperoxia may not suffice to restore cellular respiration.

Acute dietary nitrate supplementation enhances compensatory vasodilation during hypoxic exercise in older adults.

PubMed

Casey, Darren P; Treichler, David P; Ganger, Charles T; Schneider, Aaron C; Ueda, Kenichi

2015-01-15

We have previously demonstrated that aging reduces the compensatory vasodilator response during hypoxic exercise due to blunted nitric oxide (NO) signaling. Recent evidence suggests that NO bioavailability can be augmented by dietary nitrate through the nitrate-nitrite pathway. Thus we tested the hypothesis that acute dietary nitrate supplementation increases the compensatory vasodilator response to hypoxic exercise, particularly in older adults. Thirteen young (25 ± 1 yr) and 12 older (64 ± 2 yr) adults performed rhythmic forearm exercise at 20% of maximum voluntary contraction during normoxia and hypoxia (∼80% O2 saturation); both before (control) and 3 h after beetroot juice (BR) consumption. Forearm vascular conductance (FVC; ml·min(-1)·100 mmHg(-1)) was calculated from forearm blood flow (ml/min) and blood pressure (mmHg). Compensatory vasodilation was defined as the relative increase in FVC due to hypoxic exercise (i.e., % increase compared with respective normoxic exercise trial). Plasma nitrite was determined from venous blood samples obtained before the control trials and each of the exercise trials (normoxia and hypoxia) after BR. Consumption of BR increased plasma nitrite in both young and older adults (P < 0.001). During the control condition, the compensatory vasodilator response to hypoxic exercise was attenuated in older compared with young adults (3.8 ± 1.7% vs. 14.2 ± 1.2%, P < 0.001). Following BR consumption, compensatory vasodilation did not change in young (13.7 ± 3.3%, P = 0.81) adults but was substantially augmented in older adults (11.4 ± 2.1%, P < 0.01). Our data suggest that acute dietary nitrate supplementation increases the compensatory vasodilator response to hypoxic exercise in older but not young adults. Copyright © 2015 the American Physiological Society.

Immediate effects of a single exercise bout on protein O-GlcNAcylation and chromatin regulation of cardiac hypertrophy

PubMed Central

Medford, Heidi M.; Porter, Karen

2013-01-01

Cardiac hypertrophy induced by pathological stimuli is regulated by a complex formed by the repressor element 1-silencing transcription factor (REST) and its corepressor mSin3A. We previously reported that hypertrophic signaling is blunted by O-linked attachment of β-N-acetylglucosamine (O-GlcNAc) to proteins. Regular exercise induces a physiological hypertrophic phenotype in the heart that is associated with decreased O-GlcNAc levels, but a link between O-GlcNAc, the REST complex, and initiation of exercise-induced cardiac hypertrophy is not known. Therefore, mice underwent a single 15- or 30-min bout of moderate- to high-intensity treadmill running, and hearts were harvested immediately and compared with sedentary controls. Cytosolic O-GlcNAc was lower (P < 0.05) following 15 min exercise with no differences in nuclear levels (P > 0.05). There were no differences in cytosolic or nuclear O-GlcNAc levels in hearts after 30 min exercise (P > 0.05). Cellular compartment levels of O-GlcNAc transferase (OGT, the enzyme that removes the O-GlcNAc moiety from proteins), REST, mSin3A, and histone deacetylases (HDACs) 1, 2, 3, 4, and 5 were not changed with exercise. Immunoprecipitation revealed O-GlcNAcylation of OGT and HDACs 1, 2, 4, and 5 that was not changed with acute exercise; however, exercised hearts did exhibit lower interactions between OGT and REST (P < 0.05) but not between OGT and mSin3A. These data suggest that hypertrophic signaling in the heart may be initiated by as little as 15 min of exercise via intracellular changes in protein O-GlcNAcylation distribution and reduced interactions between OGT and the REST chromatin repressor. PMID:23624624

Behavioral and Neural Sustained Attention Deficits in Disruptive Mood Dysregulation Disorder and Attention-Deficit/Hyperactivity Disorder.

PubMed

Pagliaccio, David; Wiggins, Jillian Lee; Adleman, Nancy E; Curhan, Alexa; Zhang, Susan; Towbin, Kenneth E; Brotman, Melissa A; Pine, Daniel S; Leibenluft, Ellen

2017-05-01

Disruptive mood dysregulation disorder (DMDD), characterized by severe irritability, and attention-deficit/hyperactivity disorder (ADHD) are highly comorbid. This is the first study to characterize neural and behavioral similarities and differences in attentional functioning across these disorders. Twenty-seven healthy volunteers, 31 patients with DMDD, and 25 patients with ADHD (8 to 18 years old) completed a functional magnetic resonance imaging attention task. Group differences in intra-subject variability in reaction time (RT) were examined. The present functional magnetic resonance imaging analytic approach precisely quantified trial-wise associations between RT and brain activity. Group differences manifested in the relation between RT and brain activity (all regions: p < .01, F > 2.54, partial eta-squared [η p 2 ] > 0.06). Patients with DMDD showed specific alterations in the right paracentral lobule, superior parietal lobule, fusiform gyrus, and cerebellar culmen. In contrast, patients with DMDD and those with ADHD exhibited blunted compensatory increases in activity on long RT trials. In addition, youth with DMDD exhibited increased activity in the postcentral gyrus, medial frontal gyrus, and cerebellar tonsil and declive (all regions: p < .05, F > 2.46, η p 2 > 0.06). Groups in the imaging sample did not differ significantly in intra-subject variability in RT (F 2,79  = 2.664, p = .076, η p 2  = 0.063), although intra-subject variability in RT was significantly increased in youth with DMDD and ADHD when including those not meeting strict motion and accuracy criteria for imaging analysis (F 2,96  = 4.283, p = .017, η p 2  = 0.083). Patients with DMDD exhibited specific alterations in the relation between pre-stimulus brain activity and RT. Patients with DMDD and those with ADHD exhibited similar blunting of compensatory neural activity in frontal, parietal, and other regions. In addition, patients with DMDD showed increased RT variability compared with healthy youth. This work is the first to identify common and unique behavioral and neural signatures of DMDD and ADHD. Published by Elsevier Inc.

Impact of aerobic exercise on cognitive impairment and oxidative stress markers in methamphetamine-dependent patients.

PubMed

Zhang, Kai; Zhang, Qiaoyang; Jiang, Haifeng; Du, Jiang; Zhou, Chenglin; Yu, Shunying; Hashimoto, Kenji; Zhao, Min

2018-03-17

This study aimed to investigate whether 12-week moderate-intensity aerobic exercise has beneficial effects on oxidative stress markers in blood and on cognitive functions in patients who have methamphetamine dependence. Serum levels of oxidative stress markers, including total anti-oxidation capability, super oxide dismutase (SOD), catalase (CAT), and methane dicarboxylic aldehyde (MDA), were measured at baseline (all participants) and the 12-week follow-up (methamphetamine-dependent patients). Serum levels of CAT and MDA in methamphetamine-dependent patients (n = 68) were higher than those in healthy controls (n = 35) at baseline. Furthermore, the international shopping list (ISL) task scores of methamphetamine-dependent patients were significantly lower than those of the controls, indicating verbal memory deficits in methamphetamine-dependent patients. Although there were no significant interactions for all cognitive function scores, aerobic exercise improved the processing speed in methamphetamine-dependent patients. Of interest, aerobic exercise significantly attenuated a spontaneous increase in serum MDA levels in methamphetamine-dependent patients after 12-weeks of abstinence. In conclusion, this study showed that methamphetamine-dependent patients with verbal learning and memory deficits have higher serum levels of MDA, and that a 12-week aerobic exercise program may have beneficial effects on the processing speed as well as blood lipid peroxidation in methamphetamine-dependent patients. Copyright © 2018. Published by Elsevier B.V.

Voluntary Exercise Impairs Initial Delayed Spatial Alternation Performance in Estradiol Treated Ovariectomized Middle-Aged Rats

PubMed Central

Neese, Steven L.; Korol, Donna L.; Schantz, Susan L.

2013-01-01

Estrogens differentially modulate behavior in the adult female rodent. Voluntary exercise can also impact behavior, often reversing age associated decrements in memory processes. Our research group has published a series of papers reporting a deficit in the acquisition of an operant working memory task, delayed spatial alternation (DSA), following 17β-estradiol treatment to middle-aged ovariectomized (OVX) rats. The current study examined if voluntary exercise could attenuate the 17β-estradiol induced deficits on DSA performance. OVX 12-month old Long- Evans rats were implanted with a Silastic capsule containing 17β-estradiol (10% in cholesterol: low physiological range) or with a blank capsule. A subset of the 17β-estradiol and OVX untreated rats were given free access to a running wheel in their home cage. All rats were tested for 40 sessions on the DSA task. Surprisingly, we found running wheel access to impair initial acquisition of the DSA task in 17β-estradiol treated rats, an effect not seen in OVX untreated rats given running wheel access. This deficit was driven by an increase in perseverative responding on a lever no longer associated with reinforcement. We also report for the first time a 17β-estradiol induced impairment on the DSA task following a long intertrial delay (18-sec), an effect revealed following more extended testing than in our previous studies (15 additional sessions). Overall, running wheel access increased initial error rate on the DSA task in 17β-estradiol treated middle-aged OVX rats, and failed to prevent the 17β-estradiol induced deficits in performance of the operant DSA task in later testing sessions. PMID:24013039

The Effect of Karate Techniques Training on Communication Deficit of Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Bahrami, Fatimah; Movahedi, Ahmadreza; Marandi, Sayed Mohammad; Sorensen, Carl

2016-01-01

This investigation examined the long term effect of Karate techniques training on communication of children with autism spectrum disorders (ASD). Thirty school aged children with ASD were randomly assigned to an exercise (n = 15) or a control group (n = 15). Participants in the exercise group were engaged in 14 weeks of Karate techniques training.…

Acute achilles tendon repair: strength outcomes after an acute bout of exercise in recreational athletes.

PubMed

Porter, David A; Barnes, Adam F; Rund, Angela M; Kaz, Ari J; Tyndall, James A; Millis, Andrew A

2014-02-01

This is the first study to evaluate the effect of an acute bout of exercise on strength evaluation after Achilles tendon (AT) rupture and repair. Forty patients sustained an acute AT injury and met inclusion criteria for this study. At a minimum of 12 months after operative repair, patients were measured for (1) calf circumference, (2) bilateral isokinetic strength on a Cybex dynamometer before and after 30 minutes of walking at 70% maximal exertion, and (3) subjective evaluation by AAOS lower limb core and foot and ankle modules. Follow-up occurred at a mean of 32.4 ± 20.7 (range, 12-80) months after surgery, and patients were on average 44.4 ± 8.6 (range, 20-62) years old. One-tailed Student's paired t tests analyzed significance for strength and fatigue between the involved and uninvolved ankle (P < .05). The calf circumference of the involved ankle was significantly smaller than the uninvolved ankle by 1.9 cm, or 4.7%. Plantarflexion deficits of the involved ankle ranged from 12% to 18% for peak torque (P < .0001) and from 17% to 25% for work per repetition (P < .0001), but both ankles fatigued at equal proportions as measured after exercise. Dorsiflexion strength of the involved ankle increased 6% to 11% for peak torque (P = .070) and 1% to 25% for peak work (P = .386). Reported AAOS lower limb core and foot and ankle scores averaged 99.8 and 96.0, respectively. After an AT rupture with repair, patients had less plantarflexion strength, and equal dorsiflexion strength in the operative leg compared to the uninvolved, normal leg. However, subjective results indicated near normal pain and function despite mild plantarflexion strength deficits. Dorsiflexion strength was normal after repair and remained normal even after an acute bout of exercise. Plantarflexion strength ratios postexercise remained similar to pre-exercise after acute exercise bouts. Athletes reported a "flat tire" feeling while running, which suggests a probable gait adjustment as cause for long-term plantarflexion strength deficits. Level III, cohort study.

Bone Mineral Density Changes after Physical Training and Calcium Intake in Students with Attention Deficit and Hyper Activity Disorders

ERIC Educational Resources Information Center

Arab ameri, Elahe; Dehkhoda, Mohammad Reza; Hemayattalab, Rasool

2012-01-01

In this study we investigate the effects of weight bearing exercise and calcium intake on bone mineral density (BMD) of students with attention deficit and hyper activity (ADHD) disorder. For this reason 54 male students with ADHD (age 8-12 years old) were assigned to four groups with no differences in age, BMD, calcium intake, and physical…

Beneficial effects of exercise training in heart failure are lost in male diabetic rats.

PubMed

Boudia, Dalila; Domergue, Valérie; Mateo, Philippe; Fazal, Loubina; Prud'homme, Mathilde; Prigent, Héloïse; Delcayre, Claude; Cohen-Solal, Alain; Garnier, Anne; Ventura-Clapier, Renée; Samuel, Jane-Lise

2017-12-01

Exercise training has been demonstrated to have beneficial effects in patients with heart failure (HF) or diabetes. However, it is unknown whether diabetic patients with HF will benefit from exercise training. Male Wistar rats were fed either a standard (Sham, n = 53) or high-fat, high-sucrose diet ( n = 66) for 6 mo. After 2 mo of diet, the rats were already diabetic. Rats were then randomly subjected to either myocardial infarction by coronary artery ligation (MI) or sham operation. Two months later, heart failure was documented by echocardiography and animals were randomly subjected to exercise training with treadmill for an additional 8 wk or remained sedentary. At the end, rats were euthanized and tissues were assayed by RT-PCR, immunoblotting, spectrophotometry, and immunohistology. MI induced a similar decrease in ejection fraction in diabetic and lean animals but a higher premature mortality in the diabetic group. Exercise for 8 wk resulted in a higher working power developed by MI animals with diabetes and improved glycaemia but not ejection fraction or pathological phenotype. In contrast, exercise improved the ejection fraction and increased adaptive hypertrophy after MI in the lean group. Trained diabetic rats with MI were nevertheless able to develop cardiomyocyte hypertrophy but without angiogenic responses. Exercise improved stress markers and cardiac energy metabolism in lean but not diabetic-MI rats. Hence, following HF, the benefits of exercise training on cardiac function are blunted in diabetic animals. In conclusion, exercise training only improved the myocardial profile of infarcted lean rats fed the standard diet. NEW & NOTEWORTHY Exercise training is beneficial in patients with heart failure (HF) or diabetes. However, less is known of the possible benefit of exercise training for HF patients with diabetes. Using a rat model where both diabetes and MI had been induced, we showed that 2 mo after MI, 8 wk of exercise training failed to improve cardiac function and metabolism in diabetic animals in contrast to lean animals.

[Program about therapeutics education. Roll-playing exercise].

PubMed

Salinas, Carmen Martín

2011-05-01

This article presents a program about therapeutics education aimed at a patient with diabetes mellitus type 2, associated with hypertension, dyslipidemia and obesity The association of these factors constitutes the so-called metabolic syndrome, which entails an increase in the risk of heart disease. This roll-playing exercise is used in the subject Nutrition and Dietetics, given in the second academic year of the Nursing University School La Paz of Madrid, Spain, in order to strengthen self-directed learning. Solving the case comprises evaluation of the patient's self-care agency identification of the self-care deficit and those nurse interventions which are considered necessary to treat that deficit. Both three Diagnosis Taxonomy by the North American Nursing Diagnosis Association, Nursing Intervention Classification and Nursing Result Classification were used to solve it.

Preliminary evidence of altered biomechanics in adolescents with juvenile fibromyalgia.

PubMed

Sil, Soumitri; Thomas, Staci; DiCesare, Christopher; Strotman, Daniel; Ting, Tracy V; Myer, Gregory; Kashikar-Zuck, Susmita

2015-01-01

Juvenile fibromyalgia (FM) is characterized by chronic musculoskeletal pain and marked reduction in physical activity. Despite recommendations for exercise to manage juvenile FM pain, exercise adherence is poor. Because of pain and activity avoidance, adolescents with juvenile FM are at risk for altered joint mechanics that may make them susceptible to increased pain and reduced tolerance for exercise. The primary aim of this study was to assess functional deficits in patients with juvenile FM compared to healthy controls using objective biomechanical assessment. Female adolescent patients with juvenile FM (n = 17) and healthy controls (n = 14) completed biomechanical assessments, including gait analysis and tests of lower extremity strength (isokinetic knee extension/flexion and hip abduction) and functional performance (drop vertical jump test) along with self-reported measures of disability (Functional Disability Inventory), pain intensity, depressive symptoms (Children's Depression Inventory), and fear of movement (Tampa Scale of Kinesiophobia). Patients with juvenile FM demonstrated mild deficiencies in walking gait and functional performance (P < 0.05 for both) and significantly lower left knee extension and flexion strength (18-22% deficit) and bilateral hip abduction strength (34-38%) compared with healthy controls (P < 0.008 for all). Patients with juvenile FM reported significantly higher functional disability, pain intensity, depressive symptoms, and fear of movement relative to controls (P < 0.01 for all). This study showed that adolescents with juvenile FM exhibited objective alterations in biomechanics and self-reported fear of movement that may have reinforced their activity avoidance. Interventions for juvenile FM should include a focus on correcting functional deficits and instilling greater confidence in adolescents with juvenile FM to engage in exercise to improve functional outcomes. Copyright © 2015 by the American College of Rheumatology.

Aerobic Exercise and Attention Deficit Hyperactivity Disorder: Brain Research

PubMed Central

Choi, Jae Won; Han, Doug Hyun; Kang, Kyung Doo; Jung, Hye Yeon; Renshaw, Perry F.

2017-01-01

Purpose As adjuvant therapy for enhancing the effects of stimulants and thereby minimizing medication doses, we hypothesized that aerobic exercise might be an effective adjunctive therapy for enhancing the effects of methylphenidate on the clinical symptoms, cognitive function, and brain activity of adolescents with attention deficit hyperactivity disorder (ADHD). Methods Thirty-five adolescents with ADHD were randomly assigned to one of two groups in a 1/1 ratio; methylphenidate treatment + 6-wk exercise (sports-ADHD) or methylphenidate treatment + 6-wk education (edu-ADHD). At baseline and after 6 wk of treatment, symptoms of ADHD, cognitive function, and brain activity were evaluated using the Dupaul attention deficit hyperactivity disorder rating scale–Korean version (K-ARS), the Wisconsin Card Sorting Test, and 3-T functional magnetic resonance imaging, respectively. Results The K-ARS total score and perseverative errors in the sports-ADHD group decreased compared with those in the edu-ADHD group. After the 6-wk treatment period, the mean β value of the right frontal lobe in the sports-ADHD group increased compared with that in the edu-ADHD group. The mean β value of the right temporal lobe in the sports-ADHD group decreased. However, the mean β value of the right temporal lobe in the edu-ADHD group did not change. The change in activity within the right prefrontal cortex in all adolescents with ADHD was negatively correlated with the change in K-ARS scores and perseverative errors. Conclusions The current results indicate that aerobic exercise increased the effectiveness of methylphenidate on clinical symptoms, perseverative errors, and brain activity within the right frontal and temporal cortices in response to the Wisconsin card sorting test stimulation. PMID:24824770

Reduced wheel running and blunted effects of voluntary exercise in LPA1-null mice: the importance of assessing the amount of running in transgenic mice studies.

PubMed

Castilla-Ortega, Estela; Rosell-Valle, Cristina; Blanco, Eduardo; Pedraza, Carmen; Chun, Jerold; Rodríguez de Fonseca, Fernando; Estivill-Torrús, Guillermo; Santín, Luis J

2013-11-01

This work was aimed to assess whether voluntary exercise rescued behavioral and hippocampal alterations in mice lacking the lysophosphatidic acid LPA1 receptor (LPA1-null mice), studying the potential relationship between the amount of exercise performed and its effects. Normal and LPA1-null mice underwent 23 days of free wheel running and were tested for open-field behavior and adult hippocampal neurogenesis (cell proliferation, immature neurons, cell survival). Running decreased anxiety-like behavior in both genotypes but increased exploration only in the normal mice. While running affected all neurogenesis-related measures in normal mice (especially in the suprapyramidal blade of the dentate gyrus), only a moderate increase in cell survival was found in the mutants. Importantly, the LPA1-nulls showed notably reduced running. Analysis suggested that defective running in the LPA1-null mice could contribute to explain the scarce benefit of the voluntary exercise treatment. On the other hand, a literature review revealed that voluntary exercise is frequently used to modulate behavior and the hippocampus in transgenic mice, but half of the studies did not assess the quantity of running, overlooking any potential running impairments. This study adds evidence to the relevance of the quantity of exercise performed, emphasizing the importance of its assessment in transgenic mice research. Copyright © 2013 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Detection of cardiovascular autonomic neuropathy using exercise testing in patients with type 2 diabetes mellitus.

PubMed

Banthia, Smriti; Bergner, Daniel W; Chicos, Alexandru B; Ng, Jason; Pelchovitz, Daniel J; Subacius, Haris; Kadish, Alan H; Goldberger, Jeffrey J

2013-01-01

This study investigated autonomic nervous system function in subjects with diabetes during exercise and recovery. Eighteen type 2 diabetics (age 55±2 years) and twenty healthy controls (age 51±1 years) underwent two 16-min bicycle submaximal ECG stress tests followed by 45 min of recovery. During session #2, atropine (0.04 mg/kg) was administered at peak exercise, and the final two minutes of exercise and entire recovery occurred under parasympathetic blockade. Plasma catecholamines were measured throughout. Parasympathetic effect was defined as the difference between a measured parameter at baseline and after parasympathetic blockade. The parasympathetic effect on the RR interval was blunted (P=.004) in diabetic subjects during recovery. Parasympathetic effect on QT-RR slope during early recovery was diminished in the diabetes group (diabetes 0.13±0.02, control 0.21±0.02, P=.03). Subjects with diabetes had a lower heart rate recovery at 1 min (diabetes 18.5±1.9 bpm, control 27.6±1.5 bpm, P<.001). In subjects with well-controlled type 2 diabetes, even with minimal evidence of CAN using current methodology, altered cardiac autonomic balance is present and can be detected through an exercise-based assessment for CAN. The early post-exercise recovery period in diabetes was characterized by enhanced sympathoexcitation, diminished parasympathetic reactivation and delay in heart rate recovery. Copyright © 2013 Elsevier Inc. All rights reserved.

A transcriptional signature of "exercise resistance" in skeletal muscle of individuals with type 2 diabetes mellitus.

PubMed

Stephens, Natalie A; Xie, Hui; Johannsen, Neil M; Church, Timothy S; Smith, Steven R; Sparks, Lauren M

2015-09-01

Exercise benefits most, but not all, individuals with type 2 diabetes mellitus (T2DM). The aim of this study was to determine whether a proportion of individuals with T2DM would fail to demonstrate exercise-induced metabolic improvements. We hypothesized that this lack of response would be related to their skeletal muscle transcriptional profile. 42 participants with T2DM from the previously reported HART-D study underwent a 9-month supervised exercise intervention. We performed a principal components analysis to distinguish Responders from Non-Responders (n=9 each) based on: decreases in (1) HbA1c, (2) %fat (3) BMI and (4) increase in skeletal muscle mtDNA. mRNA expression patterns in muscle tissue at baseline were assessed by microarray and qRT-PCR analysis in both groups. Of 186 genes identified by microarray analysis, 70% were up-regulated in Responders and down-regulated in Non-Responders. Several genes involved in substrate metabolism and mitochondrial biogenesis were significantly different (fold-change>1.5, p<0.05) between the groups at baseline, indicating a blunted oxidative capacity at baseline in Non-Responders. These data suggest that a unique baseline expression pattern of genes involved in muscle fuel metabolism may predict an individual's lack of exercise response in metabolic outcomes, thus allowing exercise interventions to be targeted to these individuals and aid in the identification of novel approaches to treat Non-Responders in the future. Copyright © 2015 Elsevier Inc. All rights reserved.

Early environmental predictors of the affective and interpersonal constructs of psychopathy.

PubMed

Daversa, Maria T

2010-02-01

Early childhood maltreatment (i.e., physical, sexual, emotional abuse) and caregiver disruptions are hypothesized to be instrumental in altering the neurobiology of the brain, particularly the amygdala, and contributing to the development of the affective deficits examined in individuals with psychopathy. Exposure to early untoward life events in models of rodent and nonhuman primates changes the neurobiology of the stress response. It is hypothesized that these changes may permanently shape brain regions that mediate stress and emotion and therefore play a role in the etiology of affective disorders in humans. The significance of experience (e.g., the intensity/severity, chronicity/duration, and developmental timing of experiences) and how the accompanying changes in the activity of the hypothalamic-pituitary-adrenocortical system affect alterations in the amygdala are discussed as critical contributors to the etiology of psychopathy. A model is proposed in which early maltreatment experiences contribute to alterations to the amygdala and produce a blunted or dissociative response to stress, a key factor in the affective deficits observed in psychopaths.

Evoked Electrical and Cerebral Vascular Responses Following Sleep Deprivation

PubMed Central

Schei, Jennifer L.; Rector, David M.

2011-01-01

Neuronal activity elicits vascular dilation, delivering additional blood and metabolites to the activated region. With increasing neural activity, vessels stretch and may become less compliant. Most functional imaging studies assume that limits to vascular expansion are not normally reached except under pathological conditions, with the possibility that metabolism could outpace supply. However, we previously demonstrated that evoked hemodynamic responses were larger during quiet sleep when compared to both waking and REM sleep, suggesting that high basal activity during wake may elicit blunted evoked hemodynamic responses due to vascular expansion limits. We hypothesized that extended brain activity through sleep deprivation will further dilate blood vessels, and exacerbate the blunted evoked hemodynamic responses observed during wake, and dampen responses in subsequent sleep. We measured evoked electrical and hemodynamic responses from rats using auditory clicks (0.5 s, 10 Hz, 2–13 s random ISIs) for one hour following 2, 4, or 6 hours of sleep deprivation. Time-of-day matched controls were recorded continuously for 7 hours. Within quiet sleep periods following deprivation, ERP amplitude did not differ; however, the evoked vascular response was smaller with longer sleep deprivation periods. These results suggest that prolonged neural activity periods through sleep deprivation may diminish vascular compliance as indicated by the blunted vascular response. Subsequent sleep may allow vessels to relax, restoring their ability to deliver blood. These results also suggest that severe sleep deprivation or chronic sleep disturbances could push the vasculature to critical limits, leading to metabolic deficit and the potential for tissue trauma. PMID:21854966

Attention-deficit hyperactivity disorder in ancient Greece: The Obtuse Man of Theophrastus.

PubMed

Victor, Marcelo M; S da Silva, Bruna; Kappel, Djenifer B; Bau, Claiton Hd; Grevet, Eugenio H

2018-06-01

We present an ancient Greek description written by the philosopher Theophrastus in his classic book ' Characters' comparable with modern attention-deficit hyperactivity disorder. The arguments are based in one chapter of this book-The Obtuse Man-presenting features of a character closely resembling the modern description of attention-deficit hyperactivity disorder. In a free comparative exercise, we compared Theophrastus descriptions with modern Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) attention-deficit hyperactivity disorder symptoms. The sentences describing The Obtuse Man written by Theophrastus are similar to several symptoms of attention-deficit hyperactivity disorder and he would probably be currently diagnosed with this disorder as an adult. To our knowledge, this is the oldest description compatible with the current conception of attention-deficit hyperactivity disorder in adults in the Western literature. Differently than the moralistic view of ancient Greece regarding those symptoms, the medical attention-deficit hyperactivity disorder conception may be advantageous to patients since it might reduce prejudice and allow individuals to seek treatment.

Augmented sympathetic vasoconstriction in exercising forearms of postmenopausal women is reversed by oestrogen therapy

PubMed Central

Fadel, Paul J; Wang, Zhongyun; Watanabe, Hitoshi; Arbique, Debbie; Vongpatanasin, Wanpen; Thomas, Gail D

2004-01-01

Sympathetic vasoconstriction is normally attenuated in exercising muscles of young men and women. Recent evidence indicates that such modulation, termed functional sympatholysis, may be impaired in older men. Whether a similar impairment occurs in older women, and what role oestrogen deficiency might play in this impairment, are not known. Based on the strong positive correlation between circulating oestrogen levels and functional sympatholysis previously reported in female rats, we hypothesized that sympatholysis would be impaired in oestrogen-deficient postmenopausal women, and that this impairment would be reversed by oestrogen replacement. To test these hypotheses, we measured vasoconstrictor responses in the forearms of pre- and postmenopausal women using near infrared spectroscopy to detect decreases in muscle oxygenation in response to reflex activation of sympathetic nerves evoked by lower body negative pressure (LBNP). In eight premenopausal women, LBNP decreased muscle oxygenation by 20 ± 1% in resting forearm, but only by 3 ± 2% in exercising forearm (P < 0.05). In contrast, in eight postmenopausal women, LBNP decreased muscle oxygenation by 15 ± 3% in resting forearm, and by 12 ± 4% in exercising forearm (P > 0.05). After 1 month of transdermal oestradiol replacement in these women, the normal effect of exercise to blunt sympathetic vasoconstriction was restored (rest, −19 ± 3%; exercise, −2 ± 3%; P < 0.05). These data indicate that functional sympatholysis is impaired in oestrogen-deficient postmenopausal women. The effect of short-term unopposed oestrogen replacement to correct this impairment implicates a role for oestrogen in the sympathetic neural control of muscle haemodynamics during exercise. PMID:15498809

Exercise reveals impairments in left ventricular systolic function in patients with metabolic syndrome

PubMed Central

Fournier, Sara B.; Reger, Brian L.; Donley, David A.; Bonner, Daniel E.; Warden, Bradford E.; Gharib, Wissam; Failinger, Conard F.; Olfert, Melissa D.; Frisbee, Jefferson C.; Olfert, I. Mark; Chantler, Paul D.

2013-01-01

MetS is the manifestation of a cluster of cardiovascular (CV) risk factors and is associated with a three-fold increase risk of CV morbidity and mortality, which is suggested to be mediated, in part, by resting left ventricular (LV) systolic dysfunction. However, to what extent resting LV systolic function is impaired in MetS is controversial, and there are no data indicating whether LV systolic function is impaired during exercise. Accordingly, the objective of this study was to comprehensively examine LV and arterial responses to exercise in MetS individuals without diabetes and/or overt CVD compared to a healthy control population. CV function was characterized using Doppler echocardiography and gas exchange in MetS (n=27) vs. healthy controls (n=20) at rest and during peak exercise. At rest, MetS individuals displayed normal LV systolic function but reduced LV diastolic function vs. healthy controls. During peak exercise, individuals with MetS had impaired contractility; pump performance, and vasodilator reserve capacity vs. controls. A blunted contractile reserve response resulted in diminished arterial-ventricular coupling reserve and limited aerobic capacity in MetS vs. controls. These findings possess clinical importance as they provide insight to the pathophysiological changes in MetS that may predispose this population of individuals to an increased risk of CV morbidity and mortality. PMID:24036595

Acute effects of exercise and calorie restriction on triglyceride metabolism in women

PubMed Central

Bellou, Elena; Siopi, Aikaterina; Galani, Maria; Maraki, Maria; Tsekouras, Yiannis E.; Panagiotakos, Demosthenes B.; Kavouras, Stavros A.; Magkos, Faidon; Sidossis, Labros S.

2013-01-01

The mechanisms by which exercise reduces fasting plasma triglyceride (TG) concentrations in women and the effect of negative energy balance independent of muscular contraction are not known. Purpose The aim of this study was to evaluate the effects of equivalent energy deficits induced by exercise or calorie restriction on basal very low-density lipoprotein (VLDL) TG metabolism in women. Methods Eleven healthy women (age: 23.5±2.7 years, BMI: 21.6±1.4 kg/m2) underwent a stable isotopically labeled tracer infusion study to determine basal VLDL-TG kinetics after performing, in random order, three experimental trials on the previous day: i) a single exercise bout (brisk walking at 60% of peak oxygen consumption for 123±18 min, with a net energy expenditure of 2.06±0.39 MJ (~500 kcal)), ii) dietary energy restriction of 2.10±0.41 MJ, and iii) a control day of isocaloric feeding and rest (zero energy balance). Results Fasting plasma VLDL-TG concentration was ~30% lower after the exercise trial compared to the control trial (P<0.001), whereas no significant change was detected after the calorie restriction trial (P=0.297 vs control). Relative to the control condition, exercise increased the plasma clearance rate of VLDL-TG by 22% (P=0.001) and reduced hepatic VLDL-TG secretion rate by ~17% (P=0.042), whereas hypocaloric diet had no effect on VLDL-TG kinetics (P>0.2). Conclusion (i) Exercise-induced hypotriglyceridemia in women manifests through a different mechanism (increased clearance and decreased secretion of VLDL-TG) than that previously described in men (increased clearance of VLDL-TG only), and (ii) exercise affects TG homeostasis by eliciting changes in VLDL-TG kinetics that cannot be reproduced by an equivalent diet-induced energy deficit, indicating that these changes are independent of the exercise-induced negative energy balance but instead are specific to muscular contraction. PMID:23073216

Acute effects of exercise and calorie restriction on triglyceride metabolism in women.

PubMed

Bellou, Elena; Siopi, Aikaterina; Galani, Maria; Maraki, Maria; Tsekouras, Yiannis E; Panagiotakos, Demosthenes B; Kavouras, Stavros A; Magkos, Faidon; Sidossis, Labros S

2013-03-01

The mechanisms by which exercise reduces fasting plasma triglyceride (TG) concentrations in women and the effect of negative energy balance independent of muscular contraction are not known.The aim of this study was to evaluate the effects of equivalent energy deficits induced by exercise or calorie restriction on basal VLDL-TG metabolism in women. Eleven healthy women (age = 23.5 ± 2.7 yr, body mass index = 21.6 ± 1.4 kg·m-2; mean ± SD) underwent a stable isotopically labeled tracer infusion study to determine basal VLDL-TG kinetics after performing, in random order, three experimental trials on the previous day: (i) a single exercise bout (brisk walking at 60% of peak oxygen consumption for 123 ± 18 min, with a net energy expenditure of 2.06 ± 0.39 MJ, ∼500 kcal), (ii) dietary energy restriction of 2.10 ± 0.41 MJ, and (iii) a control day of isocaloric feeding and rest (zero energy balance). Fasting plasma VLDL-TG concentration was approximately 30% lower after the exercise trial compared with the control trial (P < 0.001), whereas no significant change was detected after the calorie restriction trial (P = 0.297 vs control). Relative to the control condition, exercise increased the plasma clearance rate of VLDL-TG by 22% (P = 0.001) and reduced hepatic VLDL-TG secretion rate by approximately 17% (P = 0.042), whereas hypocaloric diet had no effect on VLDL-TG kinetics (P > 0.2). (i) Exercise-induced hypotriglyceridemia in women manifests through a different mechanism (increased clearance and decreased secretion of VLDL-TG) than that previously described in men (increased clearance of VLDL-TG only), and (ii) exercise affects TG homeostasis by eliciting changes in VLDL-TG kinetics that cannot be reproduced by an equivalent diet-induced energy deficit, indicating that these changes are independent of the exercise-induced negative energy balance but instead are specific to muscular contraction.

Resistance training for activity limitations in older adults with skeletal muscle function deficits: a systematic review.

PubMed

Papa, Evan V; Dong, Xiaoyang; Hassan, Mahdi

2017-01-01

Human aging results in a variety of changes to skeletal muscle. Sarcopenia is the age-associated loss of muscle mass and is one of the main contributors to musculoskeletal impairments in the elderly. Previous research has demonstrated that resistance training can attenuate skeletal muscle function deficits in older adults, however few articles have focused on the effects of resistance training on functional mobility. The purpose of this systematic review was to 1) present the current state of literature regarding the effects of resistance training on functional mobility outcomes for older adults with skeletal muscle function deficits and 2) provide clinicians with practical guidelines that can be used with seniors during resistance training, or to encourage exercise. We set forth evidence that resistance training can attenuate age-related changes in functional mobility, including improvements in gait speed, static and dynamic balance, and fall risk reduction. Older adults should be encouraged to participate in progressive resistance training activities, and should be admonished to move along a continuum of exercise from immobility, toward the recommended daily amounts of activity.

Arm and Intensity-Matched Leg Exercise Induce Similar Inflammatory Responses.

PubMed

Leicht, Christof A; Paulson, Thomas A W; Goosey-Tolfrey, Victoria L; Bishop, Nicolette C

2016-06-01

The amount of active muscle mass can influence the acute inflammatory response to exercise, associated with reduced risk for chronic disease. This may affect those restricted to upper body exercise, for example, due to injury or disability. The purpose of this study was to compare the inflammatory responses for arm exercise and intensity-matched leg exercise. Twelve male individuals performed three 45-min constant load exercise trials after determination of peak oxygen uptake for arm exercise (V˙O2peak A) and cycling (V˙O2peak C): 1) arm cranking exercise at 60% V˙O2peak A, 2) moderate cycling at 60% V˙O2peak C, and 3) easy cycling at 60% V˙O2peak A. Cytokine, adrenaline, and flow cytometric analysis of monocyte subsets were performed before and up to 4 h postexercise. Plasma IL-6 increased from resting concentrations in all trials; however, postexercise concentrations were higher for arm exercise (1.73 ± 1.04 pg·mL) and moderate cycling (1.73 ± 0.95 pg·mL) compared with easy cycling (0.87 ± 0.41 pg·mL; P < 0.04). Similarly, the plasma IL-1ra concentration in the recovery period was higher for arm exercise (325 ± 139 pg·mL) and moderate cycling (316 ± 128 pg·mL) when compared with easy cycling (245 ± 77 pg·mL, P < 0.04). Arm exercise and moderate cycling induced larger increases in monocyte numbers and larger increases of the classical monocyte subset in the recovery period than easy cycling (P < 0.05). The postexercise adrenaline concentration was lowest for easy cycling (P = 0.04). Arm exercise and cycling at the same relative exercise intensity induces a comparable acute inflammatory response; however, cycling at the same absolute oxygen uptake as arm exercise results in a blunted cytokine, monocyte, and adrenaline response. Relative exercise intensity appears to be more important to the acute inflammatory response than modality, which is of major relevance for populations restricted to upper body exercise.

Characteristics of Coupled Nongray Radiating Gas Flows with Ablation Product Effects About Blunt Bodies During Planetary Entries. Ph.D. Thesis - North Carolina State Univ.

NASA Technical Reports Server (NTRS)

Sutton, K.

1973-01-01

A computational method was developed for the fully-coupled solution of nongray, radiating gas flows with ablation product effects about blunt bodies during planetary entries. The treatment of radiation accounts for molecular band, continuum, and atomic line transitions with a detailed frequency dependence of the absorption coefficient. The ablation of the entry body was solved as part of the solution for a steady-state ablation process. The method was applied by results at typical conditions during entry to Venus. The radiative heating rates along the downstream region of the body can exceed the stagnation point value. The radiative heating to the body is attenuated in the boundary layer at the downstream region of the body and at the stagnation point of the body. A study of the radiation, inviscid flow about spherically capped, conical bodies during planetary entries shows that the nondimensional, radiative heating distributions are nonsimilar with entry conditions. Caution should be exercised in attempting to extrapolate results from known distributions to other entry conditions for which solutions have not yet been obtained.

Clinical Effects of Dry Needling Among Asymptomatic Individuals With Hamstring Tightness: A Randomized Controlled Trial.

PubMed

Geist, Kathleen; Bradley, Claire; Hofman, Alan; Koester, Rob; Roche, Fenella; Shields, Annalise; Frierson, Elizabeth; Rossi, Ainsley; Johanson, Marie

2017-11-01

Randomized controlled trial. The aim of this study was to determine the effects of dry needling on hamstring extensibility and functional performance tests among asymptomatic individuals with hamstring muscle tightness. Dry needling has been shown to increase range of motion in the upper quarter and may have similar effects in the lower quarter. 27 subjects with hamstring extensibility deficits were randomly assigned to side of treatment (dominant or nondominant) and group (blunt needling or dry needling). The first session included measurement of hamstring extensibility and performance on 4 unilateral hop tests, instruction in home hamstring stretching exercises and needling distal to the ischial tuberosity and midbellies of the medial and lateral hamstrings. A second session, 3-5 days following the first session, included outcome measures and a second needling intervention, and a third session, 4-6 weeks following the first session, included outcome measures only. A 2 × 3 × 2 ANOVA was used to statistically analyze the data. Hamstring extensibility showed a significant side × time interaction (P < .05). The single hop for distance, timed 6-meter hop, and the crossover hop test had a significant main effect of time (P < .05). The triple hop for distance showed a significant side × time × group interaction (P < .05). It does not appear dry needling results in increased extensibility beyond that of stretching alone in asymptomatic individuals. Our study findings suggest that dry needling may improve certain dimensions of functional performance, although no clear conclusion can be made. Intervention, level 2b.

Divergent Systemic and Local Inflammatory Response to Hind Limb Demand Ischemia in Wild Type And ApoE−/− Mice

PubMed Central

Crawford, Robert S.; Albadawi, Hassan; Robaldo, Alessandro; Peck, Michael A.; Abularrage, Christopher J.; Yoo, Hyung-Jin; LaMuraglia, Glenn M.; Watkins, Michael T.

2013-01-01

Introduction Studies were designed to determine whether the ApoE−/− phenotype modulates the local skeletal muscle and systemic inflammatory (plasma) responses to lower extremity demand ischemia. The ApoE−/− phenotype is an experimental model for atherosclerosis in humans. Methods Aged female ApoE −/− and C57BL6 mice underwent femoral artery ligation, then divided into sedentary and demand ischemia (exercise) groups on day 14. Baseline and post exercise limb perfusion and hind limb function were assessed. On day 14, animals in the demand ischemia group underwent daily treadmill exercise through day 28. Sedentary mice were not exercised. On day 28, plasma and skeletal muscle from ischemic limbs were harvested from sedentary and exercised mice. Muscle was assayed for angiogenic and pro-inflammatory proteins, markers of skeletal muscle regeneration, and evidence of skeletal muscle fiber maturation. Results Hind limb ischemia was similar in ApoE −/− and C57 mice prior to the onset of exercise. Under sedentary conditions, plasma VEGF, IL-6, but not KC or MIP-2 were higher in ApoE (P<0.0001). Following exercise, plasma levels of VEGF, KC and MIP-2, but not IL-6 were lower in ApoE (P<0.004). The cytokines KC and MIP-2 in muscle was greater in exercised ApoE−/− mice as compared to C57BL6 mice (p=0.01). Increased PAR activity, and mature muscle regeneration was associated with demand ischemia in the C57BL6 mice as compared to the ApoE −/− mice (p=0.01). Conclusion Demand limb ischemia in the ApoE−/− phenotype exacerbated the expression of select systemic cytokines in plasma and blunted indices of muscle regeneration. PMID:23528286

Superficial cooling does not decrease core body temperature before, during, or after exercise in an American football uniform.

PubMed

Lopez, Rebecca M; Eberman, Lindsey E; Cleary, Michelle A

2012-12-01

The purpose of this study was to identify the effects of superficial cooling on thermoregulatory responses while exercising in a hot humid environment while wearing an American football uniform. Nine male and female subjects wore a superficial cooling garment while in a cooling (CS) experimental condition or a no cooling (NCS) control condition during an exercise task consisting of warm-up (WU), exercise (EX), and recovery (R). The exercise task simulated an American football conditioning session with subjects wearing a full American football uniform and performing anaerobic and aerobic exercises in a hot humid environment. Subjects were allowed to drink water ad libitum during rest breaks. During the WU, EX, and R periods, core body temperature (T(c)) was measured to assess the effect of the cooling garment. Neither baseline resting before warm-up T(c) nor after warm-up T(c) was significantly different between trials. No significant differences in exercise T(c) between conditions were found. Time to return to baseline T(c) revealed no significant differences between the experimental and control conditions. The authors found that the volume of fluid consumed was 34% less in the experimental condition (711.1 ± 188.0 ml) compared with the control condition (1,077.8 ± 204.8 ml). The findings indicate that the cooling garment was not effective in blunting the rise in T(c) during warm-up, attenuating a rise in T(c) during intermittent exercise, or in increasing a return to baseline T(c) during a resting recovery period in a hot humid environment while wearing an American football uniform.

Psychobiological Responses to Aerobic Exercise in Individuals With Posttraumatic Stress Disorder.

PubMed

Crombie, Kevin M; Brellenthin, Angelique G; Hillard, Cecilia J; Koltyn, Kelli F

2018-02-01

Previous reports have shown improvements in mood and increases in endocannabinoids in healthy adults following a session of aerobic exercise, but it is unclear whether adults with posttraumatic stress disorder (PTSD) experience similar responses. The purpose of this study was to examine psychobiological responses (plasma endocannabinoids [eCBs], mood, and pain) to aerobic exercise in a sample of adults with a diagnosis of PTSD (n = 12) and healthy controls (n = 12). Participants engaged in an aerobic exercise session in which they ran on a treadmill for 30 min at a moderate intensity (70 to 75% maximum heart rate [MHR]). Results indicated improvements in mood states and reductions in pain for both groups following exercise, ds = 0.19 to 1.53. Circulating concentrations of N-arachidonylethanolamine (AEA), 2-arachidonoylglycerol (2-AG), and oleoylethanolamide (OEA) significantly increased (ps = .000 to .050) following the aerobic exercise session for both groups. There were no significant time, group, or interaction effects (ps = .062 to .846) for palmitoylethanolamide (PEA) and 2-oleoylglycerol (2-OG). Although eCBs increased significantly for both groups, within-group effect size calculations indicated the healthy controls experienced a greater magnitude of change for AEA when compared with adults with PTSD, d = 1.21 and d = 0.45, respectively; as well as for 2-AG, d = 0.43 and d = 0.21, respectively. The findings from this study indicated that adults with and without PTSD reported significant mood improvements following 30 min of moderate-intensity aerobic exercise. In addition, the endocannabinoid system was activated in adults with and without PTSD, although effect sizes suggest that adults with PTSD may have a blunted endocannabinoid response to exercise. Copyright © 2018 International Society for Traumatic Stress Studies.

Adolescent social isolation stress unmasks the combined effects of adolescent exercise and adult inflammation on hippocampal neurogenesis and behavior.

PubMed

Hueston, Cara M; Cryan, John F; Nolan, Yvonne M

2017-12-04

Hippocampal neurogenesis and associated cognitive behaviors are regulated by a number of factors including stress, inflammation, and exercise. However, the interplay between these factors remains relatively unexplored, especially across the lifespan. In the current study, the effect of social isolation stress during the adolescent period on neurogenesis and hippocampal-dependent cognitive behaviors was examined. This period of the lifespan has been demonstrated to be an important time for hippocampal growth and plasticity, during which changes to hippocampal neurogenesis may have long lasting effects. Additionally, we aimed to determine whether a 'dual-hit' of adolescent stress and adult chronic neuroinflammation would potentiate any negative effects of either insult alone. Lastly, the potential positive effects of exercise during adolescence was examined to determine whether exercise could attenuate any negative impacts of these insults on hippocampal neurogenesis and behavior. The results from the current study demonstrate that social isolation stress during adolescence followed by intra-hippocampal exposure to the pro-inflammatory cytokine IL-1β in early adulthood produces deficits in both spontaneous alternations and novel object recognition. Exercise attenuated deficits in neurogenesis and novel object recognition in mice that had been exposed to the 'dual-hit' of stress and neuroinflammation. These findings indicate that adolescence represents a key period of the lifespan during which external factors such as stress and exercise can impact on hippocampal development, and may alter the response to challenges such as neuroinflammation in later life. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

The Assessment of Muscular Effort, Fatigue, and Physiological Adaptation Using EMG and Wavelet Analysis.

PubMed

Graham, Ryan B; Wachowiak, Mark P; Gurd, Brendon J

2015-01-01

Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) is a transcription factor co-activator that helps coordinate mitochondrial biogenesis within skeletal muscle following exercise. While evidence gleaned from submaximal exercise suggests that intracellular pathways associated with the activation of PGC-1α, as well as the expression of PGC-1α itself are activated to a greater extent following higher intensities of exercise, we have recently shown that this effect does not extend to supramaximal exercise, despite corresponding increases in muscle activation amplitude measured with electromyography (EMG). Spectral analyses of EMG data may provide a more in-depth assessment of changes in muscle electrophysiology occurring across different exercise intensities, and therefore the goal of the present study was to apply continuous wavelet transforms (CWTs) to our previous data to comprehensively evaluate: 1) differences in muscle electrophysiological properties at different exercise intensities (i.e. 73%, 100%, and 133% of peak aerobic power), and 2) muscular effort and fatigue across a single interval of exercise at each intensity, in an attempt to shed mechanistic insight into our previous observations that the increase in PGC-1α is dissociated from exercise intensity following supramaximal exercise. In general, the CWTs revealed that localized muscle fatigue was only greater than the 73% condition in the 133% exercise intensity condition, which directly matched the work rate results. Specifically, there were greater drop-offs in frequency, larger changes in burst power, as well as greater changes in burst area under this intensity, which were already observable during the first interval. As a whole, the results from the present study suggest that supramaximal exercise causes extreme localized muscular fatigue, and it is possible that the blunted PGC-1α effects observed in our previous study are the result of fatigue-associated increases in muscle acidosis. This should be explored in future research using further combinations of EMG and muscle biochemistry and histology.

Time of day affects heart rate recovery and variability after maximal exercise in pre-hypertensive men.

PubMed

Brito, Leandro; Peçanha, Tiago; Tinucci, Taís; Silva-Junior, Natan; Costa, Luiz; Forjaz, Claudia

2015-01-01

Heart rate (HR) recovery (HRR) and variability (HRV) after exercise are non-invasive tools used to assess cardiac autonomic regulation and cardiovascular prognosis. Autonomic recovery is slower after evening than morning exercise in healthy individuals, but this influence is unknown in subjects with autonomic dysfunction, although it may affect prognostic evaluation. This study compared post-exercise HRR and HRV after maximal morning and evening exercise in pre-hypertensive men. Ten volunteers randomly underwent two maximal exercise tests conducted in the morning (8-10 a.m.) and evening (6-8 p.m.). HRR60s (HR reduction at 60 s of recovery - prognostic index), T30 (short-term time-constant of HRR - parasympathetic reactivation marker), rMSSD30s (square root of the mean of the sum of the squares of differences between adjacent R-R intervals on subsequent 30 s segments - parasympathetic reactivation marker), and HRRτ (time constant of the first order exponential fitting of HRR - marker of sympathetic withdraw and parasympathetic reactivation) were measured. Paired t-test and two-way ANOVA were used. HRR60s and HRRτ were similar after exercise in the morning and evening (27 ± 7 vs. 29 ± 7 bpm, p = 0.111, and 79 ± 14 vs. 96 ± 29 s, p = 0.119, respectively). T30 was significantly greater after evening exercise (405 ± 215 vs. 295 ± 119 s, p = 0.002) and rMSSD30s was lower in the evening (main factor session, p = 0.009). In conclusion, in pre-hypertensive men, the prognostic index of HRR, HRR60s, is not affected by the time of day when exercise is conducted. However, post-exercise parasympathetic reactivation, evaluated by T30 and rMSSD30s, is blunted after evening exercise.

The Relation of Arm Exercise Peak Heart Rate to Stress Test Results and Outcome.

PubMed

Xian, Hong; Liu, Weijian; Marshall, Cynthia; Chandiramani, Pooja; Bainter, Emily; Martin, Wade H

2016-09-01

Arm exercise is an alternative to pharmacologic stress testing for >50% of patients unable to perform treadmill exercise, but no data exist regarding the effect of attained peak arm exercise heart rate on test sensitivity. Thus, the purpose of this investigation was to characterize the relationship of peak arm exercise heart rate responses to abnormal stress test findings, coronary revascularization, and mortality in patients unable to perform leg exercise. From 1997 until 2002, arm cycle ergometer stress tests were performed in 443 consecutive veterans age 64.1 yr (11.0 yr) (mean (SD)), of whom 253 also underwent myocardial perfusion imaging (MPI). Patients were categorized by frequency distributions of quartiles of percentage age-predicted peak heart rate (APPHR), heart rate reserve (HRR), and peak heart rate-systolic blood pressure product (PRPP). Exercise-induced ST-segment depression, abnormal MPI findings, coronary revascularization, and 12.0-yr (1.3 yr) Kaplan-Meier all-cause and cardiovascular mortality plots were then characterized by quartiles of APPHR, HRR, and PRPP. A reduced frequency of abnormal arm exercise ECG results was associated only with the lowest quartile of APPHR (≤69%) and HRR (≤43%), whereas higher frequency of abnormal MPI findings exhibited an inverse relationship trend with lower APPHR (P = 0.10) and HRR (P = 0.12). There was a strong inverse association of APPHR, HRR, and PRPP with all-cause (all P ≤ 0.01) and cardiovascular (P < 0.05) mortality. The frequency of coronary revascularization was unrelated to APPHR or HRR. Arm exercise ECG stress test sensitivity is only reduced at ≤69% APPHR or ≤43% HRR, whereas arm exercise MPI sensitivity and referral for coronary revascularization after arm exercise stress testing are not adversely affected by even a severely blunted peak heart rate. However, both all-cause mortality and cardiovascular mortality are strongly and inversely related to APPHR and HRR.

Exercise protects against high-fat diet-induced hypothalamic inflammation.

PubMed

Yi, Chun-Xia; Al-Massadi, Omar; Donelan, Elizabeth; Lehti, Maarit; Weber, Jon; Ress, Chandler; Trivedi, Chitrang; Müller, Timo D; Woods, Stephen C; Hofmann, Susanna M

2012-06-25

Hypothalamic inflammation is a potentially important process in the pathogenesis of high-fat diet-induced metabolic disorders that has recently received significant attention. Microglia are macrophage-like cells of the central nervous system which are activated by pro-inflammatory signals causing local production of specific interleukins and cytokines, and these in turn may further promote systemic metabolic disease. Whether or how this microglial activation can be averted or reversed is unknown. Since running exercise improves systemic metabolic health and has been found to promote neuronal survival as well as the recovery of brain functions after injury, we hypothesized that regular treadmill running may blunt the effect of western diet on hypothalamic inflammation. Using low-density lipoprotein receptor deficient (l dlr-/-) mice to better reflect human lipid metabolism, we first confirmed that microglial activation in the hypothalamus is severely increased upon exposure to a high-fat, or "western", diet. Moderate, but regular, treadmill running exercise markedly decreased hypothalamic inflammation in these mice. Furthermore, the observed decline in microglial activation was associated with an improvement of glucose tolerance. Our findings support the hypothesis that hypothalamic inflammation can be reversed by exercise and suggest that interventions to avert or reverse neuronal damage may offer relevant potential in obesity treatment and prevention. Copyright © 2012 Elsevier Inc. All rights reserved.

The Benefits of Exercise Training on Aerobic Capacity in Patients with Heart Failure and Preserved Ejection Fraction.

PubMed

do Prado, Danilo Marcelo Leite; Rocco, Enéas Antônio

2017-01-01

Heart failure with preserved ejection fraction (HFpEF) is defined as an inability of the ventricles to optimally accept blood from atria with blunted end- diastolic volume response by limiting the stroke volume and cardiac output. The HEpEF prevalence is higher in elderly and women and may be associated to hypertension, diabetes mellitus and atrial fibrillation. Severe exercise intolerance, manifested by dyspnea and fatigue during physical effort is the important chronic symptom in HFpEF patients, in which is the major determinant of their reduced quality of life. In this sense, several studies demonstrated reduced aerobic capacity in terms of lower peak oxygen consumption (peak VO 2 ) in patients with HFpEF. In addition, the lower aerobic capacity observed in HFpEF may be due to impaired both convective and diffusive O 2 transport (i.e. reduced cardiac output and arteriovenous oxygen difference, respectively).Exercise training program can help restore physiological function in order to increase aerobic capacity and improve the quality of life in HFpEF patients. Therefore, the primary purpose of this chapter was to clarify the physiological mechanisms associated with reduced aerobic capacity in HFpEF patients. Secondly, special focus was devoted to show how aerobic exercise training can improve aerobic capacity and quality of life in HFpEF patients.

Syndecan-4 Signaling Is Required for Exercise-Induced Cardiac Hypertrophy

PubMed Central

Xie, Jun; He, Guixin; Chen, Qinhua; Sun, Jiayin; Dai, Qin; Lu, Jianrong; Li, Guannan; Wu, Han; Li, Ran; Chen, Jianzhou; Xu, Wei; Xu, Biao

2016-01-01

Cardiac hypertrophy can be broadly classified as either physiological or pathological. Physiological stimuli such as exercise cause adaptive cardiac hypertrophy and normal heart function. Pathological stimuli including hypertension and aortic valvular stenosis cause maladaptive cardiac remodeling and ultimately heart failure. Syndecan-4 (synd4) is a transmembrane proteoglycan identified as being involved in cardiac adaptation after injury, but whether it takes part in physiological cardiac hypertrophy is unclear. We observed upregulation of synd4 in exercise-induced hypertrophic myocardium. To evaluate the role of synd4 in the physiological form of cardiac hypertrophy, mice lacking synd4 (synd4–/–) were exercised by swimming for 4 wks. Ultrasonic cardiogram (UCG) and histological analysis revealed that swimming induced the hypertrophic phenotype but was blunted in synd4–/– compared with wild-type (WT) mice. The swimming-induced activation of Akt, a key molecule in physiological hypertrophy was also more decreased than in WT controls. In cultured cardiomyocytes, synd4 overexpression could induce cell enlargement, protein synthesis and distinct physiological molecular alternation. Akt activation also was observed in synd4-overexpressed cardiomyocytes. Furthermore, inhibition of protein kinase C (PKC) prevented the synd4-induced hypertrophic phenotype and Akt phosphorylation. This study identified an essential role of synd4 in mediation of physiological cardiac hypertrophy. PMID:26835698

Why do individuals not lose more weight from an exercise intervention at a defined dose? An energy balance analysis

PubMed Central

Thomas, D. M.; Bouchard, C.; Church, T.; Slentz, C.; Kraus, W. E.; Redman, L. M.; Martin, C. K.; Silva, A. M.; Vossen, M.; Westerterp, K.; Heymsfield, S. B.

2013-01-01

Summary Weight loss resulting from an exercise intervention tends to be lower than predicted. Modest weight loss can arise from an increase in energy intake, physiological reductions in resting energy expenditure, an increase in lean tissue or a decrease in non-exercise activity. Lower than expected, weight loss could also arise from weak and invalidated assumptions within predictive models. To investigate these causes, we systematically reviewed studies that monitored compliance to exercise prescriptions and measured exercise-induced change in body composition. Changed body energy stores were calculated to determine the deficit between total daily energy intake and energy expenditures. This information combined with available measurements was used to critically evaluate explanations for low exercise-induced weight loss. We conclude that the small magnitude of weight loss observed from the majority of evaluated exercise interventions is primarily due to low doses of prescribed exercise energy expenditures compounded by a concomitant increase in caloric intake. PMID:22681398

Treadmill running prevents age-related memory deficit and alters neurotrophic factors and oxidative damage in the hippocampus of Wistar rats.

PubMed

Vanzella, Cláudia; Neves, Juliana Dalibor; Vizuete, Adriana Fernanda; Aristimunha, Dirceu; Kolling, Janaína; Longoni, Aline; Gonçalves, Carlos Alberto Saraiva; Wyse, Angela T S; Netto, Carlos Alexandre

2017-09-15

Clinical and pre-clinical studies indicate that exercise is beneficial to many aspects of brain function especially during aging. The present study investigated the effects of a treadmill running protocol in young (3month-old) and aged (22month-old) male Wistar rats, on: I) cognitive function, as assessed by spatial reference memory in the Morris water maze; II) oxidative stress parameters and the expression of neurotrophic factors BDNF, NT-3, IGF-1 and VEGF in the hippocampus. Animals of both ages were assigned to sedentary (non-exercised) and exercised (20min of daily running sessions, 3 times per week for 4weeks) groups. Cognition was assessed by a reference memory task run in the Morris water maze; twenty four hours after last session of behavioral testing hippocampi were collected for biochemical analysis. Results demonstrate that the moderate treadmill running exercise: I) prevented age-related deficits in reference memory in the Morris water maze; II) prevented the age-related increase of reactive oxygen species levels and lipid peroxidation in the hippocampus; III) caused an increase of BDNF, NT-3 and IGF-1 expression in the hippocampus of aged rats. Taken together, results suggest that both exercise molecular effects, namely the reduction of oxidative stress and the increase of neurotrophic factors expression in the hippocampus, might be related to its positive effect on memory performance in aged rats. Copyright © 2017 Elsevier B.V. All rights reserved.

Voluntary scheduled exercise alters diurnal rhythms of behaviour, physiology and gene expression in wild-type and vasoactive intestinal peptide-deficient mice

PubMed Central

Schroeder, Analyne M; Truong, Danny; Loh, Dawn H; Jordan, Maria C; Roos, Kenneth P; Colwell, Christopher S

2012-01-01

The circadian system co-ordinates the temporal patterning of behaviour and many underlying biological processes. In some cases, the regulated outputs of the circadian system, such as activity, may be able to feed back to alter core clock processes. In our studies, we used four wheel-access conditions (no access; free access; early night; and late night) to manipulate the duration and timing of activity while under the influence of a light–dark cycle. In wild-type mice, scheduled wheel access was able to increase ambulatory activity, inducing a level of exercise driven at various phases of the light–dark cycle. Scheduled exercise also manipulated the magnitude and phasing of the circadian-regulated outputs of heart rate and body temperature. At a molecular level, the phasing and amplitude of PER2::LUCIFERASE (PER2::LUC) expression rhythms in the SCN and peripheral tissues of Per2::Luc knockin mice were altered by scheduled exercise. We then tested whether scheduled wheel access could improve deficits observed in vasointestinal polypeptide-deficient mice under the influence of a light–dark cycle. We found that scheduled wheel access during the late night improved many of the behavioural, physiological and molecular deficits previously described in vasointestinal polypeptide-deficient mice. Our results raise the possibility that scheduled exercise could be used as a tool to modulate daily rhythms and, when applied, may counteract some of the negative impacts of ageing and disease on the circadian system. PMID:22988135

Nutritional Status and Physical and Mental Performance of Special Operations Soldiers Consuming the Ration, Lightweight, or the Meal, Ready-to-Eat Military Field Ration during a 30-Day Field Training Exercise

DTIC Science & Technology

1987-03-23

relationship of diet to the performance of the combat soldier. Minimal calorie intake during combat patrols in a hot humid environment. Presidio of San...endurance-trained subjects to caloric deficits induced by diet or exercise. Med. Sci. Sports Exercise 17:574-579, 1985. 8. Crowdy, J.P.. M.F. Haisman. and H...McGavock. Combat nutrition. The effects of a restricted diet on the performance of hard and proloneged shysical work. Army personnel Research

Short-Term Intensified Cycle Training Alters Acute and Chronic Responses of PGC1α and Cytochrome C Oxidase IV to Exercise in Human Skeletal Muscle

PubMed Central

Stepto, Nigel K.; Benziane, Boubacar; Wadley, Glenn D.; Chibalin, Alexander V.; Canny, Benedict J.; Eynon, Nir; McConell, Glenn K.

2012-01-01

Reduced activation of exercise responsive signalling pathways have been reported in response to acute exercise after training; however little is known about the adaptive responses of the mitochondria. Accordingly, we investigated changes in mitochondrial gene expression and protein abundance in response to the same acute exercise before and after 10-d of intensive cycle training. Nine untrained, healthy participants (mean±SD; VO2peak 44.1±17.6 ml/kg/min) performed a 60 min bout of cycling exercise at 164±18 W (72% of pre-training VO2peak). Muscle biopsies were obtained from the vastus lateralis muscle at rest, immediately and 3 h after exercise. The participants then underwent 10-d of cycle training which included four high-intensity interval training sessions (6×5 min; 90–100% VO2peak) and six prolonged moderate-intensity sessions (45–90 min; 75% VO2peak). Participants repeated the pre-training exercise trial at the same absolute work load (64% of pre-training VO2peak). Muscle PGC1-α mRNA expression was attenuated as it increased by 11- and 4- fold (P<0.001) after exercise pre- and post-training, respectively. PGC1-α protein expression increased 1.5 fold (P<0.05) in response to exercise pre-training with no further increases after the post-training exercise bout. RIP140 protein abundance was responsive to acute exercise only (P<0.01). COXIV mRNA (1.6 fold; P<0.01) and COXIV protein expression (1.5 fold; P<0.05) were increased by training but COXIV protein expression was decreased (20%; P<0.01) by acute exercise pre- and post-training. These findings demonstrate that short-term intensified training promotes increased mitochondrial gene expression and protein abundance. Furthermore, acute indicators of exercise-induced mitochondrial adaptation appear to be blunted in response to exercise at the same absolute intensity following short-term training. PMID:23285255

Diagnostic accuracy of heart-rate recovery after exercise in the assessment of diabetic cardiac autonomic neuropathy.

PubMed

Sacre, J W; Jellis, C L; Coombes, J S; Marwick, T H

2012-09-01

Poor prognosis associated with blunted post-exercise heart-rate recovery may reflect autonomic dysfunction. This study sought the accuracy of post-exercise heart-rate recovery in the diagnosis of cardiac autonomic neuropathy, which represents a serious, but often unrecognized complication of Type 2 diabetes. Clinical assessment of cardiac autonomic neuropathy and maximal treadmill exercise testing for heart-rate recovery were performed in 135 patients with Type 2 diabetes and negative exercise echocardiograms. Cardiac autonomic neuropathy was defined by abnormalities in ≥ 2 of 7 autonomic function markers, including four cardiac reflex tests and three indices of short-term (5-min) heart-rate variability. Heart-rate recovery was defined at 1-, 2- and 3-min post-exercise. Patients with cardiac autonomic neuropathy (n = 27; 20%) had lower heart-rate recovery at 1-, 2- and 3-min post-exercise (P < 0.01). Heart-rate recovery demonstrated univariate associations with autonomic function markers (r-values 0.20-0.46, P < 0.05). Area under the receiver-operating characteristic curve revealed good diagnostic performance of all heart-rate recovery parameters (range 0.80-0.83, P < 0.001). Optimal cut-offs for heart-rate recovery at 1-, 2- and 3-min post-exercise were ≤ 28 beats/min (sensitivity 93%, specificity 69%), ≤ 50 beats/min (sensitivity 96%, specificity 63%) and ≤ 52 beats/min (sensitivity 70%, specificity 84%), respectively. These criteria predicted cardiac autonomic neuropathy independently of relevant clinical and exercise test information (adjusted odds ratios 7-28, P < 0.05). Post-exercise heart-rate recovery provides an accurate diagnostic test for cardiac autonomic neuropathy in Type 2 diabetes. The high sensitivity and modest specificity suggests heart-rate recovery may be useful to screen for patients requiring clinical autonomic evaluation. © 2012 The Authors. Diabetic Medicine © 2012 Diabetes UK.

Exercise training, but not resveratrol, improves metabolic and inflammatory status in skeletal muscle of aged men

PubMed Central

Olesen, Jesper; Gliemann, Lasse; Biensø, Rasmus; Schmidt, Jakob; Hellsten, Ylva; Pilegaard, Henriette

2014-01-01

The aim was to investigate the metabolic and anti-inflammatory effects of resveratrol alone and when combined with exercise training in skeletal muscle of aged human subjects. Healthy, physically inactive men (60–72 years old) were randomized to either 8 weeks of daily intake of 250 mg resveratrol or placebo or to 8 weeks of high-intensity exercise training with 250 mg resveratrol or placebo. Before and after the interventions, resting blood samples and muscle biopsies were obtained and a one-legged knee-extensor endurance exercise test was performed. Exercise training increased skeletal muscle peroxisome proliferator-activated receptor-γ co-activator-1α mRNA ∼1.5-fold, cytochrome c protein ∼1.3-fold, cytochrome c oxidase I protein ∼1.5-fold, citrate synthase activity ∼1.3-fold, 3-hydroxyacyl-CoA dehydrogenase activity ∼1.3-fold, inhibitor of κB-α and inhibitor of κB-β protein content ∼1.3-fold and time to exhaustion in the one-legged knee-extensor endurance exercise test by ∼1.2-fold, with no significant additive or adverse effects of resveratrol on these parameters. Despite an overall ∼25% reduction in total acetylation level in skeletal muscle with resveratrol, no exclusive resveratrol-mediated metabolic effects were observed on the investigated parameters. Notably, however, resveratrol blunted an exercise training-induced decrease (∼20%) in protein carbonylation and decrease (∼40%) in tumour necrosis factor α mRNA content in skeletal muscle. In conclusion, resveratrol did not elicit metabolic improvements in healthy aged subjects; in fact, resveratrol even impaired the observed exercise training-induced improvements in markers of oxidative stress and inflammation in skeletal muscle. Collectively, this highlights the metabolic efficacy of exercise training in aged subjects and does not support the contention that resveratrol is a potential exercise mimetic in healthy aged subjects. PMID:24514907

Ovarian dysfunction, stress, and disease: a primate continuum.

PubMed

Kaplan, Jay R; Manuck, Stephen B

2004-01-01

Menopause is recognized as a period of increased risk for coronary heart disease (CHD) and osteoporosis. Vulnerability to these conditions is often attributed to the naturally occurring estrogen deficiency characteristic of this part of the life cycle. Premenopausal reductions in endogenous estrogen occasioned by functional ovarian abnormalities or failure are hypothesized to be similarly pathogenic and to accelerate development of CHD and osteoporosis prematurely, thereby increasing the health burden of older women. These functional abnormalities, which occur along a continuum from mild, luteal phase progesterone deficiency to amenorrhea, are relatively common and are often attributed to psychogenic factors (stress, anxiety, depression, or other emotional disturbance), exercise, or energy imbalance. Although numerous investigators have commented on these functional deficits, the abnormalities can be difficult to diagnose and are generally unappreciated for the contribution they may make to postmenopausal disease. Studies in nonhuman primates confirm that these deficits are easily induced by psychological stress and exercise, and that they accelerate the development of cardiovascular disease and perhaps bone loss in the presence of a typical North American diet. However, functional reproductive deficits are also reversible and are thus potentially amenable to environmental or behavioral intervention. Data from both women and nonhuman primates support the hypothesis that functional reproductive deficits are adaptive when triggered appropriately but are detrimental when activated in an environment (e.g., sedentary lifestyle, high-fat diet) permissive to the development of chronic disease.

Association of Exercise Training with Tobacco Smoking Prevents Fibrosis but has Adverse Impact on Myocardial Mechanics.

PubMed

Reis Junior, Dermeval; Antonio, Ednei Luiz; de Franco, Marcello Fabiano; de Oliveira, Helenita Antonia; Tucci, Paulo José Ferreira; Serra, Andrey Jorge

2016-12-01

There was no data for cardiac repercussion of exercise training associated with tobacco smoking. This issue is interesting because some smoking people can be enrolled in an exercise-training program. Thus, we evaluated swimming training effects on the function and structural myocardial in rats exposed to tobacco smoking. Male Wistar rats were assigned to one of four groups: C, untrained rats without exposure to tobacco smoking; E, exercised rats without exposure to tobacco smoking; CS, untrained rats exposed to tobacco smoking; ECS, exercised rats exposed to tobacco smoking. Rats swam five times a week twice daily (60min per session) for 8 weeks. Before each bout exercise, rats breathed smoke from 20 cigarettes for 60min. Twenty-four hours after the last day of the protocol, papillary muscles were isolated for in vitro analysis of myocardial mechanics. The myocardial mass and nuclear cardiomyocyte volume were used as hypertrophy markers, and collagen content was determined by picrosirius red staining. There was a well-pronounced myocardial hypertrophic effect for two interventions. The exercise blunted myocardial collagen increases induced by tobacco smoking. However, exercise and tobacco-smoking association was deleterious to myocardial performance. Thereby, in vitro experiments with papillary muscles contracting in isometric showed impairment myocardial inotropism in exercised rats exposed to tobacco smoking. This work presents novel findings on the role of exercise training on cardiac remodeling induced by tobacco smoking. Although exercise has mitigated tissue fibrosis, their association with tobacco smoking exacerbated hypertrophy and in vitro myocardial dysfunction. This is first study to show that the association of an aerobic exercise training with tobacco smoking intensifies the phenotype of pathological cardiac hypertrophy. Therefore, the combination of interventions resulted in exacerbated myocardial hypertrophy and contractility dysfunction. These findings have significant clinical implication because some smoking people can be enrolled in an exercise-training program. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Role of O-GlcNAcylation in nutritional sensing, insulin resistance and in mediating the benefits of exercise.

PubMed

Myslicki, Jason P; Belke, Darrell D; Shearer, Jane

2014-11-01

The purpose of this review is to highlight the role of O-linked β-N-acetylglucosamine (O-GlcNAc) protein modification in metabolic disease states and to summarize current knowledge of how exercise affects this important post-translational signalling pathway. O-GlcNAc modification is an intracellular tool capable of integrating energy supply with demand. The accumulation of excess energy associated with obesity and insulin resistance is mediated, in part, by the hexosamine biosynthetic pathway (HBP), which results in the O-GlcNAcylation of a myriad of proteins, thereby affecting their respective function, stability, and localization. Insulin resistance is related to the excessive O-GlcNAcylation of key metabolic proteins causing a chronic blunting of insulin signalling pathways and precipitating the accompanying pathologies, such as heart and kidney disease. Lifestyle modifications such as diet and exercise also modify the pathway. Exercise is a front-line and cost-effective therapeutic approach for insulin resistance, and recent work shows that the intervention can alter O-GlcNAc gene expression, signalling, and protein modification. However, there is currently no consensus on the effect of frequency, intensity, type, and duration of exercise on O-GlcNAc modification, the HBP, and its related enzymes. On one end of the spectrum, mild, prolonged swim training reduces O-GlcNAcylation, while on the other end, higher intensity treadmill running increases cardiac protein O-GlcNAc modification. Clearly, a balance between acute and chronic stress of exercise is needed to reap the benefits of the intervention on O-GlcNAc signalling.

Fasting hyperglycaemia blunts the reversal of impaired glucose tolerance after exercise training in obese older adults.

PubMed

Malin, S K; Kirwan, J P

2012-09-01

Lifestyle modification, consisting of exercise and weight loss, delays the progression from prediabetes to type 2 diabetes (T2D). However, no study has determined the efficacy of exercise training on glucose metabolism in the different prediabetes subtypes. Seventy-six older (65.1 ± 0.6 years) obese adults with impaired fasting glucose (IFG; n = 12), impaired glucose tolerance (IGT; n = 9) and combined glucose intolerance (IFG + IGT = CGI; n = 22) were compared with normal glucose tolerant (NGT; n = 15) and T2D (n = 18) groups after 12 weeks of exercise training (60 min/day for 5 days/week at ~85% HR(max)). An oral glucose tolerance test was used to assess glucose levels. Insulin sensitivity (IS; euglycaemic hyperinsulinaemic clamp at 40 mU/m(2)/min), β-cell function (glucose-stimulated insulin secretion corrected for IS), body composition (hydrostatic weighing/computed tomography scan) and cardiovascular fitness (treadmill VO(2) max) were also assessed. Exercise training reduced weight and increased cardiovascular fitness (p < 0.05). Exercise training lowered fasting glucose levels in IFG, CGI and T2D (p < 0.05) and 2-h glucose levels in IGT, CGI and T2D (p < 0.05). However, 2-h glucose levels were not normalized in adults with CGI compared with IGT (p < 0.05). β-Cell function improved similarly across groups (p < 0.05). Although not statistically significant, IS increased approximately 40% in IFG and IGT, but only 17% in CGI. The magnitude of improvement in glucose metabolism after 12 weeks of exercise training is not uniform across the prediabetes subtypes. Given the high risk of progressing to T2D, adults with CGI may require more aggressive therapies to prevent diabetes. © 2012 Blackwell Publishing Ltd.

Cellular adaptation to repeated eccentric exercise-induced muscle damage.

PubMed

Stupka, N; Tarnopolsky, M A; Yardley, N J; Phillips, S M

2001-10-01

Eccentrically biased exercise results in skeletal muscle damage and stimulates adaptations in muscle, whereby indexes of damage are attenuated when the exercise is repeated. We hypothesized that changes in ultrastructural damage, inflammatory cell infiltration, and markers of proteolysis in skeletal muscle would come about as a result of repeated eccentric exercise and that gender may affect this adaptive response. Untrained male (n = 8) and female (n = 8) subjects performed two bouts (bout 1 and bout 2), separated by 5.5 wk, of 36 repetitions of unilateral, eccentric leg press and 100 repetitions of unilateral, eccentric knee extension exercises (at 120% of their concentric single repetition maximum), the subjects' contralateral nonexercised leg served as a control (rest). Biopsies were taken from the vastus lateralis from each leg 24 h postexercise. After bout 2, the postexercise force deficit and the rise in serum creatine kinase (CK) activity were attenuated. Women had lower serum CK activity compared with men at all times (P < 0.05), but there were no gender differences in the relative magnitude of the force deficit. Muscle Z-disk streaming, quantified by using light microscopy, was elevated vs. rest only after bout 1 (P < 0.05), with no gender difference. Muscle neutrophil counts were significantly greater in women 24 h after bout 2 vs. rest and bout 1 (P < 0.05) but were unchanged in men. Muscle macrophages were elevated in men and women after bout 1 and bout 2 (P < 0.05). Muscle protein content of the regulatory calpain subunit remained unchanged whereas ubiquitin-conjugated protein content was increased after both bouts (P < 0.05), with a greater increase after bout 2. We conclude that adaptations to eccentric exercise are associated with attenuated serum CK activity and, potentially, an increase in the activity of the ubiquitin proteosome proteolytic pathway.

Sensory-Challenge Balance Exercises Improve Multisensory Reweighting in Fall-Prone Older Adults.

PubMed

Allison, Leslie K; Kiemel, Tim; Jeka, John J

2018-04-01

Multisensory reweighting (MSR) deficits in older adults contribute to fall risk. Sensory-challenge balance exercises may have value for addressing the MSR deficits in fall-prone older adults. The purpose of this study was to examine the effect of sensory-challenge balance exercises on MSR and clinical balance measures in fall-prone older adults. We used a quasi-experimental, repeated-measures, within-subjects design. Older adults with a history of falls underwent an 8-week baseline (control) period. This was followed by an 8-week intervention period that included 16 sensory-challenge balance exercise sessions performed with computerized balance training equipment. Measurements, taken twice before and once after intervention, included laboratory measures of MSR (center of mass gain and phase, position, and velocity variability) and clinical tests (Activities-specific Balance Confidence Scale, Berg Balance Scale, Sensory Organization Test, Limits of Stability test, and lower extremity strength and range of motion). Twenty adults 70 years of age and older with a history of falls completed all 16 sessions. Significant improvements were observed in laboratory-based MSR measures of touch gain (P = 0.006) and phase (P = 0.05), Berg Balance Scale (P = 0.002), Sensory Organization Test (P = 0.002), Limits of Stability Test (P = 0.001), and lower extremity strength scores (P = 0.005). Mean values of vision gain increased more than those for touch gain, but did not reach significance. A balance exercise program specifically targeting multisensory integration mechanisms improved MSR, balance, and lower extremity strength in this mechanistic study. These valuable findings provide the scientific rationale for sensory-challenge balance exercise to improve perception of body position and motion in space and potential reduction in fall risk.

Task-oriented aerobic exercise in chronic hemiparetic stroke: training protocols and treatment effects.

PubMed

Macko, R F; Ivey, F M; Forrester, L W

2005-01-01

Stroke is the leading cause of disability in older Americans. Each year 750,000 Americans suffer a stroke, two thirds of whom are left with neurological deficits that persistently impair function. Principal among them is hemiparetic gait that limits mobility and increases fall risk, promoting a sedentary lifestyle. These events propagate disability by physical deconditioning and "learned non-use," with further functional declines accelerated by the sarcopenia and fitness decrements of advancing age. Conventional rehabilitation care typically provides little or no structured therapeutic exercise beyond the subacute stroke recovery period, based on natural history studies showing little or no further functional motor recovery beyond 6 months after stroke. Emerging evidence suggests that new models of task-oriented exercise have the potential to improve motor function even years after stroke. This article presents treadmill as a task-oriented training paradigm to optimize locomotor relearning while eliciting cardiovascular conditioning in chronic stroke patients. Protocols for exercise testing and longitudinal aerobic training progression are presented that provide fundamental formulas that safely approach the complex task of customizing aerobic training to gait deficit severity in the high CVD risk stroke population. The beneficial effects of 6 months task-oriented treadmill exercise on cardiovascular-metabolic fitness, energy cost of hemiparetic gait, ADL mobility task performance, and leg strength are discussed with respect to the central and peripheral neuromuscular adaptations targeted by the training. Collectively, these findings constitute one initial experience in a much broader neuroscience and exercise rehabilitation development of task-oriented training paradigms that offer a multisystems approach to improving both neurological and cardiovascular health outcomes in the chronic stroke population.

Treadmill exercise ameliorates symptoms of attention deficit/hyperactivity disorder through reducing Purkinje cell loss and astrocytic reaction in spontaneous hypertensive rats

PubMed Central

Yun, Hyo-Soon; Park, Mi-Sook; Ji, Eun-Sang; Kim, Tae-Woon; Ko, Il-Gyu; Kim, Hyun-Bae; Kim, Hong

2014-01-01

Attention deficit/hyperactivity disorder (ADHD) is a neurobehavioral disorder of cognition. We investigated the effects of treadmill exercise on Purkinje cell and astrocytic reaction in the cerebellum of the ADHD rat. Adult male spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKYR) weighing 210± 10 g were used. The animals were randomly divided into four groups (n= 15): control group, ADHD group, ADHD and methylphenidate (MPH)-treated group, ADHD and treadmill exercise group. The rats in the MPH-treated group as a positive control received 1 mg/kg MPH orally once a day for 28 consecutive days. The rats in the treadmill exercise group were made to run on a treadmill for 30 min once a day for 28 days. Motor coordination and balance were determined by vertical pole test. Immunohistochemistry for the expression of calbindinD-28 and glial fibrillary acidic protein (GFAP) in the cerebellar vermis and Western blot for GFAP, Bax, and Bcl-2 were conducted. In the present results, ADHD significantly decreased balance and the number of calbindin-positive cells, while GFAP expression and Bax/Bcl-2 ratio in the cerebellum were significantly increased in the ADHD group compared to the control group (P< 0.05, respectively). In contrast, treadmill exercise and MPH alleviated the ADHD-induced the decrease of balance and the number of calbindine-positive cells, and the increase of GFAP expression and Bax/Bcl-2 ratio in the cerebellum (P< 0.05, respectively). Therefore, the present results suggested that treadmill exercise might exert ameliorating effect on ADHD through reduction of Purkinje cell loss and astrocytic reaction in the cerebellum. PMID:24678501

VO2 kinetics of constant-load exercise following bed-rest-induced deconditioning

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Goldwater, D. J.; Sandler, H.

1984-01-01

Previous studies have shown that the oxygen uptake kinetics during exercise and recovery may be changed by alterations in work intensity, prior exercise, muscle group involvement, ambient conditions, posture, disease state, and level of physical conditioning. However, the effects of detraining on oxygen uptake kinetics have not been determined. The present investigation has the objective to determine the effects of deconditioning following seven days of continuous head-down bed rest on changes in steady-state oxygen uptake, O2 deficit, and recovery oxygen uptake during the performance of constant-load exercise. The obtained results may provide support for previous proposals that submaximal oxygen uptake was significantly reduced following bed rest. The major finding was that bed-rest deconditioning resulted in a reduction of total O2 transport/utilization capacity during the transient phase of upright but not supine exercise.

Voluntary exercise confers protection against age-related deficits in brain oxygenation in awake mice model of Alzheimer's disease

NASA Astrophysics Data System (ADS)

Lu, Xuecong; Moeini, Mohammad; Li, Baoqiang; Sakadžić, Sava; Lesage, Frédéric

2018-02-01

Alzheimer's disease (AD) is a neurodegenerative disease characterized by short-term memory loss and cognitive inabilities. This work seeks to study the effects of voluntary exercise on the change in oxygen delivery in awake mice models of Alzheimer's disease by monitoring brain tissue oxygenation. Experiments were performed on Young (AD_Y, 3-4 months, n=8), Old (AD_O, 6-7 months, n=8), and Old with exercise (AD_OEX, 6-7 months, n=8) transgenic APPPS1 mice and their controls. Brain tissue oxygenation was measured by two photon phosphorescence lifetime microscopy on the left sensory motor cortex. We found that the average tissue PO2 decreased with age but were regulated by exercise. The results suggest a potential for exercise to improve brain function with age and AD.

Neural Correlates of Reward Processing in Depressed and Healthy Preschool-Age Children.

PubMed

Belden, Andy C; Irvin, Kelsey; Hajcak, Greg; Kappenman, Emily S; Kelly, Danielle; Karlow, Samantha; Luby, Joan L; Barch, Deanna M

2016-12-01

Adults and adolescents with major depressive disorder (MDD) show a blunted neural response to rewards. Depression has been validated in children as young as age 3; however, it remains unclear whether blunted response to reward is also a core feature of preschool-onset depression. If so, this would provide further validation for the continuity of the neural correlates of depression across the life span and would identify a potential target for treatment in young children. Fifty-three 4- to 7-year-old children with depression and 25 psychiatrically healthy 4- to 7-year-old children completed a simple guessing task in which points could be won or lost on each trial while event-related potentials (ERPs) were recorded. Psychiatric diagnosis was established using a preschool version of the Kiddie Schedule for Affective Disorders and Depression. Young children with depression showed a reduced differentiation between response to gains and losses, and this finding was driven by a blunted response to reward (i.e., the reward positivity [RewP]). These findings held even when controlling for co-occurring attention-deficit/hyperactivity disorder, oppositional defiant disorder, and generalized anxiety disorder. The RewP did not vary as a function of depression severity within the group with depression. Similar to adults and adolescents with depression, preschoolers with depression display reductions in responsivity to rewards as indexed by the RewP. These findings provide further evidence for continuity in the neural mechanisms associated with depression across the lifespan, and point to altered reward sensitivity as an early-emerging potential target for intervention in preschool-onset depression. Clinical trial registration information-A Randomized Controlled Trial of PCIT-ED for Preschool Depression; http://clinicaltrials.gov/; NCT02076425. Copyright © 2016 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Behavioral and Neural Sustained Attention Deficits in Bipolar Disorder and Familial Risk of Bipolar Disorder.

PubMed

Pagliaccio, David; Wiggins, Jillian Lee; Adleman, Nancy E; Harkins, Elizabeth; Curhan, Alexa; Towbin, Kenneth E; Brotman, Melissa A; Pine, Daniel S; Leibenluft, Ellen

2017-11-01

Few neuroimaging studies compare individuals affected with bipolar disorder (BP), at high familial risk of BP, and at low risk to identify endophenotypes for BP. None have examined variability in attention, despite promising behavioral work in this area. We used functional magnetic resonance imaging (fMRI) methods uniquely powered to compare the neural correlates of attention variability in these three groups. The present study examined 8- to 25-year-old individuals (n = 106) who completed an fMRI attention task: 24 with BP, 29 at risk based on a first-degree relative with BP, and 53 healthy, low-risk individuals. Group differences in intrasubject variability in reaction time were examined, and a sophisticated fMRI analytic approach was used to quantify precisely trialwise associations between reaction time and brain activity. The latter has not been examined previously in BP or risk of BP. Relative to healthy individuals, those with BP or at risk for BP exhibited increased reaction time variability (F 2,102 = 4.26, p = .02, η p 2 = .08). Importantly, we identified blunted relationships between trialwise variation in reaction time and brain activity in the inferior and middle frontal gyri, precuneus, cingulate cortex, caudate, and postcentral gyrus (all regions: p < .001, η p 2 > .06) in both at-risk and BP individuals compared with healthy, low-risk individuals. This blunting partially mediated group differences in reaction time variability (β = .010, 95% confidence interval 0.002 to 0.020, Sobel Z = 2.08, p = .038). Blunting in key frontal, cingulate, and striatal areas was evident in unaffected, at-risk individuals and in euthymic BP patients. Elucidating such novel neural endophenotypes can facilitate new approaches to BP prediction, diagnosis, and prevention. Published by Elsevier Inc.

Characterizing substance use and mental health profiles of cigar, blunt, and non-blunt marijuana users from the National Survey of Drug Use and Health.

PubMed

Cohn, Amy; Johnson, Amanda; Ehlke, Sarah; Villanti, Andrea C

2016-03-01

Smoking marijuana in a cigar (blunt use) is gaining popularity in the U.S. Research suggests that blunt users differ from exclusive cigar or marijuana users on a variety of demographic and substance use factors. Misreporting of blunts and cigars is also common, particularly among young people, and may lead to inaccurate prevalence estimates. To determine subtype differences, this study investigated the prevalence and demographic, mental health, and substance use correlates of four mutually-exclusive groups of blunt, cigar, and marijuana past 30-day users (cigar-only, blunt-only, non-blunt marijuana, or dual cigar-blunt). Data were analyzed from the 2013 National Survey of Drug Use and Health. In weighted multinomial logistic regression models, respondents who were younger, Black, and who had used tobacco, alcohol, or other drugs in the past 30-days had the highest odds of reporting blunt-only or dual cigar-blunt use. Those reporting blunt-only and dual cigar-blunt use also endorsed a greater number of marijuana and alcohol use disorder symptoms compared to those reporting cigar-only and non-blunt marijuana use. Lower marijuana risk perceptions were associated with increased odds of marijuana use with or without blunts. Major depressive episode was uniquely associated with non-blunt marijuana use. With respect to misclassifiers, respondents who reported past 30-day blunt use but not past 30-day marijuana use were younger, Black, female, and had lower education and income. Those who report blunt-only and dual cigar-blunt use showed the most severe risk profiles. Communicating health consequences and risks of blunt use should be directed toward specific subgroups. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

PDE5 inhibition alleviates functional muscle ischemia in boys with Duchenne muscular dystrophy.

PubMed

Nelson, Michael D; Rader, Florian; Tang, Xiu; Tavyev, Jane; Nelson, Stanley F; Miceli, M Carrie; Elashoff, Robert M; Sweeney, H Lee; Victor, Ronald G

2014-06-10

To determine whether phosphodiesterase type 5 (PDE5) inhibition can alleviate exercise-induced skeletal muscle ischemia in boys with Duchenne muscular dystrophy (DMD). In 10 boys with DMD and 10 healthy age-matched male controls, we assessed exercise-induced attenuation of reflex sympathetic vasoconstriction, i.e., functional sympatholysis, a protective mechanism that matches oxygen delivery to metabolic demand. Reflex vasoconstriction was induced by simulated orthostatic stress, measured as the decrease in forearm muscle oxygenation with near-infrared spectroscopy, and performed when the forearm muscles were rested or lightly exercised with rhythmic handgrip exercise. Then, the patients underwent an open-label, dose-escalation, crossover trial with single oral doses of tadalafil or sildenafil. The major new findings are 2-fold: first, sympatholysis is impaired in boys with DMD-producing functional muscle ischemia-despite contemporary background therapy with corticosteroids alone or in combination with cardioprotective medication. Second, PDE5 inhibition with standard clinical doses of either tadalafil or sildenafil alleviates this ischemia in a dose-dependent manner. Furthermore, PDE5 inhibition also normalizes the exercise-induced increase in skeletal muscle blood flow (measured by Doppler ultrasound), which is markedly blunted in boys with DMD. These data provide in-human proof of concept for PDE5 inhibition as a putative new therapeutic strategy for DMD. This study provides Class IV evidence that in patients with DMD, PDE5 inhibition restores functional sympatholysis. © 2014 American Academy of Neurology.

Exercise reveals impairments in left ventricular systolic function in patients with metabolic syndrome.

PubMed

Fournier, Sara B; Reger, Brian L; Donley, David A; Bonner, Daniel E; Warden, Bradford E; Gharib, Wissam; Failinger, Conard F; Olfert, Melissa D; Frisbee, Jefferson C; Olfert, I Mark; Chantler, Paul D

2014-01-01

Metabolic syndrome (MetS) is the manifestation of a cluster of cardiovascular risk factors and is associated with a threefold increase in the risk of cardiovascular morbidity and mortality, which is suggested to be mediated, in part, by resting left ventricular (LV) systolic dysfunction. However, to what extent resting LV systolic function is impaired in MetS is controversial, and there are no data indicating whether LV systolic function is impaired during exercise. Accordingly, the objective of this study was to examine comprehensively the LV and arterial responses to exercise in individuals with MetS without diabetes and/or overt cardiovascular disease in comparison to a healthy control population. Cardiovascular function was characterized using Doppler echocardiography and gas exchange in individuals with MetS (n = 27) versus healthy control subjects (n = 20) at rest and during peak exercise. At rest, individuals with MetS displayed normal LV systolic function but reduced LV diastolic function compared with healthy control subjects. During peak exercise, individuals with MetS had impaired contractility, pump performance and vasodilator reserve capacity versus control subjects. A blunted contractile reserve response resulted in diminished arterial-ventricular coupling reserve and limited aerobic capacity in individuals with MetS versus control subjects. These findings are of clinical importance, because they provide insight into the pathophysiological changes in MetS that may predispose this population of individuals to an increased risk of cardiovascular morbidity and mortality.

Central command does not suppress baroreflex control of cardiac sympathetic nerve activity at the onset of spontaneous motor activity in the decerebrate cat.

PubMed

Matsukawa, Kanji; Ishii, Kei; Asahara, Ryota; Idesako, Mitsuhiro

2016-10-01

Our laboratory has reported that central command blunts the sensitivity of the aortic baroreceptor-heart rate (HR) reflex at the onset of voluntary static exercise in animals. We have examined whether baroreflex control of cardiac sympathetic nerve activity (CSNA) and/or cardiovagal baroreflex sensitivity are altered at the onset of spontaneously occurring motor behavior, which was monitored with tibial nerve activity in paralyzed, decerebrate cats. CSNA exhibited a peak increase (126 ± 17%) immediately after exercise onset, followed by increases in HR and mean arterial pressure (MAP). With development of the pressor response, CSNA and HR decreased near baseline, although spontaneous motor activity was not terminated. Atropine methyl nitrate (0.1-0.2 mg/kg iv) with little central influence delayed the initial increase in HR but did not alter the response magnitudes of HR and CSNA, while atropine augmented the pressor response. The baroreflex-induced decreases in CSNA and HR elicited by brief occlusion of the abdominal aorta were challenged at the onset of spontaneous motor activity. Spontaneous motor activity blunted the baroreflex reduction in HR by aortic occlusion but did not alter the baroreflex inhibition of CSNA. Similarly, atropine abolished the baroreflex reduction in HR but did not influence the baroreflex inhibition of CSNA. Thus it is likely that central command increases CSNA and decreases cardiac vagal outflow at the onset of spontaneous motor activity while preserving baroreflex control of CSNA. Accordingly, central command must attenuate cardiovagal baroreflex sensitivity against an excess rise in MAP as estimated from the effect of muscarinic blockade. Copyright © 2016 the American Physiological Society.

Fluid and electrolyte needs for training, competition, and recovery.

PubMed

Shirreffs, Susan M; Sawka, Michael N

2011-01-01

Fluids and electrolytes (sodium) are consumed by athletes, or recommended to athletes, for a number of reasons, before, during, and after exercise. These reasons are generally to sustain total body water, as deficits (hypohydration) will increase cardiovascular and thermal strain and degrade aerobic performance. Vigorous exercise and warm/hot weather induce sweat production, which contains both water and electrolytes. Daily water (4-10 L) and sodium (3500-7000 mg) losses in active athletes during hot weather exposure can induce water and electrolyte deficits. Both water and sodium need to be replaced to re-establish "normal" total body water (euhydration). This replacement can be by normal eating and drinking practices if there is no urgency for recovery. But if rapid recovery (<24 h) is desired or severe hypohydration (>5% body mass) is encountered, aggressive drinking of fluids and consuming electrolytes should be encouraged to facilitate recovery for subsequent competition.

Muscle activation patterns in the Nordic hamstring exercise: Impact of prior strain injury.

PubMed

Bourne, M N; Opar, D A; Williams, M D; Al Najjar, A; Shield, A J

2016-06-01

This study aimed to determine: (a) the spatial patterns of hamstring activation during the Nordic hamstring exercise (NHE); (b) whether previously injured hamstrings display activation deficits during the NHE; and (c) whether previously injured hamstrings exhibit altered cross-sectional area (CSA). Ten healthy, recreationally active men with a history of unilateral hamstring strain injury underwent functional magnetic resonance imaging of their thighs before and after six sets of 10 repetitions of the NHE. Transverse (T2) relaxation times of all hamstring muscles [biceps femoris long head (BFlh); biceps femoris short head (BFsh); semitendinosus (ST); semimembranosus (SM)] were measured at rest and immediately after the NHE and CSA was measured at rest. For the uninjured limb, the ST's percentage increase in T2 with exercise was 16.8%, 15.8%, and 20.2% greater than the increases exhibited by the BFlh, BFsh, and SM, respectively (P < 0.002 for all). Previously injured hamstring muscles (n = 10) displayed significantly smaller increases in T2 post-exercise than the homonymous muscles in the uninjured contralateral limb (mean difference -7.2%, P = 0.001). No muscles displayed significant between-limb differences in CSA. During the NHE, the ST is preferentially activated and previously injured hamstring muscles display chronic activation deficits compared with uninjured contralateral muscles. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Musculoskeletal adaptations to weightlessness and development of effective countermeasures

NASA Technical Reports Server (NTRS)

Baldwin, K. M.; White, T. P.; Arnaud, S. B.; Edgerton, V. R.; Kraemer, W. J.; Kram, R.; Raab-Cullen, D.; Snow, C. M.

1996-01-01

A Research Roundtable, organized by the American College of Sports Medicine with sponsorship from the National Aeronautics and Space Administration, met in November 1995 to define research strategies for effective exercise countermeasures to weightlessness. Exercise was considered both independently of, and in conjunction with, other therapeutic modalities (e.g., pharmacological nutritional, hormonal, and growth-related factors) that could prevent or minimize the structural and functional deficits involving skeletal muscle and bone in response to chronic exposure to weightlessness, as well as return to Earth baseline function if a degree of loss is inevitable. Musculoskeletal deficits and countermeasures are described with respect to: 1) muscle and connective tissue atrophy and localized bone loss, 2) reductions in motor performance, 3) potential proneness to injury of hard and soft tissues, and 4) probable interaction between muscle atrophy and cardiovascular alterations that contribute to the postural hypotension observed immediately upon return from space flight. In spite of a variety of countermeasure protocols utilized previously involving largely endurance types of exercise, there is presently no activity-specific countermeasure(s) that adequately prevent or reduce musculoskeletal deficiencies. It seems apparent that countermeasure exercises that have a greater resistance element, as compared to endurance activities, may prove beneficial to the musculoskeletal system. Many questions remain for scientific investigation to identify efficacious countermeasure protocols, which will be imperative with the emerging era of long-term space flight.

Prolonged adenosine triphosphate infusion and exercise hyperemia in humans.

PubMed

Shepherd, John R A; Joyner, Michael J; Dinenno, Frank A; Curry, Timothy B; Ranadive, Sushant M

2016-09-01

In humans, intra-arterial ATP infusion in limbs mimics many features of exercise hyperemia. However, it remains unknown whether ATP can evoke the prolonged vasodilation seen during exercise. Therefore, we addressed two questions during a continuous 3-h brachial artery infusion of ATP [20 μg·100 ml forearm volume (FAV)(-1)·min(-1)]: 1) would skeletal muscle blood flow remain robust or wane over time (tachyphylaxis); and 2) would the hyperemic response to moderate-intensity exercise performed during the ATP administration be blunted compared with that during control (saline) infusion. Nine participants (25 ± 1 yr) performed one trial consisting of seven bouts of rhythmic handgrip exercise (20 contractions/min at 20% of maximum), two bouts during saline (control), and five bouts during 180 min of continuous ATP infusion. Five minutes of ATP infusion resulted in a 710% increase in forearm vascular conductance (FVC) from control (4.8 ± 0.77 vs. 35.0 ± 5.7 ml·min(-1)·100 mmHg(-1)·dl FAV(-1), P < 0.05). Contrary to our expectations, FVC did not wane over time with values of 35.0 ± 5.7 and 36.0 ± 7.7 ml·min(-1)·100 mmHg(-1)·dl FAV(-1) (P > 0.05), seen prior to the exercise bouts at 5 vs. 150 min, respectively. During superimposed exercise, FVC increased from 35.0 ± 5.7 to 49.6 ± 5.4 ml·min(-1)·100 mmHg(-1)·dl FAV(-1) at 5 min and 36.0 ± 7.7 to 54.5 ± 5.0 at 150 min (P < 0.05). Our findings demonstrate ATP vasodilation is prolonged over time without tachyphylaxis; however, exercise hyperemia responses remain intact. Our results challenge the metabolic theory of exercise hyperemia, suggesting a disconnect between matching of blood flow and metabolic demand. Copyright © 2016 the American Physiological Society.

Delayed systolic blood pressure recovery following exercise as a mechanism of masked uncontrolled hypertension in chronic kidney disease.

PubMed

Agarwal, Rajiv; Pappas, Maria K

2017-10-01

Among people treated for hypertension, the presence of elevated blood pressure (BP) out of the clinic but normal BP in the clinic is called masked uncontrolled hypertension (MUCH). What causes MUCH remains unknown. The purpose of this study was to answer the question of whether patients with MUCH have an increased hemodynamic reactivity to exercise and delayed hemodynamic recovery following exercise. Four groups were compared: controlled hypertension (CH, n = 58), MUCH (n = 34) and uncontrolled hypertension (UCH, n = 12), all of which had chronic kidney disease (CKD), and a group of healthy normal volunteers who did not have hypertension or CKD (n = 16). All participants underwent assessment of 24-h ambulatory BP monitoring, BP measurement during a graded symptom-limited exercise using a cycle ergometer and BP recovery over 7 min following exercise. Exercise-induced increase in systolic BP was similar among the four groups. When compared with healthy controls, recovery of systolic BP following termination of exercise was blunted among the CKD groups in unadjusted (P < 0.0001) and adjusted (P < 0.001) models. During recovery, the healthy control group had 5.9% decline in systolic BP per minute. In contrast, MUCH had only 3.3% per minute reduction and the UCH group had 0.3% reduction per minute. A test of linear trend was significant (P = 0.002, adjusted model). Because there was no impairment in the heart rate recovery among groups, we speculate that the parasympathetic pathway appears intact among treated hypertensives with CKD. However, the failure to withdraw sympathetic tone upon termination of exercise causes ongoing vasoconstriction and delayed systolic BP recovery providing a biological basis for MUCH. Delayed recovery from exercise-induced hypertension in those with poorly controlled BP provides potentially a new target to assure round-the-clock BP control. Published by Oxford University Press on behalf of ERA-EDTA 2016. This work is written by US Government employees and is in the public domain in the US.

Lack of independent effect of type 2 diabetes beyond characteristic comorbidities and medications on small muscle mass exercising muscle blood flow and exercise tolerance.

PubMed

Poitras, Veronica J; Bentley, Robert F; Hopkins-Rosseel, Diana H; LaHaye, Stephen A; Tschakovsky, Michael E

2015-08-01

Persons with type 2 diabetes (T2D) are believed to have reduced exercise tolerance; this may be partly due to impaired exercising muscle blood flow (MBF). Whether there is an impact of T2D on exercising MBF within the typical constellation of comorbidities (hypertension, dyslipidemia, obesity) and their associated medications has not been investigated. We tested the hypothesis that small muscle mass exercise tolerance is reduced in persons with T2D versus Controls (matched for age, body mass index, fitness, comorbidities, non-T2D medications) and that this is related to blunted MBF. Eight persons with T2D and eight controls completed a forearm critical force (fCFimpulse) test as a measure of exercise tolerance (10-min intermittent maximal effort forearm contractions; the average contraction impulse in the last 30 sec quantified fCFimpulse). Forearm blood flow (FBF; ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured; forearm vascular conductance (FVK) was calculated. Data are means ± SD, T2D versus Control. fCFimpulse was not different between groups (136.9 ± 47.3  N·sec vs. 163.1 ± 49.7 N·sec, P = 0.371) nor was the ∆FBF from rest to during exercise at fCFimpulse (502.9 ± 144.6 vs. 709.1 ± 289.2 mL/min, P = 0.092), or its determinants ∆FVK and ∆MAP (both P > 0.05), although there was considerable interindividual variability. ∆FBF was strongly related to fCFimpulse (r = 0.727, P = 0.002), providing support for the relationship between oxygen delivery and exercise tolerance. We conclude that small muscle mass exercising MBF and exercise tolerance are not impaired in representative persons with T2D versus appropriately matched controls. This suggests that peripheral vascular control impairment does not contribute to reduced exercise tolerance in this population. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Lack of independent effect of type 2 diabetes beyond characteristic comorbidities and medications on small muscle mass exercising muscle blood flow and exercise tolerance

PubMed Central

Poitras, Veronica J; Bentley, Robert F; Hopkins-Rosseel, Diana H; LaHaye, Stephen A; Tschakovsky, Michael E

2015-01-01

Persons with type 2 diabetes (T2D) are believed to have reduced exercise tolerance; this may be partly due to impaired exercising muscle blood flow (MBF). Whether there is an impact of T2D on exercising MBF within the typical constellation of comorbidities (hypertension, dyslipidemia, obesity) and their associated medications has not been investigated. We tested the hypothesis that small muscle mass exercise tolerance is reduced in persons with T2D versus Controls (matched for age, body mass index, fitness, comorbidities, non-T2D medications) and that this is related to blunted MBF. Eight persons with T2D and eight controls completed a forearm critical force (fCFimpulse) test as a measure of exercise tolerance (10-min intermittent maximal effort forearm contractions; the average contraction impulse in the last 30 sec quantified fCFimpulse). Forearm blood flow (FBF; ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured; forearm vascular conductance (FVK) was calculated. Data are means ± SD, T2D versus Control. fCFimpulse was not different between groups (136.9 ± 47.3  N·sec vs. 163.1 ± 49.7 N·sec, P = 0.371) nor was the ΔFBF from rest to during exercise at fCFimpulse (502.9 ± 144.6 vs. 709.1 ± 289.2 mL/min, P = 0.092), or its determinants ΔFVK and ΔMAP (both P > 0.05), although there was considerable interindividual variability. ΔFBF was strongly related to fCFimpulse (r = 0.727, P = 0.002), providing support for the relationship between oxygen delivery and exercise tolerance. We conclude that small muscle mass exercising MBF and exercise tolerance are not impaired in representative persons with T2D versus appropriately matched controls. This suggests that peripheral vascular control impairment does not contribute to reduced exercise tolerance in this population. PMID:26265750

Creatine and Caffeine: Considerations for Concurrent Supplementation.

PubMed

Trexler, Eric T; Smith-Ryan, Abbie E

2015-12-01

Nutritional supplementation is a common practice among athletes, with creatine and caffeine among the most commonly used ergogenic aids. Hundreds of studies have investigated the ergogenic potential of creatine supplementation, with consistent improvements in strength and power reported for exercise bouts of short duration (≤ 30 s) and high intensity. Caffeine has been shown to improve endurance exercise performance, but results are mixed in the context of strength and sprint performance. Further, there is conflicting evidence from studies comparing the ergogenic effects of coffee and caffeine anhydrous supplementation. Previous research has identified independent mechanisms by which creatine and caffeine may improve strength and sprint performance, leading to the formulation of multi-ingredient supplements containing both ingredients. Although scarce, research has suggested that caffeine ingestion may blunt the ergogenic effect of creatine. While a pharmacokinetic interaction is unlikely, authors have suggested that this effect may be explained by opposing effects on muscle relaxation time or gastrointestinal side effects from simultaneous consumption. The current review aims to evaluate the ergogenic potential of creatine and caffeine in the context of high-intensity exercise. Research directly comparing coffee and caffeine anhydrous is discussed, along with previous studies evaluating the concurrent supplementation of creatine and caffeine.

Energy replacement diminishes the effect of exercise on postprandial lipemia in boys.

PubMed

Thackray, Alice E; Barrett, Laura A; Tolfrey, Keith

2016-04-01

Acute bouts of exercise reduce postprandial triacylglycerol concentrations ([TAG]) in healthy boys and girls; however, it is not known whether this effect is mediated by the energy deficit. This study examined whether the exercise-induced reduction in postprandial [TAG] persists after immediate dietary replacement of the exercise energy expenditure (EE). Eighteen healthy 11- to 13-year-old boys (mean (SD): body mass 41.3 (8.4)kg; peak oxygen uptake (V̇O2) 55 (5)mL·kg(-1)·min(-1)) completed three, 2-day conditions in a within-measures, crossover design separated by 14days. On day 1, participants rested (CON), exercised at 60% peak V̇O2 inducing a net EE of 32kJ·kg(-1) body mass (EX-DEF) or completed the same exercise with the net EE replaced immediately (EX-REP). On day 2, capillary blood samples were taken in the fasted state and at pre-determined intervals throughout the 6.5h postprandial period. A standardised breakfast and lunch meal were consumed immediately and 4h, respectively, after the fasting sample. Based on ratios of the geometric means (95% confidence intervals (CI) for ratios), EX-DEF fasting [TAG] was 19% and 15% lower than CON (-32 to -4%, ES=1.15, P=0.02) and EX-REP (-29 to 0%, ES=0.91, P=0.05) respectively; CON and EX-REP were similar (-4%; P=0.59). The EX-DEF total area under the [TAG] versus time curve was 15% and 16% lower than CON (-27 to 0%, ES=0.55, P=0.05) and EX-REP (-29 to -2%, ES=0.62, P=0.03) respectively; CON and EX-REP were not different (2%; -13 to 20%, P=0.80). Immediate replacement of the exercise-induced energy deficit negates the reduction in postprandial [TAG] in boys; this highlights the importance of maintaining a negative energy balance immediately post-exercise to maximise the metabolic health benefits of exercise. Copyright © 2016 Elsevier Inc. All rights reserved.

[Balance of iron and copper in cadets of military school during physical exercise and next-day rest at different times of the year].

PubMed

Zaĭtseva, I P; Nasolodin, V V; Beliakov, R A; Arshinov, N P; Zaĭtsev, O N; Meshcheriakov, S I

2013-03-01

According to examination, with the help of emission spectrum analysis method, of 24 cadets-athletes of different specialization it was determined that during physical exercise in summer and in winter loss of ferrum and copper with excrements exceeded the intake if these microelements with food. The next day rise of impaction of microelements and decrease of excretion. But despite the positive balance of ferrum and copper, spend of these microelements during physical exercise wasn't compensated for the day of rest. That is why there is a possibility of microelement deficit.

Exercise Promotes Healthy Aging of Skeletal Muscle

PubMed Central

Cartee, Gregory D.; Hepple, Russell T.; Bamman, Marcas M.; Zierath, Juleen R.

2016-01-01

Primary aging is the progressive and inevitable process of bodily deterioration during adulthood. In skeletal muscle, primary aging causes defective mitochondrial energetics, and reduced muscle mass. Secondary aging refers to additional deleterious structural and functional age-related changes caused by diseases and lifestyle factors. Secondary aging can exacerbate deficits in mitochondrial function and muscle mass, concomitant with the development of skeletal muscle insulin resistance. Exercise opposes deleterious effects of secondary aging by preventing the decline in mitochondrial respiration, mitigating aging-related loss of muscle mass and enhancing insulin sensitivity. This review focuses on mechanisms by which exercise promotes “healthy aging” by inducing modifications in skeletal muscle. PMID:27304505

Healthy body, healthy mind?: the effectiveness of physical activity to treat ADHD in children.

PubMed

Halperin, Jeffrey M; Berwid, Olga G; O'Neill, Sarah

2014-10-01

Data from animal studies provide convincing evidence that physical exercise enhances brain development and neurobehavioral functioning in areas believed to be impaired in children with attention-deficit/hyperactivity disorder (ADHD). To a lesser but still compelling extent, results from studies in typically developing children and adults indicate beneficial effects of exercise on many of the neurocognitive functions that have been shown to be impaired in children with ADHD. Together, these data provide a strong rationale for why a program of structured physical exercise might serve as an effective intervention for children with ADHD. Copyright © 2014 Elsevier Inc. All rights reserved.

De-masking oxytocin-deficiency in craniopharyngioma and assessing its link with affective function.

PubMed

Gebert, Dorothea; Auer, Matthias K; Stieg, Mareike R; Freitag, Martin T; Lahne, Madlén; Fuss, Johannes; Schilbach, Katharina; Schopohl, Jochen; Stalla, Günter K; Kopczak, Anna

2018-02-01

Despite the high prevalence of panhypopituitarism and diabetes insipidus in patients with craniopharyngioma (CP), little is known about the functioning of the neuropeptide oxytocin in these patients. This is of special interest as tumor-associated lesions often impair sites critical for oxytocin production and release, and affective dysfunction in CP links with elsewhere reported prosocial, antidepressant and anxiolytic oxytocin effects. Using a prospective study-design, we tested whether oxytocin is reduced in CP-patients, and whether altered oxytocin levels account for affective and emotional dysfunction. 26 adult CP-patients and 26 healthy controls matched in sex and age underwent physical exercise, a stimulus previously shown to induce oxytocin release. Baseline and stimulated salivary oxytocin levels, as well as empathy, depression and anxiety scores were measured. Results showed that patients overall did not present with lower baseline oxytocin levels than controls (F[1,30]=0.21, p=0.649), but baseline oxytocin levels were indeed reduced in patients with hypothalamic damage, as assessed by MRI-based grading (F[2,9.79]=4.54, p=0.040). In response to exercise-induced stimulation, all CP-patients showed a blunted oxytocin-release compared to controls (F[1,30]=9.36, p=0.005). DI was not associated with oxytocin levels. Regarding affective function, unexpectedly, higher baseline oxytocin was related to higher trait anxiety (b=2.885, t(43)=2.421, p=0.020, CI[.478; 5.292]); the positive link with higher depression failed to reach statistical significance (b=1.928, t(43)=1.949, p=0.058, CI[-0.070; 3.927]). A blunted oxytocin-release was linked with higher state anxiety (b=-0.133, t(43)=-2.797, p=0.008, CI[-0.230; -0.037]). Empathy was not associated with oxytocin measures. In conclusion, we observed reduced baseline oxytocin levels only in CP-patients with hypothalamic damage. Exercise-induced stimulation de-masked an oxytocin-deficiency in all CP-patients. Baseline oxytocin levels and stimulated OT-responses might have different effects on affective function, which should be considered in future substitution paradigms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Acute aerobic exercise helps overcome emotion regulation deficits.

PubMed

Bernstein, Emily E; McNally, Richard J

2017-06-01

Although colloquial wisdom and some studies suggest an association between regular aerobic exercise and emotional well-being, the nature of this link remains poorly understood. We hypothesised that aerobic exercise may change the way people respond to their emotions. Specifically, we tested whether individuals experiencing difficulties with emotion regulation would benefit from a previous session of exercise and show swifter recovery than their counterparts who did not exercise. Participants (N = 80) completed measures of emotion response tendencies, mood, and anxiety, and were randomly assigned to either stretch or jog for 30 minutes. All participants then underwent the same negative and positive mood inductions, and reported their emotional responses. Analyses showed that more perceived difficulty generating regulatory strategies and engaging in goal-directed behaviours after the negative mood induction predicted more intense and persistent negative affect in response to the stressor, as would be expected. Interactions revealed that aerobic exercise attenuated these effects. Moderate aerobic exercise may help attenuate negative emotions for participants initially experiencing regulatory difficulties. This study contributes to the literature on aerobic exercise's therapeutic effects with experimental data, specifically in the realm of emotional processing.

Effects of Gabra2 Point Mutations on Alcohol Intake: Increased Binge-Like and Blunted Chronic Drinking by Mice.

PubMed

Newman, Emily L; Gunner, Georgia; Huynh, Polly; Gachette, Darrel; Moss, Stephen J; Smart, Trevor G; Rudolph, Uwe; DeBold, Joseph F; Miczek, Klaus A

2016-11-01

Alcohol use disorders are associated with single-nucleotide polymorphisms in GABRA2, the gene encoding the GABA A receptor α2-subunit in humans. Deficient GABAergic functioning is linked to impulse control disorders, intermittent explosive disorder, and to drug abuse and dependence, yet it remains unclear whether α2-containing GABA A receptor sensitivity to endogenous ligands is involved in excessive alcohol drinking. Male wild-type (Wt) C57BL/6J and point-mutated mice rendered insensitive to GABAergic modulation by benzodiazepines (BZD; H101R), allopregnanolone (ALLO) or tetrahydrodeoxycorticosterone (THDOC; Q241M), or high concentrations of ethanol (EtOH) (S270H/L277A) at α2-containing GABA A receptors were assessed for their binge-like, moderate, or escalated chronic drinking using drinking in the dark, continuous access (CA) and intermittent access (IA) to alcohol protocols, respectively. Social approach by mutant and Wt mice in forced alcohol abstinence was compared to approach by EtOH-naïve controls. Social deficits in forced abstinence were treated with allopregnanolone (0, 3.0, 10.0 mg/kg, intraperitoneal [i.p.]) or midazolam (0, 0.56, 1.0 mg/kg, i.p.). Mice with BZD-insensitive α2-containing GABA A receptors (H101R) escalated their binge-like drinking. Mutants harboring the Q241M point substitution in Gabra2 showed blunted chronic intake in the CA and IA protocols. S270H/L277A mutants consumed excessive amounts of alcohol but, unlike wild-types, they did not show forced abstinence-induced social deficits. These findings suggest a role for: (i) H101 in species-typical binge-like drinking, (ii) Q241 in escalated chronic drinking, and (iii) S270 and/or L277 in the development of forced abstinence-associated social deficits. Clinical findings report reduced BZD-binding sites in the cortex of dependent patients; the present findings suggest a specific role for BZD-sensitive α2-containing receptors. In addition, amino acid residue 241 in Gabra2 is necessary for positive modulation and activation of GABA A receptors by ALLO and THDOC; we postulate that neurosteroid action on α2-containing receptor may be necessary for escalated chronic EtOH intake. Copyright © 2016 by the Research Society on Alcoholism.

Clinical evaluation of laryngeal sensation in horses.

PubMed

Gaughan, E M; Hackett, R P; Ducharme, N G; Rakestraw, P C

1990-01-01

Sensory innervation of the larynx was examined by tactile stimulation with a blunt biopsy forceps passed through a flexible videoendoscope. Twenty horses with no evidence of laryngeal motor deficit were stimulated on 10 sites by touch with the forceps. Unilateral neurectomies of the internal branch of the left cranial laryngeal nerve were performed on 5 other horses. These horses were stimulated by touch on the same sites preoperatively and up to 1 week postoperatively. In all 25 horses the motor response of the larynx was recorded on videotape and evaluated by 2 observers blind as to treatment and time of evaluation. Normal horses responded to touch by adduction of both arytenoid cartilages, swallowing or both. This response was not altered by sedation with xylazine hydrochloride. Left cranial laryngeal neurectomized horses failed to respond to tactile stimulation of the left side, while adduction of both cartilages, swallowing or both was observed following stimulation on the right side. Laryngeal stimulation by touch with a biopsy forceps was accurate in identifying horses with complete deficits of the internal branch of the cranial laryngeal nerve.

The influence of estradiol on muscle damage and leg strength after intense eccentric exercise.

PubMed

Minahan, Clare; Joyce, Sarah; Bulmer, Andrew C; Cronin, Neil; Sabapathy, Surendran

2015-07-01

To examine the influence of estradiol on muscle damage and leg strength after intense eccentric exercise. Eight men (MEN), eight normally menstruating women (WomenNM), and eight women using oral contraceptives (WomenOC) participated in this study. Subjects performed 240 maximal-effort bilateral eccentric contractions of the quadriceps muscle groups designed to elicit exercise-induced muscle damage (EiMD). Serum creatine kinase (CK), myoglobin (Mb), and fatty acid-binding protein (FABP) concentrations were measured before (pre-) EiMD, as well as 0, 6, 24, and 48 h post-EiMD. Peak isometric quadriceps torque (i.e., leg strength) was measured pre-EiMD, as well as 24 and 48 h post-EiMD. The increases in CK, Mb, and FABP concentrations from pre- to post-EiMD were greater in MEN (10-fold, 15-fold, and fourfold, respectively) and WomenOC (sevenfold, 11-fold, and ninefold) compared with WomenNM (five-, six-, and threefold; p < 0.05). The decline in leg strength was about 10 % pre- to 24 h post-EiMD in all groups and decreased a further 10-15 % by 48 h post-EiMD in the MEN and WomenOC only. Our findings suggest an important role of estradiol in blunting the muscle damage response to intense eccentric exercise and preserving muscle function after EiMD.

Baroreflex Function in Rats after Simulated Microgravity

NASA Technical Reports Server (NTRS)

Hasser, Eileen M.

1997-01-01

Prolonged exposure of humans to decreased gravitational forces during spaceflight results in a number of adverse cardiovascular consequences, often referred to as cardiovascular deconditioning. Prominent among these negative cardiovascular effects are orthostatic intolerance and decreased exercise capacity. Rat hindlimb unweighting is an animal model which simulates weightlessness, and results in similar cardiovascular consequences. Cardiovascular reflexes, including arterial and cardiopulmonary baroreflexes, are required for normal adjustment to both orthostatic challenges and exercise. Therefore, the orthostatic intolerance and decreased exercise capacity associated with exposure to microgravity may be due to cardiovascular reflex dysfunction. The proposed studies will test the general hypothesis that hindlimb unweighting in rats results in impaired autonomic reflex control of the sympathetic nervous system. Specifically, we hypothesize that the ability to reflexly increase sympathetic nerve activity in response to decreases in arterial pressure or blood volume will be blunted due to hindlimb unweighting. There are 3 specific aims: (1) To evaluate arterial and cardiopulmonary baroreflex control of renal and lumbar sympathetic nerve activity in conscious rats subjected to 14 days of hindlimb unweighting; (2) To examine the interaction between arterial and cardiopulmonary baroreflex control of sympathetic nerve activity in conscious hindlimb unweighted rats; (3) to evaluate changes in afferent and/or central nervous system mechanisms in baroreflex regulation of the sympathetic nervous system. These experiments will provide information related to potential mechanisms for orthostatic and exercise intolerance due to microgravity.

Drinking and water balance during exercise and heat acclimation

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Brock, P. J.; Keil, L. C.; Morse, J. T.

1983-01-01

The interactions between fluid intake and balance, and plasma ion, osmotic, and endocrine responses during dehydration produced by exercise in cool and warm environments during acclimation are explored. Two groups of five male subjects performed 8 days of ergometer exercise in hot and thermoneutral conditions, respectively. The exercise trials lasted 2 hr each. Monitoring was carried out on the PV, osmotic, sodium, and endocrine concentrations, voluntary fluid intake, fluid balances, and fluid deficits. A negative correlation was observed between the plasma sodium and osmolality during acclimation. The presence of hypervolemia during acclimation is suggested as a cause of drinking, while the vasopressin concentration was not found to be a significant factor stimulating drinking. Finally, the predominant mechanism in fluid intake during exercise and heat exposure is concluded to be the renin-angiotensin II system in the presence of reductions in total body water and extracellular plasma volumes.

Effects of Moderate Aerobic Exercise Combined with Caloric Restriction on Circulating Estrogens and IGF-I in Premenopausal Women

DTIC Science & Technology

2003-10-01

lipoprotein responses to a hypocaloric low carbohydrate diet rich in monounsaturated fat and supplemented with n-3 fatty acids" (Kinesiology) 2002 Greg...as those addressing the role of physical activity and or diet in the risk of breast cancer, the battery of metabolic hormones that comprise the...proposed studies will yield new and important information regarding the degree to which an exercise and diet program that results in an energy deficit

Effects of Moderate Aerobic Exercise Combined with Caloric Restriction on Circulating Estrogens and IGF-I in Premenopausal Women

DTIC Science & Technology

2002-10-01

postprandial serum lipoprotein respomes to a hypocaloric low carbohydrate diet rich in monounsaturated fat and siqqjlemented with n-3 fatty aci...method of energy status assessment in large population-based applications, such as those addressing the role of physical activity and or diet in the...the degree to which an exercise and diet program that results in an energy deficit will reduce the risk of breast cancer. Body Study Design: The

Exercise training alters effect of high-fat feeding on the ACTH stress response in pigs.

PubMed

Jankord, Ryan; Ganjam, Venkataseshu K; Turk, James R; Hamilton, Marc T; Laughlin, M Harold

2008-06-01

Eating and physical activity behaviors influence neuroendocrine output. The purpose of this study was to test, in an animal model of diet-induced cardiovascular disease, the effects of high-fat feeding and exercise training on hypothalamo-pituitary-adrenocortical (HPA) axis activity. We hypothesized that a high-fat diet would increase circulating free fatty acids (FFAs) and decrease the adrenocorticotropic hormone (ACTH) and cortisol response to an acute stressor. We also hypothesized that exercise training would reverse the high-fat diet-induced changes in FFAs and thereby restore the ACTH and cortisol response. Pigs were placed in 1 of 4 groups (normal diet, sedentary; normal diet, exercise training; high-fat diet, sedentary; high-fat diet, exercise training; n = 8/group). Animals were placed on their respective dietary and activity treatments for 16-20 weeks. After completion of the treatments animals were anesthetized and underwent surgical intubation. Blood samples were collected after surgery and the ACTH and cortisol response to surgery was determined and the circulating concentrations of FFAs, glucose, cholesterol, insulin, and IGF-1 were measured. Consistent with our hypothesis, high-fat feeding increased FFAs by 200% and decreased the ACTH stress response by 40%. In exercise-trained animals, the high-fat diet also increased FFA; however, the increase in FFA in exercise-trained pigs was accompanied by a 60% increase in the ACTH response. The divergent effect of high-fat feeding on ACTH response was not expected, as exercise training alone had no effect on the ACTH response. Results demonstrate a significant interaction between diet and exercise and their effect on the ACTH response. The divergent effects of high-fat diet could not be explained by changes in weight gain, blood glucose, insulin, or IGF-1, as these were altered by high-fat feeding, but unaffected by exercise training. Thus, the increase in FFA with high-fat feeding may explain the blunted ACTH response to an acute stressor in sedentary animals, but cannot explain the exaggerated response in exercise trained animals.

Exercise training alters effect of high-fat feeding on the ACTH stress response in pigs

PubMed Central

Jankord, Ryan; Ganjam, Venkataseshu K.; Turk, James R.; Hamilton, Marc T.; Laughlin, M. Harold

2009-01-01

Eating and physical activity behaviors influence neuroendocrine output. The purpose of this study was to test, in an animal model of diet-induced cardiovascular disease, the effects of high-fat feeding and exercise training on hypothalamo–pituitary–adrenocortical (HPA) axis activity. We hypothesized that a high-fat diet would increase circulating free fatty acids (FFAs) and decrease the adrenocorticotropic hormone (ACTH) and cortisol response to an acute stressor. We also hypothesized that exercise training would reverse the high-fat diet-induced changes in FFAs and thereby restore the ACTH and cortisol response. Pigs were placed in 1 of 4 groups (normal diet, sedentary; normal diet, exercise training; high-fat diet, sedentary; high-fat diet, exercise training; n = 8/group). Animals were placed on their respective dietary and activity treatments for 16–20 weeks. After completion of the treatments animals were anesthetized and underwent surgical intubation. Blood samples were collected after surgery and the ACTH and cortisol response to surgery was determined and the circulating concentrations of FFAs, glucose, cholesterol, insulin, and IGF-1 were measured. Consistent with our hypothesis, high-fat feeding increased FFAs by 200% and decreased the ACTH stress response by 40%. In exercise-trained animals, the high-fat diet also increased FFA; however, the increase in FFA in exercise-trained pigs was accompanied by a 60% increase in the ACTH response. The divergent effect of high-fat feeding on ACTH response was not expected, as exercise training alone had no effect on the ACTH response. Results demonstrate a significant interaction between diet and exercise and their effect on the ACTH response. The divergent effects of high-fat diet could not be explained by changes in weight gain, blood glucose, insulin, or IGF-1, as these were altered by high-fat feeding, but unaffected by exercise training. Thus, the increase in FFA with high-fat feeding may explain the blunted ACTH response to an acute stressor in sedentary animals, but cannot explain the exaggerated response in exercise trained animals. PMID:18461098

Acute molecular responses to concurrent resistance and high-intensity interval exercise in untrained skeletal muscle

PubMed Central

Pugh, Jamie K; Faulkner, Steve H; Jackson, Andrew P; King, James A; Nimmo, Myra A

2015-01-01

Concurrent training involving resistance and endurance exercise may augment the benefits of single-mode training for the purpose of improving health. However, muscle adaptations, associated with resistance exercise, may be blunted by a subsequent bout of endurance exercise, via molecular interference. High-intensity interval training (HIIT), generating similar adaptations to endurance exercise, may offer an alternative exercise mode to traditional endurance exercise. This study examined the influence of an acute HIIT session on the molecular responses following resistance exercise in untrained skeletal muscle. Ten male participants performed resistance exercise (4 × 8 leg extensions, 70% 1RM, (RE)) or RE followed by HIIT (10 × 1 min at 90% HRmax, (RE+HIIT)). Muscle biopsies were collected from the vastus lateralis before, 2 and 6 h post-RE to determine intramuscular protein phosphorylation and mRNA responses. Phosphorylation of Akt (Ser473) decreased at 6 h in both trials (P < 0.05). Phosphorylation of mTOR (Ser2448) was higher in RE+HIIT (P < 0.05). All PGC-1α mRNA variants increased at 2 h in RE+HIIT with PGC-1α and PGC-1α-ex1b remaining elevated at 6 h, whereas RE-induced increases at 2 and 6 h for PGC-1α-ex1b only (P < 0.05). Myostatin expression decreased at 2 and 6 h in both trials (P < 0.05). MuRF-1 was elevated in RE+HIIT versus RE at 2 and 6 h (P < 0.05). Atrogin-1 was lower at 2 h, with FOXO3A downregulated at 6 h (P < 0.05). These data do not support the existence of an acute interference effect on protein signaling and mRNA expression, and suggest that HIIT may be an alternative to endurance exercise when performed after resistance exercise in the same training session to optimize adaptations. PMID:25902785

Exercise Type Affects Cardiac Vagal Autonomic Recovery After a Resistance Training Session.

PubMed

Mayo, Xián; Iglesias-Soler, Eliseo; Fariñas-Rodríguez, Juán; Fernández-Del-Olmo, Miguel; Kingsley, J Derek

2016-09-01

Mayo, X, Iglesias-Soler, E, Fariñas-Rodríguez, J, Fernández-del-Olmo, M, and Kingsley, JD. Exercise type affects cardiac vagal autonomic recovery after a resistance training session. J Strength Cond Res 30(9): 2565-2573, 2016-Resistance training sessions involving different exercises and set configurations may affect the acute cardiovascular recovery pattern. We explored the interaction between exercise type and set configuration on the postexercise cardiovagal withdrawal measured by heart rate variability and their hypotensive effect. Thirteen healthy participants (10 repetitions maximum [RM] bench press: 56 ± 10 kg; parallel squat: 91 ± 13 kg) performed 6 sessions corresponding to 2 exercises (Bench press vs. Parallel squat), 2 set configurations (Failure session vs. Interrepetition rest session), and a Control session of each exercise. Load (10RM), volume (5 sets), and rest (720 seconds) were equated between exercises and set configurations. Parallel squat produced higher reductions in cardiovagal recovery vs. Bench press (p = 0.001). These differences were dependent on the set configuration, with lower values in Parallel squat vs. Bench press for Interrepetition rest session (1.816 ± 0.711 vs. 2.399 ± 0.739 Ln HF/IRR × 10, p = 0.002), but not for Failure session (1.647 ± 0.904 vs. 1.808 ± 0.703 Ln HF/IRR × 10, p > 0.05). Set configuration affected the cardiovagal recovery, with lower values in Failure session in comparison with Interrepetition rest (p = 0.027) and Control session (p = 0.022). Postexercise hypotension was not dependent on the exercise type (p > 0.05) but was dependent on the set configuration, with lower values of systolic (p = 0.004) and diastolic (p = 0.011) blood pressure after the Failure session but not after an Interrepetition rest session in comparison with the Control session (p > 0.05). These results suggest that the exercise type and an Interrepetition rest design could blunt the decrease of cardiac vagal activity after exercise while exercising to muscular failure may contribute to the onset of postexercise hypotension.

High frequency of luteal phase deficiency and anovulation in recreational women runners: blunted elevation in follicle-stimulating hormone observed during luteal-follicular transition.

PubMed

De Souza, M J; Miller, B E; Loucks, A B; Luciano, A A; Pescatello, L S; Campbell, C G; Lasley, B L

1998-12-01

The purposes of this investigation were to evaluate the characteristics of three consecutive menstrual cycles and to determine the frequency ofluteal phase deficiency (LPD) and anovulation in a sample of sedentary and moderately exercising, regularly menstruating women. For three consecutive menstrual cycles, subjects collected daily urine samples for analysis of FSH, estrone conjugates (E1C), pregnanediol-3-glucuronide (PdG), and creatinine (Cr). Sedentary (n=11) and exercising (n=24) groups were similar in age (27.0+/-1.3 yr), weight (60.3+/-3.1 kg), gynecological age (13.8+/-1.2 yr), and menstrual cycle length (28.3+/-0.8 days). Menstrual cycles were classified by endocrine data as ovulatory, LPD, or anovulatory. No sedentary women (0%) had inconsistent menstrual cycle classifications from cycle to cycle, but 46% of the exercising women were inconsistent. The sample prevalence of LPD in the exercising women was 48%, and the 3-month sample incidence was 79%. In the sedentary women, 90% of all menstrual cycles were ovulatory (SedOvul; n=28), whereas in the exercising women only 45% were ovulatory (ExOvul; n=30); 43% were LPD (ExLPD; n=28), and 12% were anovulatory (ExAnov; n=8). In ExLPD cycles, the follicular phase was significantly longer (17.9+/-0.7 days), and the luteal phase was significantly shorter (8.2+/-0.5 days) compared to ExOvul (14.8+/-0.9 and 12.9+/-0.3 days) and SedOvul (15.9+/-0.6 and 12.9+/-0.4 days) cycles. Luteal phase PdG excretion was lower (P < 0.001) in ExLPD (2.9+/-0.3 microg/mg Cr) and ExAnov (0.8+/-0.1 microg/mg Cr) cycles compared to SedOvul cycles (5.0+/-0.4 microg/mg Cr). ExOvul cycles also had less (P < 0.01) PdG excretion during the luteal phase (3.7+/-0.3 microg/mg Cr) than the SedOvul cycles. E1C excretion during follicular phase days 2-5 was lower (P=0.05) in ExOvul, ExLPD, and ExAnov cycles compared to SedOvul cycles and remained lower (P < 0.02) in the ExLPD and ExAnov cycles during days 6-12. The elevation in FSH during the luteal-follicular transition was lower (P < 0.007) in ExLPD (0.7+/-0.1 ng/mg Cr) cycles compared to SedOvul and ExOvul cycles (1.0+/-0.1 and 1.1+/-0.1 ng/mg Cr, respectively). Energy balance and energy availability were lower (P < 0.05) in ExAnov cycles than in other menstrual cycle categories. The blunted elevation in FSH during the luteal-follicular transition in exercising women with LPD may explain their lower follicular estradiol levels. These alterations in FSH may act in concert with disrupted LH pulsatility as a primary and proximate factor in the high frequency of luteal phase and ovulatory disturbances in regularly menstruating, exercising women.

Anticipatory and consummatory pleasure and displeasure in major depressive disorder: An experience sampling study.

PubMed

Wu, Haijing; Mata, Jutta; Furman, Daniella J; Whitmer, Anson J; Gotlib, Ian H; Thompson, Renee J

2017-02-01

Pleasure and displeasure can be parsed into anticipatory and consummatory phases. However, research on pleasure and displeasure in major depressive disorder (MDD), a disorder characterized by anhedonia, has largely focused on deficits in the consummatory phase. Moreover, most studies in this area have been laboratory-based, raising the question of how component processes of pleasure and displeasure are experienced in the daily lives of depressed individuals. Using experience sampling, we compared anticipatory and consummatory pleasure and displeasure for daily activities reported by adults with MDD (n = 41) and healthy controls (n = 39). Participants carried electronic devices for one week and were randomly prompted eight times a day to answer questions about activities to which they most and least looked forward. Compared to healthy controls, MDD participants reported blunted levels of both anticipatory and consummatory pleasure and elevated levels of both anticipatory and consummatory displeasure for daily activities. Independent of MDD status, participants accurately predicted pleasure but overestimated displeasure. These results are the first to provide evidence that, across both anticipatory and consummatory phases, individuals with MDD experience blunted pleasure and elevated displeasure for daily activities. Our findings clarify the disturbances in pleasure and displeasure that characterize MDD and may inform treatment for this debilitating disorder. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Perseveration by NK1R-/- (‘knockout’) mice is blunted by doses of methylphenidate that affect neither other aspects of their cognitive performance nor the behaviour of wild-type mice in the 5-Choice Continuous Performance Test

PubMed Central

Pillidge, Katharine; Porter, Ashley J; Young, Jared W; Stanford, S Clare

2016-01-01

The underlying cause(s) of abnormalities expressed by patients with attention deficit hyperactivity disorder (ADHD) have yet to be delineated. One factor that has been associated with increased vulnerability to ADHD is polymorphism(s) of TACR1, which is the human equivalent of the rodent NK1 (substance P-preferring) receptor gene (Nk1r). We have reported previously that genetically altered mice, lacking functional NK1R (NK1R–/–), express locomotor hyperactivity, which was blunted by the first-line treatment for ADHD, methylphenidate. Here, we compared the effects of this psychostimulant (3, 10 and 30 mg/kg, intraperitoneally) on the behaviour of NK1R-/- mice and their wild types in the 5-Choice Continuous Performance Test, which emulates procedures used to study attention and response control in ADHD patients. Methylphenidate increased total trials (a measure of ‘productivity’) completed by wild types, but not by NK1R-/- mice. Conversely, this drug reduced perseveration by NK1R-/- mice, but not by wild types. Other drug-induced changes in key behaviours were not genotype dependent, especially at the highest dose: for example, % omissions (an index of inattentiveness) was increased, whereas % false alarms and % premature responses (measures of impulsivity) declined in both genotypes, indicating reduced overall response. These findings are discussed in the context of the efficacy of methylphenidate in the treatment of ADHD. Moreover, they lead to several testable proposals. First, methylphenidate does not improve attention in a subgroup of ADHD patients with a functional deficit of TACR1. Second, these patients do not express excessive false alarms when compared with other groups of subjects, but they do express excessive perseveration, which would be ameliorated by methylphenidate. PMID:27097734

Disrupted Reinforcement Learning and Maladaptive Behavior in Women with a History of Childhood Sexual Abuse: A High-Density Event-Related Potential Study

PubMed Central

Pechtel, Pia; Pizzagalli, Diego A.

2013-01-01

Context Childhood sexual abuse (CSA) has been associated with psychopathology, particularly major depressive disorder (MDD), and high-risk behaviors. Despite grave epidemiological data, the mechanisms underlying these maladaptive outcomes remain poorly understood. Objective We examined whether CSA history, particularly in conjunction with past MDD, is associated with behavioral and neural dysfunction in reinforcement learning, and whether such dysfunction is linked to maladaptive behavior. Design Participants completed a clinical evaluation and a probabilistic reinforcement task while 128-channel event-related potentials were recorded. Setting Academic setting; participants recruited from the community. Participants Fifteen remitted depressed females with CSA history (CSA+rMDD), 16 remitted depressed females without CSA history (rMDD), and 18 healthy females. Main Outcome Measures Participants’ preference for choosing the most rewarded stimulus and avoiding the most punished stimulus was evaluated. The feedback-related negativity (FRN) and error-related negativity (ERN)–hypothesized to reflect activation in the anterior cingulate cortex–were used as electrophysiological indices of reinforcement learning. Results No group differences emerged in the acquisition of reinforcement contingencies. In trials requiring to rely partially or exclusively on previously rewarded information, the CSA+rMDD group showed (1) lower accuracy (relative to both controls and rMDD), (2) blunted electrophysiological differentiation between correct and incorrect responses (relative to controls), and (3) increased activation in the subgenual anterior cingulate cortex (relative to rMDD). CSA history was not associated with impairments in avoiding the most punished stimulus. Self-harm and suicidal behaviors correlated with poorer performance of previously rewarded–but not previously punished–trials. Conclusions Irrespective of past MDD, women with CSA histories showed neural and behavioral deficits in utilizing previous reinforcement to optimize decision-making in the absence of feedback (blunted “Go learning”). While the current study provides initial evidence for reward-specific deficits associated with CSA, future research is warranted to determine if disrupted positive reinforcement learning predicts high-risk behavior following CSA. PMID:23487253

Deficits in striatal dopamine release in cannabis dependence

PubMed Central

van de Giessen, Elsmarieke; Weinstein, Jodi J.; Cassidy, Clifford M.; Haney, Margaret; Dong, Zhengchao; Ghazzaoui, Rassil; Ojeil, Najate; Kegeles, Lawrence S.; Xu, Xiaoyan; Vadhan, Nehal P.; Volkow, Nora D.; Slifstein, Mark; Abi-Dargham, Anissa

2016-01-01

Most drugs of abuse lead to a general blunting of dopamine release in the chronic phase of dependence, which contributes to poor outcome. To test whether cannabis dependence is associated with a similar dopaminergic deficit, we examined striatal and extrastriatal dopamine release in severely cannabis dependent participants (CD), free of any comorbid conditions, including nicotine use. Eleven CD and twelve healthy controls (HC) completed two positron emission tomography scans with [11C]-(+)-PHNO, before and after oral administration of d-amphetamine. CD stayed inpatient for 5–7 days prior to the scans to standardize abstinence. Magnetic Resonance Imaging (MRS) measures of glutamate in the striatum and hippocampus were obtained in the same subjects. Percent change in [11C]-(+)-PHNO binding potential (ΔBPND) was compared between groups and correlations with MRS glutamate, subclinical psychopathological and neurocognitive parameters were examined. CD had significantly lower ΔBPND in the striatum (p=0.002, effect size (ES)=1.48), including the associative striatum (p=0.003, ES=1.39), sensorimotor striatum (p=0.003, ES=1.41), and the pallidus (p=0.012, ES=1.16). Lower dopamine release in the associative striatum correlated with inattention and negative symptoms in CD, and with poorer working memory and probabilistic category learning performance in both CD and HC. No relationships to MRS glutamate and amphetamine-induced subclinical positive symptoms were detected. In conclusion, this study provides evidence that severe cannabis dependence -without the confounds of any comorbidity- is associated with a deficit in striatal dopamine release. This deficit extends to other extrastriatal areas and predicts subclinical psychopathology. PMID:27001613

Deficits in striatal dopamine release in cannabis dependence.

PubMed

van de Giessen, E; Weinstein, J J; Cassidy, C M; Haney, M; Dong, Z; Ghazzaoui, R; Ojeil, N; Kegeles, L S; Xu, X; Vadhan, N P; Volkow, N D; Slifstein, M; Abi-Dargham, A

2017-01-01

Most drugs of abuse lead to a general blunting of dopamine release in the chronic phase of dependence, which contributes to poor outcome. To test whether cannabis dependence is associated with a similar dopaminergic deficit, we examined striatal and extrastriatal dopamine release in severely cannabis-dependent participants (CD), free of any comorbid conditions, including nicotine use. Eleven CD and 12 healthy controls (HC) completed two positron emission tomography scans with [ 11 C]-(+)-PHNO, before and after oral administration of d-amphetamine. CD stayed inpatient for 5-7 days prior to the scans to standardize abstinence. Magnetic resonance spectroscopy (MRS) measures of glutamate in the striatum and hippocampus were obtained in the same subjects. Percent change in [ 11 C]-(+)-PHNO-binding potential (ΔBP ND ) was compared between groups and correlations with MRS glutamate, subclinical psychopathological and neurocognitive parameters were examined. CD had significantly lower ΔBP ND in the striatum (P=0.002, effect size (ES)=1.48), including the associative striatum (P=0.003, ES=1.39), sensorimotor striatum (P=0.003, ES=1.41) and the pallidus (P=0.012, ES=1.16). Lower dopamine release in the associative striatum correlated with inattention and negative symptoms in CD, and with poorer working memory and probabilistic category learning performance in both CD and HC. No relationships to MRS glutamate and amphetamine-induced subclinical positive symptoms were detected. In conclusion, this study provides evidence that severe cannabis dependence-without the confounds of any comorbidity-is associated with a deficit in striatal dopamine release. This deficit extends to other extrastriatal areas and predicts subclinical psychopathology.

Carnitine Acetyltransferase Mitigates Metabolic Inertia and Muscle Fatigue during Exercise.

PubMed

Seiler, Sarah E; Koves, Timothy R; Gooding, Jessica R; Wong, Kari E; Stevens, Robert D; Ilkayeva, Olga R; Wittmann, April H; DeBalsi, Karen L; Davies, Michael N; Lindeboom, Lucas; Schrauwen, Patrick; Schrauwen-Hinderling, Vera B; Muoio, Deborah M

2015-07-07

Acylcarnitine metabolites have gained attention as biomarkers of nutrient stress, but their physiological relevance and metabolic purpose remain poorly understood. Short-chain carnitine conjugates, including acetylcarnitine, derive from their corresponding acyl-CoA precursors via the action of carnitine acetyltransferase (CrAT), a bidirectional mitochondrial matrix enzyme. We show here that contractile activity reverses acetylcarnitine flux in muscle, from net production and efflux at rest to net uptake and consumption during exercise. Disruption of this switch in mice with muscle-specific CrAT deficiency resulted in acetyl-CoA deficit, perturbed energy charge, and diminished exercise tolerance, whereas acetylcarnitine supplementation produced opposite outcomes in a CrAT-dependent manner. Likewise, in exercise-trained compared to untrained humans, post-exercise phosphocreatine recovery rates were positively associated with CrAT activity and coincided with dramatic shifts in muscle acetylcarnitine dynamics. These findings show acetylcarnitine serves as a critical acetyl buffer for working muscles and provide insight into potential therapeutic strategies for combatting exercise intolerance. Copyright © 2015 Elsevier Inc. All rights reserved.

Estimating the total energy demand for supra-maximal exercise using the VO2-power regression from an incremental exercise test.

PubMed

Aisbett, B; Le Rossignol, P

2003-09-01

The VO2-power regression and estimated total energy demand for a 6-minute supra-maximal exercise test was predicted from a continuous incremental exercise test. Sub-maximal VO2-power co-ordinates were established from the last 40 seconds (s) of 150-second exercise stages. The precision of the estimated total energy demand was determined using the 95% confidence interval (95% CI) of the estimated total energy demand. The linearity of the individual VO2-power regression equations was determined using Pearson's correlation coefficient. The mean 95% CI of the estimated total energy demand was 5.9 +/- 2.5 mL O2 Eq x kg(-1) x min(-1), and the mean correlation coefficient was 0.9942 +/- 0.0042. The current study contends that the sub-maximal VO2-power co-ordinates from a continuous incremental exercise test can be used to estimate supra-maximal energy demand without compromising the precision of the accumulated oxygen deficit (AOD) method.

Cerebral Hemodynamics During Exercise and Recovery in Heart Transplant Recipients.

PubMed

Gayda, Mathieu; Desjardins, Audrey; Lapierre, Gabriel; Dupuy, Olivier; Fraser, Sarah; Bherer, Louis; Juneau, Martin; White, Michel; Gremeaux, Vincent; Labelle, Véronique; Nigam, Anil

2016-04-01

The aims of this work were (1) to compare cerebral oxygenation-perfusion (COP), central hemodynamics, and peak oxygen uptake (V˙o2peak) in heart transplant recipients (HTRs) vs age-matched healthy controls (AMHCs) during exercise and recovery and (2) to study the relationships between COP, central hemodynamics, and V˙o2peak in HTRs and AMHCs. Twenty-six HTRs (3 women) and 27 AMHCs (5 women) were recruited. Maximal cardiopulmonary function (gas exchange analysis), cardiac hemodynamics (impedance cardiography), and left frontal COP (near-infrared spectroscopy) were measured continuously during and after a maximal ergocycle (Ergoline 800S, Bitz, Germany) test. Compared with AMHCs, HTRs had lower V˙o2peak, maximal cardiac index (CImax), and maximal ventilatory variables (P < 0.05). COP was lower during exercise (oxyhemoglobin [ΔO2Hb], 50% and 75% of V˙O2peak, total hemoglobin [ΔtHb], 100% of V˙O2peak; P < 0.05), and recovery in HTRs (ΔO2Hb, minutes 2-5; ΔtHb, minutes 1-5; P < 0.05) compared with AMHCs. End-tidal pressure of CO2 was lower during exercise compared with that in AMHCs (P < 0.0001). In HTRs, CImax was positively correlated with exercise cerebral hemodynamics (R = 0.54-0.60; P < 0.01). In HTRs, COP was reduced during exercise and recovery compared with that in AMHCs, potentially because of a combination of blunted cerebral vasodilation by CO2, cerebrovascular dysfunction, reduced cardiac function, and medication. The impaired V˙O2peak observed in HTRs was mainly caused by reduced maximal ventilation and CI. In HTRs, COP is impaired and is correlated with cardiac function, potentially impacting cognitive function. Therefore, we need to study which interventions (eg, exercise training) are most effective for improving or normalizing (or both) COP during and after exercise in HTRs. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Postprandial walking is better for lowering the glycemic effect of dinner than pre-dinner exercise in type 2 diabetic individuals.

PubMed

Colberg, Sheri R; Zarrabi, Lida; Bennington, Linda; Nakave, Abhijeet; Thomas Somma, C; Swain, David P; Sechrist, Scott R

2009-07-01

In prior studies of exercise done before or after breakfast and lunch, postprandial activity generally reduces glycemia more than pre-meal. This study sought to examine the effects of exercise before or after an evening meal. Examined the differing effects of a single bout of pre- or postprandial moderate exercise or no exercise on the glycemic response to an evening (dinner) meal in individuals with type 2 diabetes. Community-dwelling participants tested at a research university in Virginia. Twelve men and women subjects (mean age of 61.4+/-2.7 years) with type 2 diabetes treated with diet and/or oral medications. Three trials conducted on separate days consisting of a rest day when subjects consumed a standardized dinner with a moderate glycemic effect and 2 exercise days when they undertook 20 minutes of self-paced treadmill walking immediately before or 15 to 20 minutes after eating. Blood samples taken every 30 minutes over a 4-hour period and later assayed for plasma glucose; from these data both absolute and relative changes in glucose levels were determined, as well as the total glucose area under the curve (AUC) of the 4-hour testing period. Initial samples were additionally assayed for glycated hemoglobin and lipid levels. Twenty minutes of self-paced walking done shortly after meal consumption resulted in lower plasma glucose levels at the end of exercise compared to values at the same time point when subjects had walked pre-dinner. Total glucose AUC over 4-hours was not significantly different among trials. Postprandial walking may be more effective at lowering the glycemic impact of the evening meal in individuals with type 2 diabetes compared with pre-meal or no exercise and may be an effective means to blunt postprandial glycemic excursions.

Effects of exercise on mobility in people with Parkinson's disease.

PubMed

van der Kolk, Nicolien M; King, Laurie A

2013-09-15

Parkinson's disease is a prevalent neurodegenerative disorder for which only symptomatic treatment exists. Gait and balance disturbance is common in Parkinson's disease and is a major contributor to increased disability and decreased health-related quality of life and survival. Balance and gait deficits in Parkinson's disease are notoriously difficult to treat and are not significantly helped by pharmacological or surgical treatment. The last two decades have seen a dramatic increase in the research and clinical interest in using exercise as a treatment for mobility problems in people with Parkinson's disease. With exciting advances in basic science research suggesting neurochemical and neuroplastic changes after exercise, an increasing number of high-quality studies are documenting particular aspects of mobility improving after exercise. Exercise has the potential to help both motor (gait, balance, strength) and nonmotor (depression, apathy, fatigue, constipation) aspects of Parkinson's disease as well as secondary complications of immobility (cardiovascular, osteoporosis). This perspective article focuses primarily on recent evidence on the effects of exercise in improving mobility while highlighting the importance of targeted exercise intervention for maximizing the benefits of exercise. Suggestions for exercise guidelines, adherence issues, and directions for future research are provided. © 2013 Movement Disorder Society.

Effect of acute inspiratory muscle exercise on blood flow of resting and exercising limbs and glucose levels in type 2 diabetes.

PubMed

Corrêa, Ana Paula dos Santos; Antunes, Cristiano Fetter; Figueira, Franciele Ramos; de Castro, Marina Axmann; Ribeiro, Jorge Pinto; Schaan, Beatriz D'Agord

2015-01-01

To evaluate the effects of inspiratory loading on blood flow of resting and exercising limbs in patients with diabetic autonomic neuropathy. Ten diabetic patients without cardiovascular autonomic neuropathy (DM), 10 patients with cardiovascular autonomic neuropathy (DM-CAN) and 10 healthy controls (C) were randomly assigned to inspiratory muscle load of 60% or 2% of maximal inspiratory pressure (PImax) for approximately 5 min, while resting calf blood flow (CBF) and exercising forearm blood flow (FBF) were measured. Reactive hyperemia was also evaluated. From the 20 diabetic patients initially allocated, 6 wore a continuous glucose monitoring system to evaluate the glucose levels during these two sessions (2%, placebo or 60%, inspiratory muscle metaboreflex). Mean age was 58 ± 8 years, and mean HbA1c, 7.8% (62 mmol/mol) (DM and DM-CAN). A PImax of 60% caused reduction of CBF in DM-CAN and DM (P<0.001), but not in C, whereas calf vascular resistance (CVR) increased in DM-CAN and DM (P<0.001), but not in C. The increase in FBF during forearm exercise was blunted during 60% of PImax in DM-CAN and DM, and augmented in C (P<0.001). Glucose levels decreased by 40 ± 18.8% (P<0.001) at 60%, but not at 2%, of PImax. A negative correlation was observed between reactive hyperemia and changes in CVR (Beta coefficient = -0.44, P = 0.034). Inspiratory muscle loading caused an exacerbation of the inspiratory muscle metaboreflex in patients with diabetes, regardless of the presence of neuropathy, but influenced by endothelial dysfunction. High-intensity exercise that recruits the diaphragm can abruptly reduce glucose levels.

Vitamin C and E supplementation alters protein signalling after a strength training session, but not muscle growth during 10 weeks of training

PubMed Central

Paulsen, G; Hamarsland, H; Cumming, K T; Johansen, R E; Hulmi, J J; Børsheim, E; Wiig, H; Garthe, I; Raastad, T

2014-01-01

This study investigated the effects of vitamin C and E supplementation on acute responses and adaptations to strength training. Thirty-two recreationally strength-trained men and women were randomly allocated to receive a vitamin C and E supplement (1000 mg day−1 and 235 mg day−1, respectively), or a placebo, for 10 weeks. During this period the participants’ training involved heavy-load resistance exercise four times per week. Muscle biopsies from m. vastus lateralis were collected, and 1 repetition maximum (1RM) and maximal isometric voluntary contraction force, body composition (dual-energy X-ray absorptiometry), and muscle cross-sectional area (magnetic resonance imaging) were measured before and after the intervention. Furthermore, the cellular responses to a single exercise session were assessed midway in the training period by measurements of muscle protein fractional synthetic rate and phosphorylation of several hypertrophic signalling proteins. Muscle biopsies were obtained from m. vastus lateralis twice before, and 100 and 150 min after, the exercise session (4 × 8RM, leg press and knee-extension). The supplementation did not affect the increase in muscle mass or the acute change in protein synthesis, but it hampered certain strength increases (biceps curl). Moreover, increased phosphorylation of p38 mitogen-activated protein kinase, Extracellular signal-regulated protein kinases 1 and 2 and p70S6 kinase after the exercise session was blunted by vitamin C and E supplementation. The total ubiquitination levels after the exercise session, however, were lower with vitamin C and E than placebo. We concluded that vitamin C and E supplementation interfered with the acute cellular response to heavy-load resistance exercise and demonstrated tentative long-term negative effects on adaptation to strength training. PMID:25384788

Cardiovascular Benefits of Moderate Exercise Training in Marfan Syndrome: Insights From an Animal Model.

PubMed

Mas-Stachurska, Aleksandra; Siegert, Anna-Maria; Batlle, Monsterrat; Gorbenko Del Blanco, Darya; Meirelles, Thayna; Rubies, Cira; Bonorino, Fabio; Serra-Peinado, Carla; Bijnens, Bart; Baudin, Julio; Sitges, Marta; Mont, Lluís; Guasch, Eduard; Egea, Gustavo

2017-09-25

Marfan syndrome (MF) leads to aortic root dilatation and a predisposition to aortic dissection, mitral valve prolapse, and primary and secondary cardiomyopathy. Overall, regular physical exercise is recommended for a healthy lifestyle, but dynamic sports are strongly discouraged in MF patients. Nonetheless, evidence supporting this recommendation is lacking. Therefore, we studied the role of long-term dynamic exercise of moderate intensity on the MF cardiovascular phenotype. In a transgenic mouse model of MF ( Fbn1 C1039G/+ ), 4-month-old wild-type and MF mice were subjected to training on a treadmill for 5 months; sedentary littermates served as controls for each group. Aortic and cardiac remodeling was assessed by echocardiography and histology. The 4-month-old MF mice showed aortic root dilatation, elastic lamina rupture, and tunica media fibrosis, as well as cardiac hypertrophy, left ventricular fibrosis, and intramyocardial vessel remodeling. Over the 5-month experimental period, aortic root dilation rate was significantly greater in the sedentary MF group, compared with the wild-type group (∆mm, 0.27±0.07 versus 0.13±0.02, respectively). Exercise significantly blunted the aortic root dilation rate in MF mice compared with sedentary MF littermates (∆mm, 0.10±0.04 versus 0.27±0.07, respectively). However, these 2 groups were indistinguishable by aortic root stiffness, tunica media fibrosis, and elastic lamina ruptures. In MF mice, exercise also produced cardiac hypertrophy regression without changes in left ventricular fibrosis. Our results in a transgenic mouse model of MF indicate that moderate dynamic exercise mitigates the progression of the MF cardiovascular phenotype. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Neuropsychological findings in a patient with Kernohan's notch.

PubMed

Clement, V L; Sherer, M

1996-05-01

This case report describes the use of neuropsychological testing to Iocalize and diagnose lesions The testing was instrumental in disentangling contradictory symptoms to reveal a Kernohan's notch (later confirmed by MRI), thus ruling out incorrect diagnoses We describe the case of a 36-year-old right-handed man who developed a left epidural hematoma after suffering head trauma from a blunt instrument Sequelae 2 months post-injury included left hemiparesis (ipsilateral to the lesion), dysphonic speech, severe naming/word-finding deficits, and severe memory impairment This patient's symptom pattern presented somewhat of a mystery as his cognitive deficits appeared consistent with left hemisphere damage, while his left motor symptoms suggested right hemisphere damage Medical records were inconsistent Deficits on neuropsychological testing at 3 months post-injury included impairment in verbal and visual memory, confrontation naming, and left-sided motor function Attention, visual-spatial skills, nonverbal problem solving, and right motor speed and coordination were intact A herniation syndrome, Kernohan's notch, was considered to be the most likely explanation This phenomenon occurs when a mass occupying lesion causes significant midline shift of the midbrain, pressing the contralateral cerebral peduncle against the tentorium This pressure produces an ischemic infact in the region of the corticospinal (motor) pathways Subsequent MRI confirmed a lesion in the right cerebral crus The pattern of neuropsychological finding in this patient is discussed.

Performance deficits of mGluR8 knockout mice in learning tasks: the effects of null mutation and the background genotype.

PubMed

Gerlai, R; Adams, B; Fitch, T; Chaney, S; Baez, M

2002-08-01

mGluR8 is a G-protein coupled metabotropic glutamate receptor expressed in the mammalian brain. Members of the mGluR family have been shown to be modulators of neural plasticity and learning and memory. Here we analyze the consequences of a null mutation at the mGluR8 gene locus generated using homologous recombination in embryonic stem cells by comparing the learning performance of the mutants with that of wild type controls in the Morris water maze (MWM) and the context and cue dependent fear conditioning (CFC). Our results revealed robust performance deficits associated with the genetic background, the ICR outbred strain, in both mGluR8 null mutant and the wild type control mice. Mice of this strain origin suffered from impaired vision as compared to CD1 or C57BL/6 mice, a significant impediment in MWM, a visuo-spatial learning task. The CFC task, being less dependent on visual cues, allowed us to reveal subtle performance deficits in the mGluR8 mutants: novelty induced hyperactivity and temporally delayed and blunted responding to shocks and temporally delayed responding to contextual stimuli were detected. The role of mGluR8 as a presynaptic autoreceptor and its contribution to cognitive processes are hypothesized and the utility of gene targeting as compared to pharmacological methods is discussed.

Effect of exercise intensity on abdominal fat loss during calorie restriction in overweight and obese postmenopausal women: a randomized, controlled trial1234

PubMed Central

Nicklas, Barbara J; Wang, Xuewen; You, Tongjian; Lyles, Mary F; Demons, Jamehl; Easter, Linda; Berry, Michael J; Lenchik, Leon; Carr, J Jeffrey

2009-01-01

Background: Exercise intensity may affect the selective loss of abdominal adipose tissue. Objective: This study showed whether aerobic exercise intensity affects the loss of abdominal fat and improvement in cardiovascular disease risk factors under conditions of equal energy deficit in women with abdominal obesity. Design: This was a randomized trial in 112 overweight and obese [body mass index (in kg/m2): 25–40; waist circumference >88 cm], postmenopausal women assigned to one of three 20-wk interventions of equal energy deficit: calorie restriction (CR only), CR plus moderate-intensity aerobic exercise (CR + moderate-intensity), or CR plus vigorous-intensity exercise (CR + vigorous-intensity). The diet was a controlled program of underfeeding during which meals were provided at individual calorie levels (≈400 kcal/d). Exercise (3 d/wk) involved treadmill walking at an intensity of 45–50% (moderate-intensity) or 70–75% (vigorous-intensity) of heart rate reserve. The primary outcome was abdominal visceral fat volume. Results: Average weight loss for the 95 women who completed the study was 12.1 kg (±4.5 kg) and was not significantly different across groups. Maximal oxygen uptake (O2max) increased more in the CR + vigorous-intensity group than in either of the other groups (P < 0.05). The CR-only group lost relatively more lean mass than did either exercise group (P < 0.05). All groups showed similar decreases in abdominal visceral fat (≈25%; P < 0.001 for all). However, changes in visceral fat were inversely related to increases in O2max (P < 0.01). Changes in lipids, fasting glucose or insulin, and 2-h glucose and insulin areas during the oral-glucose-tolerance test were similar across treatment groups. Conclusion: With a similar amount of total weight loss, lean mass is preserved, but there is not a preferential loss of abdominal fat when either moderate- or vigorous-intensity aerobic exercise is performed during caloric restriction. This trial was registered at clinicaltrials.gov as NCT00664729. PMID:19211823

Pulmonary oxygen uptake kinetics during exercise in subclinical hypothyroidism.

PubMed

Werneck, Francisco Zacaron; Coelho, Emerson Filipino; de Lima, Jorge Roberto Perrout; Laterza, Mateus Camaroti; Barral, Marselha Marques; Teixeira, Patrícia de Fátima Dos Santos; Vaisman, Mário

2014-06-01

Patients with subclinical hypothyroidism (SCH) have lower exercise tolerance, but the impact on oxygen uptake (VO2) kinetics is unknown. This study evaluated VO2 kinetics during and after a constant load submaximal exercise in SCH. The study included 19 women with SCH (thyrotropin (TSH)=6.87±2.88 μIU/mL, free thyroxine (fT4)=0.97±0.15 ng/dL) and 19 controls (TSH=2.29±0.86 μIU/mL, T4=0.99±0.11 ng/dL) aged between 20 and 55 years. Ergospirometry exercise testing was performed for six minutes with a constant load of 50 W, followed by six minutes of passive recovery. The VO2 kinetics was quantified by the mean response time (MRT), which is the exponential time constant and approximates the time needed to reach 63% of change in VO2 (ΔVO2). The O2 deficit-energy supplied by anaerobic metabolism at the onset of exercise-and O2 debit-extra energy demand during the recovery period-were calculated by the formula MRT×ΔVO2. Values are mean±standard deviation. In the rest-exercise transition, patients with SCH showed slower VO2 kinetics (MRT=47±8 sec vs. 40±6 sec, p=0.004) and a higher oxygen deficit (580±102 mL vs. 477±95 mL, p=0.003) than controls respectively. In the exercise-recovery transition, patients with SCH also showed slower VO2 kinetics (MRT=54±6 sec vs. 44±6 sec, p=0.001) and a higher oxygen debit (679±105 mL vs. 572±104 mL, p=0.003). The VO2 kinetics showed a significant correlation with TSH (p<0.05). This study demonstrates that women with SCH have the slowest VO2 kinetics in the onset and recovery of a constant-load submaximal exercise and highlights that this impairment is already manifest in the early stage of the disease.

Cross-activation and Detraining Effects of Tongue Exercise in Aged Rats

PubMed Central

Schaser, Allison J.; Ciucci, Michelle R.; Connor, Nadine P.

2015-01-01

Voice and swallowing deficits can occur with aging. Tongue exercise paired with a swallow may be used to treat swallowing disorders, but may also benefit vocal function due to cross-system activation effects. It is unknown how exercise-based neuroplasticity contributes to behavior and maintenance following treatment. Eighty rats were used to examine behavioral parameters and changes in neurotrophins after tongue exercise paired with a swallow. Tongue forces and ultrasonic vocalizations were recorded before and after training/detraining in young and old rats. Tissue was analyzed for neurotrophin content. Results showed tongue exercise paired with a swallow was associated with increased tongue forces at all ages. Gains diminished after detraining in old rats. Age-related changes in vocalizations, neurotrophin 4 (NT4), and brain derived neurotrophic factor (BDNF) were found. Minimal cross-system activation effects were observed. Neuroplastic benefits were demonstrated with exercise in old rats through behavioral improvements and up-regulation of BDNF in the hypoglossal nucleus. Tongue exercise paired with a swallow should be developed, studied, and optimized in human clinical research to treat swallowing and voice disorders in elderly people. PMID:26477376

Utilization of the graded universal testing system to increase the efficiency for assessing aerobic and anaerobic capacity

NASA Technical Reports Server (NTRS)

Rodgers, Sandra L.

1992-01-01

The in-flight exercise test performed by cosmonauts as part of the Russian Exercise Countermeasure Program is limited to 5 minutes due to communication restrictions. During a recent graded exercise test on a U.S. Shuttle flight, the test was terminated early due to an upcoming loss of signal (LOS) with the ground. This exercise test was a traditional test where the subject's exercise capacity dictates the length of the test. For example, one crew member may take 15 minutes to complete the test, while another may take 18 minutes. The traditional exercise test limits the flight schedulers to large blocks of space flight time in order to provide medical and research personnel information on the fitness capacity (maximal oxygen uptake: VO2max) of crew members during flight. A graded exercise test that would take a finite amount of time and a set preparation and recovery time would ease this problem by allowing flight schedulers to plan exercise tests in advance of LOS. The Graded Universal Testing System (GUTS) was designed to meet this goal. Fitness testing of astronauts before and after flight provides pertinent data on many variables. The Detailed Supplemental Objective (DSO608) protocol (6) is one of the graded exercise tests (GXT) currently used in astronaut testing before and after flight. Test times for this protocol have lasted from 11 to 18 minutes. Anaerobic capacity is an important variable that is currently not being evaluated before and after flight. Recent reports (1,2,5) from the literature have suggested that the oxygen deficit at supramaximal exercise is a measure of anaerobic capacity. We postulated that the oxygen deficit at maximal exercise would be an indication of anaerobic capacity. If this postulate can be accepted, then the efficiency of acquiring data from a graded exercise test would increase at least twofold. To examine this hypothesis anaerobic capacity was measured using a modified treadmill test (3,4) designed to exhaust the anaerobic systems in approximately 45 to 75 seconds. Lactate concentration in the blood was analyzed after all tests, since lactate is the end-product of anaerobic energy production. Therefore, the peak lactate response is an additional indication of anaerobic capacity. A preliminary comparison of the GUTS and the DSO608 suggests that the GUTS protocol would increase the efficiency of VO2max testing of astronauts before and after flight. Results for anaerobic capacity have not been tabulated.

An event-related potential investigation of the acute effects of aerobic and coordinative exercise on inhibitory control in children with ADHD.

PubMed

Ludyga, Sebastian; Brand, Serge; Gerber, Markus; Weber, Peter; Brotzmann, Mark; Habibifar, Fahimeh; Pühse, Uwe

2017-12-01

The current body of evidence suggests that an aerobic exercise session has a beneficial effect on inhibitory control, whereas the impact of coordinative exercise on this executive function has not yet been examined in children with ADHD. Therefore, the present study aims to investigate the acute effects of aerobic and coordinative exercise on behavioral performance and the allocation of attentional resources in an inhibitory control task. Using a cross-over design, children with ADHD-combined type and healthy comparisons completed a Flanker task before and after 20min moderately-intense cycling exercise, coordinative exercise and an inactive control condition. During the task, stimulus-locked event-related potentials were recorded with electroencephalography. Both groups showed an increase of P300 amplitude and decrease of reaction time after exercise compared to the control condition. Investigating the effect of exercise modality, aerobic exercise led to greater increases of P300 amplitude and reductions in reaction time than coordinative exercise in children with ADHD. The findings suggest that a single exercise bout improves inhibitory control and the allocation of attentional resources. There were some indications that an aerobic exercise session seems to be more efficient than coordinative exercise in reducing the inhibitory control deficits that persist in children with ADHD. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Exercise Promotes Healthy Aging of Skeletal Muscle.

PubMed

Cartee, Gregory D; Hepple, Russell T; Bamman, Marcas M; Zierath, Juleen R

2016-06-14

Primary aging is the progressive and inevitable process of bodily deterioration during adulthood. In skeletal muscle, primary aging causes defective mitochondrial energetics and reduced muscle mass. Secondary aging refers to additional deleterious structural and functional age-related changes caused by diseases and lifestyle factors. Secondary aging can exacerbate deficits in mitochondrial function and muscle mass, concomitant with the development of skeletal muscle insulin resistance. Exercise opposes deleterious effects of secondary aging by preventing the decline in mitochondrial respiration, mitigating aging-related loss of muscle mass and enhancing insulin sensitivity. This review focuses on mechanisms by which exercise promotes "healthy aging" by inducing modifications in skeletal muscle. Copyright © 2016 Elsevier Inc. All rights reserved.

Improvements in insulin sensitivity are blunted by subclinical hypothyroidism.

PubMed

Amati, Francesca; Dubé, John J; Stefanovic-Racic, Maja; Toledo, Frederico G; Goodpaster, Bret H

2009-02-01

Exercise- and weight loss-induced improvements in insulin resistance (IR) are variable; some individuals experience robust enhancements in insulin sensitivity, whereas others do not. Thyroid hormone status is related to IR, but it is not clear whether subclinical hypothyroidism may help to explain the variability in improvements in IR with diet and exercise. The purpose of this study was to examine whether thyroid hormone status is related to the improvement in insulin sensitivity and physical fitness after weight loss and exercise training. By retrospective nested case-control analysis, eight subclinical hypothyroid (sHT) subjects and eight matched euthyroid controls underwent a euglycemic hyperinsulinemic clamp and peak oxygen uptake test, before and after a 16-wk program of moderate aerobic exercise combined with diet-induced weight loss. All subjects were middle-aged (57.3 +/- 3.3 yr), were overweight to obese (body mass index = 33.1 +/- 0.8 kg m(-2)), and had impaired glucose tolerance. The improvement in insulin sensitivity was significantly lower (P < 0.05) in the sHT group than in the euthyroid group. Both groups performed similar amounts of regular exercise and lost a significant amount of body weight during the intervention. VO(2peak) tended to improve in the euthyroid group but not in the sHT group. Subclinical hypothyroidism may interfere with beneficial adaptations on muscle metabolism and physical fitness that typically occur with weight loss and increased physical activity. These results may have significant clinical implications because of the high prevalence of both hypothyroidism and insulin resistance in the aging population.

Methodological and clinical implications of a three-in-one Russian doll design for tracking health trajectories and improving health and function through innovative exercise treatments in adults with disability.

PubMed

Rimmer, James H; Herman, Cassandra; Wingo, Brooks; Fontaine, Kevin; Mehta, Tapan

2018-03-14

Hybrid research designs targeting adults with neurologic disability are critical for improving the efficiency of models that can identify, track and intervene on identified health issues. Our Russian doll framework encompasses three study phases. Phase 1 involves prospectively following a cohort of participants with disability to examine the relationships between rates of health and functional deficits (e.g., pain, fatigue, deconditioning), functional measures (e.g., cardiorespiratory endurance, strength, balance), and environmental and sociocultural factors. In Phase 2, eligible participants with neurologic disability from Phase 1 (in our example, individuals with multiple sclerosis) are screened and randomized to a clinical exercise efficacy trial. In Phase 3, study participants are enrolled in a home-based teleexercise trial to test the feasibility and replicability of delivering the clinical exercise study in the home. This unique three-in-one Russian doll framework serves as a foundation for informing and guiding researchers and clinicians in treating certain health and functional deficits in people with neurologic disability using exercise as a primary treatment modality in both the clinical and home settings. It offers a unique perspective for understanding the critical issues of functioning, health maintenance and quality of life for people with neurologic disability across a longitudinal framework. Study 2 ClinicalTrials.gov identifier NCT02533882 (retroactively registered 03/06/2015). Study 3 ClinicalTrials.gov identifier NCT03108950 (retroactively registered 04/05/2017).

Audio-Visual Stimulation in Conjunction with Functional Electrical Stimulation to Address Upper Limb and Lower Limb Movement Disorder.

PubMed

Kumar, Deepesh; Verma, Sunny; Bhattacharya, Sutapa; Lahiri, Uttama

2016-06-13

Neurological disorders often manifest themselves in the form of movement deficit on the part of the patient. Conventional rehabilitation often used to address these deficits, though powerful are often monotonous in nature. Adequate audio-visual stimulation can prove to be motivational. In the research presented here we indicate the applicability of audio-visual stimulation to rehabilitation exercises to address at least some of the movement deficits for upper and lower limbs. Added to the audio-visual stimulation, we also use Functional Electrical Stimulation (FES). In our presented research we also show the applicability of FES in conjunction with audio-visual stimulation delivered through VR-based platform for grasping skills of patients with movement disorder.

Regulation of sympathetic nervous system function after cardiovascular deconditioning

NASA Technical Reports Server (NTRS)

Hasser, E. M.; Moffitt, J. A.

2001-01-01

Humans subjected to prolonged periods of bed rest or microgravity undergo deconditioning of the cardiovascular system, characterized by resting tachycardia, reduced exercise capability, and a predisposition for orthostatic intolerance. These changes in cardiovascular function are likely due to a combination of factors, including changes in control of body fluid balance or cardiac alterations resulting in inadequate maintenance of stroke volume, altered arterial or venous vascular function, reduced activation of cardiovascular hormones, and diminished autonomic reflex function. There is evidence indicating a role for each of these mechanisms. Diminished reflex activation of the sympathetic nervous system and subsequent vasoconstriction appear to play an important role. Studies utilizing the hindlimb-unloaded (HU) rat, an animal model of deconditioning, evaluated the potential role of altered arterial baroreflex control of the sympathetic nervous system. These studies indicate that HU results in blunted baroreflex-mediated activation of both renal and lumbar sympathetic nerve activity in response to a hypotensive stimulus. HU rats are less able to maintain arterial pressure during hemorrhage, suggesting that diminished ability to increase sympathetic activity has functional consequences for the animal. Reflex control of vasopressin secretion appears to be enhanced following HU. Blunted baroreflex-mediated sympathoexcitation appears to involve altered central nervous system function. Baroreceptor afferent activity in response to changes in arterial pressure is unaltered in HU rats. However, increases in efferent sympathetic nerve activity for a given decrease in afferent input are blunted after HU. This altered central nervous system processing of baroreceptor inputs appears to involve an effect at the rostral ventrolateral medulla (RVLM). Specifically, it appears that tonic GABAA-mediated inhibition of the RVLM is enhanced after HU. Augmented inhibition apparently arises from sources other than the caudal ventrolateral medulla. If similar alterations in control of the sympathetic nervous system occur in humans in response to cardiovascular deconditioning, it is likely that they play an important role in the observed tendency for orthostatic intolerance. Combined with potential changes in vascular function, cardiac function, and hypovolemia, the predisposition for orthostatic intolerance following cardiovascular deconditioning would be markedly enhanced by blunted ability to reflexly activate the sympathetic nervous system.

High Protein Diet Maintains Glucose Production During Exercise-Induced Energy Deficit: A Controlled Trial

DTIC Science & Technology

2011-04-28

medication known to impact macronutrient metabolism, or possessed any cardiovascular or musculoskeletal conditions that prohibited strenuous...able to maintain GP during the period of increased energy expenditure and negative energy balance suggests that manipulation of macronutrient intake

Effects of Intermittent Fasting, Caloric Restriction, and Ramadan Intermittent Fasting on Cognitive Performance at Rest and During Exercise in Adults.

PubMed

Cherif, Anissa; Roelands, Bart; Meeusen, Romain; Chamari, Karim

2016-01-01

The aim of this review was to highlight the potent effects of intermittent fasting on the cognitive performance of athletes at rest and during exercise. Exercise interacts with dietary factors and has a positive effect on brain functioning. Furthermore, physical activity and exercise can favorably influence brain plasticity. Mounting evidence indicates that exercise, in combination with diet, affects the management of energy metabolism and synaptic plasticity by affecting molecular mechanisms through brain-derived neurotrophic factor, an essential neurotrophin that acts at the interface of metabolism and plasticity. The literature has also shown that certain aspects of physical performance and mental health, such as coping and decision-making strategies, can be negatively affected by daylight fasting. However, there are several types of intermittent fasting. These include caloric restriction, which is distinct from fasting and allows subjects to drink water ad libitum while consuming a very low-calorie food intake. Another type is Ramadan intermittent fasting, which is a religious practice of Islam, where healthy adult Muslims do not eat or drink during daylight hours for 1 month. Other religious practices in Islam (Sunna) also encourage Muslims to practice intermittent fasting outside the month of Ramadan. Several cross-sectional and longitudinal studies have shown that intermittent fasting has crucial effects on physical and intellectual performance by affecting various aspects of bodily physiology and biochemistry that could be important for athletic success. Moreover, recent findings revealed that immunological variables are also involved in cognitive functioning and that intermittent fasting might impact the relationship between cytokine expression in the brain and cognitive deficits, including memory deficits.

Do exercises used in injury prevention programmes modify cutting task biomechanics? A systematic review with meta-analysis.

PubMed

Pappas, Evangelos; Nightingale, Elizabeth J; Simic, Milena; Ford, Kevin R; Hewett, Timothy E; Myer, Gregory D

2015-05-01

Some injury prevention programmes aim to reduce the risk of ACL rupture. Although the most common athletic task leading to ACL rupture is cutting, there is currently no consensus on how injury prevention programmes influence cutting task biomechanics. To systematically review and synthesise the scientific literature regarding the influence of injury prevention programme exercises on cutting task biomechanics. The three largest databases (Medline, EMBASE and CINAHL) were searched for studies that investigated the effect of injury prevention programmes on cutting task biomechanics. When possible meta-analyses were performed. Seven studies met the inclusion criteria. Across all studies, a total of 100 participants received exercises that are part of ACL injury prevention programmes and 76 participants served in control groups. Most studies evaluated variables associated with the quadriceps dominance theory. The meta-analysis revealed decreased lateral hamstrings electromyography activity (p ≤ 0.05) while single studies revealed decreased quadriceps and increased medial hamstrings activity and decreased peak knee flexion moment. Findings from single studies reported that ACL injury prevention exercises reduce neuromuscular deficits (knee valgus moment, lateral trunk leaning) associated with the ligament and trunk dominance theories, respectively. The programmes we analysed appear most effective when they emphasise individualised biomechanical technique correction and target postpubertal women. The exercises used in injury prevention programmes have the potential to improve cutting task biomechanics by ameliorating neuromuscular deficits linked to ACL rupture, especially when they emphasise individualised biomechanical technique correction and target postpubertal female athletes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Abnormal heart rate recovery and deficient chronotropic response after submaximal exercise in young Marfan syndrome patients.

PubMed

Peres, Paulo; Carvalho, Antônio C; Perez, Ana Beatriz A; Medeiros, Wladimir M

2016-10-01

Marfan syndrome patients present important cardiac structural changes, ventricular dysfunction, and electrocardiographic changes. An abnormal heart rate response during or after exercise is an independent predictor of mortality and autonomic dysfunction. The aim of the present study was to compare heart rate recovery and chronotropic response obtained by cardiac reserve in patients with Marfan syndrome subjected to submaximal exercise. A total of 12 patients on β-blocker therapy and 13 off β-blocker therapy were compared with 12 healthy controls. They were subjected to submaximal exercise with lactate measurements. The heart rate recovery was obtained in the first minute of recovery and corrected for cardiac reserve and peak lactate concentration. Peak heart rate (141±16 versus 155±17 versus 174±8 bpm; p=0.001), heart rate reserve (58.7±9.4 versus 67.6±14.3 versus 82.6±4.8 bpm; p=0.001), heart rate recovery (22±6 versus 22±8 versus 34±9 bpm; p=0.001), and heart rate recovery/lactate (3±1 versus 3±1 versus 5±1 bpm/mmol/L; p=0.003) were different between Marfan groups and controls, respectively. All the patients with Marfan syndrome had heart rate recovery values below the mean observed in the control group. The absolute values of heart rate recovery were strongly correlated with the heart rate reserve (r=0.76; p=0.001). Marfan syndrome patients have reduced heart rate recovery and chronotropic deficit after submaximal exercise, and the chronotropic deficit is a strong determinant of heart rate recovery. These changes are suggestive of autonomic dysfunction.

Physiological and Functional Alterations after Spaceflight and Bed Rest.

PubMed

Mulavara, Ajitkumar P; Peters, Brian T; Miller, Chris A; Kofman, Igor S; Reschke, Millard F; Taylor, Laura C; Lawrence, Emily L; Wood, Scott J; Laurie, Steven S; Lee, Stuart M C; Buxton, Roxanne E; May-Phillips, Tiffany R; Stenger, Michael B; Ploutz-Snyder, Lori L; Ryder, Jeffrey W; Feiveson, Alan H; Bloomberg, Jacob J

2018-04-03

Exposure to microgravity causes alterations in multiple physiological systems, potentially impacting the ability of astronauts to perform critical mission tasks. The goal of this study was to determine the effects of spaceflight on functional task performance and to identify the key physiological factors contributing to their deficits. A test battery comprised of 7 functional tests and 15 physiological measures was used to investigate the sensorimotor, cardiovascular and neuromuscular adaptations to spaceflight. Astronauts were tested before and after 6-month spaceflights. Subjects were also tested before and after 70 days of 6° head-down bed rest, a spaceflight analog, to examine the role of axial body unloading on the spaceflight results. These subjects included Control and Exercise groups to examine the effects of exercise during bed rest. Spaceflight subjects showed the greatest decrement in performance during functional tasks that required the greatest demand for dynamic control of postural equilibrium which was paralleled by similar decrements in sensorimotor tests that assessed postural and dynamic gait control. Other changes included reduced lower limb muscle performance and increased heart rate to maintain blood pressure. Exercise performed during bed rest prevented detrimental change in neuromuscular and cardiovascular function, however, both bed rest groups experienced functional and balance deficits similar to spaceflight subjects. Bed rest data indicates that body support unloading experienced during spaceflight contributes to postflight postural control dysfunction. Further, the bed rest results in the Exercise group of subjects confirm that resistance and aerobic exercises performed during spaceflight can play an integral role in maintaining neuromuscular and cardiovascular function, which can help in reducing decrements in functional performance. These results indicate that a countermeasure to mitigate postflight postural control dysfunction is required to maintain functional performance.

Endocrinology and Pediatric Exercise Science-2016.

PubMed

Eliakim, Alon

2017-02-01

The Pediatric Exercise Science Year That Was section aims to highlight the most important (to the author's opinion) manuscripts that were published in 2016 in the field of endocrinology and pediatric exercise science. This year's selection includes studies showing that 1) Induction of T4 to T3 conversion by type 2 deiodinase following aerobic exercise in skeletal muscles was associated with concomitant increase in peroxisome proliferatoractivated receptor-γ coactivator-1α, and mitochondrial oxidative capacity and therefore plays an important mechanistic role in the muscle adaptation to exercise training. 2) Hypothyroidism in fetal and early postnatal life was associated with impaired spatial learning and memory and with reduced hippocampal brain-derived neurotrophic factor in male and female rat pups. Forced (treadmill) and voluntary (wheel) exercise alleviated all these biochemical and neuro-cognitive deficits. 3) The relationship between different exercise intensities and carbohydrate requirements to maintain euglycemia at basal insulin levels among adolescent and young adults with Type 1 diabetes are nonlinear but rather inverted- U with no exogenous glucose required to maintain stable glucose level at high-intensity exercise (80%). The implication of these studies to the pediatric population, their importance and the new research avenues that were opened by these studies is emphasized.

Rolling and scrolling: The portrayal of marijuana cigars (blunts) on YouTube.

PubMed

Montgomery, LaTrice; Yockey, Andrew

2018-01-01

Blunts are partially or fully hollowed-out cigars or cigarillos that are filled with marijuana. Despite the high prevalence of blunt use, very few studies assess this specific method of cannabis administration. YouTube, a popular video-sharing website, has the potential to provide insights into blunt use. The purpose of this study was to examine the content of YouTube videos that discuss blunts. A sample of 41 videos was coded for content. The 41 videos had a total of 27,579,636 views. Most of the individuals in the videos were male (85%) and many appeared to be White (80%) and under the age of 25 (46%). Only 34% of the videos had an age restriction. The majority of messages in the videos promoted blunt use (93%) and showed at least one person rolling (76%) and/or smoking (66%) a blunt. The videos mainly consisted of introductions to blunt use (76%) and tips and personal experiences with blunt use (73%). YouTube videos on blunt use are readily available and primarily promote the use of blunts. Future research should continue to monitor YouTube content and develop videos on social media platforms that inform consumers of the health effects associated with blunt use.

Rolling and scrolling: The portrayal of marijuana cigars (blunts) on YouTube

PubMed Central

Montgomery, LaTrice; Yockey, Andrew

2018-01-01

Background Blunts are partially or fully hollowed-out cigars or cigarillos that are filled with marijuana. Despite the high prevalence of blunt use, very few studies assess this specific method of cannabis administration. YouTube, a popular video-sharing website, has the potential to provide insights into blunt use. Methods The purpose of this study was to examine the content of YouTube videos that discuss blunts. A sample of 41 videos was coded for content. Results The 41 videos had a total of 27,579,636 views. Most of the individuals in the videos were male (85%) and many appeared to be White (80%) and under the age of 25 (46%). Only 34% of the videos had an age restriction. The majority of messages in the videos promoted blunt use (93%) and showed at least one person rolling (76%) and/or smoking (66%) a blunt. The videos mainly consisted of introductions to blunt use (76%) and tips and personal experiences with blunt use (73%). Conclusions YouTube videos on blunt use are readily available and primarily promote the use of blunts. Future research should continue to monitor YouTube content and develop videos on social media platforms that inform consumers of the health effects associated with blunt use. PMID:29887756

Preamputation evaluation of lower-limb skeletal muscle perfusion with H(2) (15)O positron emission tomography.

PubMed

Scremin, Oscar U; Figoni, Stephen F; Norman, Keith; Scremin, A M Erika; Kunkel, Charles F; Opava-Rutter, Dorene; Schmitter, Eric D; Bert, Alberto; Mandelkern, Mark

2010-06-01

To establish whether muscle blood flow (MBF) measurements with O-water positron emission tomography could reliably identify patients with critical limb ischemia and detect and quantify a distal deficit in skeletal MBF in these cases. O-water positron emission tomography scans were performed at rest or during unloaded ankle plantar and dorsiflexion exercise of the diseased leg in 17 subjects with leg ischemia or on a randomly selected leg of 18 age-matched healthy control subjects. TcPO2 was evaluated with Novametrix monitors and perfusion of skin topically heated to 44 degrees C and adjacent nonheated areas with a Moor Instruments laser Doppler imaging scanner. The enhancement of MBF induced by exercise was significantly lower in ischemic than in normal legs, and the sensitivity and specificity of this phenomenon were similar to those of laser Doppler imaging or TcPO2 in identifying ischemia subjects. In addition, the exercise MBF deficit was predominant at the distal-leg levels, indicating the ability of the technique to help determine the correct level of amputation. Skeletal MBF of legs with severe ischemia can be detected accurately with O-water positron emission tomography and could add valuable information about viability of skeletal muscle in the residual limb when deciding the level of an amputation.

Blunt Criterion trauma model for head and chest injury risk assessment of cal. 380 R and cal. 22 long blank cartridge actuated gundog retrieval devices.

PubMed

Frank, Matthias; Bockholdt, Britta; Peters, Dieter; Lange, Joern; Grossjohann, Rico; Ekkernkamp, Axel; Hinz, Peter

2011-05-20

Blunt ballistic impact trauma is a current research topic due to the widespread use of kinetic energy munitions in law enforcement. In the civilian setting, an automatic dummy launcher has recently been identified as source of blunt impact trauma. However, there is no data on the injury risk of conventional dummy launchers. It is the aim of this investigation to predict potential impact injury to the human head and chest on the basis of the Blunt Criterion which is an energy based blunt trauma model to assess vulnerability to blunt weapons, projectile impacts, and behind-armor-exposures. Based on experimentally investigated kinetic parameters, the injury risk of two commercially available gundog retrieval devices (Waidwerk Telebock, Germany; Turner Richards, United Kingdom) was assessed using the Blunt Criterion trauma model for blunt ballistic impact trauma to the head and chest. Assessing chest impact, the Blunt Criterion values for both shooting devices were higher than the critical Blunt Criterion value of 0.37, which represents a 50% risk of sustaining a thoracic skeletal injury of AIS 2 (moderate injury) or AIS 3 (serious injury). The maximum Blunt Criterion value (1.106) was higher than the Blunt Criterion value corresponding to AIS 4 (severe injury). With regard to the impact injury risk to the head, both devices surpass by far the critical Blunt Criterion value of 1.61, which represents a 50% risk of skull fracture. Highest Blunt Criterion values were measured for the Turner Richards Launcher (2.884) corresponding to a risk of skull fracture of higher than 80%. Even though the classification as non-guns by legal authorities might implicate harmlessness, the Blunt Criterion trauma model illustrates the hazardous potential of these shooting devices. The Blunt Criterion trauma model links the laboratory findings to the impact injury patterns of the head and chest that might be expected. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

A double-blind randomized pilot trial comparing computerized cognitive exercises to Tetris in adolescents with attention-deficit/hyperactivity disorder.

PubMed

Bikic, Aida; Christensen, Torben Østergaard; Leckman, James F; Bilenberg, Niels; Dalsgaard, Søren

2017-08-01

The purpose of this trial was to examine the feasibility and efficacy of computerized cognitive exercises from Scientific Brain Training (SBT), compared to the computer game Tetris as an active placebo, in a pilot study of adolescents with attention-deficit/hyperactivity disorder (ADHD). Eighteen adolescents with ADHD were randomized to treatment or control intervention for 7 weeks. Outcome measures were cognitive test, symptom, and motivation questionnaires. SBT and Tetris were feasible as home-based interventions, and participants' compliance was high, but participants perceived both interventions as not very interesting or helpful. There were no significant group differences on cognitive and ADHD-symptom measures after intervention. Pre-post intra-group measurement showed that the SBT had a significant beneficial effect on sustained attention, while the active placebo had significant beneficial effects on working memory, both with large effect sizes. Although no significant differences were found between groups on any measure, there were significant intra-group changes for each group.

Can sensory attention focused exercise facilitate the utilization of proprioception for improved balance control in PD?

PubMed

Lefaivre, Shannon C; Almeida, Quincy J

2015-02-01

Impaired sensory processing in Parkinson's disease (PD) has been argued to contribute to balance deficits. Exercises aimed at improving sensory feedback and body awareness have the potential to ameliorate balance deficits in PD. Recently, PD SAFEx™, a sensory and attention focused rehabilitation program, has been shown to improve motor deficits in PD, although balance control has never been evaluated. The objective of this study was to measure the effects of PD SAFEx™ on balance control in PD. Twenty-one participants with mild to moderate idiopathic PD completed 12 weeks of PD SAFEx™ training (three times/week) in a group setting. Prior to training, participants completed a pre-assessment evaluating balance in accordance with an objective, computerized test of balance (modified clinical test of sensory integration and balance (m-CTSIB) and postural stability testing (PST)) protocols. The m-CTSIB was our primary outcome measure, which allowed assessment of balance in both eyes open and closed conditions, thus enabling evaluation of specific sensory contributions to balance improvement. At post-test, a significant interaction between time of assessment and vision condition (p=.014) demonstrated that all participants significantly improved balance control, specifically when eyes were closed. Balance control did not change from pre to post with eyes open. These results provide evidence that PD SAFEx™ is effective at improving the ability to utilize proprioceptive information, resulting in improved balance control in the absence of vision. Enhancing the ability to utilize proprioception for individuals with PD is an important intermediary to improving balance deficits. Copyright © 2015. Published by Elsevier B.V.

The potential link between sugar-sweetened beverage consumption and post-exercise airway narrowing across puberty: a longitudinal cohort study.

PubMed

Emerson, Sam R; Rosenkranz, Sara K; Rosenkranz, Richard R; Kurti, Stephanie P; Harms, Craig A

2016-09-01

The prevalence of asthma is rising, presenting serious public health challenges. Recent data suggest that sugar-sweetened beverage (SSB) consumption plays a role in asthma aetiology. The purpose of the present study was to determine whether SSB consumption is linked to post-exercise airway narrowing (predictor of asthma development) across puberty. Participants completed pulmonary function tests, physical activity and dietary habit questionnaires, and an exercise test to exhaustion. Community in Manhattan, Kansas, USA. We recruited ten boys and ten girls from an original cohort of forty participants tested in our laboratory approximately 5 years prior. Participants were aged 9·7 (sd 0·9) years at baseline and 14·7 (sd 0·9) years at follow-up. Pre-puberty, boys consumed 6·8 (sd 4·8) servings/week and girls consumed 6·9 (sd 3·7) servings/week, while post-puberty boys consumed 11·5 (sd 5·3) servings/week and girls consumed 7·7 (sd 4·3) servings/week. Using Pearson correlation, SSB consumption was not significantly related to post-exercise airway narrowing at pre-puberty (r=-0·35, P=0·130). In linear regression analyses, SSB consumption was significantly related to post-exercise airway narrowing post-puberty before (standardized β=-0·60, P=0·005) but not after (standardized β=-0·33, P=0·211) adjustment for confounders. Change in SSB consumption from pre- to post-puberty was significantly associated with post-exercise airway narrowing post-puberty (r=-0·61, P=0·010) and change in post-exercise airway narrowing from pre- to post-puberty (r=-0·45, P=0·048) when assessed via Pearson correlations. These findings suggest a possible link between SSB consumption and asthma development during maturation. Reduced SSB intake may be a possible public health avenue for blunting rising asthma prevalence.

Dose-response effects of aerobic exercise on estrogen among women at high risk for breast cancer: a randomized controlled trial.

PubMed

Schmitz, Kathryn H; Williams, Nancy I; Kontos, Despina; Domchek, Susan; Morales, Knashawn H; Hwang, Wei-Ting; Grant, Lorita L; DiGiovanni, Laura; Salvatore, Domenick; Fenderson, Desire'; Schnall, Mitchell; Galantino, Mary Lou; Stopfer, Jill; Kurzer, Mindy S; Wu, Shandong; Adelman, Jessica; Brown, Justin C; Good, Jerene

2015-11-01

Medical and surgical interventions for elevated breast cancer risk (e.g., BRCA1/2 mutation, family history) focus on reducing estrogen exposure. Women at elevated risk may be interested in less aggressive approaches to risk reduction. For example, exercise might reduce estrogen, yet has fewer serious side effects and less negative impact than surgery or hormonal medications. Randomized controlled trial. Increased risk defined by risk prediction models or BRCA mutation status. Eligibility: Age 18-50, eumenorrheic, non-smokers, and body mass index (BMI) between 21 and 50 kg/m(2). 139 were randomized. Treadmill exercise: 150 or 300 min/week, five menstrual cycles. Control group maintained exercise <75 min/week. Area under curve (AUC) for urinary estrogen. Secondary measures: urinary progesterone, quantitative digitized breast dynamic contrast-enhanced magnetic resonance imaging background parenchymal enhancement. Mean age 34 years, mean BMI 26.8 kg/m(2). A linear dose-response relationship was observed such that every 100 min of exercise is associated with 3.6 % lower follicular phase estrogen AUC (linear trend test, p = 0.03). No changes in luteal phase estrogen or progesterone levels. There was also a dose-response effect noted: for every 100 min of exercise, there was a 9.7 % decrease in background parenchymal enhancement as measured by imaging (linear trend test, p = 0.009). Linear dose-response effect observed to reduce follicular phase estrogen exposure measured via urine and hormone sensitive breast tissue as measured by imaging. Future research should explore maintenance of effects and extent to which findings are repeatable in lower risk women. Given the high benefit to risk ratio, clinicians can inform young women at increased risk that exercise may blunt estrogen exposure while considering whether to try other preventive therapies.

Myocardial blood flow and its transit time, oxygen utilization, and efficiency of highly endurance-trained human heart.

PubMed

Heinonen, Ilkka; Kudomi, Nobuyuki; Kemppainen, Jukka; Kiviniemi, Antti; Noponen, Tommi; Luotolahti, Matti; Luoto, Pauliina; Oikonen, Vesa; Sipilä, Hannu T; Kopra, Jaakko; Mononen, Ilkka; Duncker, Dirk J; Knuuti, Juhani; Kalliokoski, Kari K

2014-07-01

Highly endurance-trained athlete's heart represents the most extreme form of cardiac adaptation to physical stress, but its circulatory alterations remain obscure. In the present study, myocardial blood flow (MBF), blood mean transit time (MTT), oxygen extraction fraction (OEF) and consumption (MVO2), and efficiency of cardiac work were quantified in highly trained male endurance athletes and control subjects at rest and during supine cycling exercise using [(15)O]-labeled radiotracers and positron emission tomography. Heart rate and MBF were lower in athletes both at rest and during exercise. OEF increased in response to exercise in both groups, but was higher in athletes (70 ± 21 vs. 63 ± 11 % at rest and 86 ± 13 vs. 73 ± 10 % during exercise). MTT was longer and vascular resistance higher in athletes both at rest and during exercise, but arterial content of 2,3-diphosphoglycerate (oxygen affinity) was unchanged. MVO2 per gram of myocardium trended (p = 0.08) lower in athletes both at rest and during exercise, while myocardial efficiency of work and MVO2 per beat were not different between groups. Arterial levels of free fatty acids were ~twofold higher in athletes likely leading to higher myocardial fatty acid oxidation and hence oxygen cost, which may have blunted the bradycardia-induced decrease in MVO2. Finally, the observed group differences in MBF, OEF, MTT and vascular resistance remained significant also after they were controlled for differences in MVO2. In conclusion, in highly endurance-trained human heart, increased myocardial blood transition time enables higher oxygen extraction levels with a lower myocardial blood flow and higher vascular resistance. These physiological adaptations to exercise training occur independently of the level of oxygen consumption and together with training-induced bradycardia may serve as mechanisms to increase functional reserve of the human heart.

Divergent systemic and local inflammatory response to hind limb demand ischemia in wild-type and ApoE-/- mice.

PubMed

Crawford, Robert S; Albadawi, Hassan; Robaldo, Alessandro; Peck, Michael A; Abularrage, Christopher J; Yoo, Hyung-Jin; Lamuraglia, Glenn M; Watkins, Michael T

2013-08-01

We designed studies to determine whether the ApoE-/- phenotype modulates the local skeletal muscle and systemic inflammatory (plasma) responses to lower extremity demand ischemia. The ApoE-/- phenotype is an experimental model for atherosclerosis in humans. Aged female ApoE-/- and C57BL6 mice underwent femoral artery ligation, then were divided into sedentary and demand ischemia (exercise) groups on day 14. We assessed baseline and postexercise limb perfusion and hind limb function. On day 14, animals in the demand ischemia group underwent daily treadmill exercise through day 28. Sedentary mice were not exercised. On day 28, we harvested plasma and skeletal muscle from ischemic limbs from sedentary and exercised mice. We assayed muscle for angiogenic and proinflammatory proteins, markers of skeletal muscle regeneration, and evidence of skeletal muscle fiber maturation. Hind limb ischemia was similar in ApoE-/- and C57 mice before the onset of exercise. Under sedentary conditions, plasma vascular endothelial cell growth factor and interleukin-6, but not keratinocyte chemoattractant factor (KC) or macrophage inflammatory protein-2 (MIP-2), were higher in ApoE (P < 0.0001). After exercise, plasma levels of vascular endothelial cell growth factor, KC, and MIP-2, but not IL-6, were lower in ApoE (P < 0.004). The cytokines KC and MIP-2 in muscle were greater in exercised ApoE-/- mice compared with C57BL6 mice (P = 0.01). Increased poly-ADP-ribose activity and mature muscle regeneration were associated with demand ischemia in the C57BL6 mice, compared with the ApoE-/- mice (P = 0.01). Demand limb ischemia in the ApoE-/- phenotype exacerbated the expression of select systemic cytokines in plasma and blunted indices of muscle regeneration. Copyright © 2013 Elsevier Inc. All rights reserved.

Regulation of skeletal muscle blood flow during exercise in ageing humans

PubMed Central

Hearon, Christopher M.

2015-01-01

Abstract The regulation of skeletal muscle blood flow and oxygen delivery to contracting skeletal muscle is complex and involves the mechanical effects of muscle contraction; local metabolic, red blood cell and endothelium‐derived substances; and the sympathetic nervous system (SNS). With advancing age in humans, skeletal muscle blood flow is typically reduced during dynamic exercise and this is due to a lower vascular conductance, which could ultimately contribute to age‐associated reductions in aerobic exercise capacity, a primary predictor of mortality in both healthy and diseased ageing populations. Recent findings have highlighted the contribution of endothelium‐derived substances to blood flow control in contracting muscle of older adults. With advancing age, impaired nitric oxide availability due to scavenging by reactive oxygen species, in conjunction with elevated vasoconstrictor signalling via endothelin‐1, reduces the local vasodilatory response to muscle contraction. Additionally, ageing impairs the ability of contracting skeletal muscle to blunt sympathetic vasoconstriction (i.e. ‘functional sympatholysis’), which is critical for the proper regulation of tissue blood flow distribution and oxygen delivery, and could further reduce skeletal muscle perfusion during high intensity and/or large muscle mass exercise in older adults. We propose that initiation of endothelium‐dependent hyperpolarization is the underlying signalling event necessary to properly modulate sympathetic vasoconstriction in contracting muscle, and that age‐associated impairments in red blood cell adenosine triphosphate release and stimulation of endothelium‐dependent vasodilatation may explain impairments in both local vasodilatation and functional sympatholysis with advancing age in humans. PMID:26332887

Physiology and Assessment as Low-Hanging Fruit for Education Overhaul

ERIC Educational Resources Information Center

Ribeiro, Sidarta; Mota, Natália Bezerra; da Rocha Fernandes, Valter; Deslandes, Andrea Camaz; Brockington, Guilherme; Copelli, Mauro

2016-01-01

Physiology and assessment constitute major bottlenecks of school learning among students with low socioeconomic status. The limited resources and household overcrowding typical of poverty produce deficits in nutrition, sleep, and exercise that strongly hinder physiology and hence learning. Likewise, overcrowded classrooms hamper the assessment of…

The back squat: A proposed assessment of functional deficits and technical factors that limit performance

PubMed Central

Myer, Gregory D.; Kushner, Adam M.; Brent, Jensen L.; Schoenfeld, Brad J.; Hugentobler, Jason; Lloyd, Rhodri S.; Vermeil, Al; Chu, Donald A.; Harbin, Jason; McGill, Stuart M.

2014-01-01

Fundamental movement competency is essential for participation in physical activity and for mitigating the risk of injury, which are both key elements of health throughout life. The squat movement pattern is arguably one of the most primal and critical fundamental movements necessary to improve sport performance, to reduce injury risk and to support lifelong physical activity. Based on current evidence, this first (1 of 2) report deconstructs the technical performance of the back squat as a foundation training exercise and presents a novel dynamic screening tool that incorporates identification techniques for functional deficits that limit squat performance and injury resilience. The follow-up report will outline targeted corrective methodology for each of the functional deficits presented in the assessment tool. PMID:25506270

Review of recent studies on interventions for cognitive deficits in patients with cancer.

PubMed

Gehring, Karin; Roukema, Jan Anne; Sitskoorn, Margriet M

2012-02-01

Research has demonstrated that patients with cancer experience cognitive deficits, often due to aggressive anticancer treatments. In this article, we critically review the interventional studies that have been conducted to investigate beneficial effects on cognitive function in cancer patients. Pharmacological agents that have been studied include psychostimulants, such as methylphenidate and modafinil, erythropoietin, and hormonal (supplement) treatments for patients who receive hormonal suppression therapy. In addition, several cognitive rehabilitation programs have been evaluated in cancer patients. Recently, the approach of physical exercise to treat cognitive deficits has received great interest, and findings from novel studies are keenly anticipated. Although, in general, the studies reviewed were well designed, future studies may wish to include larger sample sizes and pay more attention to the accurate assessment of cognitive function.

Cannabis problem experiences among users of the tobacco-cannabis combination known as blunts.

PubMed

Fairman, Brian J

2015-05-01

In most of the world, cannabis smokers mix loose tobacco inside a joint, pipe, spliff, or cone. More recently, a 'blunt' formulation combines these two drugs by inserting cannabis into a hollowed-out cigar. Epidemiological research linking simultaneous use of these two drugs and the development of cannabis use disorders (CUD) remains unclear. This study estimates associations linking blunt smoking with levels and subtypes of cannabis problems. Cross-sectional data on 27,767 past-year cannabis users were analyzed from the US National Survey on Drug Use and Health (NSDUH) conducted from 2009 to 2012. Ten self-reported items of DSM-IV CUD features elicited a single latent trait of cannabis problem (CP) severity, which was then regressed on past-year blunt smoking and past-month blunt frequency measures within the context of a conceptual model. Differential item functioning (DIF) analysis evaluated potential bias in CP feature response by blunt smoking history. Past-year blunt smoking was associated with higher CP severity compared to cannabis users who did not smoke blunts. Days of blunt smoking in the past month also predicted higher CP severity than less frequent blunt use. Those smoking blunts experienced more subjectively felt tolerance and having spent more time obtaining or using cannabis, but were less likely to experience other problems, even at the same level of CP severity. These findings suggest smoking blunts might promote the development of problematic cannabis use. Responses to cannabis problems differed by history of blunt smoking, possibly implicating an influence of tobacco on measurement of cannabis use disorders. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Prevalence of female athlete triad characteristics in a club triathlon team.

PubMed

Hoch, Anne Z; Stavrakos, John E; Schimke, Jane E

2007-05-01

To determine the prevalence of the female athlete triad in club triathletes. Cross-sectional. Academic medical center in the midwestern United States. Fifteen women (mean age, 35+/-6 y). Not applicable. Disordered eating and menstrual status were determined by questionnaires. Energy status was determined by a 3-day food record, resting energy expenditure, and exercise energy output. Bone mineral density (BMD) was measured in the total left hip and lumbar spine (L2-4) by dual-energy x-ray absorptiometry. Sixty percent of the triathletes were found to be in calorie deficit, 53% had a carbohydrate deficit, 47% had a fat deficit, 40% had a protein deficit, and 33% had a calcium deficit. Forty percent of triathletes reported a history of amenorrhea. BMD was normal in the lumbar spine (L2-4) (1.3+/-0.1 g/cm(2)) and total left hip (1.1+/-0.1 g/cm(2)). Triathletes are at risk for components of the female athlete triad. Continued efforts need to be directed at prevention through education of athletes, coaches, parents, and health care professionals.

Effects of Pomegranate Juice Supplementation on Oxidative Stress Biomarkers Following Weightlifting Exercise

PubMed Central

Turki, Mouna; Hammouda, Omar; Chtourou, Hamdi; Trabelsi, Khaled; Bouaziz, Mohamed; Abdelkarim, Osama; Hoekelmann, Anita; Ayadi, Fatma; Souissi, Nizar; Bailey, Stephen J.; Driss, Tarak; Yaich, Sourour

2017-01-01

The aim of this study was to test the hypothesis that pomegranate juice supplementation would blunt acute and delayed oxidative stress responses after a weightlifting training session. Nine elite weightlifters (21.0 ± 1 years) performed two Olympic-Weightlifting sessions after ingesting either the placebo or pomegranate juice supplements. Venous blood samples were collected at rest and 3 min and 48 h after each session. Compared to the placebo condition, pomegranate juice supplementation attenuated the increase in malondialdehyde (−12.5%; p < 0.01) and enhanced the enzymatic (+8.6% for catalase and +6.8% for glutathione peroxidase; p < 0.05) and non-enzymatic (+12.6% for uric acid and +5.7% for total bilirubin; p < 0.01) antioxidant responses shortly (3 min) after completion of the training session. Additionally, during the 48 h recovery period, pomegranate juice supplementation accelerated (p < 0.05) the recovery kinetics of the malondialdehyde (5.6%) and the enzymatic antioxidant defenses compared to the placebo condition (9 to 10%). In conclusion, supplementation with pomegranate juice has the potential to attenuate oxidative stress by enhancing antioxidant responses assessed acutely and up to 48 h following an intensive weightlifting training session. Therefore, elite weightlifters might benefit from blunted oxidative stress responses following intensive weightlifting sessions, which could have implications for recovery between training sessions. PMID:28758938

Effects of Pomegranate Juice Supplementation on Oxidative Stress Biomarkers Following Weightlifting Exercise.

PubMed

Ammar, Achraf; Turki, Mouna; Hammouda, Omar; Chtourou, Hamdi; Trabelsi, Khaled; Bouaziz, Mohamed; Abdelkarim, Osama; Hoekelmann, Anita; Ayadi, Fatma; Souissi, Nizar; Bailey, Stephen J; Driss, Tarak; Yaich, Sourour

2017-07-29

The aim of this study was to test the hypothesis that pomegranate juice supplementation would blunt acute and delayed oxidative stress responses after a weightlifting training session. Nine elite weightlifters (21.0 ± 1 years) performed two Olympic-Weightlifting sessions after ingesting either the placebo or pomegranate juice supplements. Venous blood samples were collected at rest and 3 min and 48 h after each session. Compared to the placebo condition, pomegranate juice supplementation attenuated the increase in malondialdehyde (-12.5%; p < 0.01) and enhanced the enzymatic (+8.6% for catalase and +6.8% for glutathione peroxidase; p < 0.05) and non-enzymatic (+12.6% for uric acid and +5.7% for total bilirubin; p < 0.01) antioxidant responses shortly (3 min) after completion of the training session. Additionally, during the 48 h recovery period, pomegranate juice supplementation accelerated ( p < 0.05) the recovery kinetics of the malondialdehyde (5.6%) and the enzymatic antioxidant defenses compared to the placebo condition (9 to 10%). In conclusion, supplementation with pomegranate juice has the potential to attenuate oxidative stress by enhancing antioxidant responses assessed acutely and up to 48 h following an intensive weightlifting training session. Therefore, elite weightlifters might benefit from blunted oxidative stress responses following intensive weightlifting sessions, which could have implications for recovery between training sessions.

Effect of Chronic Athletic Activity on Brown Fat in Young Women.

PubMed

Singhal, Vibha; Maffazioli, Giovana D; Ackerman, Kate E; Lee, Hang; Elia, Elisa F; Woolley, Ryan; Kolodny, Gerald; Cypess, Aaron M; Misra, Madhusmita

2016-01-01

The effect of chronic exercise activity on brown adipose tissue (BAT) is not clear, with some studies showing positive and others showing negative associations. Chronic exercise is associated with increased resting energy expenditure (REE) secondary to increased lean mass and a probable increase in BAT. Many athletes are in a state of relative energy deficit suggested by lower fat mass and hypothalamic amenorrhea. States of severe energy deficit such as anorexia nervosa are associated with reduced BAT. There are no data regarding the impact of chronic exercise activity on BAT volume or activity in young women and it is unclear whether relative energy deficiency modifies the effects of exercise on BAT. We assessed cold induced BAT volume and activity in young female athletes compared with non-athletes, and further evaluated associations of BAT with measures of REE, body composition and menstrual status. The protocol was approved by our Institutional Review Board. Written informed consent was obtained from all participants prior to study initiation. This was a cross-sectional study of 24 women (16 athletes and8 non-athletes) between 18-25 years of age. Athletes were either oligo-amenorrheic (n = 8) or eumenorrheic (n = 8).We used PET/CT scans to determine cold induced BAT activity, VMAX Encore 29 metabolic cart to obtain measures of REE, and DXA for body composition. Athletes and non-athletes did not differ for age or BMI. Compared with non-athletes, athletes had lower percent body fat (p = 0.002), higher percent lean mass (p = 0.01) and trended higher in REE (p = 0.09). BAT volume and activity in athletes trended lower than in non-athletes (p = 0.06; p = 0.07, respectively). We found negative associations of BAT activity with duration of amenorrhea (r = -0.46, p = 0.02).BAT volume correlated inversely with lean mass (r = -0.46, p = 0.02), and positively with percent body fat, irisin and thyroid hormones. Our study shows a trend for lower BAT in young female athletes compared with non-athletes, and shows associations of brown fat with menstrual status and body composition. Brown fat may undergo adaptive reductions with increasing energy deficit.

Less-than-expected weight loss in normal-weight women undergoing caloric restriction and exercise is accompanied by preservation of fat-free mass and metabolic adaptations.

PubMed

Koehler, K; De Souza, M J; Williams, N I

2017-03-01

Normal-weight women frequently restrict their caloric intake and exercise, but little is known about the effects on body weight, body composition and metabolic adaptations in this population. We conducted a secondary analysis of data from a randomized controlled trial in sedentary normal-weight women. Women were assigned to a severe energy deficit (SEV: -1062±80 kcal per day; n=9), a moderate energy deficit (MOD: -633±71 kcal per day; n=7) or energy balance (BAL; n=9) while exercising five times per week for 3 months. Outcome variables included changes in body weight, body composition, resting metabolic rate (RMR) and metabolic hormones associated with energy conservation. Weight loss occurred in SEV (-3.7±0.9 kg, P<0.001) and MOD (-2.7±0.8 kg; P=0.003), but weight loss was significantly less than predicted (SEV: -11.1±1.0 kg; MOD: -6.5±1.1 kg; both P<0.001 vs actual). Fat mass declined in SEV (P<0.001) and MOD (P=0.006), whereas fat-free mass remained unchanged in all groups (P>0.33). RMR decreased by -6±2% in MOD (P=0.020). In SEV, RMR did not change on a group level (P=0.66), but participants whose RMR declined lost more weight (P=0.020) and had a higher baseline RMR (P=0.026) than those whose RMR did not decrease. Characteristic changes in leptin (P=0.003), tri-iodothyronine (P=0.013), insulin-like growth factor-1 (P=0.016) and ghrelin (P=0.049) occurred only in SEV. The energy deficit and adaptive changes in RMR explained 54% of the observed weight loss. In normal-weight women, caloric restriction and exercise resulted in less-than-predicted weight loss. In contrast to previous literature, weight loss consisted almost exclusively of fat mass, whereas fat-free mass was preserved.

Exercise-induced neuroprotective effects on neurodegenerative diseases: the key role of trophic factors.

PubMed

Campos, Carlos; Rocha, Nuno Barbosa F; Lattari, Eduardo; Paes, Flávia; Nardi, António E; Machado, Sérgio

2016-06-01

Age-related neurodegenerative disorders, like Alzheimer's or Parkinson's disease, are becoming a major issue to public health care. Currently, there is no effective pharmacological treatment to address cognitive impairment in these patients. Here, we aim to explore the role of exercise-induced trophic factor enhancement in the prevention or delay of cognitive decline in patients with neurodegenerative diseases. There is a significant amount of evidence from animal and human studies that links neurodegenerative related cognitive deficits with changes on brain and peripheral trophic factor levels. Several trials with elderly individuals and patients with neurodegenerative diseases report exercise induced cognitive improvements and changes on trophic factor levels including BDNF, IGF-I, among others. Further studies with healthy aging and clinical populations are needed to understand how diverse exercise interventions produce different variations in trophic factor signaling. Genetic profiles and potential confounders regarding trophic factors should also be addressed in future trials.

Anti-inflammatory effects of physical activity in relationship to improved cognitive status in humans and mouse models of Alzheimer's disease.

PubMed

Stranahan, Alexis M; Martin, Bronwen; Maudsley, Stuart

2012-01-01

Physical activity has been correlated with a reduced incidence of cognitive decline and Alzheimer's disease in human populations. Although data from intervention-based randomized trials is scarce, there is some indication that exercise may confer protection against age-related deficits in cognitive function. Data from animal models suggests that exercise, in the form of voluntary wheel running, is associated with reduced amyloid deposition and enhanced clearance of amyloid beta, the major constituent of plaques in Alzheimer's disease. Treadmill exercise has also been shown to ameliorate the accumulation of phosphorylated tau, an essential component of neurofibrillary tangles in Alzheimer's models. A common therapeutic theme arising from studies of exercise-induced neuroprotection in human populations and in animal models involves reduced inflammation in the central nervous system. In this respect, physical activity may promote neuronal resilience by reducing inflammation.

Attention deficit and attention training in early twentieth-century Japan.

PubMed

Takeda, Toshinobu; Ando, Mizuho; Kumagai, Keiko

2015-06-01

Yuzero Motora (1856-1912), regarded as the first professional Japanese psychologist, tried to address students' attention difficulties through attention training methods of his own design. His reports contain the first description of ADHD-like symptoms in the history of Japan. Motora viewed "distractibility" as the irregular transition of attention. Students with low scores and attention difficulties who participated in Motora's exercises showed improvement in arithmetic, psychological testing, and certain aspects of daily life. This article describes Motora's theoretical conception of attention and attention training methodology, the history of attention deficit and attention training, and the significance of Motora's experiments.

Factors Associated with Blunt Cerebrovascular Injury in Patients with Cervical Spine Injury

PubMed Central

NAKAJIMA, Hiroyuki; NEMOTO, Manabu; TORIO, Tetsuya; TAKEDA, Ririko; OOIGAWA, Hidetoshi; ARAKI, Ryuichiro; KURITA, Hiroki

2014-01-01

Blunt cerebrovascular injury (BCVI) is known to be a potentially fatal complication of cervical spine injury (CSI). Methods for screening the appropriate population remain to be elucidated, especially in Japan. This retrospective study was conducted to predict the risk factors relevant to BCVIs. Among 92 patients with CSI transferred to our institution from April 2007 to March 2012, 40 patients (35 men, 5 women) with neurological deficits and/or significant cervical spine fracture including fracture of transversarium, facet, body, lamina, and spinous process, underwent multi-detector computed tomography angiography (MDCTA) and magnetic resonance angiography (MRA), which identified 10 patients with BCVI [2 carotid artery injuries (BCAIs) and 9 vertebral artery injuries (BVAIs); 1 patient suffered both]. Univariate analyses exploring associations between individual risk factors and BCVI and BVAI were performed using Fisher's exact test and Chi-square test for dichotomous variables and the unpaired t-test for continuous variables. Multiple logistic regression analyses for BCVI and BVAI were carried out using stepwise methods. On univariate and multivariate analysis, hyperextension injury was significantly associated with BVAI (p = 0.01 and p = 0.02), and subluxation (dislocation of vertebral body > 5 mm) was a significant predictor of BCVI (p = 0.04 and p = 0.03) and BVAI (p = 0.01 and p = 0.01). Prompt evaluation for BCVIs is recommended in CSI patients with hyperextension injury and dislocation of the vertebral body. PMID:24390186

The First Experience of Triple Nerve Transfer in Proximal Radial Nerve Palsy.

PubMed

Emamhadi, Mohammadreza; Andalib, Sasan

2018-01-01

Injury to distal portion of posterior cord of brachial plexus leads to palsy of radial and axillary nerves. Symptoms are usually motor deficits of the deltoid muscle; triceps brachii muscle; and extensor muscles of the wrist, thumb, and fingers. Tendon transfers, nerve grafts, and nerve transfers are options for surgical treatment of proximal radial nerve palsy to restore some motor functions. Tendon transfer is painful, requires a long immobilization, and decreases donor muscle strength; nevertheless, nerve transfer produces promising outcomes. We present a patient with proximal radial nerve palsy following a blunt injury undergoing triple nerve transfer. The patient was involved in a motorcycle accident with complete palsy of the radial and axillary nerves. After 6 months, on admission, he showed spontaneous recovery of axillary nerve palsy, but radial nerve palsy remained. We performed triple nerve transfer, fascicle of ulnar nerve to long head of the triceps branch of radial nerve, flexor digitorum superficialis branch of median nerve to extensor carpi radialis brevis branch of radial nerve, and flexor carpi radialis branch of median nerve to posterior interosseous nerve, for restoration of elbow, wrist, and finger extensions, respectively. Our experience confirmed functional elbow, wrist, and finger extensions in the patient. Triple nerve transfer restores functions of the upper limb in patients with debilitating radial nerve palsy after blunt injuries. Copyright © 2017 Elsevier Inc. All rights reserved.

Exercise Induced Neuroplasticity to Enhance Therapeutic Outcomes of Cognitive Remediation in Schizophrenia: Analyzing the Role of Brai nderived Neurotrophic Factor.

PubMed

Campos, Carlos; Rocha, Nuno B F; Lattari, Eduardo; Nardi, Antonio E; Machado, Sergio

2017-01-01

Cognitive impairment is a major manifestation of schizophrenia and a crucial treatment target as these deficits are closely related to patients' functional outcomes. Cognitive remediation is the gold-standard practice to address cognitive deficits in schizophrenia. There is clear evidence stating that cognitive remediation improves cognitive function and promotes structural neuroplastic changes in patients with schizophrenia, with brain-derived neurotrophic factor (BDNF) expression emerging as a potential biomarker for its efficacy. This is particularly important as there is clear evidence relating atypical BDNF expression to cognitive impairment in patients with schizophrenia. Despite the valuable role of cognitive remediation in the management of schizophrenia, there is still a need to develop methods that allow maximizing its efficacy. In this review, we present a hypothesis arguing that cognitive remediation efficacy for patients with schizophrenia can be enhanced by aerobic exercise-induced BDNF upregulation. There have been a few trials reporting that combining aerobic exercise with cognitive training was superior to cognitive training alone to improve cognitive functioning in patients with schizophrenia. Furthermore, there is preliminary evidence suggesting that combined aerobic and cognitive training can increase peripheral BDNF levels. Thereby, engaging in aerobic exercise in close temporal proximity to cognitive remediation may allow achieving a state of neuroplastic readiness in the brain, facilitating cognitive functioning enhancement. Although this hypothesis still lacks evidence, future clinical trials using cognitive remediation for schizophrenia should explore strategies to maximize neuroplasticity and achieve optimal cognitive improvements. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Neural response during anticipation of monetary loss is elevated in adult attention deficit hyperactivity disorder.

PubMed

Wilbertz, Gregor; Delgado, Mauricio R; Tebartz Van Elst, Ludger; Maier, Simon; Philipsen, Alexandra; Blechert, Jens

2017-06-01

Risky behaviour seriously impacts the life of adult patients with attention deficit hyperactivity disorder (ADHD). Such behaviours have often been attributed to their exaggerated reward seeking, but dysfunctional anticipation of negative outcomes might also play a role. The present study compared adult patients with ADHD (n = 28) with matched healthy controls (n = 28) during anticipation of monetary losses versus gains while undergoing functional magnetic resonance imaging (fMRI) and skin conductance recording. Skin conductance was higher during anticipation of losses compared to gains in both groups. Affective ratings of predictive cues did not differ between groups. ADHD patients showed increased activity in bilateral amygdalae, left anterior insula (region of interest analysis) and left temporal pole (whole brain analysis) compared to healthy controls during loss versus gain anticipation. In the ADHD group higher insula and temporal pole activations went along with more negative affective ratings. Neural correlates of loss anticipation are not blunted but rather increased in ADHD, possibly due to a life history of repeated failures and the respective environmental sanctions. Behavioural adaptations to such losses, however, might differentiate them from controls: future research should study whether negative affect might drive more risk seeking than risk avoidance.

Acute effects of aerobic exercise on cognitive function in individuals with Parkinson's disease.

PubMed

Silveira, Carolina R A; Roy, Eric A; Almeida, Quincy J

2018-04-03

Deficits in executive functions are highly prevalent in Parkinson's disease (PD). Although chronic physical exercise has been shown to improve executive functions in PD, evidence of acute exercise effects is limited. This study aimed to evaluate the effects of an acute bout of exercise on cognitive processes underlying executive functions in PD. Twenty individuals with PD were assessed in both a Control and an Exercise conditions. In each condition, individuals started performing a simple and a choice reaction time (RT) task. Subsequently, participants were asked to sit on a cycle ergometer (Control) or cycle (Exercise) for 20 min in counterbalanced order. Participants were asked to repeat both reaction time tasks after 15-min rest period in both conditions. While no differences were found in simple RT, participants showed faster choice RT post Exercise as well as Control conditions (p = .012). Participants had slower choice RT for target stimulus compared to non-target stimuli irrespective of time or experimental condition (p < .001). There was no change in accuracy following experimental conditions. Results suggest that individuals with PD may not respond behaviourally to a single bout of exercise. The lack of selective effects of exercise on cognition suggests that practice effects may have influenced previous research. Future studies should assess whether neurophysiological changes might occur after an acute bout of exercise in PD. Copyright © 2018 Elsevier B.V. All rights reserved.

Cardiovascular response to exercise training in the systemic right ventricle of adults with transposition of the great arteries

PubMed Central

Shafer, K M; Janssen, L; Carrick-Ranson, G; Rahmani, S; Palmer, D; Fujimoto, N; Livingston, S; Matulevicius, S A; Forbess, L W; Brickner, B; Levine, B D

2015-01-01

We aimed to assess the haemodynamic effects of exercise training in transposition of the great arteries (TGA) patients with systemic right ventricles (SRVs). TGA patients have limited exercise tolerance and early mortality due to systemic (right) ventricular failure. Whether exercise training enhances or injures the SRV is unclear. Fourteen asymptomatic patients (34 ± 10 years) with TGA and SRV were enrolled in a 12 week exercise training programme (moderate and high-intensity workouts). Controls were matched on age, gender, BMI and physical activity. Exercise testing pre- and post- training included: (a) submaximal and peak; (b) prolonged (60 min) submaximal endurance and (c) high-intensity intervals. Oxygen uptake (; Douglas bag technique), cardiac output (, foreign-gas rebreathing), ventricular function (echocardiography and cardiac MRI) and serum biomarkers were assessed. TGA patients had lower peak , , and stroke volume (SV), a blunted / slope, and diminished SV response to exercise (SV increase from rest: TGA = 15.2%, controls = 68.9%, P < 0.001) compared with controls. After training, TGA patients increased peak by 6 ± 8.5%, similar to controls (interaction P = 0.24). The magnitude of SV reserve on initial testing correlated with training response (r = 0.58, P = 0.047), though overall, no change in peak was observed. High-sensitivity troponin T (hs-TnT) and N-terminal prohormone of brain naturetic peptide (NT pro-BNP) were low and did not change with acute exercise or after training. Our data show that TGA patients with SRVs in this study safely participated in exercise training and improved peak . Neither prolonged submaximal exercise, nor high-intensity intervals, nor short-term exercise training seem to injure the systemic right ventricle. Key Points Patients with transposition of the great arteries (TGA) and systemic right ventricles have premature congestive heart failure; there is also a growing concern that athletes who perform extraordinary endurance exercise may injure the right ventricle. Therefore we felt it essential to determine whether exercise training might injure a systemic right ventricle which is loaded with every heartbeat. Previous studies have shown that short term exercise training is feasible in TGA patients, but its effect on ventricular function is unclear. We demonstrate that systemic right ventricular function is preserved (and may be improved) in TGA patients with exercise training programmes that are typical of recreational and sports participation, with no evidence of injury on biomarker assessment. Stroke volume reserve during exercise correlates with exercise training response in our TGA patients, identifying this as a marker of a systemic right ventricle (SRV) that may most tolerate (and possibly even be improved by) exercise training. PMID:25809342

Fiscal Challenge: An Experiential Exercise in Policy Making

ERIC Educational Resources Information Center

Aguilar, Mike; Soques, Daniel

2015-01-01

In this article, the authors introduce a pedagogical innovation that is designed to enhance students' understanding of fiscal policy in general, and the national debt and deficit in particular. The innovation leverages the educational advantages offered through a competitive environment by pitting teams of students against one another with the…

Differential involvement of IL-6 in the early and late phase of 1-methylnicotinamide (MNA) release in Concanavalin A-induced hepatitis.

PubMed

Sternak, Magdalena; Jakubowski, Andrzej; Czarnowska, Elzbieta; Slominska, Ewa M; Smolenski, Ryszard T; Szafarz, Malgorzata; Walczak, Maria; Sitek, Barbara; Wojcik, Tomasz; Jasztal, Agnieszka; Kaminski, Karol; Chlopicki, Stefan

2015-09-01

Exogenous 1-methylnicotinamide (MNA) displays anti-inflammatory activity. The aim of this work was to characterize the profile of release of endogenous MNA during the initiation and progression of murine hepatitis induced by Concanavalin A (ConA). In particular we aimed to clarify the role of interleukin-6 (IL-6) as well as the energy state of hepatocytes in MNA release in early and late phases of ConA-induced hepatitis in mice. Hepatitis was induced by ConA in IL-6(+/+) and IL-6(-/-) mice, and various parameters of liver inflammation and injury, as well as the energy state of hepatocytes, were analysed in relation to MNA release. The decrease in ATP/ADP and NADH/NAD ratios, cytokine release (IL-6, IFN-ɤ), acute phase response (e.g. haptoglobin) and liver injury (alanine aminotransaminase, ALT) were all blunted in ConA-induced hepatitis in IL-6(-/-) mice as compared to IL-6(+/+) mice. The release of MNA in response to Con A was also significantly blunted in IL-6(-/-) mice as compared to IL-6(+/+) mice in the early stage of ConA-induced hepatitis. In turn, nicotinamide N-methyltransferase (NNMT) and aldehyde oxidase (AO) activities were blunted in the liver and MNA plasma concentration was elevated to similar degree in the late stage after Concanavalin A in IL-6(+/+) and IL-6(-/-) mice. In conclusion, we demonstrated that in ConA-induced hepatitis, early, but not late MNA release was IL-6-dependent. Our results suggest that in the initiation and early hepatitis, MNA release is linked to the energy deficit/impaired redox status in hepatocytes, while in a later phase, MNA release is rather linked to the systemic inflammation. Copyright © 2015 Elsevier B.V. All rights reserved.

Heart rate recovery after maximal exercise is blunted in hypertensive seniors.

PubMed

Best, Stuart A; Bivens, Tiffany B; Dean Palmer, M; Boyd, Kara N; Melyn Galbreath, M; Okada, Yoshiyuki; Carrick-Ranson, Graeme; Fujimoto, Naoki; Shibata, Shigeki; Hastings, Jeffrey L; Spencer, Matthew D; Tarumi, Takashi; Levine, Benjamin D; Fu, Qi

2014-12-01

Abnormal heart rate recovery (HRR) after maximal exercise may indicate autonomic dysfunction and is a predictor for cardiovascular mortality. HRR is attenuated with aging and in middle-age hypertensive patients, but it is unknown whether HRR is attenuated in older-age adults with hypertension. This study compared HRR among 16 unmedicated stage 1 hypertensive (HTN) participants [nine men/seven women; 68 ± 5 (SD) yr; awake ambulatory blood pressure (BP) 149 ± 10/87 ± 7 mmHg] and 16 normotensive [control (CON)] participants (nine men/seven women; 67 ± 5 yr; 122 ± 4/72 ± 5 mmHg). HR, BP, oxygen uptake (V̇o2), cardiac output (Qc), and stroke volume (SV) were measured at rest, at two steady-state work rates, and graded exercise to peak during maximal treadmill exercise. During 6 min of seated recovery, the change in HR (ΔHR) was obtained every minute and BP every 2 min. In addition, HRR and R-R interval (RRI) recovery kinetics were analyzed using a monoexponential function, and the indexes (HRRI and RRII) were calculated. Maximum V̇o2, HR, Qc, and SV responses during exercise were not different between groups. ΔHR was significantly different (P < 0.001) between the HTN group (26 ± 8) and the CON group (36 ± 12 beats/min) after 1 min of recovery but less convincing at 2 min (P = 0.055). BP recovery was similar between groups. HRRI was significantly lower (P = 0.016), and there was a trend of lower RRII (P = 0.066) in the HTN group compared with the CON group. These results show that in older-age adults, HRR is attenuated further with the presence of hypertension, which may be attributable to an impairment of autonomic function. Copyright © 2014 the American Physiological Society.

Effect of inspired air conditions on exercise-induced bronchoconstriction and urinary CC16 levels in athletes.

PubMed

Bolger, C; Tufvesson, E; Anderson, S D; Devereux, G; Ayres, J G; Bjermer, L; Sue-Chu, M; Kippelen, P

2011-10-01

Injury to the airway epithelium has been proposed as a key susceptibility factor for exercise-induced bronchoconstriction (EIB). Our goals were to establish whether airway epithelial cell injury occurs during EIB in athletes and whether inhalation of warm humid air inhibits this injury. Twenty-one young male athletes (10 with a history of EIB) performed two 8-min exercise tests near maximal aerobic capacity in cold dry (4°C, 37% relative humidity) and warm humid (25°C, 94% relative humidity) air on separate days. Postexercise changes in urinary CC16 were used as a biomarker of airway epithelial cell perturbation and injury. Bronchoconstriction occurred in eight athletes in the cold dry environment and was completely blocked by inhalation of warm humid air [maximal fall in forced expiratory volume in 1 s = 18.1 ± 2.1% (SD) in cold dry air and 1.7 ± 0.8% in warm humid air, P < 0.01]. Exercise caused an increase in urinary excretion of CC16 in all subjects (P < 0.001), but this rise in CC16 was blunted following inhalation of warm humid air [median CC16 increase pre- to postchallenge = 1.91 and 0.35 ng/μmol in cold dry and warm humid air, respectively, in athletes with EIB (P = 0.017) and 1.68 and 0.48 ng/μmol in cold dry and warm humid air, respectively, in athletes without EIB (P = 0.002)]. The results indicate that exercise hyperpnea transiently disrupts the airway epithelium of all athletes (not only in those with EIB) and that inhalation of warm moist air limits airway epithelial cell perturbation and injury.

Heart rate recovery after maximal exercise is blunted in hypertensive seniors

PubMed Central

Best, Stuart A.; Bivens, Tiffany B.; Dean Palmer, M.; Boyd, Kara N.; Melyn Galbreath, M.; Okada, Yoshiyuki; Carrick-Ranson, Graeme; Shibata, Shigeki; Hastings, Jeffrey L.; Spencer, Matthew D.; Tarumi, Takashi; Levine, Benjamin D.; Fu, Qi

2014-01-01

Abnormal heart rate recovery (HRR) after maximal exercise may indicate autonomic dysfunction and is a predictor for cardiovascular mortality. HRR is attenuated with aging and in middle-age hypertensive patients, but it is unknown whether HRR is attenuated in older-age adults with hypertension. This study compared HRR among 16 unmedicated stage 1 hypertensive (HTN) participants [nine men/seven women; 68 ± 5 (SD) yr; awake ambulatory blood pressure (BP) 149 ± 10/87 ± 7 mmHg] and 16 normotensive [control (CON)] participants (nine men/seven women; 67 ± 5 yr; 122 ± 4/72 ± 5 mmHg). HR, BP, oxygen uptake (V̇o2), cardiac output (Qc), and stroke volume (SV) were measured at rest, at two steady-state work rates, and graded exercise to peak during maximal treadmill exercise. During 6 min of seated recovery, the change in HR (ΔHR) was obtained every minute and BP every 2 min. In addition, HRR and R-R interval (RRI) recovery kinetics were analyzed using a monoexponential function, and the indexes (HRRI and RRII) were calculated. Maximum V̇o2, HR, Qc, and SV responses during exercise were not different between groups. ΔHR was significantly different (P < 0.001) between the HTN group (26 ± 8) and the CON group (36 ± 12 beats/min) after 1 min of recovery but less convincing at 2 min (P = 0.055). BP recovery was similar between groups. HRRI was significantly lower (P = 0.016), and there was a trend of lower RRII (P = 0.066) in the HTN group compared with the CON group. These results show that in older-age adults, HRR is attenuated further with the presence of hypertension, which may be attributable to an impairment of autonomic function. PMID:25301897

Severe energy deficit at high altitude inhibits skeletal muscle mTORC1-mediated anabolic signaling without increased ubiquitin proteasome activity.

PubMed

Margolis, Lee M; Carbone, John W; Berryman, Claire E; Carrigan, Christopher T; Murphy, Nancy E; Ferrando, Arny A; Young, Andrew J; Pasiakos, Stefan M

2018-06-07

Muscle loss at high altitude (HA) is attributable to energy deficit and a potential dysregulation of anabolic signaling. Exercise and protein ingestion can attenuate the effects of energy deficit on muscle at sea level (SL). Whether these effects are observed when energy deficit occurs at HA is unknown. To address this, muscle obtained from lowlanders ( n = 8 males) at SL, acute HA (3 h, 4300 m), and chronic HA (21 d, -1766 kcal/d energy balance) before [baseline (Base)] and after 80 min of aerobic exercise followed by a 2-mile time trial [postexercise (Post)] and 3 h into recovery (Rec) after ingesting whey protein (25 g) were analyzed using standard molecular techniques. At SL, Post, and REC, p-mechanistic target of rapamycin (mTOR) Ser2448 , p-p70 ribosomal protein S6 kinase (p70S6K) Ser424/421 , and p-ribosomal protein S6 (rpS6) Ser235/236 were similar and higher ( P < 0.05) than Base. At acute HA, Post p-mTOR Ser2448 and Post and REC p-p70S6K Ser424/421 were not different from Base and lower than SL ( P < 0.05). At chronic HA, Post and Rec p-mTOR Ser2448 and p-p70S6K Ser424/421 were not different from Base and lower than SL, and, independent of time, p-rpS6 Ser235/236 was lower than SL ( P < 0.05). Post proteasome activity was lower ( P < 0.05) than Base and Rec, independent of phase. Our findings suggest that HA exposure induces muscle anabolic resistance that is exacerbated by energy deficit during acclimatization, with no change in proteolysis.-Margolis, L. M., Carbone, J. W., Berryman, C. E., Carrigan, C. T., Murphy, N. E., Ferrando, A. A., Young, A. J., Pasiakos, S. M. Severe energy deficit at high altitude inhibits skeletal muscle mTORC1-mediated anabolic signaling without increased ubiquitin proteasome activity.

AltitudeOmics: impaired pulmonary gas exchange efficiency and blunted ventilatory acclimatization in humans with patent foramen ovale after 16 days at 5,260 m.

PubMed

Elliott, Jonathan E; Laurie, Steven S; Kern, Julia P; Beasley, Kara M; Goodman, Randall D; Kayser, Bengt; Subudhi, Andrew W; Roach, Robert C; Lovering, Andrew T

2015-05-01

A patent foramen ovale (PFO), present in ∼40% of the general population, is a potential source of right-to-left shunt that can impair pulmonary gas exchange efficiency [i.e., increase the alveolar-to-arterial Po2 difference (A-aDO2)]. Prior studies investigating human acclimatization to high-altitude with A-aDO2 as a key parameter have not investigated differences between subjects with (PFO+) or without a PFO (PFO-). We hypothesized that in PFO+ subjects A-aDO2 would not improve (i.e., decrease) after acclimatization to high altitude compared with PFO- subjects. Twenty-one (11 PFO+) healthy sea-level residents were studied at rest and during cycle ergometer exercise at the highest iso-workload achieved at sea level (SL), after acute transport to 5,260 m (ALT1), and again at 5,260 m after 16 days of high-altitude acclimatization (ALT16). In contrast to PFO- subjects, PFO+ subjects had 1) no improvement in A-aDO2 at rest and during exercise at ALT16 compared with ALT1, 2) no significant increase in resting alveolar ventilation, or alveolar Po2, at ALT16 compared with ALT1, and consequently had 3) an increased arterial Pco2 and decreased arterial Po2 and arterial O2 saturation at rest at ALT16. Furthermore, PFO+ subjects had an increased incidence of acute mountain sickness (AMS) at ALT1 concomitant with significantly lower peripheral O2 saturation (SpO2). These data suggest that PFO+ subjects have increased susceptibility to AMS when not taking prophylactic treatments, that right-to-left shunt through a PFO impairs pulmonary gas exchange efficiency even after acclimatization to high altitude, and that PFO+ subjects have blunted ventilatory acclimatization after 16 days at altitude compared with PFO- subjects. Copyright © 2015 the American Physiological Society.

Prescribing Aerobic Exercise Intensity without a Cardiopulmonary Exercise Test Post Stroke: Utility of the Six-Minute Walk Test.

PubMed

Marzolini, Susan; Oh, Paul; Corbett, Dale; Dooks, Daryl; Calouro, Marcella; MacIntosh, Bradley J; Goodman, Rachel; Brooks, Dina

2016-09-01

The cardiopulmonary exercise test (CPET) is an established method for determining target exercise training intensity (ventilatory threshold [VAT]) and cardiovascular risk; unfortunately, CPET is not readily accessible to people post stroke. The objective of this study was to determine the utility of the 6-minute walk test (6MWT) as a less resource-intensive alternative to CPET for prescribing exercise intensity to people post stroke with motor impairments. Sixty participants (male, 71.7%; 13.5 ± 22.5 [mean ± standard deviation] months post stroke; age 64.5 ± 12.5 years, with a Chedoke-McMaster Stroke Assessment score of 4.9 ± .9 of the leg) underwent 6MWT, CPET, balance, strength, and cognition assessments. 6MWT heart rate (hr) was significantly lower than VAT-hr (92.3 ± 14.8 beats⋅min(-1) versus 99.8 ± 15.7 beats⋅min(-1), respectively, P < .001; correlation r = .7, P < .001). Bland-Altman analysis revealed that the 6MWT underestimated the VAT-hr by 7.7 ± 11.5%. The 95% confidence interval of the mean bias was large (14.8% and -30.3%), reflecting poor agreement, with 71.7% (n = 43) of the participants unable to reach a walking intensity at or above the VAT-hr. Lower oxygen uptake at the VAT (β = .655, P = .004), higher 6MWT-hr (β = 1.07, P = .01), and better balance (β = 1.128, P = .04) were associated with greater utility of the 6MWT for prescribing exercise. The 6MWT-hr was not interchangeable with the target training VAT-hr determined by CPET. However, in combination with CPET, the 6MWT will indicate when deficits preclude walking alone as the primary exercise modality for optimizing cardiovascular fitness. Future studies to develop a less resource-intensive, multimodal alternative to the CPET for prescribing exercise are needed. A modality that minimizes the effect of stroke deficits, specifically poor balance, should be included. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Hyponatremia in distance runners: fluid and sodium balance during exercise.

PubMed

Noakes, Tim

2002-08-01

Since its first description in 1985, two opposing theories have evolved to explain the etiology of symptomatic hyponatremia of exercise. The first holds that the condition occurs only in athletes who lose both water and sodium during exercise, and fail to fully replace their sodium losses. The second theory holds that the symptomatic form of this condition occurs in athletes who generate a whole body fluid overload as a result of an excessive fluid intake during prolonged exercise. It is argued that the promotion of the idea that athletes should drink as much as possible during exercise has produced, rather than prevented, the recent increase in the incidence of this condition. A series of case reports and laboratory studies reported in the past 2 years have established that it is a whole body fluid overload, resulting from sustained high rates of fluid intake, that causes the symptomatic hyponatremia of exercise. There is no evidence that, in the absence of fluid overload, the usual sodium deficits generated during exercise can cause this condition. These findings confirm that the potentially fatal condition of symptomatic hyponatremia would be eliminated from sport immediately if all athletes were advised of the dangers of ingesting as much fluid as possible during any exercise that lasts more than 4 hours.

Cannabis Problem Experiences Among Users of the Tobacco-Cannabis Combination Known As Blunts

PubMed Central

Fairman, Brian J.

2015-01-01

Background In most of the world, cannabis smokers mix loose tobacco inside a joint, pipe, spliff, or cone. More recently, a ‘blunt’ formulation combines these two drugs by inserting cannabis into a hollowed-out cigar. Epidemiological research linking simultaneous use of these two drugs and the development of cannabis use disorders (CUD) remains unclear. This study estimates associations linking blunt smoking with levels and subtypes of cannabis problems. Methods Cross-sectional data on 27,767 past-year cannabis users were analyzed from the US National Survey on Drug Use and Health (NSDUH) conducted from 2009–2012. Ten self-reported items of DSM-IV CUD features elicited a single latent trait of cannabis problem (CP) severity, which was then regressed on past-year blunt smoking and past-month blunt frequency measures within the context of a conceptual model. Differential item functioning (DIF) analysis evaluated potential bias in CP feature response by blunt smoking history. Results Past-year blunt smoking was associated with higher CP severity compared to cannabis users who did not smoke blunts. Days of blunt smoking in the past month also predicted higher CP severity than less frequent blunt use. Those smoking blunts experienced more subjectively felt tolerance and having spent more time obtaining or using cannabis, but were less likely to experience other problems, even at the same level of CP severity. Conclusions These findings suggest smoking blunts might promote the development of problematic cannabis use. Responses to cannabis problems differed by history of blunt smoking, possibly implicating an influence of tobacco on measurement of cannabis use disorders. PMID:25746234

The role of sensory augmentation for people with vestibular deficits: Real-time balance aid and/or rehabilitation device?

PubMed

Sienko, K H; Whitney, S L; Carender, W J; Wall, C

2017-01-01

This narrative review highlights findings from the sensory augmentation field for people with vestibular deficits and addresses the outstanding questions that are critical to the translation of this technology into clinical and/or personal use. Prior research has demonstrated that the real-time use of visual, vibrotactile, auditory, and multimodal sensory augmentation technologies can improve balance during static and dynamic stance tasks within a laboratory setting. However, its application in improving gait requires additional investigation, as does its efficacy as a rehabilitation device for people with vestibular deficits. In some locomotor studies involving sensory augmentation, gait velocity decreased and secondary task performance worsened, and subjects negatively altered their segmental control strategies when cues were provided following short training sessions. A further question is whether the retention and/or carry-over effects of training with a sensory augmentation technology exceed the retention and/or carry-over effects of training alone, thereby supporting its use as a rehabilitation device. Preliminary results suggest that there are short-term improvements in balance performance following a small number of training sessions with a sensory augmentation device. Long-term clinical and home-based controlled training studies are needed. It is hypothesized that sensory augmentation provides people with vestibular deficits with additional sensory input to promote central compensation during a specific exercise/activity; however, research is needed to substantiate this theory. Major obstacles standing in the way of its use for these critical applications include determining exercise/activity specific feedback parameters and dosage strategies. This paper summarizes the reported findings that support sensory augmentation as a balance aid and rehabilitation device, but does not critically examine efficacy or the quality of the research methods used in the reviewed studies.

The outcome of hip exercise in patellofemoral pain: A systematic review.

PubMed

Thomson, Catherine; Krouwel, Oliver; Kuisma, Raija; Hebron, Clair

2016-12-01

Patellofemoral pain (PFP) is one of the most common lower extremity conditions seen in clinical practice. Current evidence shows that there are hip strength deficits, delayed onset and shorter activation of gluteus medius in people with PFP. The aim of this review was to systematically review the literature to investigate the outcome of hip exercise in people with PFP. AMED, CINAHL, Cochrane, EMBASE, PEDro, Pubmed, Science direct and SPORTDiscus databases were searched from inception to November 2014 for RCTs, non-randomised studies and case studies. Two independent reviewers assessed each paper for inclusion and quality. Twenty one papers were identified; eighteen investigating strengthening exercise, two investigating the effect of neuromuscular exercise and one study investigated the effect of hip exercise for the prevention of PFP. Hip and knee strengthening programmes were shown to be equally effective. Limited evidence indicates that the addition of hip exercise to an exercise programme is beneficial. Limited evidence demonstrates that motor skill retraining in a participant group who displayed abnormal hip alignment in running improves pain. The evidence consistently demonstrated that both hip strengthening and neuromuscular exercise has a beneficial effect on pain and function in people with PFP. Strengthening exercise predominantly addressed abductor and external rotator muscle groups. A consensus from PFP researchers for standardisation of methodology is recommended to enable meaningful comparison between trials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Changes in gut hormone levels and negative energy balance during aerobic exercise in obese young males.

PubMed

Ueda, Shin-ya; Yoshikawa, Takahiro; Katsura, Yoshihiro; Usui, Tatsuya; Nakao, Hayato; Fujimoto, Shigeo

2009-04-01

We examined whether changes in gut hormone levels due to a single bout of aerobic exercise differ between obese young males and normal controls, and attempted to determine the involvement of hormonal changes during exercise in the regulation of energy balance (EB) in these obese subjects. Seven obese and seven age-matched subjects of normal weight participated in exercise and rest sessions. Subjects consumed a standardized breakfast that was followed by constant cycling exercise at 50% VO(2max) or rest for 60 min. At lunch, a test meal was presented, and energy intake (EI) and relative energy intake (REI) were calculated. Blood samples were obtained at 30 min intervals during both sessions for measurement of glucose, insulin, glucagon, ghrelin, peptide YY (PYY), and glucagon-like peptide-1 (GLP-1). Plasma levels of PYY and GLP-1 were increased by exercise, whereas plasma ghrelin levels were unaffected by exercise. The areas under the curve (AUC) of the time courses of PYY and GLP-1 levels did not significantly differ between the two groups. In contrast, EI and REI were decreased by exercise in both groups, and energy deficit was significantly larger in obese subjects than in normal controls. The present findings suggest that short-term EB during a single exercise session might be regulated not by increased amounts of these gut hormones per se.

Let's Be Blunt: Consumption Methods Matter Among Black Marijuana Smokers.

PubMed

Montgomery, LaTrice; Bagot, Kara

2016-05-01

Despite the high prevalence of blunt (i.e., hollowed-out cigars that are filled with marijuana) use among Black marijuana smokers, few studies have examined if and how blunt users differ from traditional joint users. The current study compared the prevalence and patterns of use for those who smoked blunts in the past month (i.e., blunt users) with those who used marijuana through other methods (i.e., other marijuana users). The sample included 935 Black past-month marijuana smokers participating in the 2013 National Survey on Drug Use and Health. Among past-month marijuana smokers, 73.2% were blunt users and 26.8% were other marijuana users. Overall, blunt users initiated marijuana use at an earlier age (15.9 vs. 17.3 years, p < .01) and reported more days of marijuana use in the past month (16 vs. 8 days, p < .01) than did other marijuana users. There were also differences by gender. Among females, blunt users reported a higher odds of past-year marijuana abuse or dependence (23.8%) than other marijuana users (11.2%) (adjusted odds ratio = 1.23, 95% CI [1.12, 3.17], p < .01). However, blunt-using males reported similar odds of past-year marijuana abuse or dependence (approximately 25%) as other marijuana-using males. These findings highlight the need for targeted interventions for blunt users as a subgroup of marijuana users, especially among Black females, who may be at increased risk for developing a marijuana use disorder as a result of blunt smoking.

Cyclin D2 is a critical mediator of exercise-induced cardiac hypertrophy.

PubMed

Luckey, Stephen W; Haines, Chris D; Konhilas, John P; Luczak, Elizabeth D; Messmer-Kratzsch, Antke; Leinwand, Leslie A

2017-12-01

A number of signaling pathways underlying pathological cardiac hypertrophy have been identified. However, few studies have probed the functional significance of these signaling pathways in the context of exercise or physiological pathways. Exercise studies were performed on females from six different genetic mouse models that have been shown to exhibit alterations in pathological cardiac adaptation and hypertrophy. These include mice expressing constitutively active glycogen synthase kinase-3β (GSK-3βS9A), an inhibitor of CaMK II (AC3-I), both GSK-3βS9A and AC3-I (GSK-3βS9A/AC3-I), constitutively active Akt (myrAkt), mice deficient in MAPK/ERK kinase kinase-1 (MEKK1 -/- ), and mice deficient in cyclin D2 (cyclin D2 -/- ). Voluntary wheel running performance was similar to NTG littermates for five of the mouse lines. Exercise induced significant cardiac growth in all mouse models except the cyclin D2 -/- mice. Cardiac function was not impacted in the cyclin D2 -/- mice and studies using a phospho-antibody array identified six proteins with increased phosphorylation (greater than 150%) and nine proteins with decreased phosphorylation (greater than 33% decrease) in the hearts of exercised cyclin D2 -/- mice compared to exercised NTG littermate controls. Our results demonstrate that unlike the other hypertrophic signaling molecules tested here, cyclin D2 is an important regulator of both pathologic and physiological hypertrophy. Impact statement This research is relevant as the hypertrophic signaling pathways tested here have only been characterized for their role in pathological hypertrophy, and not in the context of exercise or physiological hypertrophy. By using the same transgenic mouse lines utilized in previous studies, our findings provide a novel and important understanding for the role of these signaling pathways in physiological hypertrophy. We found that alterations in the signaling pathways tested here had no impact on exercise performance. Exercise induced cardiac growth in all of the transgenic mice except for the mice deficient in cyclin D2. In the cyclin D2 null mice, cardiac function was not impacted even though the hypertrophic response was blunted and a number of signaling pathways are differentially regulated by exercise. These data provide the field with an understanding that cyclin D2 is a key mediator of physiological hypertrophy.

Screening CT angiography for pediatric blunt cerebrovascular injury with emphasis on the cervical "seatbelt sign".

PubMed

Desai, N K; Kang, J; Chokshi, F H

2014-09-01

There are no standard screening guidelines to evaluate blunt cerebrovascular injury in children. The purpose of this retrospective study was to understand the clinical and radiologic risk factors associated with pediatric blunt cerebrovascular injury on CTA of the neck with primary attention to the cervical "seatbelt sign." Radiology reports from 2002 to 2012 were queried for the examination "CTA neck." The electronic medical record was reviewed for mechanism of injury, Glasgow Coma Scale score, and physical examination findings. Radiology reports from adjunct radiographic studies were reviewed. CTA neck examinations with reported blunt cerebrovascular injury were reviewed to confirm imaging findings. Patients with penetrating injury or those without a history of trauma were excluded. Four hundred sixty-three patients underwent CTA of the neck; 137 had blunt trauma. Forty-two of 85 patients involved in a motor vehicle collision had a cervical seatbelt sign; none had blunt cerebrovascular injury. Nine vessels (4 vertebral arteries, 4 ICAs, 1 common carotid artery) in 8 patients ultimately were diagnosed with various grades (I-IV) of blunt cerebrovascular injury, representing 5.8% (8/137) of the population screened for blunt neck trauma. The mean Glasgow Coma Scale score was significantly lower (P=.02) in the blunt cerebrovascular injury group versus the non-blunt cerebrovascular injury group. Although not statistically significant, patients with blunt cerebrovascular injury had a higher tendency to have additional traumatic injuries, primarily basilar skull fractures (P=.05) and intracranial hemorrhage (P=.13). A common indication for neck CTA, the cervical seatbelt sign, was not associated with blunt cerebrovascular injury. With the exception of Glasgow Coma Scale score, no single risk factor was statistically significant in predicting vascular injury in this series. © 2014 by American Journal of Neuroradiology.

Lifelong physical activity affects mini mental state exam scores in individuals over 55 years of age.

PubMed

Nemati Karimooy, Habibollah; Hosseini, Mahmoud; Nemati, Maryam; Esmaily, Habib Ollah

2012-04-01

The positive effects of physical activity on cognition have been widely documented. Human studies and the results obtained from animal models of Alzheimer's disease (AD) have shown that if commenced early in life, exercise effectively reduces the development of cognitive deficits caused by aging. In the present study, the scores on Mini Mental State Exam (MMSE) of individuals over 55 years old who had a history of exercising have been compared to those without a history of exercising. This research was carried out on 273 individuals over 55 years of age. The subjects were randomly chosen from different areas of Mashhad and from exercise clubs. Each person completed a personal information form containing data such as demographics in addition to details of their involvement in sporting activity. Subjects were categorized as follows: 1- non-exercised, 2- exercised. The people in group 2 were then divided into non-professionally exercised (with a history of 2-10 years exercising) or professionally--exercised subjects (i.e. people who were currently, or had previously been members of an exercise club and/or had been trained for at least 10 years). Out of 273 subjects questioned in the present study, 229 were males and 44 were females. The MMSE score in men was significantly higher than women (p < 0.001). The exercised individuals of both sexes had significantly higher scores compared to non-exercised group (p < 0.001). There was no significant difference between professionally- exercised individuals of either sex in comparison with exercised ones. It is suggested that lifelong physical activity and exercise affects cognitive performance in old age. Copyright © 2011 Elsevier Ltd. All rights reserved.

Suicide by blunt head trauma - Two cases with striking similarities.

PubMed

Park, Hyejin; Lee, Bongwoo; Yoon, Connie

2015-10-01

There have been several forensic pathological studies on the distinction between falls from height and homicidal blows in blunt head trauma, but few studies have focused on suicidal blows. Self-inflicted blunt head trauma is usually a part of a complex suicide with more than one suicidal method applied. Actually, no reports on suicide indicate blunt head trauma to be the singular cause of death in recent publications. Cases with self-inflicted blunt trauma are often challenging for those involved in the investigation because they are confronted with findings that are also found in homicides. A refined guideline to differentiate suicidal blows from homicidal blows in blunt head trauma allows for a more accurate representation of the events surrounding death. This paper presents two cases of suicide by self-inflicted blunt head trauma in which blunt head trauma from repeatedly hitting the decedent's head with a hammer was considered to be the only cause of death. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The effect of puberty on fat oxidation rates during exercise in overweight and normal-weight girls.

PubMed

Chu, L; Riddell, M C; Schneiderman, J E; McCrindle, B W; Hamilton, J K

2014-01-01

Excess weight is often associated with insulin resistance (IR) and may disrupt fat oxidation during exercise. This effect is further modified by puberty. While studies have shown that maximal fat oxidation rates (FOR) during exercise decrease with puberty in normal-weight (NW) and overweight (OW) boys, the effect of puberty in NW and OW girls is unclear. Thirty-three NW and OW girls ages 8-18 yr old completed a peak aerobic capacity test on a cycle ergometer. FOR were calculated during progressive submaximal exercise. Body composition and Tanner stage were determined. For each participant, a best-fit polynomial curve was constructed using fat oxidation vs. exercise intensity to estimate max FOR. In a subset of the girls, IR derived from an oral glucose tolerance test (n = 20), and leptin and adiponectin levels (n = 11) were assessed in relation to FOR. NW pre-early pubertal girls had higher max FOR [6.9 ± 1.4 mg·kg fat free mass (FFM)(-1)·min(-1)] than NW mid-late pubertal girls (2.2 ± 0.9 mg·kg FFM(-1)·min(-1)) (P = 0.002), OW pre-early pubertal girls (3.8 ± 2.1 mg·kg FFM(-1)·min(-1)), and OW mid-late pubertal girls (3.3 ± 0.9 mg·kg FFM(-1)·min(-1)) (P < 0.05). Bivariable analyses showed positive associations between FOR with homeostatic model assessment of IR (P = 0.001), leptin (P < 0.001), and leptin-to-adiponectin ratio (P = 0.001), independent of percent body fat. Max FOR decreased in NW girls during mid-late puberty; however, this decrease associated with puberty was blunted in OW girls due to lower FOR in pre-early puberty. The presence of IR due to obesity potentially masks the effect of puberty on FOR during exercise in girls.

Nitric oxide-dependent modulation of sympathetic neural control of oxygenation in exercising human skeletal muscle

PubMed Central

Chavoshan, Bahman; Sander, Mikael; Sybert, Troy E; Hansen, Jim; Victor, Ronald G; Thomas, Gail D

2002-01-01

Nitric oxide (NO) attenuates α-adrenergic vasoconstriction in contracting rodent skeletal muscle, but it is unclear if NO plays a similar role in human muscle. We therefore hypothesized that in humans, NO produced in exercising skeletal muscle blunts the vasoconstrictor response to sympathetic activation. We assessed vasoconstrictor responses in the microcirculation of human forearm muscle using near-infrared spectroscopy to measure decreases in muscle oxygenation during reflex sympathetic activation evoked by lower body negative pressure (LBNP). Experiments were performed before and after NO synthase inhibition produced by systemic infusion of NG-nitro-l-arginine methyl ester (l-NAME). Before l-NAME, LBNP at −20 mmHg decreased muscle oxygenation by 20 ± 2 % in resting forearm and by 2 ± 3 % in exercising forearm (n = 20), demonstrating metabolic modulation of sympathetic vasoconstriction. As expected, l-NAME increased mean arterial pressure by 17 ± 3 mmHg, leading to baroreflex-mediated supression of baseline muscle sympathetic nerve activity (SNA). The increment in muscle SNA in response to LBNP at −20 mmHg also was attenuated after l-NAME (before, +14 ± 2; after, +8 ± 1 bursts min−1; n = 6), but this effect of l-NAME was counteracted by increasing LBNP to −40 mmHg (+19 ± 2 bursts min−1). After l-NAME, LBNP at −20 mmHg decreased muscle oxygenation similarly in resting (−11 ± 3 %) and exercising (−10 ± 2 %) forearm (n = 12). Likewise, LBNP at −40 mmHg decreased muscle oxygenation both in resting (−19 ± 4 %) and exercising (−21 ± 5 %) forearm (n = 8). These data advance the hypothesis that NO plays an important role in modulating sympathetic vasoconstriction in the microcirculation of exercising muscle, because such modulation is abrogated by NO synthase inhibition with l-NAME. PMID:11927694

Vitamin C and E supplementation alters protein signalling after a strength training session, but not muscle growth during 10 weeks of training.

PubMed

Paulsen, G; Hamarsland, H; Cumming, K T; Johansen, R E; Hulmi, J J; Børsheim, E; Wiig, H; Garthe, I; Raastad, T

2014-12-15

This study investigated the effects of vitamin C and E supplementation on acute responses and adaptations to strength training. Thirty-two recreationally strength-trained men and women were randomly allocated to receive a vitamin C and E supplement (1000 mg day(-1) and 235 mg day(-1), respectively), or a placebo, for 10 weeks. During this period the participants' training involved heavy-load resistance exercise four times per week. Muscle biopsies from m. vastus lateralis were collected, and 1 repetition maximum (1RM) and maximal isometric voluntary contraction force, body composition (dual-energy X-ray absorptiometry), and muscle cross-sectional area (magnetic resonance imaging) were measured before and after the intervention. Furthermore, the cellular responses to a single exercise session were assessed midway in the training period by measurements of muscle protein fractional synthetic rate and phosphorylation of several hypertrophic signalling proteins. Muscle biopsies were obtained from m. vastus lateralis twice before, and 100 and 150 min after, the exercise session (4 × 8RM, leg press and knee-extension). The supplementation did not affect the increase in muscle mass or the acute change in protein synthesis, but it hampered certain strength increases (biceps curl). Moreover, increased phosphorylation of p38 mitogen-activated protein kinase, Extracellular signal-regulated protein kinases 1 and 2 and p70S6 kinase after the exercise session was blunted by vitamin C and E supplementation. The total ubiquitination levels after the exercise session, however, were lower with vitamin C and E than placebo. We concluded that vitamin C and E supplementation interfered with the acute cellular response to heavy-load resistance exercise and demonstrated tentative long-term negative effects on adaptation to strength training. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

Preventive role of exercise training in autonomic, hemodynamic, and metabolic parameters in rats under high risk of metabolic syndrome development.

PubMed

Moraes-Silva, Ivana Cinthya; Mostarda, Cristiano; Moreira, Edson Dias; Silva, Kleiton Augusto Santos; dos Santos, Fernando; de Angelis, Kátia; Farah, Vera de Moura Azevedo; Irigoyen, Maria Claudia

2013-03-15

High fructose consumption contributes to metabolic syndrome incidence, whereas exercise training promotes several beneficial adaptations. In this study, we demonstrated the preventive role of exercise training in the metabolic syndrome derangements in a rat model. Wistar rats receiving fructose overload in drinking water (100 g/l) were concomitantly trained on a treadmill (FT) or kept sedentary (F) for 10 wk. Control rats treated with normal water were also submitted to exercise training (CT) or sedentarism (C). Metabolic evaluations consisted of the Lee index and glycemia and insulin tolerance test (kITT). Blood pressure (BP) was directly measured, whereas heart rate (HR) and BP variabilities were evaluated in time and frequency domains. Renal sympathetic nerve activity was also recorded. F rats presented significant alterations compared with all the other groups in insulin resistance (in mg · dl(-1) · min(-1): F: 3.4 ± 0.2; C: 4.7 ± 0.2; CT: 5.0 ± 0.5 FT: 4.6 ± 0.4), mean BP (in mmHG: F: 117 ± 2; C: 100 ± 2; CT: 98 ± 2; FT: 105 ± 2), and Lee index (in g/mm: F = 0.31 ± 0.001; C = 0.29 ± 0.001; CT = 0.27 ± 0.002; FT = 0.28 ± 0.002), confirming the metabolic syndrome diagnosis. Exercise training blunted all these derangements. Additionally, FS group presented autonomic dysfunction in relation to the others, as seen by an ≈ 50% decrease in baroreflex sensitivity and 24% in HR variability, and increases in sympathovagal balance (140%) and in renal sympathetic nerve activity (45%). These impairments were not observed in FT group, as well as in C and CT. Correlation analysis showed that both Lee index and kITT were associated with vagal impairment caused by fructose. Therefore, exercise training plays a preventive role in both autonomic and hemodynamic alterations related to the excessive fructose consumption.

Intravenous sub-anesthetic ketamine for perioperative analgesia

PubMed Central

Gorlin, Andrew W; Rosenfeld, David M; Ramakrishna, Harish

2016-01-01

Ketamine, an N-methyl-d-aspartate antagonist, blunts central pain sensitization at sub-anesthetic doses (0.3 mg/kg or less) and has been studied extensively as an adjunct for perioperative analgesia. At sub-anesthetic doses, ketamine has a minimal physiologic impact though it is associated with a low incidence of mild psychomimetic symptoms as well as nystagmus and double vision. Contraindications to its use do exist and due to ketamine's metabolism, caution should be exercised in patients with renal or hepatic dysfunction. Sub-anesthetic ketamine improves pain scores and reduces perioperative opioid consumption in a broad range of surgical procedures. In addition, there is evidence that ketamine may be useful in patients with opioid tolerance and for preventing chronic postsurgical pain. PMID:27275042

Randomized Controlled Trial of Exercise for ADHD and Disruptive Behavior Disorders.

PubMed

Bustamante, Eduardo Esteban; Davis, Catherine Lucy; Frazier, Stacy Lynn; Rusch, Dana; Fogg, Louis F; Atkins, Marc S; Marquez, David Xavier

2016-07-01

The objective of this study is to test the feasibility and impact of a 10-wk after-school exercise program for children with attention deficit hyperactivity disorder and/or disruptive behavior disorders living in an urban poor community. Children were randomized to an exercise program (n = 19) or a comparable but sedentary attention control program (n = 16). Cognitive and behavioral outcomes were collected pre-/posttest. Intent-to-treat mixed models tested group-time and group-time-attendance interactions. Effect sizes were calculated within and between groups. Feasibility was evidenced by 86% retention, 60% attendance, and average 75% maximum HR. Group-time results were null on the primary outcome, parent-reported executive function. Among secondary outcomes, between-group effect sizes favored exercise on hyperactive symptoms (d = 0.47) and verbal working memory (d = 0.26), and controls on visuospatial working memory (d = -0.21) and oppositional defiant symptoms (d = -0.37). In each group, within-group effect sizes were moderate to large on most outcomes (d = 0.67 to 1.60). A group-time-attendance interaction emerged on visuospatial working memory (F[1,33] = 7.42, P < 0.05), such that attendance to the control program was related to greater improvements (r = 0.72, P < 0.01), whereas attendance to the exercise program was not (r = 0.25, P = 0.34). Although between-group findings on the primary outcome, parent-reported executive function, were null, between-group effect sizes on hyperactivity and visuospatial working memory may reflect adaptations to the specific challenges presented by distinct formats. Both groups demonstrated substantial within-group improvements on clinically relevant outcomes. Findings underscore the importance of programmatic features, such as routines, engaging activities, behavior management strategies, and adult attention, and highlight the potential for after-school programs to benefit children with attention deficit hyperactivity disorder and disruptive behavior disorder living in urban poverty where health needs are high and services resources few.

Exercise training improves vascular mitochondrial function

PubMed Central

Park, Song-Young; Rossman, Matthew J.; Gifford, Jayson R.; Bharath, Leena P.; Bauersachs, Johann; Richardson, Russell S.; Abel, E. Dale; Symons, J. David

2016-01-01

Exercise training is recognized to improve cardiac and skeletal muscle mitochondrial respiratory capacity; however, the impact of chronic exercise on vascular mitochondrial respiratory function is unknown. We hypothesized that exercise training concomitantly increases both vascular mitochondrial respiratory capacity and vascular function. Arteries from both sedentary (SED) and swim-trained (EX, 5 wk) mice were compared in terms of mitochondrial respiratory function, mitochondrial content, markers of mitochondrial biogenesis, redox balance, nitric oxide (NO) signaling, and vessel function. Mitochondrial complex I and complex I + II state 3 respiration and the respiratory control ratio (complex I + II state 3 respiration/complex I state 2 respiration) were greater in vessels from EX relative to SED mice, despite similar levels of arterial citrate synthase activity and mitochondrial DNA content. Furthermore, compared with the SED mice, arteries from EX mice displayed elevated transcript levels of peroxisome proliferative activated receptor-γ coactivator-1α and the downstream targets cytochrome c oxidase subunit IV isoform 1, isocitrate dehydrogenase (Idh) 2, and Idh3a, increased manganese superoxide dismutase protein expression, increased endothelial NO synthase phosphorylation (Ser1177), and suppressed reactive oxygen species generation (all P < 0.05). Although there were no differences in EX and SED mice concerning endothelium-dependent and endothelium-independent vasorelaxation, phenylephrine-induced vasocontraction was blunted in vessels from EX compared with SED mice, and this effect was normalized by NOS inhibition. These training-induced increases in vascular mitochondrial respiratory capacity and evidence of improved redox balance, which may, at least in part, be attributable to elevated NO bioavailability, have the potential to protect against age- and disease-related challenges to arterial function. PMID:26825520

Hypoxic exercise training causes erythrocyte senescence and rheological dysfunction by depressed Gardos channel activity.

PubMed

Mao, Tso-Yen; Fu, Li-Lan; Wang, Jong-Shyan

2011-08-01

Despite enhancing cardiopulmonary and muscular fitness, the effect of hypoxic exercise training (HE) on hemorheological regulation remains unclear. This study investigates how HE modulates erythrocyte rheological properties and further explores the underlying mechanisms in the hemorheological alterations. Twenty-four sedentary males were randomly divided into hypoxic (HE; n = 12) and normoxic (NE; n = 12) exercise training groups. The subjects were trained on 60% of maximum work rate under 15% (HE) or 21% (NE) O(2) condition for 30 min daily, 5 days weekly for 5 wk. The results demonstrated that HE 1) downregulated CD47 and CD147 expressions on erythrocytes, 2) decreased actin and spectrin contents in erythrocytes, 3) reduced erythrocyte deformability under shear flow, and 4) diminished erythrocyte volume changed by hypotonic stress. Treatment of erythrocytes with H(2)O(2) that mimicked in vivo prooxidative status resulted in the cell shrinkage, rigidity, and phosphatidylserine exposure, whereas HE enhanced the eryptotic responses to H(2)O(2). However, HE decreased the degrees of clotrimazole to blunt ionomycin-induced shrinkage, rigidity, and cytoskeleton breakdown of erythrocytes, referred to as Gardos effects. Reduced erythrocyte deformability by H(2)O(2) was inversely related to the erythrocyte Gardos effect on the rheological function. Conversely, NE intervention did not significantly change resting and exercise erythrocyte rheological properties. Therefore, we conclude that HE rather than NE reduces erythrocyte deformability and volume regulation, accompanied by an increase in the eryptotic response to oxidative stress. Simultaneously, this intervention depresses Gardos channel-modulated erythrocyte rheological functions. Results of this study provide further insight into erythrocyte senescence induced by HE.

Influence of Single-Nucleotide Polymorphisms in PPAR-δ, PPAR-γ, and PRKAA2 on the Changes in Anthropometric Indices and Blood Measurements through Exercise-Centered Lifestyle Intervention in Japanese Middle-Aged Men

PubMed Central

Iyadomi, Minako; Taniguchi, Hiroaki; Higaki, Yasuki; Tanaka, Hiroaki; Horita, Mikako; Tanaka, Keitaro

2018-01-01

The purpose of the current study was to examine the influence of single-nucleotide polymorphisms (SNPs) in the peroxisome proliferator-activated receptor-δ (PPAR-δ), PPAR-γ, and α2 isoforms of the catalytic subunit of AMP-activated protein kinase (PRKAA2) on the extent of changes in anthropometric indices and blood measurements through exercise-centered lifestyle intervention in middle-aged men. A total of 109 Japanese middle-aged male subjects (47.0 ± 0.4 years) participated in the baseline health checkup, 6-month exercise-centered lifestyle intervention, and second checkup conducted several months after the subject completed the intervention. The body mass index (BMI), waist circumference, and clinical measurements, including hemoglobin Alc (HbA1c), triglyceride (TG), alanine aminotransferase (ALT), and γ-glutamyl-transpeptidase (γ-GTP), were measured at the baseline and second checkup. The three SNPs of PPAR-δ A/G (rs2267668), PPAR-γ C/G (rs1801282), and PRKAA2 A/G (rs1418442) were determined. Blunted responses in the reduction in the BMI and waist circumference were observed in A/A carriers of PPAR-δ SNP compared with G allele carriers (all p < 0.05). The A/A carriers also displayed less-marked improvements in HbA1c, TG, ALT, and γ-GTP (all p < 0.05). The current results suggest that A/A carriers of PPAR-δ SNP (rs2267668) may enjoy fewer beneficial effects of exercise-centered lifestyle intervention on anthropometric indices and blood measurements. PMID:29494521

What Did You Expect?: The Interaction Between Cigarette and Blunt vs. Non-Blunt Marijuana Use among African American Young Adults

PubMed Central

Ramo, Danielle

2017-01-01

Background Marijuana and tobacco co-use is highly prevalent among African American young adults. In an effort to inform prevention and treatment interventions, the current study examined the expectancies around the co-use of marijuana and cigarettes among African American young adults. Methods An anonymous online survey recruited African American adults (N = 111) age 18 to 29 who reported past-month marijuana and cigarette co-use. Participants completed the 14-item Nicotine and Marijuana Interaction Expectancy (NAMIE) Questionnaire, with three scales: (1) marijuana use increases tobacco use and urges, (2) tobacco use increases marijuana use and urges and (3) smoking to cope with marijuana urges. Participants also answered questions about marijuana and tobacco initiation and use. Analyses were conducted separately for blunt co-users (i.e., blunt and cigarette use) and non-blunt co-users (i.e., non-blunt marijuana and cigarette use). Results A majority of co-users (66%) used blunts as a form of co-use. Non-blunt co-users had higher expectancy scores on NAMIE scales 2 and 3 than blunt co-users. However, only blunt co-users showed a positive association between severity of marijuana use and NAMIE scales 2 (p <.01) and 3 (p <.01). Conclusions Findings provide further evidence for the use of the NAMIE and suggest a need to assess and address expectations regarding marijuana and tobacco co-use in prevention and treatment interventions, especially among young African American adults who co-use blunts and cigarettes. PMID:29333104

Melatonin therapy for blunt trauma and strenuous exercise: A mechanism involving cytokines, NFκB, Akt, MAFBX and MURF-1.

PubMed

Maarman, Gerald J; Reiter, Russel J

2018-08-01

Muscle injury occurs due to trauma, strenuous exercise or sports activities; most people affected are athletes. Ineffectively treated muscle injury can negatively affect sports careers and quality of life after retirement from sports. Reports have indicated that the current therapeutic management of muscle injury, particularly anti-inflammatory drugs, are not necessarily effective. Therefore, better therapies are required. Accumulating evidence has demonstrated melatonin's potent antioxidant and anti-inflammatory actions against muscle pathology in sarcopenia or atrophy in systemic disease. However, the underlying mechanisms for the protective effect of melatonin in the context of trauma/strenuous exercise are multifactorial and not well described. This paper reviews data on melatonin's impact on muscle injury and findings that points toward the mechanisms through which melatonin achieves muscle protection. The general concept described in this review is that melatonin inhibits NFκB, reduces cytokine expression, increases Akt that downregulates the ratio of MAF BX and MURF-1 in order to limit the extent of muscle injury and promote muscle recovery post-injury. The work discussed in this review supports the notion that melatonin may be considered a possible therapy against trauma/sports related muscle injury. Inclusion of melatonin as a therapy in sports medicine could therefore provide a better treatment option for injured athletes and sports individuals.

Oxygen uptake kinetics of constant-load work - Upright vs. supine exercise

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Goldwater, D. J.; Sandler, H.

1984-01-01

Supine and upright positions were used in a comparitive study of the effects of constant load exercise on oxygen uptake (VO2), O2 deficit, steady-state VO2 and VO2 following recovery from constant load work. Ten male subjects (36-40 yr.) performed one submaximal exercise test in the supine and one test in the upright position consisting of 5 min rest and 5 min cycle ergometer exercise at 700 kg/min followed by ten minutes of recovery. It is found that the significant difference in VO2 kinetics during exercise in the upright compared to supine position resulted from changes in oxygen transport and utilization mechanisms rather than changes in mechanical efficiency. To the extent that data measured in the supine position can be used to estimate physiological responses to zero gravity, it is suggested that limitation of systemic O2 consumption may be the result of slow rates of oxygen uptake during transient periods of muscular work. Significant reductions in the rate of steady-state VO2 attainment at submaximal work intensities may produce an onset of muscle fatigue and exhaustion.

Exercise for methamphetamine dependence: rationale, design, and methodology.

PubMed

Mooney, Larissa J; Cooper, Christopher; London, Edythe D; Chudzynski, Joy; Dolezal, Brett; Dickerson, Daniel; Brecht, Mary-Lynn; Peñate, Jose; Rawson, Richard A

2014-01-01

Effective pharmacotherapies to treat methamphetamine (MA) dependence have not been identified, and behavioral therapies are marginally effective. Based on behavioral studies demonstrating the potential efficacy of aerobic exercise for improving depressive symptoms, anxiety, cognitive deficits, and substance use outcomes, the study described here is examining exercise as a potential treatment for MA-dependent individuals. This study is randomizing 150 participants with MA dependence at a residential treatment facility for addictive disorders to receive either a thrice-weekly structured aerobic and resistance exercise intervention or a health education condition. Recruitment commenced in March, 2010. Enrollment and follow-up phases are ongoing, and recruitment is exceeding targeted enrollment rates. Seeking evidence for a possibly effective adjunct to traditional behavioral approaches for treatment of MA dependence, this study is assessing the ability of an 8-week aerobic and resistance exercise protocol to reduce relapse to MA use during a 12-week follow-up period after discharge from residential-based treatment. The study also is evaluating improvements in health and functional outcomes during and after the protocol. This paper describes the design and methods of the study. Copyright © 2013 Elsevier Inc. All rights reserved.

Rapamycin does not prevent increases in myofibrillar or mitochondrial protein synthesis following endurance exercise

PubMed Central

Philp, Andrew; Schenk, Simon; Perez-Schindler, Joaquin; Hamilton, D Lee; Breen, Leigh; Laverone, Erin; Jeromson, Stewart; Phillips, Stuart M; Baar, Keith

2015-01-01

Abstract The present study aimed to investigate the role of the mechanistic target of rapamycin complex 1 (mTORC1) in the regulation of myofibrillar (MyoPS) and mitochondrial (MitoPS) protein synthesis following endurance exercise. Forty-two female C57BL/6 mice performed 1 h of treadmill running (18 m min−1; 5° grade), 1 h after i.p. administration of rapamycin (1.5 mg · kg−1) or vehicle. To quantify skeletal muscle protein fractional synthesis rates, a flooding dose (50 mg · kg−1) of l-[ring-13C6]phenylalanine was administered via i.p. injection. Blood and gastrocnemius muscle were collected in non-exercised control mice, as well as at 0.5, 3 and 6 h after completing exercise (n = 4 per time point). Skeletal muscle MyoPS and MitoPS were determined by measuring isotope incorporation in their respective protein pools. Activation of the mTORC1-signalling cascade was measured via direct kinase activity assay and immunoblotting, whereas genes related to mitochondrial biogenesis were measured via a quantitative RT-PCR. MyoPS increased rapidly in the vehicle group post-exercise and remained elevated for 6 h, whereas this response was transiently blunted (30 min post-exercise) by rapamycin. By contrast, MitoPS was unaffected by rapamycin, and was increased over the entire post-exercise recovery period in both groups (P < 0.05). Despite rapid increases in both MyoPS and MitoPS, mTORC1 activation was suppressed in both groups post-exercise for the entire 6 h recovery period. Peroxisome proliferator activated receptor-γ coactivator-1α, pyruvate dehydrogenase kinase 4 and mitochondrial transcription factor A mRNA increased post-exercise (P < 0.05) and this response was augmented by rapamycin (P < 0.05). Collectively, these data suggest that endurance exercise stimulates MyoPS and MitoPS in skeletal muscle independently of mTORC1 activation. Key points Previous studies have shown that endurance exercise increases myofibrillar (MyoPS) and mitochondrial (MitoPS) protein synthesis in skeletal muscle. The mechanistic target of rapamycin (mTOR) is considered to be a key intracellular nutrient-sensing protein complex, which activates MyoPS in response to anabolic stimuli. Little is known regarding the regulation of MyoPS and MitoPS in response to endurance exercise. In the present study, we show that MyoPS and MitoPS increase in skeletal muscle following endurance exercise, despite suppression of mTORC1 during the post-exercise recovery period. Our data suggests that mTORC1 independent processes regulate both MyoPS and MitoPS following acute endurance exercise. PMID:26227152

The impact of exercise intensity on whole body and adipose tissue metabolism during energy restriction in sedentary overweight men and postmenopausal women.

PubMed

Walhin, Jean-Philippe; Dixon, Natalie C; Betts, James A; Thompson, Dylan

2016-12-01

This study aimed to establish whether vigorous-intensity exercise offers additional adipose-related health benefits and metabolic improvements compared to energy-matched moderate-intensity exercise. Thirty-eight sedentary overweight men (n = 24) and postmenopausal women (n = 14) aged 52 ± 5 years (mean ± standard deviations [SD]) were prescribed a 3-week energy deficit (29302 kJ∙week -1 ) achieved by increased isocaloric moderate or vigorous-intensity exercise (+8372 kJ∙week -1 ) and simultaneous restricted energy intake (-20930 kJ∙week -1 ). Participants were randomly assigned to either an energy-matched vigorous (VIG; n = 18) or moderate (MOD; n = 20) intensity exercise group (five times per week at 70% or 50% maximal oxygen uptake, respectively). At baseline and follow-up, fasted blood samples and abdominal subcutaneous adipose tissue biopsies were obtained and oral glucose tolerance tests conducted. Body mass was reduced similarly in both groups (∆ 2.4 ± 1.1 kg and ∆ 2.4 ± 1.4 kg, respectively, P < 0.05). Insulinemic responses to a standard glucose load decreased similarly at follow-up relative to baseline in VIG (∆ 8.6 ± 15.4 nmol.120 min.l -1 ) and MOD (∆ 5.4 ± 8.5 nmol.120 min.l -1 ; P < 0.05). Expression of SREBP-1c and FAS in adipose tissue was significantly down-regulated, whereas expression of PDK4 and hormone-sensitive lipase (HSL) was significantly up-regulated in both groups (P < 0.05). Thus, when energy expenditure and energy deficit are matched, vigorous or moderate-intensity exercise combined with energy restriction provide broadly similar (positive) changes in metabolic control and adipose tissue gene expression. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Effects of moderate treadmill exercise and fluoxetine on behavioural and cognitive deficits, hypothalamic-pituitary-adrenal axis dysfunction and alternations in hippocampal BDNF and mRNA expression of apoptosis - related proteins in a rat model of post-traumatic stress disorder.

PubMed

Shafia, Sakineh; Vafaei, Abbas Ali; Samaei, Seyed Afshin; Bandegi, Ahmad Reza; Rafiei, Alireza; Valadan, Reza; Hosseini-Khah, Zahra; Mohammadkhani, Raziyeh; Rashidy-Pour, Ali

2017-03-01

Post-traumatic stress disorder (PTSD) is a condition that develops after an individual has experienced a major trauma. Currently, selective serotonin reuptake inhibitors (SSRIs) like fluoxetine are the first-line choice in PTSD drug treatment but their moderate response rates and side effects indicate an urgent need for the development of new treatment. Physical activity is known to improve symptoms of certain neuropsychiatric disorders. The present study investigated the effects of moderate treadmill exercise, the antidepressant fluoxetine and the combined treatment on behavioural deficits, and hypothalamic-pituitary-adrenal (HPA) axis dysfunction. We also examined alternations in hippocampal brain-derived neurotrophic factor (BDNF) and mRNA expression of apoptosis - related proteins in a rat model of PTSD: the single prolonged stress (SPS) model. Rats were exposed to SPS (restraint for 2h, forced swimming for 20min and ether anaesthesia) and were then kept undisturbed for 14days. After that, SPS rats were subjected to chronic treatment with fluoxetine (10mg/kg/day, for 4weeks), moderate treadmill running (4weeks, 5day per week) and the combined treatment (fluoxetine plus treadmill exercise), followed by behavioural, biochemical and apoptosis markers assessments. SPS rats exhibited increased anxiety levels in the elevated plus maze and light/dark box, impaired fear conditioning and extinction in inhibitory avoidance (IA) task, impaired spatial memory in a recognition location memory task and enhanced negative feedback on the HPA axis following a dexamethasone suppression test. SPS rats also showed reduced hippocampal BDNF and enhanced apoptosis. Moderate treadmill exercise, fluoxetine and the combined treatment alleviated the SPS-induced alterations in terms of anxiety levels, HPA axis inhibition, IA conditioning and extinction, hippocampal BDNF and apoptosis markers. Furthermore, the combined treatment was more effective than fluoxetine alone, but in most tests, the effects of the combined treatment were similar to those of exercise alone, suggesting that exercise is the main factor in the beneficial effects of the combined therapy in PTSD patients. Copyright © 2017 Elsevier Inc. All rights reserved.

A 24-Week Multi-Modality Exercise Program Improves Executive Control in Older Adults with a Self-Reported Cognitive Complaint: Evidence from the Antisaccade Task.

PubMed

Heath, Matthew; Shellington, Erin; Titheridge, Sam; Gill, Dawn P; Petrella, Robert J

2017-01-01

Exercise programs involving aerobic and resistance training (i.e., multiple-modality) have shown promise in improving cognition and executive control in older adults at risk, or experiencing, cognitive decline. It is, however, unclear whether cognitive training within a multiple-modality program elicits an additive benefit to executive/cognitive processes. This is an important question to resolve in order to identify optimal training programs that delay, or ameliorate, executive deficits in persons at risk for further cognitive decline. In the present study, individuals with a self-reported cognitive complaint (SCC) participated in a 24-week multiple-modality (i.e., the M2 group) exercise intervention program. In addition, a separate group of individuals with a SCC completed the same aerobic and resistance training as the M2 group but also completed a cognitive-based stepping task (i.e., multiple-modality, mind-motor intervention: M4 group). Notably, pre- and post-intervention executive control was examined via the antisaccade task (i.e., eye movement mirror-symmetrical to a target). Antisaccades are an ideal tool for the study of individuals with subtle executive deficits because of its hands- and language-free nature and because the task's neural mechanisms are linked to neuropathology in cognitive decline (i.e., prefrontal cortex). Results showed that M2 and M4 group antisaccade reaction times reliably decreased from pre- to post-intervention and the magnitude of the decrease was consistent across groups. Thus, multi-modality exercise training improved executive performance in persons with a SCC independent of mind-motor training. Accordingly, we propose that multiple-modality training provides a sufficient intervention to improve executive control in persons with a SCC.

High-Intensity Interval Training and Isocaloric Moderate-Intensity Continuous Training Result in Similar Improvements in Body Composition and Fitness in Obese Individuals.

PubMed

Martins, Catia; Kazakova, Irina; Ludviksen, Marit; Mehus, Ingar; Wisloff, Ulrik; Kulseng, Bard; Morgan, Linda; King, Neil

2016-06-01

This study aimed to determine the effects of 12 weeks of isocaloric programs of high-intensity intermittent training (HIIT) or moderate-intensity continuous training (MICT) or a short-duration HIIT (1/2HIIT) inducing only half the energy deficit on a cycle ergometer, on body weight and composition, cardiovascular fitness, resting metabolism rate (RMR), respiratory exchange ratio (RER), nonexercise physical activity (PA) levels and fasting and postprandial insulin response in sedentary obese individuals. Forty-six sedentary obese individuals (30 women), with a mean BMI of 33.3 ± 2.9 kg/m2 and a mean age of 34.4 ± 8.8 years were randomly assigned to one of the three training groups: HIIT (n = 16), MICT (n = 14) or 1/2HIIT (n = 16) and exercise was performed 3 times/week for 12 weeks. Overall, there was a significant reduction in body weight, waist (p < .001) and hip (p < .01) circumference,, trunk and leg fat mass (FM; p < .01) and an increase in trunk and leg fat free mass (FFM; p < .01) and cardiovascular fitness (VO2max in ml/kg/min; p < .001) with exercise. However, no significant differences were observed between groups. There was no significant change in RMR, RER, nonexercise PA levels, fasting insulin or insulin sensitivity with exercise or between groups. There was a tendency for a reduction in AUC insulin with exercise (p = .069), but no differences between groups. These results indicate that isocaloric training protocols of HIIT or MICT (or 1/2HIIT inducing only half the energy deficit) exert similar metabolic and cardiovascular improvements in sedentary obese individuals.

Stress Testing of an Artificial Pancreas System With Pizza and Exercise Leads to Improvements in the System's Fuzzy Logic Controller.

PubMed

Mauseth, Richard; Lord, Sandra M; Hirsch, Irl B; Kircher, Robert C; Matheson, Don P; Greenbaum, Carla J

2015-09-14

Under controlled conditions, the Dose Safety artificial pancreas (AP) system controller, which utilizes "fuzzy logic" (FL) methodology to calculate and deliver appropriate insulin dosages based on changes in blood glucose, successfully managed glycemic excursions. The aim of this study was to show whether stressing the system with pizza (high carbohydrate/high fat) meals and exercise would reveal deficits in the performance of the Dose Safety FL controller (FLC) and lead to improvements in the dosing matrix. Ten subjects with type 1 diabetes (T1D) were enrolled and participated in 30 studies (17 meal, 13 exercise) using 2 versions of the FLC. After conducting 13 studies with the first version (FLC v2.0), interim results were evaluated and the FLC insulin-dosing matrix was modified to create a new controller version (FLC v2.1) that was validated through regression testing using v2.0 CGM datasets prior to its use in clinical studies. The subsequent 17 studies were performed using FLC v2.1. Use of FLC v2.1 vs FLC v2.0 in the pizza meal tests showed improvements in mean blood glucose (205 mg/dL vs 232 mg/dL, P = .04). FLC v2.1 versus FLC v2.0 in exercise tests showed improvements in mean blood glucose (146 mg/dL vs 201 mg/dL, P = .004), percentage time spent >180 mg/dL (19.3% vs 46.7%, P = .001), and percentage time spent 70-180 mg/dL (80.0% vs 53.3%, P = .002). Stress testing the AP system revealed deficits in the FLC performance, which led to adjustments to the dosing matrix followed by improved FLC performance when retested. © 2015 Diabetes Technology Society.

The aging musculoskeletal system and obesity-related considerations with exercise

PubMed Central

Vincent, Heather K.; Raiser, Sara N.; Vincent, Kevin R.

2012-01-01

Advancing age and adiposity contribute to musculoskeletal degenerative diseases and the development of sarcopenic obesity. The etiology of muscle loss is multifactorial, and includes inflammation, oxidative stress and hormonal changes, and is worsened by activity avoidance due to fear of pain. The risk for mobility disability and functional impairment rises with severity of obesity in the older adult. Performance measures of walking distance, walking speed, chair rise, stair climb, body transfers and ability to navigate obstacles on a course are adversely affected in this population, and this reflects decline in daily physical functioning. Exercise training is an ideal intervention to counteract the effects of aging and obesity. The 18 randomized controlled trials of exercise studies with or without diet components reviewed here indicate that 3–18 month programs that included aerobic and strengthening exercise (2–3 days per week) with caloric restriction (typically 750 kcal deficit/day), induced the greatest change in functional performance measures compared with exercise or diet alone. Importantly, resistance exercise attenuates muscle mass loss with the interventions. These interventions can also combat factors that invoke sarcopenia, including inflammation, oxidative stress and insulin resistance. Therefore, regular multimodal exercise coupled with diet appears to be very effective for counteracting sarocpenic obesity and improving mobility and function in the older, obese adult. PMID:22440321

Predictors of Energy Compensation during Exercise Interventions: A Systematic Review

PubMed Central

Riou, Marie-Ève; Jomphe-Tremblay, Simon; Lamothe, Gilles; Stacey, Dawn; Szczotka, Agnieszka; Doucet, Éric

2015-01-01

Weight loss from exercise-induced energy deficits is usually less than expected. The objective of this systematic review was to investigate predictors of energy compensation, which is defined as body energy changes (fat mass and fat-free mass) over the total amount of exercise energy expenditure. A search was conducted in multiple databases without date limits. Of 4745 studies found, 61 were included in this systematic review with a total of 928 subjects. The overall mean energy compensation was 18% ± 93%. The analyses indicated that 48% of the variance of energy compensation is explained by the interaction between initial fat mass, age and duration of exercise interventions. Sex, frequency, intensity and dose of exercise energy expenditure were not significant predictors of energy compensation. The fitted model suggested that for a shorter study duration, lower energy compensation was observed in younger individuals with higher initial fat mass (FM). In contrast, higher energy compensation was noted for younger individuals with lower initial FM. From 25 weeks onward, energy compensation was no longer different for these predictors. For studies of longer duration (about 80 weeks), the energy compensation approached 84%. Lower energy compensation occurs with short-term exercise, and a much higher level of energy compensation accompanies long-term exercise interventions. PMID:25988763

Differential effect of central command on aortic and carotid sinus baroreceptor-heart rate reflexes at the onset of spontaneous, fictive motor activity.

PubMed

Matsukawa, Kanji; Ishii, Kei; Kadowaki, Akito; Liang, Nan; Ishida, Tomoko

2012-08-15

Our laboratory has reported that central command blunts the sensitivity of the aortic baroreceptor-heart rate (HR) reflex at the onset of voluntary static exercise in conscious cats and spontaneous contraction in decerebrate cats. The purpose of this study was to examine whether central command attenuates the sensitivity of the carotid sinus baroreceptor-HR reflex at the onset of spontaneous, fictive motor activity in paralyzed, decerebrate cats. We confirmed that aortic nerve (AN)-stimulation-induced bradycardia was markedly blunted to 26 ± 4.4% of the control (21 ± 1.3 beats/min) at the onset of spontaneous motor activity. Although the baroreflex bradycardia by electrical stimulation of the carotid sinus nerve (CSN) was suppressed (P < 0.05) to 86 ± 5.6% of the control (38 ± 1.2 beats/min), the inhibitory effect of spontaneous motor activity was much weaker (P < 0.05) with CSN stimulation than with AN stimulation. The baroreflex bradycardia elicited by brief occlusion of the abdominal aorta was blunted to 36% of the control (36 ± 1.6 beats/min) during spontaneous motor activity, suggesting that central command is able to inhibit the cardiomotor sensitivity of arterial baroreflexes as the net effect. Mechanical stretch of the triceps surae muscle never affected the baroreflex bradycardia elicited by AN or CSN stimulation and by aortic occlusion, suggesting that muscle mechanoreflex did not modify the cardiomotor sensitivity of aortic and carotid sinus baroreflex. Since the inhibitory effect of central command on the carotid baroreflex pathway, associated with spontaneous motor activity, was much weaker compared with the aortic baroreflex pathway, it is concluded that central command does not force a generalized modulation on the whole pathways of arterial baroreflexes but provides selective inhibition for the cardiomotor component of the aortic baroreflex.

Low- and high-intensity treadmill exercise attenuates chronic morphine-induced anxiogenesis and memory impairment but not reductions in hippocampal BDNF in female rats.

PubMed

Ghodrati-Jaldbakhan, Shahrbanoo; Ahmadalipour, Ali; Rashidy-Pour, Ali; Vafaei, Abbas Ali; Miladi-Gorji, Hossein; Alizadeh, Maryam

2017-05-15

Previous studies from our laboratory have shown that treadmill exercise alleviates the deficits in cognitive functions and anxiety behaviors induced by chronic exposure to morphine in male rats. In this study, we investigated the effects of low and high intensities of treadmill exercise on spatial memory, anxiety-like behaviors, and biochemical changes in the hippocampus and serum of morphine-treated female rats. The adult virgin female rats were injected with bi-daily doses (10mg/kg, at 12h intervals) of morphine over a period of 10days. Following these injections, the rats were exercised under low or high intensities for 30min per session on five days a week for four weeks. After exercise training, object location memory, anxiety profile, hippocampal BDNF, and serum corticosterone and BDNF were examined. Morphine-treated animals exhibited increased anxiety levels, impaired object location memory, and reduced hippocampal BDNF. Exercise alleviated these impairing effects on anxiety profile and memory but not hippocampal BDNF. The high-intensity exercise even further reduced the hippocampal BDNF. Additionally, both exercise regimens in the morphine group and the high exercise in the saline group reduced serum BDNF. Finally, the high-intensity exercise enhanced corticosterone serum. These findings indicate that the negative cognitive and behavioral effects of chronic exposure to morphine could be relieved by forced exercise in female rats. However, the exercise intensity is an important factor to be considered during exercise training. Finally, the correlation between changes of brain and serum BDNF and cognitive functions following morphine exposure needs further research. Copyright © 2017 Elsevier B.V. All rights reserved.

Hormonal responses during a prolonged military field exercise with variable exercise intensity.

PubMed

Kyröläinen, Heikki; Karinkanta, Jari; Santtila, Matti; Koski, Harri; Mäntysaari, Matti; Pullinen, Teemu

2008-03-01

The purpose of the present study was to test the hypothesis that the magnitude of hormonal concentration alterations during a prolonged military field exercise with constant energy intake (EI) is influenced by changes in energy deficit (ED) induced by varying the exercise intensity. Basal serum hormone concentrations were measured in a group of healthy young male volunteers (n = 7) during a 20-day field exercise. During the first week of the exercise, the average ED was 4,000 kcal/day (P-I), in the second week only 450 kcal/day (P-II), and in the last week 1,000 kcal/day (P-III). During the first 5 days of the field exercise, significant increases in cortisol (COR, +32%) and growth hormone (GH, +616%) concentrations were observed, while insulin (INS, -70%), total testosterone (TES, -27%), free testosterone (TES(free), -26%) decreased. However, after these initial responses, COR and GH returned to the pre-exercise level by the beginning of P-II. Also TES and TES(free) recovered to the pre-exercise level by the beginning of P-III, and INS by the end of P-III. The concentration of TES (+29%) increased above the pre-exercise level by the beginning of P-III. Serum thyroxin (T(4)) concentration was significantly lesser (-12%) and urine urea concentration significantly higher (+78%) after the field exercise than before it. Therefore, it can be concluded that the lower levels of ED in the second and third phase (ED <1,000 kcal/day) allowed recovery of hormonal changes observed in the first phase with ED much greater than 1,000 kcal/day.

Plasma Actin, Gelsolin and Orosomucoid Levels after Eccentric Exercise.

PubMed

Tékus, Éva; Váczi, Márk; Horváth-Szalai, Zoltán; Ludány, Andrea; Kőszegi, Tamás; Wilhelm, Márta

2017-02-01

The present study investigated the acute effect of eccentric exercise on blood plasma actin, gelsolin (GSN) and orosomucoid (AGP) levels in untrained and moderately trained individuals, and their correlation with exercise induced muscle damage (EIMD) markers (CK, intensity of muscle soreness and maximal voluntary contraction torque deficit). Healthy physical education students (6 untrained, 12 moderately trained) participated in this research. Actin, GSN, AGP and CK levels were measured in blood plasma at baseline, immediately, 1 h, 6 h and 24 h post-exercise comprising 90 eccentric quadriceps contractions performed on a dynamometer. There was significant time main effect for GSN, AGP, CK and significant difference was found between baseline and the lowest value of post-exercise GSN (p < 0.05), as well as baseline and the highest value of post-exercise AGP (p < 0.05). Relationships were found between GSN levels and other indirect EIMD markers (between all GSN levels at post-exercise and CK activity at 6 h, p < 0.05; GSNMIN and muscle soreness at post-exercise, p < 0.04), GSN and AGP; however, actin did not correlate at any time points with GSN. Actin, GSN, AGP and CK responses after eccentric exercise do not seem sensitive to training status. The plasma actin level is used as an indicator of injury, however, our results suggest that it is not an accurate marker of EIMD, while plasma GSN concentrations show a better relationship with EIMD and the post-exercise inflammatory process. The elevated plasma AGP and the correlation between GSN and AGP seem to be promising for assessment of exercise-induced muscle injury.

Plasma Actin, Gelsolin and Orosomucoid Levels after Eccentric Exercise

PubMed Central

Váczi, Márk; Horváth-Szalai, Zoltán; Ludány, Andrea; Kőszegi, Tamás; Wilhelm, Márta

2017-01-01

Abstract The present study investigated the acute effect of eccentric exercise on blood plasma actin, gelsolin (GSN) and orosomucoid (AGP) levels in untrained and moderately trained individuals, and their correlation with exercise induced muscle damage (EIMD) markers (CK, intensity of muscle soreness and maximal voluntary contraction torque deficit). Healthy physical education students (6 untrained, 12 moderately trained) participated in this research. Actin, GSN, AGP and CK levels were measured in blood plasma at baseline, immediately, 1 h, 6 h and 24 h post-exercise comprising 90 eccentric quadriceps contractions performed on a dynamometer. There was significant time main effect for GSN, AGP, CK and significant difference was found between baseline and the lowest value of post-exercise GSN (p < 0.05), as well as baseline and the highest value of post-exercise AGP (p < 0.05). Relationships were found between GSN levels and other indirect EIMD markers (between all GSN levels at post-exercise and CK activity at 6 h, p < 0.05; GSNMIN and muscle soreness at post-exercise, p < 0.04), GSN and AGP; however, actin did not correlate at any time points with GSN. Actin, GSN, AGP and CK responses after eccentric exercise do not seem sensitive to training status. The plasma actin level is used as an indicator of injury, however, our results suggest that it is not an accurate marker of EIMD, while plasma GSN concentrations show a better relationship with EIMD and the post-exercise inflammatory process. The elevated plasma AGP and the correlation between GSN and AGP seem to be promising for assessment of exercise-induced muscle injury. PMID:28469748

Effects of a selected exercise programon executive function of children with attention deficit hyperactivity disorder.

PubMed

Memarmoghaddam, M; Torbati, H T; Sohrabi, M; Mashhadi, A; Kashi, A

2016-01-01

Introduction. The aim of this study was to examine the effectiveness of a Selected exercise program on the executive function of children with ADHD. Method. The participants were 40 male students, aged 7-11 years. The participants were randomly assigned into two groups (experimental and control). The experimental group participated in an exercise program for 24 sessions, 90 minutes per session. The control group did not receive any intervention. Before and after the exercise period, all the participants were assessed with Stroop and Go-No-Go tests, and the resulting data were analyzed by using MANCOVA. Result. The results showed that the cognitive inhibition of the children in the experimental group was significantly different compared with the control group (p < 0.05). Additionally, there was a significant difference between the experimental and control groups in the behavioral inhibition (p < 0.05). Conclusion. An organized physical activity helps to improve the executive function in children with ADHD.

Interventions to address chronic disease and HIV: strategies to promote exercise and nutrition among HIV-infected individuals.

PubMed

Botros, Diana; Somarriba, Gabriel; Neri, Daniela; Miller, Tracie L

2012-12-01

Food insecurity, micronutrient deficits, dyslipidemia, insulin resistance, obesity, cardiovascular disease, and bone disorders complicate the treatment of HIV infection. Nutrition and exercise interventions can be effective in ameliorating these symptoms that are associated with HIV and antiretroviral therapy (ART). In this literature review, we examine the most recent nutrition and exercise interventions for HIV-infected patients. Macronutrient supplementation can be useful in treating malnutrition and wasting. Multivitamin (vitamin B complex, vitamin C, and vitamin E) supplements and vitamin D may improve quality of life and decrease morbidity and mortality. Nutritional counseling and exercise interventions are effective for treating obesity, fat redistribution, and metabolic abnormalities. Physical activity interventions improve body composition, strength, and fitness in HIV-infected individuals. Taken collectively, the evidence suggests that a proactive approach to nutrition and physical activity guidance and interventions can improve outcomes and help abrogate the adverse metabolic, cardiovascular, and psychological consequences of HIV and its treatments.

Blunt Cardiac Injury in the Severely Injured – A Retrospective Multicentre Study

PubMed Central

Hanschen, Marc; Kanz, Karl-Georg; Kirchhoff, Chlodwig; Khalil, Philipe N.; Wierer, Matthias; van Griensven, Martijn; Laugwitz, Karl-Ludwig; Biberthaler, Peter; Lefering, Rolf; Huber-Wagner, Stefan

2015-01-01

Background Blunt cardiac injury is a rare trauma entity. Here, we sought to evaluate the relevance and prognostic significance of blunt cardiac injury in severely injured patients. Methods In a retrospective multicentre study, using data collected from 47,580 patients enrolled to TraumaRegister DGU (1993-2009), characteristics of trauma, prehospital / hospital trauma management, and outcome analysis were correlated to the severity of blunt cardiac injury. The severity of cardiac injury was assessed according to the abbreviated injury score (AIS score 1-6), the revised injury severity score (RISC) allowed comparison of expected outcome with injury severity-dependent outcome. N = 1.090 had blunt cardiac trauma (AIS 1-6) (2.3% of patients). Results Predictors of blunt cardiac injury could be identified. Sternal fractures indicate a high risk of the presence of blunt cardiac injury (AIS 0 [control]: 3.0%; AIS 1: 19.3%; AIS 2-6: 19.1%). The overall mortality rate was 13.9%, minor cardiac injury (AIS 1) and severe cardiac injury (AIS 2-6) are associated with higher rates. Severe blunt cardiac injury (AIS 4 and AIS 5-6) is associated with a higher mortality (OR 2.79 and 4.89, respectively) as compared to the predicted average mortality (OR 2.49) of the study collective. Conclusion Multiple injured patients with blunt cardiac trauma are at high risk to be underestimated. Careful evaluation of trauma patients is able to predict the presence of blunt cardiac injury. The severity of blunt cardiac injury needs to be stratified according to the AIS score, as the patients’ outcome is dependent on the severity of cardiac injury. PMID:26136126

Research on the drag reduction performance induced by the counterflowing jet for waverider with variable blunt radii

NASA Astrophysics Data System (ADS)

Li, Shi-bin; Wang, Zhen-guo; Barakos, George N.; Huang, Wei; Steijl, Rene

2016-10-01

Waverider will endure the huge aero-heating in the hypersonic flow, thus, it need be blunt for the leading edge. However, the aerodynamic performance will decrease for the blunt waverider because of the drag hoik. How to improve the aerodynamic performance and reduce the drag and aero-heating is very important. The variable blunt radii method will improve the aerodynamic performance, however, the huge aero-heating and bow shock wave at the head is still serious. In the current study, opposing jet is used in the waverider with variable blunt radii to improve its performance. The three-dimensional coupled implicit Reynolds-averaged Navier-Stokes(RANS) equation and the two equation SST k-ω turbulence model have been utilized to obtain the flow field properties. The numerical method has been validated against the available experimental data in the open literature. The obtained results show that the L/D will drop 7-8% when R changes from 2 to 8. The lift coefficient will increase, and the drag coefficient almost keeps the same when the variable blunt radii method is adopted, and the L/D will increase. The variable blunt radii method is very useful to improve the whole characteristics of blunt waverider and the L/D can improve 3%. The combination of the variable blunt radii method and opposing jet is a novel way to improve the whole performance of blunt waverider, and L/D can improve 4-5%. The aperture as a novel way of opposing jet is suitable for blunt waverider and also useful to improve the aerodynamic and aerothermodynamic characteristics of waverider in the hypersonic flow. There is the optimal P0in/P0 that can make the detached shock wave reattach the lower surface again so that the blunt waverider can get the better aerodynamic performance.

Energetics of Table Tennis and Table Tennis-Specific Exercise Testing.

PubMed

Zagatto, Alessandro Moura; Leite, Jorge Vieira de Mello; Papoti, Marcelo; Beneke, Ralph

2016-11-01

To test the hypotheses that the metabolic profile of table tennis is dominantly aerobic, anaerobic energy is related to the accumulated duration and intensity of rallies, and activity and metabolic profile are interrelated with the individual fitness profile determined via table tennis-specific tests. Eleven male experienced table tennis players (22 ± 3 y, 77.6 ± 18.9 kg, 177.1 ± 8.1 cm) underwent 2 simulated table tennis matches to analyze aerobic (W OXID ) energy, anaerobic glycolytic (W BLC ) energy, and phosphocreatine breakdown (W PCr ); a table tennis-specific graded exercise test to measure ventilatory threshold and peak oxygen uptake; and an exhaustive supramaximal table tennis effort to determine maximal accumulated deficit of oxygen. W OXID , W BLC , and W PCr corresponded to 96.5% ± 1.7%, 1.0% ± 0.7%, and 2.5% ± 1.4%, respectively. W OXID was interrelated with rally duration (r = .81) and number of shots per rally (r = .77), whereas match intensity was correlated with WPCr (r = .62) and maximal accumulated oxygen deficit (r = .58). The metabolic profile of table tennis is predominantly aerobic and interrelated with the individual fitness profile determined via table tennis-specific tests. Table tennis-specific ventilatory threshold determines the average oxygen uptake and overall W OXID , whereas table tennis-specific maximal accumulated oxygen deficit indicates the ability to use and sustain slightly higher blood lactate concentration and W BLC during the match.

Muscle Oxygen Supply Impairment during Exercise in Poorly Controlled Type 1 Diabetes

PubMed Central

TAGOUGUI, SEMAH; LECLAIR, ERWAN; FONTAINE, PIERRE; MATRAN, RÉGIS; MARAIS, GAELLE; AUCOUTURIER, JULIEN; DESCATOIRE, AURÉLIEN; VAMBERGUE, ANNE; OUSSAIDENE, KAHINA; BAQUET, GEORGES; HEYMAN, ELSA

2015-01-01

ABSTRACT Purpose Aerobic fitness, as reflected by maximal oxygen (O2) uptake (V˙O2max), is impaired in poorly controlled patients with type 1 diabetes. The mechanisms underlying this impairment remain to be explored. This study sought to investigate whether type 1 diabetes and high levels of glycated hemoglobin (HbA1c) influence O2 supply including O2 delivery and release to active muscles during maximal exercise. Methods Two groups of patients with uncomplicated type 1 diabetes (T1D-A, n = 11, with adequate glycemic control, HbA1c <7.0%; T1D-I, n = 12 with inadequate glycemic control, HbA1c >8%) were compared with healthy controls (CON-A, n = 11; CON-I, n = 12, respectively) matched for physical activity and body composition. Subjects performed exhaustive incremental exercise to determine V˙O2max. Throughout the exercise, near-infrared spectroscopy allowed investigation of changes in oxyhemoglobin, deoxyhemoglobin, and total hemoglobin in the vastus lateralis. Venous and arterialized capillary blood was sampled during exercise to assess arterial O2 transport and factors able to shift the oxyhemoglobin dissociation curve. Results Arterial O2 content was comparable between groups. However, changes in total hemoglobin (i.e., muscle blood volume) was significantly lower in T1D-I compared with that in CON-I. T1D-I also had impaired changes in deoxyhemoglobin levels and increase during high-intensity exercise despite normal erythrocyte 2,3-diphosphoglycerate levels. Finally, V˙O2max was lower in T1D-I compared with that in CON-I. No differences were observed between T1D-A and CON-A. Conclusions Poorly controlled patients displayed lower V˙O2max and blunted muscle deoxyhemoglobin increase. The latter supports the hypotheses of increase in O2 affinity induced by hemoglobin glycation and/or of a disturbed balance between nutritive and nonnutritive muscle blood flow. Furthermore, reduced exercise muscle blood volume in poorly controlled patients may warn clinicians of microvascular dysfunction occurring even before overt microangiopathy. PMID:24983346

Does this adult patient have a blunt intra-abdominal injury?

PubMed

Nishijima, Daniel K; Simel, David L; Wisner, David H; Holmes, James F

2012-04-11

Blunt abdominal trauma often presents a substantial diagnostic challenge. Well-informed clinical examination can identify patients who require further diagnostic evaluation for intra-abdominal injuries after blunt abdominal trauma. To systematically assess the precision and accuracy of symptoms, signs, laboratory tests, and bedside imaging studies to identify intra-abdominal injuries in patients with blunt abdominal trauma. We conducted a structured search of MEDLINE (1950-January 2012) and EMBASE (1980-January 2012) to identify English-language studies examining the identification of intra-abdominal injuries. A separate, structured search was conducted for studies evaluating bedside ultrasonography. We included studies of diagnostic accuracy for intra-abdominal injury that compared at least 1 finding with a reference standard of abdominal computed tomography, diagnostic peritoneal lavage, laparotomy, autopsy, and/or clinical course for intra-abdominal injury. Twelve studies on clinical findings and 22 studies on bedside ultrasonography met inclusion criteria for data extraction. Critical appraisal and data extraction were independently performed by 2 authors. The prevalence of intra-abdominal injury in adult emergency department patients with blunt abdominal trauma among all evidence level 1 and 2 studies was 13% (95% CI, 10%-17%), with 4.7% (95% CI, 2.5%-8.6%) requiring therapeutic surgery or angiographic embolization of injuries. The presence of a seat belt sign (likelihood ratio [LR] range, 5.6-9.9), rebound tenderness (LR, 6.5; 95% CI, 1.8-24), hypotension (LR, 5.2; 95% CI, 3.5-7.5), abdominal distention (LR, 3.8; 95% CI, 1.9-7.6), or guarding (LR, 3.7; 95% CI, 2.3-5.9) suggest an intra-abdominal injury. The absence of abdominal tenderness to palpation does not rule out an intra-abdominal injury (summary LR, 0.61; 95% CI, 0.46-0.80). The presence of intraperitoneal fluid or organ injury on bedside ultrasound assessment is more accurate than any history and physical examination findings (adjusted summary LR, 30; 95% CI, 20-46); conversely, a normal ultrasound result decreases the chance of injury detection (adjusted summary LR, 0.26; 95% CI, 0.19-0.34). Test results increasing the likelihood of intra-abdominal injury include a base deficit less than -6 mEq/L (LR, 18; 95% CI, 11-30), elevated liver transaminases (LR range, 2.5-5.2), hematuria (LR range, 3.7-4.1), anemia (LR range, 2.2-3.3), and abnormal chest radiograph (LR range, 2.5-3.8). Symptoms and signs may be most useful in combination, particularly in identification of patients who do not need further diagnostic workup. Bedside ultrasonography has the highest accuracy of all individual findings, but a normal result does not rule out an intra-abdominal injury. Combinations of clinical findings may be most useful to determine which patients do not require further evaluation, but the ideal combination of variables for identifying patients without intra-abdominal injury requires further study.

64-MDCT angiography of blunt vascular injuries of the neck.

PubMed

Chokshi, Falgun H; Munera, Felipe; Rivas, Luis A; Henry, Robert P; Quencer, Robert M

2011-03-01

CT angiography (CTA) using 64-MDCT enables timely evaluation of injuries associated with blunt neck trauma. The purpose of this article is to familiarize the reader with the most frequent CTA signs of blunt vascular injury. CTA is a valuable tool to detect blunt vascular injuries, especially using its multiplanar and 3D reconstruction capabilities.

Abnormal auditory pattern perception in schizophrenia.

PubMed

Haigh, Sarah M; Coffman, Brian A; Murphy, Timothy K; Butera, Christiana D; Salisbury, Dean F

2016-10-01

Mismatch negativity (MMN) in response to deviation from physical sound parameters (e.g., pitch, duration) is reduced in individuals with long-term schizophrenia (Sz), suggesting deficits in deviance detection. However, MMN can appear at several time intervals as part of deviance detection. Understanding which part of the processing stream is abnormal in Sz is crucial for understanding MMN pathophysiology. We measured MMN to complex pattern deviants, which have been shown to produce multiple MMNs in healthy controls (HC). Both simple and complex MMNs were recorded from 27 Sz and 27 matched HC. For simple MMN, pitch- and duration-deviants were presented among frequent standard tones. For complex MMN, patterns of five single tones were repeatedly presented, with the occasional deviant group of tones containing an extra sixth tone. Sz showed smaller pitch MMN (p=0.009, ~110ms) and duration MMN (p=0.030, ~170ms) than healthy controls. For complex MMN, there were two deviance-related negativities. The first (~150ms) was not significantly different between HC and SZ. The second was significantly reduced in Sz (p=0.011, ~400ms). The topography of the late complex MMN was consistent with generators in anterior temporal cortex. Worse late MMN in Sz was associated with increased emotional withdrawal, poor attention, lack of spontaneity/conversation, and increased preoccupation. Late MMN blunting in schizophrenia suggests a deficit in later stages of deviance processing. Correlations with negative symptoms measures are preliminary, but suggest that abnormal complex auditory perceptual processes may compound higher-order cognitive and social deficits in the disorder. Copyright © 2016 Elsevier B.V. All rights reserved.

The Changing Pattern and Implications of Multiple Organ Failure (MOF) After Blunt Injury With Hemorrhagic Shock

PubMed Central

Minei, Joseph P.; Cuschieri, Joseph; Sperry, Jason; Moore, Ernest E.; West, Michael A.; Harbrecht, Brian G.; O’Keefe, Grant E.; Cohen, Mitchell J.; Moldawer, Lyle L.; Tompkins, Ronald G.; Maier, Ronald V.

2012-01-01

Objective To describe the incidence of post-injury multiple organ failure (MOF) and its relationship to nosocomial infection and mortality in trauma centers employing evidence-based standard operating procedures (SOPs). Design Prospective cohort study wherein SOPs were developed and implemented to optimize post-injury care. Setting Seven U.S. Level I trauma centers. Patients Severely injured patients (> 16 years old) with a blunt mechanism, systolic hypotension (< 90 mmHg) and/or base deficit (> 6 meq/L), need for blood transfusion within the first 12 hrs, and an abbreviated injury score (AIS) ≥ two excluding brain injury were eligible for inclusion. Measurements and Main Results 1,002 patients were enrolled and 916 met inclusion criteria. Daily markers of organ dysfunction were prospectively recorded for all patients while receiving intensive care. Overall, 29% of patients developed MOF. Development of MOF was early (median time of two days), short - lived, and predicted an increased incidence of NI, whereas, persistence of MOF predicted mortality. However, surprisingly, NI did not increase subsequent MOF and there was no evidence of a “second-hit” induced late onset MOF. Conclusions MOF remains common after severe injury. Contrary to current paradigms, the onset is only early, and not bimodal, nor is it associated with a “second-hit” induced late onset. MOF is associated with subsequent NI and increased mortality. SOP-driven interventions may be associated with a decrease in late MOF and morbidity. PMID:22020243

Frontal-striatum dysfunction during reward processing: Relationships to amotivation in schizophrenia.

PubMed

Chung, Yu Sun; Barch, Deanna M

2016-04-01

Schizophrenia is characterized by deficits of context processing, thought to be related to dorsolateral prefrontal cortex (DLPFC) impairment. Despite emerging evidence suggesting a crucial role of the DLPFC in integrating reward and goal information, we do not know whether individuals with schizophrenia can represent and integrate reward-related context information to modulate cognitive control. To address this question, 36 individuals with schizophrenia (n = 29) or schizoaffective disorder (n = 7) and 27 healthy controls performed a variant of a response conflict task (Padmala & Pessoa, 2011) during fMRI scanning, in both baseline and reward conditions, with monetary incentives on some reward trials. We used a mixed state-item design that allowed us to examine both sustained and transient reward effects on cognitive control. Different from predictions about impaired DLPFC function in schizophrenia, we found an intact pattern of increased sustained DLPFC activity during reward versus baseline blocks in individuals with schizophrenia at a group level but blunted sustained activations in the putamen. Contrary to our predictions, individuals with schizophrenia showed blunted cue-related activations in several regions of the basal ganglia responding to reward-predicting cues. Importantly, as predicted, individual differences in anhedonia/amotivation symptoms severity were significantly associated with reduced sustained DLPFC activation in the same region that showed overall increased activity as a function of reward. These results suggest that individual differences in motivational impairments in schizophrenia may be related to dysfunction of the DLPFC and striatum in motivationally salient situations. (c) 2016 APA, all rights reserved).

Vascular compliance limits during sleep deprivation and recovery sleep.

PubMed

Phillips, Derrick J; Schei, Jennifer L; Rector, David M

2013-10-01

Our previous studies showed that evoked hemodynamic responses are smaller during wake compared to sleep; suggesting neural activity is associated with vascular expansion and decreased compliance. We explored whether prolonged activity during sleep deprivation may exacerbate vascular expansion and blunt hemodynamic responses. Evoked auditory responses were generated with periodic 65 dB speaker clicks over a 72-h period and measured with cortical electrodes. Evoked hemodynamic responses were measured simultaneously with optical techniques using three light-emitting diodes, and a photodiode. Animals were housed in separate 30×30×80 cm enclosures, tethered to a commutator system and maintained on a 12-h light/dark cycle. Food and water were available ad libitum. Seven adult female Sprague-Dawley rats. Following a 24-h baseline recording, sleep deprivation was initiated for 0 to 10 h by gentle handling, followed by a 24-h recovery sleep recording. Evoked electrical and hemodynamic responses were measured before, during, and after sleep deprivation. Following deprivation, evoked hemodynamic amplitudes were blunted. Steady-state oxyhemoglobin concentration increased during deprivation and remained high during the initial recovery period before returning to baseline levels after approximately 9-h. Sleep deprivation resulted in blood vessel expansion and decreased compliance while lower basal neural activity during recovery sleep may allow blood vessel compliance to recover. Chronic sleep restriction or sleep deprivation could push the vasculature to critical levels, limiting blood delivery, and leading to metabolic deficits with the potential for neural trauma.

ADHD Expressive Writing Difficulties of ADHD Children: When Good Declarative Knowledge Is Not Sufficient

ERIC Educational Resources Information Center

Re, Anna Maria; Cornoldi, Cesare

2010-01-01

A large body of evidence shows that many of the academic difficulties Attention Deficit Hyperactivity Disorder (ADHD) children have may be related to their problems in executive control. However, the particular case of expressive writing has not been deeply explored. The present study examines the typical school exercise of writing a letter.…

Does Somatosensory Discrimination Activate Different Brain Areas in Children with Unilateral Cerebral Palsy Compared to Typically Developing Children? An fMRI Study

ERIC Educational Resources Information Center

Van de Winckel, Ann; Verheyden, Geert; Wenderoth, Nici; Peeters, Ron; Sunaert, Stefan; Van Hecke, Wim; De Cock, Paul; Desloovere, Kaat; Eyssen, Maria; Feys, Hilde

2013-01-01

Aside from motor impairment, many children with unilateral cerebral palsy (CP) experience altered tactile, proprioceptive, and kinesthetic awareness. Sensory deficits are addressed in rehabilitation programs, which include somatosensory discrimination exercises. In contrast to adult stroke patients, data on brain activation, occurring during…

Effect of Selected Balance Exercises on the Dynamic Balance of Children with Visual Impairments

ERIC Educational Resources Information Center

Jazi, Shirin Davarpanah; Purrajabi, Fatemeh; Movahedi, Ahmadreza; Jalali, Shahin

2012-01-01

Introduction: Maintaining balance while walking is of utmost importance for individuals with visual impairments because deficits in dynamic balance have been associated with a high risk of falling. Thus, the primary aim of the study presented here was to determine whether balance training effects the dynamic balance of children with visual…

Exercise Deficit Disorder in Youth: An Emergent Health Concern for School Nurses

ERIC Educational Resources Information Center

Faigenbaum, Avery D.; Gipson-Jones, Trina L.; Myer, Gregory D.

2012-01-01

Although the benefits of regular physical activity are widely acknowledged, recent findings indicate that a growing number of youth are not as active as they should be. The impact of a sedentary lifestyle during childhood on lifelong pathological processes and associated health care costs have created a need for immediate action to manage, if not…

Effect of Chronic Athletic Activity on Brown Fat in Young Women

PubMed Central

Singhal, Vibha; Maffazioli, Giovana D.; Ackerman, Kate E.; Lee, Hang; Elia, Elisa F.; Woolley, Ryan; Kolodny, Gerald; Cypess, Aaron M.; Misra, Madhusmita

2016-01-01

Background The effect of chronic exercise activity on brown adipose tissue (BAT) is not clear, with some studies showing positive and others showing negative associations. Chronic exercise is associated with increased resting energy expenditure (REE) secondary to increased lean mass and a probable increase in BAT. Many athletes are in a state of relative energy deficit suggested by lower fat mass and hypothalamic amenorrhea. States of severe energy deficit such as anorexia nervosa are associated with reduced BAT. There are no data regarding the impact of chronic exercise activity on BAT volume or activity in young women and it is unclear whether relative energy deficiency modifies the effects of exercise on BAT. Purpose We assessed cold induced BAT volume and activity in young female athletes compared with non-athletes, and further evaluated associations of BAT with measures of REE, body composition and menstrual status. Methods The protocol was approved by our Institutional Review Board. Written informed consent was obtained from all participants prior to study initiation. This was a cross-sectional study of 24 women (16 athletes and8 non-athletes) between 18–25 years of age. Athletes were either oligo-amenorrheic (n = 8) or eumenorrheic (n = 8).We used PET/CT scans to determine cold induced BAT activity, VMAX Encore 29 metabolic cart to obtain measures of REE, and DXA for body composition. Results Athletes and non-athletes did not differ for age or BMI. Compared with non-athletes, athletes had lower percent body fat (p = 0.002), higher percent lean mass (p = 0.01) and trended higher in REE (p = 0.09). BAT volume and activity in athletes trended lower than in non-athletes (p = 0.06; p = 0.07, respectively). We found negative associations of BAT activity with duration of amenorrhea (r = -0.46, p = 0.02).BAT volume correlated inversely with lean mass (r = -0.46, p = 0.02), and positively with percent body fat, irisin and thyroid hormones. Conclusions Our study shows a trend for lower BAT in young female athletes compared with non-athletes, and shows associations of brown fat with menstrual status and body composition. Brown fat may undergo adaptive reductions with increasing energy deficit. PMID:27243823

Acute administration of high doses of taurine does not substantially improve high-intensity running performance and the effect on maximal accumulated oxygen deficit is unclear.

PubMed

Milioni, Fabio; Malta, Elvis de Souza; Rocha, Leandro George Spinola do Amaral; Mesquita, Camila Angélica Asahi; de Freitas, Ellen Cristini; Zagatto, Alessandro Moura

2016-05-01

The aim of the present study was to investigate the effects of acute administration of taurine overload on time to exhaustion (TTE) of high-intensity running performance and alternative maximal accumulated oxygen deficit (MAODALT). The study design was a randomized, placebo-controlled, crossover design. Seventeen healthy male volunteers (age: 25 ± 6 years; maximal oxygen uptake: 50.5 ± 7.6 mL·kg(-1)·min(-1)) performed an incremental treadmill-running test until voluntary exhaustion to determine maximal oxygen uptake and exercise intensity at maximal oxygen uptake. Subsequently, participants completed randomly 2 bouts of supramaximal treadmill-running at 110% exercise intensity at maximal oxygen uptake until exhaustion (placebo (6 g dextrose) or taurine (6 g) supplementation), separated by 1 week. MAODALT was determined using a single supramaximal effort by summating the contribution of the phosphagen and glycolytic pathways. When comparing the results of the supramaximal trials (i.e., placebo and taurine conditions) no differences were observed for high-intensity running TTE (237.70 ± 66.00 and 277.30 ± 40.64 s; p = 0.44) and MAODALT (55.77 ± 8.22 and 55.06 ± 7.89 mL·kg(-1); p = 0.61), which seem to indicate trivial and unclear differences using the magnitude-based inferences approach, respectively. In conclusion, acute 6 g taurine supplementation before exercise did not substantially improve high-intensity running performance and showed an unclear effect on MAODALT.

Interactive decision-making in people with schizotypal traits: a game theory approach

PubMed Central

Wout, Mascha van ’t; Sanfey, Alan G.

2010-01-01

Studies that have investigated whether deficits in social cognition observed in schizophrenia are also present in schizotypal individuals have largely been inconclusive, and none of these studies have examined social interactive behavior. Here, we investigated interactive decision-making behavior in individuals differing in the amount of schizotypal symptoms using tasks derived from Game Theory. In total 1691 undergraduate students were screened with the Schizotypal Personality Questionnaire-Brief version. We selected 69 people distributed across the full schizotypal continuum to participate in Ultimatum and Dictator Games in which they played against human and non-human, computer partners. The results showed that higher levels of schizotypal symptoms, particularly positive and disorganized schizotypy, were related to proposing higher offers to all partners. Additionally, the amount of interpersonal schizotypal symptoms was associated with an increased acceptance rate of very unfair offers from human partners, possibly reflecting a blunted emotional response to such offers. We conclude that positive and disorganized schizotypal symptoms are associated with less adequate bargaining behavior, similar to what has been recently observed in patients with schizophrenia. The observed similarities on Ultimatum Game behavior between patients with schizophrenia and individuals with more schizotypal symptoms contribute to the growing evidence that social cognitive deficits may represent a marker of vulnerability to schizophrenia. PMID:20538347

Risperidone Added to Psychostimulant in Children with Severe Aggression and Attention-Deficit/Hyperactivity Disorder: Lack of Effect on Attention and Short-Term Memory.

PubMed

Farmer, Cristan A; Epstein, Jeffery N; Findling, Robert L; Gadow, Kenneth D; Arnold, L Eugene; Kipp, Heidi; Kolko, David J; Butter, Eric; Schneider, Jayne; Bukstein, Oscar G; McNamara, Nora K; Molina, Brooke S G; Aman, Michael G

2017-03-01

Professionals have periodically expressed concern that atypical antipsychotics may cause cognitive blunting in treated patients. In this study, we report data from a double-blind, randomized, controlled study of stimulant plus placebo versus combined stimulant and risperidone to evaluate the effects of the atypical antipsychotic on attention and short-term memory. A total of 165 (n = 83 combined treatment; n = 82 stimulant plus placebo) children with attention-deficit/hyperactivity disorder and severe physical aggression, aged 6-12 years, were evaluated with Conners' Continuous Performance Test (CPT-II) and the Wechsler Intelligence Scale for Children-III (WISC) Digit Span subscale at baseline, after 3 weeks of stimulant-only treatment, and after six additional weeks of randomized treatment (stimulant+placebo vs. stimulant+risperidone). At 3 weeks, improvement on CPT-II performance (Commissions and Reaction Time Standard Error; p < 0.001) and on Digit Span memory performance (p < 0.006) was noted for the full sample. At study week 9, no difference in CPT-II or Digit Span performance was observed between the randomized groups (ps = 0.41 to 0.83). Similar to other studies, we found no deleterious effects on attention and short-term memory associated with short-term use of risperidone. NCT00796302.

Aerodynamic performance investigation on waverider with variable blunt radius in hypersonic flows

NASA Astrophysics Data System (ADS)

Li, Shibin; Wang, Zhenguo; Huang, Wei; Xu, Shenren; Yan, Li

2017-08-01

Waverider is an important candidate for the design of hypersonic vehicles. However, the ideal waverider cannot be manufactured because of its sharp leading edge, so the leading edge should be blunted. In the paper, the HMB solver and laminar flow model have been utilized to obtain the flow field properties around the blunt waverider with the freestream Mach number being 8.0, and several novel strategies have been suggested to improve the aerodynamic performance of blunt waverider. The numerical method has been validated against experimental data, and the Stanton number(St) of the predicted result has been analyzed. The obtained results show good agreement with the experimental data. Stmax decreases by 58% and L/D decreases by 8.2% when the blunt radius increases from 0.0002 m to 0.001 m. ;Variable blunt waverider; is a good compromise for aerodynamic performance and thermal insulation. The aero-heating characteristics are very sensitive to Rmax. The position of the smallest blunt radius has a great effect on the aerodynamic performance. In addition, the type of blunt leading edge has a great effect on the aero-heating characteristics when Rmax is fixed. Therefore, out of several designs, Type 4is the best way to achieve the good overall performance. The ;Variable blunt waverider; not only improves the aerodynamic performance, but also makes the aero-heating become evenly-distributed, leading to better aero-heating characteristics.

Drug-Intake Methods and Social Identity: The Use of Marijuana in Blunts among Southeast Asian Adolescents and Emerging Adults

ERIC Educational Resources Information Center

Soller, Brian; Lee, Juliet P.

2010-01-01

This article examines why Southeast Asian American adolescents and emerging adults in two urban settings prefer to use "blunts," or hollowed-out cigars filled with marijuana, over other methods of drug intake. Rationales for preferring blunts were both instrumental and social. Blunts allowed users to more easily share marijuana, the preferred drug…

Weapon Use in Korean Homicide: Differences Between Homicides Involving Sharp and Blunt Instruments.

PubMed

Park, Jisun; Son, Hyeonseo

2017-10-23

On the basis of information regarding 276 homicides committed in South Korea between 1987 and 2008, we compared offenders' and victims' characteristics, injury locations, weapon-related behavior, and offending behavior between homicides involving sharp and blunt instruments. The victims of sharp-force homicide were much younger relative to those of blunt-force homicide. In addition, homicides involving blunt instruments were more likely to be committed by offenders who lived with the victims. Most sharp-force homicides involved injuries to the torso, while blunt-force homicides involved mainly head injuries. Furthermore, perpetrators of sharp-force homicides tended to preselect their weapons, while those of blunt-force homicides were likely to use weapons of opportunity. Logistic regression analysis identified a number of factors, including injury location and body transportation, which significantly predicted weapon type. As this was the first South Korean study to compare sharp- and blunt-force homicides, the results have practical implications for homicide investigations. © 2017 American Academy of Forensic Sciences.

Crack blunting and the strength of soft elastic solids

NASA Astrophysics Data System (ADS)

Hui, C.-Y.; Jagota, A.; Bennison, S. J.; Londono, J. D.

2003-06-01

When a material is so soft that the cohesive strength (or adhesive strength, in the case of interfacial fracture) exceeds the elastic modulus of the material, we show that a crack will blunt instead of propagating. Large-deformation finite-element model (FEM) simulations of crack initiation, in which the debonding processes are quantified using a cohesive zone model, are used to support this hypothesis. An approximate analytic solution, which agrees well with the FEM simulation, gives additional insight into the blunting process. The consequence of this result on the strength of soft, rubbery materials is the main topic of this paper. We propose two mechanisms by which crack growth can occur in such blunted regions. We have also performed experiments on two different elastomers to demonstrate elastic blunting. In one system, we present some details on a void growth mechanism for ultimate failure, post-blunting. Finally, we demonstrate how crack blunting can shed light on some long-standing problems in the area of adhesion and fracture of elastomers.

Examining the Effect of Binge Eating and Disinhibition on Compensatory Changes in Energy Balance following Exercise among Overweight and Obese Women

PubMed Central

Emery, Rebecca L.; Levine, Michele D.; Jakicic, John M.

2016-01-01

Some women behaviorally compensate for the energy expended during exercise by increasing their energy intake or becoming more sedentary, thereby decreasing their energy expenditure. Although behavioral compensation can attenuate or even reverse the energy deficit generated by exercise, few data are available on predictors of compensatory responses to exercise. The present study aimed to identify eating-related predictors of compensatory changes in energy balance following exercise. Overweight and obese, physically inactive women (N = 48) completed self-report measures of disinhibition and binge eating and participated in two experimental conditions, exercise and rest, in counterbalanced order. Energy intake and expenditure were measured for 24-hours following each experimental condition to estimate energy balance. On average, women were 21.33 ± 2.09 years old and 63% were white. Of the sample, 63% compensated for the energy expended during exercise by increasing their energy intake or decreasing their energy expenditure. Linear mixed effects modeling with repeated measurement showed that disinhibition was not predictive of behavioral compensation. However, there was a significant difference between the negative energy balance observed following the rest condition and the positive energy balance observed following the exercise condition among women who reported binge eating, which was driven by a tendency to spend less time being physically active and more time being sedentary following exercise. These findings indicate that women who binge eat may be at greatest risk of compensating for exercise. Future research is needed to better understand psychosocial predictors and common mechanisms through which behavioral compensation is promoted. PMID:27064752

Melatonin Supplementation Ameliorates Energy Charge and Oxidative Stress Induced by Acute Exercise in Rat Heart Tissue

PubMed Central

Cimen, Behzat; Uz, Ali; Cetin, Ihsan; Cimen, Leyla; Cetin, Aysun

2017-01-01

Background Regular physical exercises may help people to be more resistant to everyday problems; however, how acute and intense exercises affect the heart tissues functioning with maximum capacity and how melatonin changes the effect of acute and intense exercises are still not obvious. We aimed to comprehend whether melatonin intravenous injection supports the oxidative/antioxidative conditions and energy charge in heart tissues of rats exposed to acute swimming exercise. Methods Thirty Wistar-albino male rats were categorized into 3 groups with equal number of subjects. Control group performed no application, and acute intensive swimming exercise group were subjected to acute intensive swimming exercise for 30 minutes, and melatonin group were applied 25 mg/kg single dose melatonin administration prior to 30 minutes acute intensive swimming exercise. The levels of malondialdehyde (MDA), and superoxide dismutase, catalase and glutathione peroxidase activities were measured by spectrophotometric method; and the levels of 3-nitrotyrosine (3-NT) and energy charge were determined by a high performance liquid chromatography. Results Tissue MDA and 3-NT levels of the acute intensive exercise group were found to be higher than the control group. It was also found that the melatonin administration increased the energy charge and antioxidant activities, while decreased tissue MDA and 3-NT levels in heart tissues. Our results provide evidence for melatonin that can exert potent protective effects on oxidative stress and energy charge for heart tissues in acute swimming exercise. Conclusions These findings suggest that the direct beneficial effects of melatonin could be potentially applied on prevention of oxidative stress and energy deficit. PMID:28959107

Effects of small nose bluntness on static stability and Magnus characteristics of a projectile shape at Mach 0.91 and 3.03

NASA Astrophysics Data System (ADS)

Kayser, Lyle D.

1986-07-01

Wind tunnel test results on a typical projectile shape with small nose bluntness are reported. Flat and hemispherical nose tip results are shown in addition to sharp nose tip results. The effects of nose bluntness on static stability are shown to be negligible at both Mach 0.91 and 3.02. The effects of nose bluntness on Magnus force and Magnus moment were not large, but of sufficient magnitude to indicate that such bluntness should not be neglected in a numerical flow field computation.

Evaluation of Critical Care Monitor Technology During the US Navy Strong Angel Exercise

NASA Technical Reports Server (NTRS)

Johannesen, John; Rasbury, Jack

2003-01-01

The NASA critical path road map identifies "trauma and acute medical problems" as a clinical capability risk category (http://criticalDath.isc.nasa.gov). Specific risks include major trauma, organ laceration or contusion, hemoperitoneum, pulmonary failure, pneumo- and hemothorax, burn, open bone fracture, blunt head trauma, and penetrating injury. Mitigation of these risks includes the capability for critical care monitoring. Currently, the International Space Station (ISS) Crew Health Care System (CHeCS) does not provide such a capability. The Clinical Space Medicine Strategic Planning Forum (4/8/97), sponsored by NASA Medical Operations, identified the development of trauma care capabilities as one of the top priorities for space medicine. The Clinical Care Capability Development Project (CCCDP) subsequently undertook the task to address this need.

WHEN FUE GOES WRONG!

PubMed Central

Poswal, Arvind; Bhutia, Sangay; Mehta, Ruby

2011-01-01

Follicular unit extraction (FUE) is an accepted method of extracting individual follicular unit grafts for hair transplant surgery. Since follicles are harvested from the back of the scalp using tiny punches resulting in minimal scarring, it has gained rapid acceptance among the patients. However, due care needs to be exercised while performing FUE. FUE should not be confused with the older plug graft extraction methods of coring out hair-bearing skin plugs. Lack of due diligence while performing such extractions can lead to subluxation of the grafts into the subdermal layer of scalp. Overtumescence of the scalp donor area, use of blunt punches and trying to “core” out the full thickness grafts can all contribute to this. The following cases illustrate some pitfalls to be avoided while performing FUE and the adverse consequences if they occur. PMID:22121268

The Chronic Effect of Interval Training on Energy Intake: A Systematic Review and Meta-Analysis

PubMed Central

Holland, David J.; Coombes, Jeff S.; Leveritt, Michael D.

2018-01-01

Single bouts of acute exercise do not appear to increase subsequent energy intake (EI), even when energy deficit is large. However, studies have shown a compensatory effect on EI following chronic exercise, and it remains unclear whether this is affected by exercise intensity. We investigated the chronic effect of high-intensity interval training (HIIT) and sprint interval training (SIT) on EI when compared with moderate-intensity continuous training (MICT) or no exercise (CON). Databases were searched until 13 March 2017 for studies measuring EI in response to chronic exercise (≥4 weeks of duration) of a high-intensity interval nature. Meta-analysis was conducted for between-group comparisons on EI (kilojoules) and bodyweight (kg). Results showed large heterogeneity, and therefore, metaregression analyses were conducted. There were no significant differences in EI between HIIT/SIT versus MICT (P=0.282), HIIT/SIT versus CON (P=0.398), or MICT versus CON (P=0.329). Although bodyweight was significantly reduced after HIIT/SIT versus CON but not HIIT/SIT versus MICT (in studies measuring EI), this was not clinically meaningful (<2% mean difference). In conclusion, there is no compensatory increase in EI following a period of HIIT/SIT compared to MICT or no exercise. However, this review highlights important methodological considerations for future studies. PMID:29808115

The aging musculoskeletal system and obesity-related considerations with exercise.

PubMed

Vincent, Heather K; Raiser, Sara N; Vincent, Kevin R

2012-07-01

Advancing age and adiposity contribute to musculoskeletal degenerative diseases and the development of sarcopenic obesity. The etiology of muscle loss is multifactorial, and includes inflammation, oxidative stress and hormonal changes, and is worsened by activity avoidance due to fear of pain. The risk for mobility disability and functional impairment rises with severity of obesity in the older adult. Performance measures of walking distance, walking speed, chair rise, stair climb, body transfers and ability to navigate obstacles on a course are adversely affected in this population, and this reflects decline in daily physical functioning. Exercise training is an ideal intervention to counteract the effects of aging and obesity. The 18 randomized controlled trials of exercise studies with or without diet components reviewed here indicate that 3-18 month programs that included aerobic and strengthening exercise (2-3 days per week) with caloric restriction (typically 750 kcal deficit/day), induced the greatest change in functional performance measures compared with exercise or diet alone. Importantly, resistance exercise attenuates muscle mass loss with the interventions. These interventions can also combat factors that invoke sarcopenia, including inflammation, oxidative stress and insulin resistance. Therefore, regular multimodal exercise coupled with diet appears to be very effective for counteracting sarocpenic obesity and improving mobility and function in the older, obese adult. Copyright © 2012 Elsevier B.V. All rights reserved.

A randomized controlled trial of water-based exercise for cardiovascular fitness in individuals with chronic stroke

PubMed Central

Chu, Kelly S; Eng, Janice J; Dawson, Andrew S; Harris, Jocelyn E.; Ozkaplan, Atila; Gylfadóttir, Sif

2011-01-01

Objective To evaluate the effect of an 8-week water-based exercise program (experimental group) over an upper extremity function program (control group) to increase cardiovascular fitness within a community setting for individuals with stroke. Design Single-blind randomized controlled trial Setting Public community centre Participants 12 community-dwelling individuals who have had a stroke with mild to moderate motor deficits; volunteer sample Intervention Experimental and control groups participated in group exercise programs undertaken in one hour sessions, three times per week for 8 weeks. The experimental group undertook chest deep water exercises at targeted heart rates. The control group performed arm and hand exercises while sitting. Main Outcome Measures The primary outcome measure was cardiovascular fitness (VO2max). Secondary measures were maximal workload, muscle strength, gait speed, and the Berg Balance Score. Results The experimental group attained significant improvements over the control group in cardiovascular fitness, maximal workload, gait speed, and paretic lower extremity muscle strength. The relatively short program (8 weeks) of water-based exercise resulted in a large improvement (22%) in cardiovascular fitness in a small group of individuals with stroke with relatively high function. Conclusions A water-based exercise program can be undertaken in the community as a group program and may be an effective means to promote fitness in individuals with stroke. PMID:15179638

Differential Effects of Nebivolol vs Metoprolol on Functional Sympatholysis in Hypertensive Humans

PubMed Central

Price, Angela; Raheja, Prafull; Wang, Zhongyun; Arbique, Debbie; Adams-Huet, Beverley; Mitchell, Jere H.; Victor, Ronald G.; Thomas, Gail D.; Vongpatanasin, Wanpen

2013-01-01

In young healthy humans, sympathetic vasoconstriction is markedly blunted during exercise to optimize blood flow to the metabolically active muscle. This phenomenon known as functional sympatholysis is impaired in hypertensive humans and rats by angiotensin II-dependent mechanisms involving oxidative stress and inactivation of nitric oxide (NO). Nebivolol is a β1−adrenergic receptor blocker that has NO-dependent vasodilatory and antioxidant properties. We therefore asked if nebivolol would restore functional sympatholysis in hypertensive humans. In 21 subjects with stage I hypertension, we measured muscle oxygenation and forearm blood flow (FBF) responses to reflex increases in sympathetic nerve activity (SNA) evoked by lower body negative pressure (LBNP) at rest and during rhythmic handgrip exercise at baseline, after 12 weeks of nebivolol (5–20 mg/day), or metoprolol (100–300 mg/day), using a double-blind crossover design. We found that nebivolol had no effect on LBNP-induced decreases in oxygenation and FBF in resting forearm (from −29±5 to −30±5% and from −29±3 to −29±3%, respectively; p=NS). However, nebivolol attenuated the LBNP-induced reduction in oxygenation and FBF in exercising forearm (from −14±4% to −1±5% and from −15 ±2% to −6±2%, respectively, both p < 0.05). This effect of nebivolol on oxygenation and FBF in exercising forearm was not observed with metoprolol in the same subjects despite a similar reduction in BP. Nebivolol had no effect on SNA at rest or during handgrip, suggesting a direct effect on vascular function. Thus, our data demonstrate that nebivolol restored functional sympatholysis in hypertensive humans by a mechanism that does not involve β1-adrenergic receptors. PMID:23547240

Neurovascular Response during Exercise and Mental Stress in Anabolic Steroid Users.

PubMed

Porello, Rafael Armani; Dos Santos, Marcelo Rodrigues; DE Souza, Francis Ribeiro; DA Fonseca, Guilherme Wesley Peixoto; Sayegh, Ana Luiza Carrari; DE Oliveira, Tiago Franco; Akiho, César Abreu; Yonamine, Maurício; Pereira, Rosa Maria Rodrigues; Negrão, Carlos Eduardo; Alves, Maria-Janieire DE Nazaré Nunes

2018-03-01

Increased resting muscle sympathetic nerve activity (MSNA) and lower forearm blood flow (FBF) were observed in young men who use anabolic androgenic steroids (AAS). However, the response of MSNA and FBF in AAS users triggered by muscle mechanoreflex and central command has never been tested. In addition, we evaluated the blood pressure (BP) and heart rate (HR) responses during these maneuvers. Nineteen AAS users (AASU) 31 ± 6 yr of age and 18 AAS nonusers (AASNU) 29 ± 4 yr of age were recruited. All participants were involved in strength training. AAS use was determined using a urine test (liquid chromatography with tandem mass spectrometry). MSNA was measured using the microneurography technique. FBF was measured by using venous occlusion plethysmography. BP was measured using an automatic oscillometric device. HR was recorded continuously through ECG. Isometric handgrip exercise was performed at 30% of the maximal voluntary contraction for 3 min, and mental stress was elicited by the Stroop color-word test for 4 min. The MSNA and FBF responses during exercise were similar between AASU and AASNU, with a trend toward higher MSNA (bursts per minute; P = 0.084) and lower forearm vascular conductance (FVC; units; P = 0.084) in AASU than in AASNU. During mental stress, AASU showed a significantly higher MSNA (P < 0.05) and lower FBF (P < 0.05) compared with AASNU. During both maneuvers, HR and BP increased linearly in both groups; however, AASU showed a significantly higher HR compared with AASNU. During muscle mechanoreflex activation (isometric exercise), AASU have normal MSNA and FBF responses, whereas during central command (mental stress) stimulation, AASU have exacerbated MSNA and blunted vasodilation. Therefore, mental stress seems to exacerbate neurovascular control throughout stress reaction situations in AASU.

Central command: control of cardiac sympathetic and vagal efferent nerve activity and the arterial baroreflex during spontaneous motor behaviour in animals.

PubMed

Matsukawa, Kanji

2012-01-01

Feedforward control by higher brain centres (termed central command) plays a role in the autonomic regulation of the cardiovascular system during exercise. Over the past 20 years, workers in our laboratory have used the precollicular-premammillary decerebrate animal model to identify the neural circuitry involved in the CNS control of cardiac autonomic outflow and arterial baroreflex function. Contrary to the traditional idea that vagal withdrawal at the onset of exercise causes the increase in heart rate, central command did not decrease cardiac vagal efferent nerve activity but did allow cardiac sympathetic efferent nerve activity to produce cardiac acceleration. In addition, central command-evoked inhibition of the aortic baroreceptor-heart rate reflex blunted the baroreflex-mediated bradycardia elicited by aortic nerve stimulation, further increasing the heart rate at the onset of exercise. Spontaneous motor activity and associated cardiovascular responses disappeared in animals decerebrated at the midcollicular level. These findings indicate that the brain region including the caudal diencephalon and extending to the rostral mesencephalon may play a role in generating central command. Bicuculline microinjected into the midbrain ventral tegmental area of decerebrate rats produced a long-lasting repetitive activation of renal sympathetic nerve activity that was synchronized with the motor nerve discharge. When lidocaine was microinjected into the ventral tegmental area, the spontaneous motor activity and associated cardiovascular responses ceased. From these findings, we conclude that cerebral cortical outputs trigger activation of neural circuits within the caudal brain, including the ventral tegmental area, which causes central command to augment cardiac sympathetic outflow at the onset of exercise in decerebrate animal models.

The effects of lower than conventional doses of oral nadolol on relative beta 1/beta 2-adrenoceptor blockade.

PubMed

Wheeldon, N M; McDevitt, D G; Lipworth, B J

1994-08-01

1. The aim of the present study was to evaluate the relative beta 1/beta 2 antagonist selectivity of the beta-adrenoceptor blocker nadolol, in lower than conventional clinical doses. 2. Eight normal volunteers received single oral doses of either placebo (PL), nadolol 5 mg (N5), 20 mg (N20) or 80 mg (N80) in a single-blind, randomised crossover design. beta 1-adrenoceptor antagonism was assessed by attenuation of exercise tachycardia, and beta 2-adrenoceptor blockade by effects on salbutamol-induced chronotropic, hypokalaemic and finger tremor responses. The relative percentage attenuation of beta 2 and beta 1-mediated responses was calculated and expressed as beta 2:beta 1 selectivity ratios. 3. Nadolol produced dose-related reductions in exercise tachycardia in keeping with increasing beta 1-adrenoceptor blockade; mean % reduction (95% CI) compared with placebo: N5 10.7 (6.6 to 14.8), N20 21.4 (17.3 to 25.4), N80 38.9 (34.8 to 42.9). However, even the lowest dose of nadolol (5 mg) produced almost complete blunting of beta 2-mediated effects and significantly increase exercise hyperkalaemia; peak exercise hyperkalaemia (mmol l-1) (means and 95% CI): PL 4.88 (4.68 to 5.07), N5 5.36 (5.17 to 5.55), N20 5.48 (5.28 to 5.67), N80 5.42 (5.22 to 5.61). beta 2:beta 1 selectivity ratios significantly increased as the dose of nadolol was reduced. 4. These data suggest that whereas in the clinical dose range nadolol behaves as a non-selective beta-adrenoceptor antagonist, as the dose is reduced this drug demonstrates an increasing degree of selectivity for the beta 2-adrenoceptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise Preconditioning Improves Traumatic Brain Injury Outcomes

PubMed Central

Taylor, Jordan M.; Montgomery, Mitchell H.; Gregory, Eugene J.; Berman, Nancy E.J.

2015-01-01

Purpose To determine whether 6 weeks of exercise performed prior to traumatic brain injury (TBI) could improve post-TBI behavioral outcomes in mice, and if exercise increases neuroprotective molecules (vascular endothelial growth factor-A [VEGF-A], erythropoietin [EPO], and heme oxygenase-1 [HO-1]) in brain regions responsible for movement (sensorimotor cortex) and memory (hippocampus). Methods 120 mice were randomly assigned to one of four groups: 1) no exercise + no TBI (NOEX-NOTBI [n=30]), 2) no exercise + TBI (NOEX-TBI [n=30]), 3) exercise + no TBI (EX-NOTBI [n=30]), and 4) exercise + TBI (EX-TBI [n=30]). The gridwalk task and radial arm water maze were used to evaluate sensorimotor and cognitive function, respectively. Quantitative real time polymerase chain reaction and immunostaining were performed to investigate VEGF-A, EPO, and HO-1 mRNA and protein expression in the right cerebral cortex and ipsilateral hippocampus. Results EX-TBI mice displayed reduced post-TBI sensorimotor and cognitive deficits when compared to NOEX-TBI mice. EX-NOTBI and EX-TBI mice showed elevated VEGF-A and EPO mRNA in the cortex and hippocampus, and increased VEGF-A and EPO staining of sensorimotor cortex neurons 1 day post-TBI and/or post-exercise. EX-TBI mice also exhibited increased VEGF-A staining of hippocampal neurons 1 day post-TBI/post-exercise. NOEX-TBI mice demonstrated increased HO-1 mRNA in the cortex (3 days post-TBI) and hippocampus (3 and 7 days post-TBI), but HO-1 was not increased in mice that exercised. Conclusions Improved TBI outcomes following exercise preconditioning are associated with increased expression of specific neuroprotective genes and proteins (VEGF-A and EPO, but not HO-1) in the brain. PMID:26165153

Individual variability in compensatory eating following acute exercise in overweight and obese women.

PubMed

Hopkins, Mark; Blundell, John E; King, Neil A

2014-10-01

While compensatory eating following acute aerobic exercise is highly variable, little is known about the underlying mechanisms that contribute to the alterations in exercise-induced eating behaviour. Overweight and obese women (body mass index=29.6±4.0 kg/m(2)) performed a bout of cycling individually tailored to expend 400 kcal (EX) or a time-matched no exercise control condition in a randomised, counter-balanced order. 60 min after the cessation of exercise, an ad libitum test meal was provided. Substrate oxidation and subjective appetite ratings were measured during exercise/time-matched rest, and during the period between the cessation of exercise and food consumption. While ad libitum energy intake (EI) did not differ between EX and the control condition (666.0±203.9 vs 664.6±174.4 kcal, respectively; ns), there was a marked individual variability in compensatory EI. The difference in EI between EX and the control condition ranged from -234.3 to 278.5 kcal. Carbohydrate oxidation during exercise was positively associated with postexercise EI, accounting for 37% of the variance in EI (r=0.57; p=0.02). These data indicate that the capacity of acute exercise to create a short-term energy deficit in overweight and obese women is highly variable. Furthermore, exercise-induced CHO oxidation can explain a part of the variability in acute exercise-induced compensatory eating. Postexercise compensatory eating could serve as an adaptive response to facilitate the restoration of carbohydrate balance. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Impaired Skeletal Muscle Vasodilation during Exercise in Heart Failure with Preserved Ejection Fraction

PubMed Central

Lee, Joshua F.; Barrett-O’Keefe, Zachary; Nelson, Ashley D.; Garten, Ryan S.; Ryan, John J.; Nativi-Nicolau, Jose N.; Richardson, Russell S.; Wray, D. Walter

2016-01-01

Background Exercise intolerance is a hallmark symptom of heart failure patients with preserved ejection fraction (HFpEF), which may be related to an impaired ability to appropriately increase blood flow to the exercising muscle. Methods We evaluated leg blood flow (LBF, ultrasound Doppler), heart rate (HR), stroke volume (SV), cardiac output (CO), and mean arterial blood pressure (MAP, photoplethysmography) during dynamic, single leg knee-extensor (KE) exercise in HFpEF patients (n = 21; 68 ± 2 yrs) and healthy controls (n = 20; 71 ± 2 yrs). Results HFpEF patients exhibited a marked attrition during KE exercise, with only 60% able to complete the exercise protocol. In participants who completed all exercise intensities (0-5-10-15W; HFpEF, n = 13; Controls, n = 16), LBF was not different at 0W and 5W, but was 15-25% lower in HFpEF compared to controls at 10W and 15W (P < 0.001). Likewise, leg vascular conductance (LVC), an index of vasodilation, was not different at 0W and 5W, but was 15-20% lower in HFpEF compared to controls at 10W and 15W (P < 0.05). In contrast to these peripheral deficits, exercise-induced changes in central variables (HR, SV, CO), as well as MAP, were similar between groups. Conclusions These data reveal a marked reduction in LBF and LVC in HFpEF patients during exercise that cannot be attributed to a disease-related alteration in central hemodynamics, suggesting that impaired vasodilation in the exercising skeletal muscle vasculature may play a key role in the exercise intolerance associated with this patient population. PMID:26970959

Exercise preconditioning improves traumatic brain injury outcomes.

PubMed

Taylor, Jordan M; Montgomery, Mitchell H; Gregory, Eugene J; Berman, Nancy E J

2015-10-05

To determine whether 6 weeks of exercise performed prior to traumatic brain injury (TBI) could improve post-TBI behavioral outcomes in mice, and if exercise increases neuroprotective molecules (vascular endothelial growth factor-A [VEGF-A], erythropoietin [EPO], and heme oxygenase-1 [HO-1]) in brain regions responsible for movement (sensorimotor cortex) and memory (hippocampus). 120 mice were randomly assigned to one of four groups: (1) no exercise+no TBI (NOEX-NOTBI [n=30]), (2) no exercise+TBI (NOEX-TBI [n=30]), (3) exercise+no TBI (EX-NOTBI [n=30]), and (4) exercise+TBI (EX-TBI [n=30]). The gridwalk task and radial arm water maze were used to evaluate sensorimotor and cognitive function, respectively. Quantitative real time polymerase chain reaction and immunostaining were performed to investigate VEGF-A, EPO, and HO-1 mRNA and protein expression in the right cerebral cortex and ipsilateral hippocampus. EX-TBI mice displayed reduced post-TBI sensorimotor and cognitive deficits when compared to NOEX-TBI mice. EX-NOTBI and EX-TBI mice showed elevated VEGF-A and EPO mRNA in the cortex and hippocampus, and increased VEGF-A and EPO staining of sensorimotor cortex neurons 1 day post-TBI and/or post-exercise. EX-TBI mice also exhibited increased VEGF-A staining of hippocampal neurons 1 day post-TBI/post-exercise. NOEX-TBI mice demonstrated increased HO-1 mRNA in the cortex (3 days post-TBI) and hippocampus (3 and 7 days post-TBI), but HO-1 was not increased in mice that exercised. Improved TBI outcomes following exercise preconditioning are associated with increased expression of specific neuroprotective genes and proteins (VEGF-A and EPO, but not HO-1) in the brain. Copyright © 2015 Elsevier B.V. All rights reserved.

Availability of tobacco products associated with use of marijuana cigars (blunts).

PubMed

Lipperman-Kreda, Sharon; Lee, Juliet P; Morrison, Chris; Freisthler, Bridget

2014-01-01

This study examines factors associated with availability of tobacco products for marijuana cigars (i.e., blunts) in 50 non-contiguous mid-sized California communities. The study is based on data collected in 943 tobacco outlets. Neighborhood demographics, community adult marijuana prevalence, medical marijuana policy and access to medical marijuana dispensaries and delivery services were included. Multilevel logistic regression analyses indicated that compared with small markets, availability of tobacco products associated with use of blunts was significantly higher in convenience stores, smoke/tobacco shops and liquor stores. None of the neighborhood demographics were associated with availability of blunt wrappers and only a small percent of Whites was positively associated with availability of blunt cigars, small cigars or cigarillos at the store. Controlling for outlet type and neighborhood demographics, higher city prevalence of adult marijuana use was associated with greater availability of blunt wrappers. Also, policy that permits medical marijuana dispensaries or private cultivation was positively associated with availability of tobacco products for blunts. Density of medical marijuana dispensaries and delivery services, however, was negatively associated with greater availability of these products at tobacco outlets. Results suggest that availability of tobacco products associated with blunts is similar in neighborhoods with different socioeconomic status and racial and ethnic composition. Results also suggest the important role that community norms that support marijuana use or legalization of medical marijuana and medical marijuana policy may play in increasing availability of tobacco products associated with blunts. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Availability of Tobacco Products Associated with Use of Marijuana Cigars (Blunts)

PubMed Central

Juliet, P. Lee; Morrison, Chris; Bridget, Freisthler

2013-01-01

Objectives This study examines factors associated with availability of tobacco products for marijuana cigars (i.e., blunts) in 50 non-contiguous mid-sized California communities. Methods The study is based on data collected in 943 tobacco outlets. Neighborhood demographics, community adult marijuana prevalence, medical marijuana policy and access to medical marijuana dispensaries and delivery services were included. Results Multilevel logistic regression analyses indicated that compared with small markets, availability of tobacco products associated with use of blunts was significantly higher in convenience stores, smoke/tobacco shops and liquor stores. None of the neighborhood demographics were associated with availability of blunt wrappers and only a small percent of Whites was positively associated with availability of blunt cigars, small cigars or cigarillos at the store. Controlling for outlet type and neighborhood demographics, higher city prevalence of adult marijuana use was associated with greater availability of blunt wrappers. Also, policy that permits medical marijuana dispensaries or private cultivation was positively associated with availability of tobacco products for blunts. Density of medical marijuana dispensaries and delivery services, however, was negatively associated with greater availability of these products at tobacco outlets. Conclusions Results suggest that availability of tobacco products associated with blunts is similar in neighborhoods with different socioeconomic status and racial and ethnic composition. Results also suggest the important role that community norms that support marijuana use or legalization of medical marijuana and medical marijuana policy may play in increasing availability of tobacco products associated with blunts. PMID:24290366

Exercise after Stroke: Patient Adherence and Beliefs after Discharge from Rehabilitation.

PubMed

Miller, Kristine K; Porter, Rebecca E; DeBaun-Sprague, Erin; Van Puymbroeck, Marieke; Schmid, Arlene A

2017-03-01

Most people complete post-stroke rehabilitation within the first 6 months after stroke even though benefits from exercise are believed to persist well beyond 6 months. Physical and Occupational therapists provide home exercise programs (HEP) to instruct patients on exercises to continue after discharge from rehabilitation. Unfortunately, there is little known about HEP adherence rates in adults with stroke. The objectives of this project were to (1) determine the adherence rate with post-rehabilitation HEP and reasons for non-adherence, (2) assess for interactions between HEP adherence and self-report of depression and fatigue, and (3) determine patient beliefs about the benefit of exercise during stroke recovery. This was a cross-sectional, survey study. A survey was developed and distributed during stroke support group meetings to determine adherence rates with post rehabilitation HEP, reasons for non-adherence, and patient beliefs about the benefit of exercise. Eighty-nine percent of participants reported receiving a HEP and 65.3% of those reported being adherent with at least part of the HEP. Several reasons for non-adherence were identified, including 'doing different exercises than the ones given by the physical therapist', as the most frequently given reason. Study participants identified positive roles of exercise in their recovery from stroke. Patient adherence with HEP after discharge from rehabilitation is less than ideal. Reasons for non-adherence are varied. Rehabilitation therapists need to be able to identify and help patients manage barriers to HEP adherence to promote management of residual deficits.

Changes in executive function after acute bouts of passive cycling in Parkinson's disease.

PubMed

Ridgel, Angela L; Kim, Chul-Ho; Fickes, Emily J; Muller, Matthew D; Alberts, Jay L

2011-04-01

Individuals with Parkinson's disease (PD) often experience cognitive declines. Although pharmacologic therapies are helpful in treating motor deficits in PD, they do not appear to be effective for cognitive complications. Acute bouts of moderate aerobic exercise have been shown to improve cognitive function in healthy adults. However, individuals with PD often have difficulty with exercise. This study examined the effects of passive leg cycling on executive function in PD. Executive function was assessed with Trail-Making Test (TMT) A and B before and after passive leg cycling. Significant improvements on the TMT-B test occurred after passive leg cycling. Furthermore, the difference between times to complete the TMT-B and TMT-A significantly decreased from precycling to postcycling. Improved executive function after passive cycling may be a result of increases in cerebral blood flow. These findings suggest that passive exercise could be a concurrent therapy for cognitive decline in PD.

How to Help Children with Learning Differences Reach Their Full Potential

ERIC Educational Resources Information Center

Lavoie, Theresa

2008-01-01

This article is the third part of a 10-part series that explores Attention Deficit Hyperactivity Disorder (ADHD). It offers and discusses tips on how to help children with learning differences reach their full potential. These include: (1) start with good nutrition; (2) be sure your child is exercising; (3) make sure your child is getting enough…

The Effects of Curriculum in Motion on Reading Scores for Male Students with Attention Deficit/Hyperactivity Disorder

ERIC Educational Resources Information Center

Pritchard, Jan Teena

2013-01-01

The most basic and fundamental skill for academic success is the ability to read. The purpose of this 1-group pretest and posttest pre-experimental quantitative study was to investigate how a unique instructional approach, called "curriculum in motion" with an emphasis on therapeutic martial arts and Brain Gym exercises influenced…

A Combined CFD/Characteristic Method for Prediction and Design of Hypersonic Inlet with Nose Bluntness

NASA Astrophysics Data System (ADS)

Gao, Wenzhi; Li, Zhufei; Yang, Jiming

Leading edge bluntness is widely used in hypersonic inlet design for thermal protection[1]. Detailed research of leading edge bluntness on hypersonic inlet has been concentrated on shock shape correlation[2], boundary layer flow[3], inlet performance[4], etc. It is well known that blunted noses cause detached bow shocks which generate subsonic regions around the noses and entropy layers in the flowfield.

Blunt gastric injuries.

PubMed

Oncel, Didem; Malinoski, Darren; Brown, Carlos; Demetriades, Demetrios; Salim, Ali

2007-09-01

Gastric rupture after blunt abdominal trauma is a rare injury with few reports in the literature. The purpose of this study was to review our experience with blunt gastric injuries and compare outcomes with small bowel or colon injuries. All patients with hollow viscus perforations after blunt abdominal trauma from 1992 to 2005 at our level I trauma center were reviewed. Of 35,033 blunt trauma admissions, there were 268 (0.7%) patients with a total of 319 perforating hollow viscus injuries, 25 (0.07%) of which were blunt gastric injuries. When compared with the small bowel or colon injuries, the blunt gastric injury group had a higher Injury Severity Score (22 versus 17, P = 0.04), more patients with a chest Abbreviated Injury Score greater than 2 (36% versus 12%, P < 0.01), and a shorter interval from injury to laparotomy (221 versus 366 minutes, P = 0.017). Multivariate analysis identified five independent risk factors for mortality: age older than 55 years, head Abbreviated Injury Score greater than 2, chest Abbreviated Injury Score greater than 2, the presence of hypotension on admission, and Glasgow Coma Scale 8 or less. The results of this study suggest that mortality in patients with blunt hollow viscus injuries can be attributed to concurrent head and chest injuries, but not the specific hollow viscus organ that is injured.

Traumatic diaphragmatic injury: a review of CT signs and the difference between blunt and penetrating injury

PubMed Central

Panda, Ananya; Kumar, Atin; Gamanagatti, Shivanand; Patil, Aruna; Kumar, Subodh; Gupta, Amit

2014-01-01

PURPOSE We aimed to present the frequency of computed tomography (CT) signs of diaphragmatic rupture and the differences between blunt and penetrating trauma. MATERIALS AND METHODS The CT scans of 23 patients with surgically proven diaphragmatic tears (both blunt and penetrating) were retrospectively reviewed for previously described CT signs of diaphragmatic injuries. The overall frequency of CT signs was reported; frequency of signs in right- and left-sided injuries and blunt and penetrating trauma were separately tabulated and statistically compared. RESULTS The discontinuous diaphragm sign was the most common sign, observed in 95.7% of patients, followed by diaphragmatic thickening (69.6%). While the dependent viscera sign and collar sign were exclusively observed in blunt-trauma patients, organ herniation (P = 0.05) and dangling diaphragm (P = 0.0086) signs were observed significantly more often in blunt trauma than in penetrating trauma. Contiguous injury on either side of the diaphragm was observed more often in penetrating trauma (83.3%) than in blunt trauma (17.7%). CONCLUSION Knowledge of the mechanism of injury and familiarity with all CT signs of diaphragmatic injury are necessary to avoid a missed diagnosis because there is variability in the overall occurrence of these signs, with significant differences between blunt and penetrating trauma. PMID:24412818

Cognitive Effects of ThinkRx Cognitive Rehabilitation Training for Eleven Soldiers with Brain Injury: A Retrospective Chart Review

PubMed Central

Ledbetter, Christina; Moore, Amy Lawson; Mitchell, Tanya

2017-01-01

Cognitive rehabilitation training is a promising technique for remediating the cognitive deficits associated with brain injury. Extant research is dominated by computer-based interventions with varied results. Results from clinician-delivered cognitive rehabilitation are notably lacking in the literature. The current study examined the cognitive outcomes following ThinkRx, a clinician-delivered cognitive rehabilitation training program for soldiers recovering from traumatic brain injury and acquired brain injury. In a retrospective chart review, we examined cognitive outcomes of 11 cases who had completed an average of 80 h of ThinkRx cognitive rehabilitation training delivered by clinicians and supplemented with digital training exercises. Outcome measures included scores from six cognitive skill batteries on the Woodcock Johnson – III Tests of Cognitive Abilities. Participants achieved gains in all cognitive skills tested and achieved statistically significant changes in long-term memory, processing speed, auditory processing, and fluid reasoning with very large effect sizes. Clinically significant changes in multiple cognitive skills were also noted across cases. Results of the study suggest that ThinkRx clinician-delivered cognitive training supplemented with digital exercises may be a viable method for targeting the cognitive deficits associated with brain injury. PMID:28588534

Compromised Dopaminergic Encoding of Reward Accompanying Suppressed Willingness to Overcome High Effort Costs Is a Prominent Prodromal Characteristic of the Q175 Mouse Model of Huntington's Disease.

PubMed

Covey, Dan P; Dantrassy, Hannah M; Zlebnik, Natalie E; Gildish, Iness; Cheer, Joseph F

2016-05-04

Huntington's disease (HD) is a heritable neurodegenerative disorder caused by expansion of CAG (glutamine) repeats in the HTT gene. A prodromal stage characterized by psychiatric disturbances normally precedes primary motor symptoms and suppressed motivation represents one of the earliest and most common psychiatric symptoms. Although dopamine in the nucleus accumbens (NAc) critically regulates motivation and altered dopamine signaling is implicated in HD, the nature of dopaminergic deficits and contribution to symptoms in HD is poorly understood. We therefore tested whether altered NAc dopamine release accompanies motivational deficits in the Q175 knock-in HD mouse model. Q175 mice express a CAG expansion of the human mutant huntingtin allele in the native mouse genome and gradually manifest symptoms late in life, closely mimicking the genotypic context and disease progression in human HD. Sub-second extracellular dopamine release dynamics were monitored using fast-scan cyclic voltammetry, whereas motivation was assessed using a progressive ratio reinforcement schedule. As the response ratio (lever presses per reward) escalated, Q175 mice exerted less effort to earn fewer rewards versus wild-type (WT). Moreover, dopamine released at reward delivery dynamically encoded increasing reward cost in WT but not Q175 mice. Deficits were specific to situations of high effortful demand as no difference was observed in locomotion, free feeding, hedonic processing, or reward seeking when the response requirement was low. This compromised dopaminergic encoding of reward delivery coincident with suppressed motivation to work for reward in Q175 mice provides novel, neurobiological insight into an established and clinically relevant endophenotype of prodromal HD. Psychiatric impairments in Huntington's disease (HD) typically manifest early in disease progression, before motor deficits. However, the neurobiological factors contributing to psychiatric symptoms are poorly understood. We used a mouse HD model and assessed whether impaired dopamine release in the nucleus accumbens (NAc), a brain region critical to goal-directed behaviors, accompanies motivational deficits, one of the most common early HD symptoms. HD mice exhibited blunted motivation to work for food reward coincident with diminished dopamine release to reward receipt. Motivational and NAc dopaminergic deficits were not associated with gross motor deficits or impaired food seeking when effortful demands were low. This work identifies a specific prodromal HD phenotype associated with a prominent and previously unidentified neurobiological impairment. Copyright © 2016 the authors 0270-6474/16/364993-10$15.00/0.

Avenanthramide supplementation attenuates eccentric exercise-inflicted blood inflammatory markers in women.

PubMed

Koenig, Ryan T; Dickman, Jonathan R; Kang, Choung-Hun; Zhang, Tianou; Chu, Yi-Fang; Ji, Li Li

2016-01-01

Rigorous exercise is known to generate reactive oxygen species (ROS) and inflict inflammatory response. The present study investigated whether dietary supplementation of avenanthramides (AVA) in oats would increase antioxidant protection and reduce inflammation in humans after an acute bout of eccentric exercise. Young women (age 18-30 years, N = 16) were randomly divided into two groups in a double-blinded fashion, receiving two cookies made of oat flour providing 9.2 mg AVA (AVA) or 0.4 mg AVA (Control, C) each day for 8 weeks. Before and after the dietary regimen each group of subjects ran downhill (DR) on a treadmill at -9% grade for 1 h at a speed to elicit 75% of maximal heart rate. Blood samples were collected at rest, immediately and 24 h post-DR. Before dietary supplementation plasma creatine kinase activity and tumor necrosis factor (TNF)-α concentration were increased immediately after DR (P < 0.05), whereas neutrophil respiratory burst (NRB) was elevated 24 h post-DR (P < 0.05). CK and TNF-α response to DR was abolished during post-supplementation tests in both AVA and C groups, whereas NRB was blunted only in AVA but not in C. Plasma interleukin-6 level and mononuclear cell nuclear factor (NF) κB activity were not affected by DR either before or after dietary supplementation, but were lowered 24 h post-DR in AVA versus C (P < 0.05). Both groups increased plasma total antioxidant activity following 8-week dietary regimen (P < 0.05), whereas only AVA group increased resting plasma glutathione (GSH) concentration (P < 0.05), decreased glutathione disulfide response to DR, and lowered erythrocyte GSH peroxidase activity (P < 0.05). Our data of pre- and post-supplementation difference reflect an interaction between repeated measure effect of eccentric exercise and AVA in diet. Long-term AVA supplementation can attenuate blood inflammation markers, decrease ROS generation and NFkB activation, and increased antioxidant capacity during an eccentric exercise bout.

Altered Arterial Stiffness and Subendocardial Viability Ratio in Young Healthy Light Smokers after Acute Exercise

PubMed Central

Doonan, Robert J.; Scheffler, Patrick; Yu, Alice; Egiziano, Giordano; Mutter, Andrew; Bacon, Simon; Carli, Franco; Daskalopoulos, Marios E.; Daskalopoulou, Stella S.

2011-01-01

Background Studies showed that long-standing smokers have stiffer arteries at rest. However, the effect of smoking on the ability of the vascular system to respond to increased demands (physical stress) has not been studied. The purpose of this study was to estimate the effect of smoking on arterial stiffness and subendocardial viability ratio, at rest and after acute exercise in young healthy individuals. Methods/Results Healthy light smokers (n = 24, pack-years = 2.9) and non-smokers (n = 53) underwent pulse wave analysis and carotid-femoral pulse wave velocity measurements at rest, and 2, 5, 10, and 15 minutes following an exercise test to exhaustion. Smokers were tested, 1) after 12h abstinence from smoking (chronic condition) and 2) immediately after smoking one cigarette (acute condition). At rest, chronic smokers had higher augmentation index and lower aortic pulse pressure than non-smokers, while subendocardial viability ratio was not significantly different. Acute smoking increased resting augmentation index and decreased subendocardial viability ratio compared with non-smokers, and decreased subendocardial viability ratio compared with the chronic condition. After exercise, subendocardial viability ratio was lower, and augmentation index and aortic pulse pressure were higher in non-smokers than smokers in the chronic and acute conditions. cfPWV rate of recovery of was greater in non-smokers than chronic smokers after exercise. Non-smokers were also able to achieve higher workloads than smokers in both conditions. Conclusion Chronic and acute smoking appears to diminish the vascular response to physical stress. This can be seen as an impaired ‘vascular reserve’ or a blunted ability of the blood vessels to accommodate the changes required to achieve higher workloads. These changes were noted before changes in arterial stiffness or subendocardial viability ratio occurred at rest. Even light smoking in young healthy individuals appears to have harmful effects on vascular function, affecting the ability of the vascular bed to respond to increased demands. PMID:22028821

The effect of combined resistance exercise training and vitamin D3 supplementation on musculoskeletal health and function in older adults: a systematic review and meta-analysis.

PubMed

Antoniak, Anneka Elizabeth; Greig, Carolyn A

2017-07-20

In older adults, there is a blunted responsiveness to resistance training and reduced muscle hypertrophy compared with younger adults. There is evidence that both exercise training and vitamin D supplementation may benefit musculoskeletal health in older adults, and it is plausible that in combination their effects may be additive. The aim of this systematic review was to evaluate the effectiveness of combined resistance exercise training and vitamin D 3 supplementation on musculoskeletal health in older adults. A comprehensive search of electronic databases, including Science Direct, Medline, PubMed, Google Scholar and Cochrane Central Register of Controlled Trials (Cochrane CENTRAL accessed by Wiley Science) was conducted. Eligible studies were randomised controlled trials including men and women (aged ≥65 years or mean age ≥65 years); enlisting resistance exercise training and vitamin D 3 supplementation; including outcomes of muscle strength, function, muscle power, body composition, serum vitamin D/calcium status or quality of life comparing results with a control group. The review was informed by a preregistered protocol (http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42015020157). Seven studies including a total of 792 participants were identified. Studies were categorised into two groups; group 1 compared vitamin D 3 supplementation and exercise training versus exercise alone (describing the additive effect of vitamin D 3 supplementation when combined with resistance exercise training) and group 2 compared vitamin D 3 supplementation and exercise training versus vitamin D 3 supplementation alone (describing the additive effect of resistance exercise training when combined with vitamin D 3 supplementation).Meta-analyses for group 1 found muscle strength of the lower limb to be significantly improved within the intervention group (0.98, 95% CI 0.73 to 1.24, p<0.001); all other outcomes showed small but non-significant positive effects for the intervention group. The short physical performance battery (SPPB), timed up and go (TUG), muscle strength of the lower limb and femoral neck bone mineral density showed significantly greater improvements in the intervention group for group 2 comparisons. This review provides tentative support for the additive effect of resistance exercise and vitamin D 3 supplementation for the improvement of muscle strength in older adults. For other functional variables, such as SPPB and TUG, no additional benefit beyond exercise was shown. Further evidence is required to draw firm conclusions or make explicit recommendations regarding combined exercise and vitamin D 3 supplementation. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Comparison of rehydration regimens for rehabilitation of firefighters performing heavy exercise in thermal protective clothing: a report from the fireground rehab evaluation (FIRE) trial.

PubMed

Hostler, David; Bednez, James C; Kerin, Sarah; Reis, Steven E; Kong, Pui Wah; Morley, Julia; Gallagher, Michael; Suyama, Joe

2010-01-01

Performing fire suppression activities results in cardiovascular stress, hyperthermia, and hypohydration. Fireground rehabilitation (rehab) is recommended to blunt the deleterious effects of these conditions. We tested the hypothesis that three rehydration fluids provided after exercise while wearing thermal protective clothing (TPC) would produce different heart rate or core temperature responses during a second bout of exercise in TPC. On three occasions, 18 euhydrated firefighters (16 men, two women) wearing TPC completed a standardized, 50-minute bout of upper and lower body exercise in a hot room that mimicked the National Fire Protection Association (NFPA) rehabilitation guidelines of "two cylinders before rehab" (20 minutes of work, 10 minutes of recovery, 20 minutes of work). After an initial bout of exercise (bout 1), subjects were randomly assigned water, sport drink, or an intravenous (IV) infusion of normal saline equal to the amount of body mass lost during exercise. After rehydration, the subject performed a second bout of exercise (bout 2). Heart rates, core and skin temperatures, and exercise durations were compared with a two-way analysis of variance (ANOVA). Subjects were firefighters with a mean (+/- standard deviation [SD]) age of 28.2 +/- 11.3 years and a mean peak oxygen consumption (VO(2peak)) of 37.4 +/- 3.4 mL/kg/min. The mean amount of fluid provided during the rehabilitation period was 527 +/- 302 mL. No subject could complete either the pre- or postrehydration 50-minute bout of exercise. The mean (+/-SD) times to exhaustion were longer (p < 0.001) in bout 1 (25.9 +/- 12.9 min, water; 28.0 +/- 14.1 min, sport drink; 27.4 +/- 13.8 min, IV) compared with bout 2 (15.6 +/- 9.6 min, water; 14.7 +/- 8.6 min, sport drink; 15.7 +/- 8.0 min, IV) for all groups but did not differ by intervention. All subjects approached their age-predicted maximum heart rate at the end of bout 1 (180 +/- 11 bpm) and bout 2 (176 +/- 13 bpm). Core temperature rose 1.1 degrees C +/- 0.7 degrees C during bout 1 and 0.5 degrees C +/- 0.4 degrees C during bout 2. Core temperatures, heart rates, and exercise times during bout 2 did not differ between the rehydration fluids. Performances during a second bout of exercise in TPC did not differ when firefighters were rehydrated with water, sport drink, or IV normal saline when full rehydration was provided. Of concern was the inability of all subjects to complete two consecutive periods of heavy exercise in TPC, suggesting that the NFPA's "two cylinders before rehab" guideline may not be appropriate in continuous heavy work scenarios.

Comparison of rehydration regimens for rehabilitation of firefighters performing heavy exercise in thermal protective clothing: A report from the Fireground Rehab Evaluation (FIRE) trial

PubMed Central

Hostler, David; Bednez, James C; Kerin, Sarah; Reis, Steven E; Kong, Pui Wah; Morley, Julia; Gallagher, Michael; Suyama, Joe

2010-01-01

Background: Fire suppression activities results in cardiovascular stress, hyperthermia, and hypohydration. Fireground rehabilitation (rehab) is recommended to blunt the deleterious effects of these conditions. Objective: We tested the hypothesis that three rehydration fluids provided after exercise in thermal protective clothing (TPC) would produce different heart rate or core temperature responses during a second bout of exercise in TPC. Methods: On three occasions, 18 euhydrated firefighters (16 males, 2 females) wearing TPC completed a standardized, 50-minute bout of upper and lower body exercise in a hot room that mimicked the National Fire Protection Association (NFPA) rehabilitation guidelines of “two cylinders before rehab” (20 min work, 10 min recovery, 20 min work). After an initial bout of exercise, subjects were randomly assigned water, sport drink, or an intravenous (IV) infusion of normal saline equal to the amount of body mass lost during exercise. After rehydration, the subject performed a second bout of exercise. Heart rate, core and skin temperature, and exercise duration were compared with a two-way ANOVA. Results: Subjects were firefighters aged 28.2±11.3 years with a VO2peak of 37.4±3.4 ml/kg/min. 527±302 mL of fluid were provided during the rehabilitation period. No subject could complete either the pre- or post-rehydration 50-minute bout of exercise. Mean (SD) time to exhaustion (min) was longer (p<0.001) in bout 1 (25.9±12.9 min. water, 28.0±14.1 min. sport drink, 27.4±13.8 min. IV) compared to bout 2 (15.6±9.6 min. water, 14.7±8.6 min. sport drink, 15.7±8.0 min. IV) for all groups but did not differ by intervention. All subjects approached age predicted maximum heart rate at the end of bout 1 (180±11 bpm) and bout 2 (176±13 bpm). Core temperature rose 1.1±0.7°C during bout 1 and 0.5±0.4°C during bout 2. Core temperature, heart rate, and exercise time during bout 2 did not differ between rehydration fluids. Conclusions: Performance during a second bout of exercise in TPC did not differ when firefighters were rehydrated with water, sport drink, or IV normal saline when full rehydration is provided. Of concern was the inability of all subjects to complete two consecutive periods of heavy exercise in TPC suggesting the NFPA “two cylinders before rehab” guideline may not be appropriate in continuous heavy work scenarios. PMID:20095824

The use of laparoscopy in the diagnosis and treatment of blunt and penetrating abdominal injuries: 10-year experience at a level 1 trauma center.

PubMed

Johnson, Jeremy J; Garwe, Tabitha; Raines, Alexander R; Thurman, Joseph B; Carter, Sandra; Bender, Jeffrey S; Albrecht, Roxie M

2013-03-01

Diagnostic laparoscopy (DL) has decreased the rate of nontherapeutic laparotomy for patients suffering from penetrating injuries. We evaluated whether DL similarly lowers the rate of nontherapeutic laparotomy for patients with blunt injuries. All patients undergoing DL over a 10-year period (ie, 2001-2010) in a single level 1 trauma center were classified by the mechanism of injury. Demographic and perioperative data were compared using the Student t and Fisher exact tests. There were 131 patients included, 22 of whom sustained blunt injuries. Patients suffering from blunt injuries were more severely injured (Injury Severity Score 18.0 vs 7.3, P = .0001). The most common indication for DL after blunt injury was a computed tomographic scan concerning for bowel injury (59.1%). The rate of nontherapeutic laparotomy for patients sustaining penetrating vs blunt injury was 1.8% and nil, respectively. DL, when coupled with computed tomographic findings, is an effective tool for the initial management of patients with blunt injuries. Copyright © 2013 Elsevier Inc. All rights reserved.

Clinical and radiological outcomes following traumatic Grade 3 and 4 vertebral artery injuries: a 10-year retrospective analysis from a Level I trauma center. The Parkland Carotid and Vertebral Artery Injury Survey.

PubMed

Scott, William W; Sharp, Steven; Figueroa, Stephen A; Eastman, Alexander L; Hatchette, Charles V; Madden, Christopher J; Rickert, Kim L

2015-05-01

Grade 3 and 4 blunt vertebral artery (VA) injuries may carry a different natural course from that of lower-grade blunt VA injuries. Proper screening, management, and follow-up of these injuries remain controversial. Grade 3 and 4 blunt VA injuries were analyzed to define their natural history and establish a rational management plan based on lesion progression and cerebral infarction. A retrospective review of a prospectively maintained database of all blunt traumatic carotid and vertebral artery injuries from August 2003 to April 2013 was performed, and Grade 3 and 4 blunt VA injuries were identified. Grade 3 injuries were defined as stenosis of the vessel greater than 50% or the development of a pseudoaneurysm, and Grade 4 injuries were defined as complete vessel occlusion. Demographic information, radiographic imaging findings, number of imaging sessions performed per individual, length of radiographic follow-up, radiographic outcome at end of follow-up, treatment(s) provided, and documentation of ischemic stroke or transient ischemic attack were recorded. A total of 79 high-grade (Grade 3 and 4) blunt VA injuries in 67 patients were identified. Fifty-nine patients with 66 high-grade blunt VA injuries were available for follow-up. There were 17 patients with 23 Grade 3 injuries and 42 patients with 43 Grade 4 injuries. The mean follow-up duration was 58 days for Grade 3 and 67 days for Grade 4 blunt VA injuries. Repeat imaging of Grade 3 blunt VA injuries showed that 39% of injuries were radiographically stable, 43% resolved, and 13% improved, while 1 injury radiographically worsened. Repeat imaging of the Grade 4 blunt VA injuries showed that 65% of injuries were radiographically stable (persistent occlusion), 30% improved (recanalization of the vessel), and in 2 cases (5%) the injury resolved. All Grade 3 injuries that were treated were managed with aspirin or clopidogrel alone, as were the majority of Grade 4 injuries. There were 3 cerebral infarctions thought to be related to Grade 4 blunt VA injuries, which were likely present on admission. All 3 of these patients died at a mean of 13.7 days after hospital admission. No cerebral infarctions directly related to Grade 3 blunt VA injuries were identified. The majority of high-grade blunt VA injuries remain stable or are improved at final follow-up. Despite a 4% rate of radiographic worsening in the Grade 3 blunt VA injury group and a 35% recanalization rate in the Grade 4 blunt VA injury group, there were no adverse clinical outcomes associated with these radiographic changes. No cerebral infarctions were noted in the Grade 3 group. A 7% stroke rate was identified in the Grade 4 blunt VA injury group; however, this was confined to the immediate postinjury period and was associated with 100% mortality. While these data suggest that these high-grade vertebral artery injuries may require less intensive radiographic follow-up, future prospective studies are needed to make conclusive changes related to treatment and management.

Effects of hypothyroidism on the skeletal muscle blood flow response to contractions.

PubMed

Bausch, L; McAllister, R M

2003-04-01

Hypothyroidism is associated with impaired blood flow to skeletal muscle under whole body exercise conditions. It is unclear whether poor cardiac and/or vascular function account for blunted muscle blood flow. Our experiment isolated a small group of hindlimb muscles and simulated exercise via tetanic contractions. We hypothesized that muscle blood flow would be attenuated in hypothyroid rats (HYPO) compared with euthyroid rats (EUT). Rats were made hypothyroid by mixing propylthiouracil in their drinking water (2.35 x 10-3 mol/l). Treatment efficacy was evidenced by lower serum T3 concentrations and resting heart rates in HYPO (both P<0.05). In the experimental preparation, isometric contractions of the lower right hindlimb muscles at a rate of 30 tetani/min were induced via sciatic nerve stimulation. Regional blood flows were determined by the radiolabelled microsphere method at three time points: rest, 2 min of contractions and 10 min of contractions. Muscle blood flow generally increased from rest ( approximately 5-10 ml/min per 100 g) through contractions for both groups. Further, blood flow during contractions did not differ between groups for any muscle (eg. red section of gastrocnemius muscle; EUT, 59.9 +/- 14.1; HYPO, 61.1 +/- 15.0; NS between groups). These findings indicate that hypothyroidism does not significantly impair skeletal muscle blood flow when only a small muscle mass is contracting. Our findings suggest that impaired blood flow under whole body exercise is accounted for by inadequate cardiac function rather than abnormal vascular function.

Effects of insulin resistance on skeletal muscle growth and exercise capacity in type 2 diabetic mouse models

PubMed Central

Ostler, Joseph E.; Maurya, Santosh K.; Dials, Justin; Roof, Steve R.; Devor, Steven T.; Ziolo, Mark T.

2014-01-01

Type 2 diabetes mellitus is associated with an accelerated muscle loss during aging, decreased muscle function, and increased disability. To better understand the mechanisms causing this muscle deterioration in type 2 diabetes, we assessed muscle weight, exercise capacity, and biochemistry in db/db and TallyHo mice at prediabetic and overtly diabetic ages. Maximum running speeds and muscle weights were already reduced in prediabetic db/db mice when compared with lean controls and more severely reduced in the overtly diabetic db/db mice. In contrast to db/db mice, TallyHo muscle size dramatically increased and maximum running speed was maintained during the progression from prediabetes to overt diabetes. Analysis of mechanisms that may contribute to decreased muscle weight in db/db mice demonstrated that insulin-dependent phosphorylation of enzymes that promote protein synthesis was severely blunted in db/db muscle. In addition, prediabetic (6-wk-old) and diabetic (12-wk-old) db/db muscle exhibited an increase in a marker of proteasomal protein degradation, the level of polyubiquitinated proteins. Chronic treadmill training of db/db mice improved glucose tolerance and exercise capacity, reduced markers of protein degradation, but only mildly increased muscle weight. The differences in muscle phenotype between these models of type 2 diabetes suggest that insulin resistance and chronic hyperglycemia alone are insufficient to rapidly decrease muscle size and function and that the effects of diabetes on muscle growth and function are animal model-dependent. PMID:24425761

Acute effect of walking on energy intake in overweight/obese women

PubMed Central

Unick, Jessica L.; Otto, Amy D.; Goodpaster, Bret H.; Helsel, Diane L.; Pellegrini, Christine A.; Jakicic, John M.

2013-01-01

This study examined the acute effect of a bout of walking on hunger, energy intake, and appetite-regulating hormones [acylated ghrelin and glucagon-like peptide-1 (GLP-1)] in 19 overweight/obese women (BMI:32.5±4.3kg/m2). Subjects underwent two experimental testing sessions in a counterbalanced order: exercise and rest. Subjects walked at a moderate-intensity for approximately 40 minutes or rested for a similar duration. Subjective feelings of hunger were assessed and blood was drawn at 5 time points (pre-, post-, 30-minutes, 60-minutes, 120-minutes post-testing). Ad-libitum energy intake consumed 1–2 hours post-exercise/rest was assessed and similar between conditions (mean ± standard deviation; exercise: 551.5±245.1 kcals [2.31±1.0MJ] vs. rest: 548.7±286.9 kcals [2.29±1.2MJ]). However, when considering the energy cost of exercise, relative energy intake was significantly lower following exercise (197.8±256.5 kcals [0.83±1.1MJ]) compared to rest (504.3±290.1 kcals [2.11±1.2MJ]). GLP-1 was lower in the exercise vs. resting condition while acylated ghrelin and hunger were unaltered by exercise. None of these variables were associated with energy intake. In conclusion, hunger and energy intake were unaltered by a bout of walking suggesting that overweight/obese individuals do not acutely compensate for the energy cost of the exercise bout through increased caloric consumption. This allows for an energy deficit to persist post-exercise, having potentially favorable implications for weight control. PMID:20674640

Cognitive function in Japanese women with posttraumatic stress disorder: Association with exercise habits.

PubMed

Narita-Ohtaki, Ryoko; Hori, Hiroaki; Itoh, Mariko; Lin, Mingming; Niwa, Madoka; Ino, Keiko; Imai, Risa; Ogawa, Sei; Sekiguchi, Atsushi; Matsui, Mie; Kunugi, Hiroshi; Kamo, Toshiko; Kim, Yoshiharu

2018-08-15

Posttraumatic stress disorder (PTSD) has been associated with cognitive impairments, yet little is documented on the cognitive function of PTSD patients in Asian countries. It is shown that regular exercise can reduce PTSD symptoms, while no study has investigated the association between exercise and cognition in PTSD patients. This study aimed to examine cognitive functions of Japanese women with PTSD, and to explore the association between regular exercise and cognitive functions. Forty-two women with DSM-IV PTSD and 66 demographically matched healthy control women participated in this study. Most of the patients developed PTSD after experiencing interpersonal violence. Cognitive functions were assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Regular exercise habit was assessed by a self-reported questionnaire. Compared to controls, PTSD patients performed significantly more poorly in all cognitive domains examined, including immediate memory, visuospatial construction, language, attention, delayed memory, as well as the total score of RBANS (all p < 0.001). Compared to PTSD patients without the habit of exercise, those who habitually exercised showed significantly better performance on delayed memory (p = 0.006), which survived after controlling for potentially confounding variables in a multiple regression model. The cross-sectional design and relatively small sample size limited our findings. PTSD in Japanese women is associated with pervasively impaired cognitive functions, including notable impairments in verbal memory. Such memory deficits might be improved by regular exercise, although further studies are needed to investigate the causal relationship between exercise and cognition in PTSD. Copyright © 2018 Elsevier B.V. All rights reserved.

Isolated rupture of the gallbladder following blunt abdominal trauma: case report

PubMed Central

Epstein, Marina Gabrielle; da Silva, Dorivaldo Lopes; Elias, Naim Carlos; Sica, Gustavo Tricta Augusto; Fávaro, Murillo de Lima; Ribeiro, Marcelo Augusto Fontenelle

2013-01-01

ABSTRACT Gallbladder rupture following blunt abdominal trauma is a rare event recognized on evaluation and treatment of other visceral injuries during laparotomy. Isolated gallbladder rupture secondary to blunt abdominal trauma is even more uncommon. The clinical presentation of gallbladder injury is variable, resulting in a delay in diagnosis and treatment. We report the case of a patient who suffered an isolated gallbladder rupture due to blunt abdominal trauma. PMID:23843066

Management of adult blunt hepatic trauma.

PubMed

Kozar, Rosemary A; McNutt, Michelle K

2010-12-01

To review the nonoperative and operative management of blunt hepatic injury in the adult trauma population. Although liver injury scale does not predict need for surgical intervention, a high-grade complex liver injury should alert the physician to a patient at increased risk of hepatic complications following nonoperative management. Blunt hepatic injury remains a frequent intraabdominal injury in the adult trauma population. The management of blunt hepatic injury has undergone a major paradigm shift from mandatory operative exploration to nonoperative management. Hemodynamic instability with a positive focused abdominal sonography for trauma and peritonitis are indications for emergent operative intervention. Although surgical intervention for blunt hepatic trauma is not as common as in years past, it is imperative that the current trauma surgeon be familiar with the surgical skill set to manage complex hepatic injuries. This study represents a review of both nonoperative and operative management of blunt hepatic injury.

Longitudinal attentional engagement rescues mice from age-related cognitive declines and cognitive inflexibility

PubMed Central

Matzel, Louis D.; Light, Kenneth R.; Wass, Christopher; Colas-Zelin, Danielle; Denman-Brice, Alexander; Waddel, Adam C.; Kolata, Stefan

2011-01-01

Learning, attentional, and perseverative deficits are characteristic of cognitive aging. In this study, genetically diverse CD-1 mice underwent longitudinal training in a task asserted to tax working memory capacity and its dependence on selective attention. Beginning at 3 mo of age, animals were trained for 12 d to perform in a dual radial-arm maze task that required the mice to remember and operate on two sets of overlapping guidance (spatial) cues. As previously reported, this training resulted in an immediate (at 4 mo of age) improvement in the animals' aggregate performance across a battery of five learning tasks. Subsequently, these animals received an additional 3 d of working memory training at 3-wk intervals for 15 mo (totaling 66 training sessions), and at 18 mo of age were assessed on a selective attention task, a second set of learning tasks, and variations of those tasks that required the animals to modify the previously learned response. Both attentional and learning abilities (on passive avoidance, active avoidance, and reinforced alternation tasks) were impaired in aged animals that had not received working memory training. Likewise, these aged animals exhibited consistent deficits when required to modify a previously instantiated learned response (in reinforced alternation, active avoidance, and spatial water maze). In contrast, these attentional, learning, and perseverative deficits were attenuated in aged animals that had undergone lifelong working memory exercise. These results suggest that general impairments of learning, attention, and cognitive flexibility may be mitigated by a cognitive exercise regimen that requires chronic attentional engagement. PMID:21521768

Examination of Cognitive Function During Six Months of Calorie Restriction: Results of a Randomized Controlled Trial

PubMed Central

Martin, Corby K.; Anton, Stephen D.; Han, Hongmei; York-Crowe, Emily; Redman, Leanne M.; Ravussin, Eric; Williamson, Donald A.

2009-01-01

Background Calorie restriction increases longevity in many organisms, and calorie restriction or its mimetic might increase longevity in humans. It is unclear if calorie restriction/dieting contributes to cognitive impairment. During this randomized controlled trial, the effect of 6 months of calorie restriction on cognitive functioning was tested. Methods Participants (n = 48) were randomized to one of four groups: (1) control (weight maintenance), (2) calorie restriction (CR; 25% restriction), (3) CR plus structured exercise (CR + EX, 12.5% restriction plus 12.5% increased energy expenditure via exercise), or (4) low-calorie diet (LCD; 890 kcal/d diet until 15% weight loss, followed by weight maintenance). Cognitive tests (verbal memory, visual memory, attention/concentration) were conducted at baseline and months 3 and 6. Mixed linear models tested if cognitive function changed significantly from baseline to months 3 and 6, and if this change differed by group. Correlation analysis was used to determine if average daily energy deficit (quantified from change in body energy stores) was associated with change in cognitive test performance for the three dieting groups combined. Results No consistent pattern of verbal memory, visual retention/memory, or attention/concentration deficits emerged during the trial. Daily energy deficit was not significantly associated with change in cognitive test performance. Conclusions This randomized controlled trial suggests that calorie restriction/dieting was not associated with a consistent pattern of cognitive impairment. These conclusions must be interpreted in the context of study limitations, namely small sample size and limited statistical power. Previous reports of cognitive impairment might reflect sampling biases or information processing biases. PMID:17518698

Longitudinal attentional engagement rescues mice from age-related cognitive declines and cognitive inflexibility.

PubMed

Matzel, Louis D; Light, Kenneth R; Wass, Christopher; Colas-Zelin, Danielle; Denman-Brice, Alexander; Waddel, Adam C; Kolata, Stefan

2011-01-01

Learning, attentional, and perseverative deficits are characteristic of cognitive aging. In this study, genetically diverse CD-1 mice underwent longitudinal training in a task asserted to tax working memory capacity and its dependence on selective attention. Beginning at 3 mo of age, animals were trained for 12 d to perform in a dual radial-arm maze task that required the mice to remember and operate on two sets of overlapping guidance (spatial) cues. As previously reported, this training resulted in an immediate (at 4 mo of age) improvement in the animals' aggregate performance across a battery of five learning tasks. Subsequently, these animals received an additional 3 d of working memory training at 3-wk intervals for 15 mo (totaling 66 training sessions), and at 18 mo of age were assessed on a selective attention task, a second set of learning tasks, and variations of those tasks that required the animals to modify the previously learned response. Both attentional and learning abilities (on passive avoidance, active avoidance, and reinforced alternation tasks) were impaired in aged animals that had not received working memory training. Likewise, these aged animals exhibited consistent deficits when required to modify a previously instantiated learned response (in reinforced alternation, active avoidance, and spatial water maze). In contrast, these attentional, learning, and perseverative deficits were attenuated in aged animals that had undergone lifelong working memory exercise. These results suggest that general impairments of learning, attention, and cognitive flexibility may be mitigated by a cognitive exercise regimen that requires chronic attentional engagement.

Cognitive Resilience and Psychological Responses across a Collegiate Rowing Season.

PubMed

Shields, Morgan R; Brooks, M Alison; Koltyn, Kelli F; Kim, Jee-Seon; Cook, Dane B

2017-11-01

Student-athletes face numerous challenges across their competitive season. Although mood states have been previously studied, little is known about adaptations in other psychological responses, specifically cognition. The purpose of this study was to characterize cognitive function, mood, sleep, and stress responses at select time points of a season in collegiate rowers. It was hypothesized that during baseline, typical training, and recovery, athletes would show positive mental health profiles, in contrast to decreases in cognition with increases in negative mood and measurements of stress during peak training. Male and female Division I rowers (N = 43) and healthy controls (N = 23) were enrolled and assessed at baseline, typical training, peak training, and recovery. At each time point, measures of cognitive performance (Stroop color-naming task), academic and exercise load, perceived cognitive deficits, mood states, sleep, and stress (via self-report and salivary cortisol) were recorded. Repeated-measures ANOVA revealed significant group-time interactions for perceived exercise load, cognitive deficits, mood states, and perceived stress (P < 0.05). For athletes during peak training, the perception of cognitive deficits was positively correlated with mood disturbance (r = 0.54, P < 0.05) and perceived stress (r = 0.55, P < 0.05) and negatively correlated with response accuracy during incongruent Stroop trials (r = -0.38, P < 0.05). Cognitive performance did not change over the course of the season for either group. Cortisol and sleepiness changed over the course of the season but no significant interactions were observed. These results demonstrate that various psychological responses change over the course of a season, but they also highlight adaptation indicative of cognitive resilience among student-athletes.

Postoperative pain and neuropathy after caesarean operation featuring blunt or sharp opening of the fascia: a randomised, parallel group, double-blind study.

PubMed

Yazici Yilmaz, Fatma; Aydogan Mathyk, Begum; Yildiz, Serhat; Yenigul, Nefise Nazli; Saglam, Ceren

2018-03-21

The purpose of this study was to compare postoperative pain and neuropathy after primary caesarean sections with either blunt or sharp fascial expansions. A total of 123 women undergoing primary caesarean sections were included in the study. The sharp group had 61 patients, and the blunt group had 62. In the sharp group, the fascia was incised sharply and extended using scissors. In blunt group, the fascia was bluntly opened by lateral finger-pulling. The primary outcome was postoperative pain. The long-term chronic pain scores were significantly lower in the blunt group during mobilisation (p = .012 and p = .022). Neuropathy was significantly more prevalent in the sharp group at both 1 and 3 months postoperatively (p = .043 and p = .016, respectively). The odds ratio (OR) and 95%CI for postoperative neuropathy at 1 and 3 months were as follows; OR 3.71, 95%CI 0.97-14.24 and OR 5.67, 95%CI 1.18-27.08, respectively. The OR for postoperative pain after 3 months was 3.26 (95%CI 1.09-9.73). The prevelance of postsurgical neuropathy and chronic pain at 3 months were significantly lower in the blunt group. Blunt fascial opening reduces the complication rate of postoperative pain and neuropathy after caesarean sections. Impact statement What is already known on this subject? The anatomic relationship of the abdominal fascia and the anterior abdominal wall nerves is a known fact. The fascia during caesarean sections can be opened by either a sharp or blunt extension. Data on the isolated impact of different fascial incisions on postoperative pain is limited. What do the results of this study add? The postoperative pain scores on the incision area are lower in the bluntly opened group compared to the sharp fascial incision group. By extending the fascia bluntly, a decrease in trauma and damage to nerves was observed. What are the implications of these findings for clinical practice and/or future research? The lateral extension of the fascia during caesarean sections must be done cautiously to prevent temporary damage to nerves and vessels. The blunt opening of the fascia by lateral finger pulling might be a preferred method over the sharp approach that uses scissors. We included only primary caesarean cases, however, comparisons of blunt and sharp fascial incisions in patients with more than one abdominal surgery should be explored in future studies.

Measurements of Supersonic Wing Tip Vortices

NASA Technical Reports Server (NTRS)

Smart, Michael K.; Kalkhoran, Iraj M.; Benston, James

1994-01-01

An experimental survey of supersonic wing tip vortices has been conducted at Mach 2.5 using small performed 2.25 chords down-stream of a semi-span rectangular wing at angle of attack of 5 and 10 degrees. The main objective of the experiments was to determine the Mach number, flow angularity and total pressure distribution in the core region of supersonic wing tip vortices. A secondary aim was to demonstrate the feasibility of using cone probes calibrated with a numerical flow solver to measure flow characteristics at supersonic speeds. Results showed that the numerically generated calibration curves can be used for 4-hole cone probes, but were not sufficiently accurate for conventional 5-hole probes due to nose bluntness effects. Combination of 4-hole cone probe measurements with independent pitot pressure measurements indicated a significant Mach number and total pressure deficit in the core regions of supersonic wing tip vortices, combined with an asymmetric 'Burger like' swirl distribution.

Management of Sub-axial Cervical Spine Injuries

PubMed Central

Zaveri, Gautam; Das, Gurdip

2017-01-01

Sub-axial cervical spine injuries are commonly seen in patients with blunt trauma. They may be associated with spinal cord injury resulting in tetraplegia and severe permanent disability. Immobilization of the neck, maintenance of blood pressure and oxygenation, rapid clinical and radiological assessment of all injuries, and realignment of the spinal column are the key steps in the emergency management of these injuries. The role of intravenous methylprednisolone administration in acute spinal cord injuries remains controversial. The definitive management of these injuries is based upon recognition of the fracture pattern, assessment of the degree of instability, the presence or absence of neurologic deficit, and other patient related factors that may influence the outcome. Nonoperative treatment comprises of some form of external immobilization for 8 to 12 weeks, followed by imaging to assess fracture healing, and to rule out instability. The goals of surgery are realignment of the vertebral column, decompression of the neural elements and instrumented stabilization. PMID:29200479

Trunk Exercises Improve Gait Symmetry in Parkinson Disease: A Blind Phase II Randomized Controlled Trial.

PubMed

Hubble, Ryan P; Naughton, Geraldine; Silburn, Peter A; Cole, Michael H

2018-03-01

Deficits in step-to-step symmetry and trunk muscle activations have been linked to falls in Parkinson disease. Given such symptoms are poorly managed with anti-parkinsonian medications, alternate therapies are needed. This blind phase II randomized controlled trial sought to establish whether exercise can improve step-to-step symmetry in Parkinson disease. Twenty-four Parkinson disease patients with a falls history completed baseline assessments of symptom severity, balance confidence, mobility, and quality of life. Step-to-step symmetry was assessed by deriving harmonic ratios from three-dimensional accelerations collected for the head and trunk. Patients were randomly assigned to either 12 wks of exercise and falls prevention education or falls prevention education only. Both groups repeated the baseline tests 12 and 24 wks after the initial assessment. The Australian and New Zealand Clinical Trials Registry number is ACTRN12613001175763. At 12 wks, the exercise group had statistically significant and clinically relevant improvements in anterior-posterior step-to-step trunk symmetry. In contrast, the education group recorded statistically significant and clinically meaningful reductions in medial-lateral and vertical step-to-step trunk symmetry at 12 wks. Given that step-to-step symmetry improved for the exercise group and declined for the education group after intervention, active interventions seem more suited to increasing independence and quality of life for people with Parkinson disease. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to do the following: (1) Describe the effect deficits in trunk muscle function have on gait in individuals with Parkinson disease; (2) Identify the benefits of targeted trunk exercises on step-to-step symmetry; and (3) Discuss the benefits of improving step-to-step symmetry in individuals with Parkinson disease. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 0.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Examining the effect of binge eating and disinhibition on compensatory changes in energy balance following exercise among overweight and obese women.

PubMed

Emery, Rebecca L; Levine, Michele D; Jakicic, John M

2016-08-01

Some women behaviorally compensate for the energy expended during exercise by increasing their energy intake or becoming more sedentary, thereby decreasing their energy expenditure. Although behavioral compensation can attenuate or even reverse the energy deficit generated by exercise, few data are available on predictors of compensatory responses to exercise. The present study aimed to identify eating-related predictors of compensatory changes in energy balance following exercise. Overweight and obese, physically inactive women (N=48) completed self-report measures of disinhibition and binge eating and participated in two experimental conditions, exercise and rest, in counterbalanced order. Energy intake and expenditure were measured for 24-hours following each experimental condition to estimate energy balance. On average, women were 21.33±2.09years old and 63% were white. Of the sample, 63% compensated for the energy expended during exercise by increasing their energy intake or decreasing their energy expenditure. Linear mixed effects modeling with repeated measurement showed that disinhibition was not predictive of behavioral compensation. However, there was a significant difference between the negative energy balance observed following the rest condition and the positive energy balance observed following the exercise condition among women who reported binge eating, which was driven by a tendency to spend less time being physically active and more time being sedentary following exercise. These findings indicate that women who binge eat may be at greatest risk of compensating for exercise. Future research is needed to better understand psychosocial predictors and common mechanisms through which behavioral compensation is promoted. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of acute exercise with and without carbohydrate replacement on postprandial lipid metabolism.

PubMed

Harrison, Michael; O'Gorman, Donal J; McCaffrey, Noel; Hamilton, Marc T; Zderic, Theodore W; Carson, Brian P; Moyna, Niall M

2009-03-01

Acute exercise, undertaken on the day before an oral fat tolerance test (OFTT), typically reduces postprandial triglycerides (TG) and increases high-density lipoprotein-cholesterol (HDL-C). However, the benefits of acute exercise may be overstated when studies do not account for compensatory changes in dietary intake. The objective of this study was to determine the influence of acute exercise, with and without carbohydrate (CHO) replacement, on postprandial lipid metabolism. Eight recreationally active young men underwent an OFTT on the morning after three experimental conditions: no exercise [control (Con)], prolonged exercise without CHO replacement (Ex-Def) and prolonged exercise with CHO replacement to restore CHO and energy balance (Ex-Bal). The exercise session in Ex-Def and Ex-Bal consisted of 90 min cycle ergometry at 70% peak oxygen uptake (Vo(2peak)) followed by 10 maximal 1-min sprints. CHO replacement was achieved using glucose solutions consumed at 0, 2, and 4 h postexercise. Muscle glycogen was 40 +/- 4% (P < 0.05) and 94 +/- 3% (P = 0.24) of Con values on the morning of the Ex-Def and Ex-Bal OFTT, respectively. Postprandial TG were 40 +/- 14% lower and postprandial HDL-C, free fatty acids, and 3-hydroxybutyrate were higher in Ex-Def compared with Con (P < 0.05). Most importantly, these exercise effects were not evident in Ex-Bal. Postprandial insulin and glucose and the homeostatic model assessment of insulin resistance (HOMA(IR)) were not significantly different across trials. There was no relation between the changes in postprandial TG and muscle glycogen across trials. In conclusion, the influence of acute exhaustive exercise on postprandial lipid metabolism is largely dependent on the associated CHO and energy deficit.

Aerobic Exercise Improves Cognitive Functioning in People With Schizophrenia: A Systematic Review and Meta-Analysis

PubMed Central

Stubbs, Brendon; Rosenbaum, Simon; Vancampfort, Davy; Malchow, Berend; Schuch, Felipe; Elliott, Rebecca; Nuechterlein, Keith H.; Yung, Alison R.

2017-01-01

Abstract Cognitive deficits are pervasive among people with schizophrenia and treatment options are limited. There has been an increased interest in the neurocognitive benefits of exercise, but a comprehensive evaluation of studies to date is lacking. We therefore conducted a meta-analysis of all controlled trials investigating the cognitive outcomes of exercise interventions in schizophrenia. Studies were identified from a systematic search across major electronic databases from inception to April 2016. Meta-analyses were used to calculate pooled effect sizes (Hedges g) and 95% CIs. We identified 10 eligible trials with cognitive outcome data for 385 patients with schizophrenia. Exercise significantly improved global cognition (g = 0.33, 95% CI = 0.13–0.53, P = .001) with no statistical heterogeneity (I2 = 0%). The effect size in the 7 studies which were randomized controlled trials was g = 0.43 (P < .001). Meta-regression analyses indicated that greater amounts of exercise are associated with larger improvements in global cognition (β = .005, P = .065). Interventions which were supervised by physical activity professionals were also more effective (g = 0.47, P < .001). Exercise significantly improved the cognitive domains of working memory (g = 0.39, P = .024, N = 7, n = 282), social cognition (g = 0.71, P = .002, N = 3, n = 81), and attention/vigilance (g = 0.66, P = .005, N = 3, n = 104). Effects on processing speed, verbal memory, visual memory and reasoning and problem solving were not significant. This meta-analysis provides evidence that exercise can improve cognitive functioning among people with schizophrenia, particularly from interventions using higher dosages of exercise. Given the challenges in improving cognition, and the wider health benefits of exercise, a greater focus on providing supervised exercise to people with schizophrenia is needed. PMID:27521348

On sweat analysis for quantitative estimation of dehydration during physical exercise.

PubMed

Ring, Matthias; Lohmueller, Clemens; Rauh, Manfred; Eskofier, Bjoern M

2015-08-01

Quantitative estimation of water loss during physical exercise is of importance because dehydration can impair both muscular strength and aerobic endurance. A physiological indicator for deficit of total body water (TBW) might be the concentration of electrolytes in sweat. It has been shown that concentrations differ after physical exercise depending on whether water loss was replaced by fluid intake or not. However, to the best of our knowledge, this fact has not been examined for its potential to quantitatively estimate TBW loss. Therefore, we conducted a study in which sweat samples were collected continuously during two hours of physical exercise without fluid intake. A statistical analysis of these sweat samples revealed significant correlations between chloride concentration in sweat and TBW loss (r = 0.41, p <; 0.01), and between sweat osmolality and TBW loss (r = 0.43, p <; 0.01). A quantitative estimation of TBW loss resulted in a mean absolute error of 0.49 l per estimation. Although the precision has to be improved for practical applications, the present results suggest that TBW loss estimation could be realizable using sweat samples.

Benefits of physical exercise training on cognition and quality of life in frail older adults.

PubMed

Langlois, Francis; Vu, Thien Tuong Minh; Chassé, Kathleen; Dupuis, Gilles; Kergoat, Marie-Jeanne; Bherer, Louis

2013-05-01

Frailty is a state of vulnerability associated with increased risks of fall, hospitalization, cognitive deficits, and psychological distress. Studies with healthy senior suggest that physical exercise can help improve cognition and quality of life. Whether frail older adults can show such benefits remains to be documented. A total of 83 participants aged 61-89 years were assigned to an exercise-training group (3 times a week for 12 weeks) or a control group (waiting list). Frailty was determined by a complete geriatric examination using specific criteria. Pre- and post-test measures assessed physical capacity, cognitive performance, and quality of life. Compared with controls, the intervention group showed significant improvement in physical capacity (functional capacities and physical endurance), cognitive performance (executive functions, processing speed, and working memory), and quality of life (global quality of life, leisure activities, physical capacity, social/family relationships, and physical health). Benefits were overall equivalent between frail and nonfrail participants. Physical exercise training leads to improved cognitive functioning and psychological well-being in frail older adults.

A hybrid CFD/characteristics method for fast characterization of hypersonic blunt forebody/inlet flow

NASA Astrophysics Data System (ADS)

Gao, WenZhi; Li, ZhuFei; Yang, JiMing

2015-10-01

A hybrid CFD/characteristic method (CCM) was proposed for fast design and evaluation of hypersonic inlet flow with nose bluntness, which targets the combined advantages of CFD and method of characteristics. Both the accuracy and efficiency of the developed CCM were verified reliably, and it was well demonstrated for the external surfaces design of a hypersonic forebody/inlet with nose bluntness. With the help of CCM method, effects of nose bluntness on forebody shock shapes and the flowfield qualities which dominate inlet performance were examined and analyzed on the two-dimensional and axisymmetric configurations. The results showed that blunt effects of a wedge forebody are more substantial than that of related cone cases. For a conical forebody with a properly blunted nose, a recovery of the shock front back to that of corresponding sharp nose is exhibited, accompanied with a gradually fading out of entropy layer effects. Consequently a simplification is thought to be reasonable for an axisymmetric inlet with a proper compression angle, and a blunt nose of limited radius can be idealized as a sharp nose, as the spillage and flow variations at the entrance are negligible, even though the nose scale increases to 10% cowl lip radius. Whereas for two-dimensional inlets, the blunt effects are substantial since not only the inlet capturing/starting capabilities, but also the flow uniformities are obviously degraded.

One bout of open skill exercise improves cross-modal perception and immediate memory in healthy older adults who habitually exercise.

PubMed

O'Brien, Jessica; Ottoboni, Giovanni; Tessari, Alessia; Setti, Annalisa

2017-01-01

One single bout of exercise can be associated with positive effects on cognition, due to physiological changes associated with muscular activity, increased arousal, and training of cognitive skills during exercise. While the positive effects of life-long physical activity on cognitive ageing are well demonstrated, it is not well established whether one bout of exercise is sufficient to register such benefits in older adults. The aim of this study was to test the effect of one bout of exercise on two cognitive processes essential to daily life and known to decline with ageing: audio-visual perception and immediate memory. Fifty-eight older adults took part in a quasi-experimental design study and were divided into three groups based on their habitual activity (open skill exercise (mean age = 69.65, SD = 5.64), closed skill exercise, N = 18, 94% female; sedentary activity-control group, N = 21, 62% female). They were then tested before and after their activity (duration between 60 and 80 minutes). Results showed improvement in sensitivity in audio-visual perception in the open skill group and improvements in one of the measures of immediate memory in both exercise groups, after controlling for baseline differences including global cognition and health. These findings indicate that immediate benefits for cross-modal perception and memory can be obtained after open skill exercise. However, improvements after closed skill exercise may be limited to memory benefits. Perceptual benefits are likely to be associated with arousal, while memory benefits may be due to the training effects provided by task requirements during exercise. The respective role of qualitative and quantitative differences between these activities in terms of immediate cognitive benefits should be further investigated. Importantly, the present results present the first evidence for a modulation of cross-modal perception by exercise, providing a plausible avenue for rehabilitation of cross-modal perception deficits, which are emerging as a significant contributor to functional decline in ageing.

Cervical spine injuries in civilian victims of explosions: Should cervical collars be used?

PubMed

Klein, Yoram; Arieli, Izhar; Sagiv, Shaul; Peleg, Kobi; Ben-Galim, Peleg

2016-06-01

Semirigid cervical collars (SRCCs) are routinely applied to victims of explosions as part of the prehospital trauma protocols. Previous studies have shown that the use of SRCC in penetrating injuries is not justified because of the scarcity of unstable cervical spine injuries and the risk of obscuring other neck injuries. Explosion can inflict injuries by fragments penetration, blast injury, blunt force, and burns. The purpose of the study was to determine the occurrence of cervical spine instability without irreversible neurologic deficit and other potentially life-threatening nonskeletal neck injuries among victims of explosions. The potential benefits and risks of SRCC application in explosion-related injuries were evaluated. This is a retrospective cohort study of all explosion civilian victims admitted to Israeli hospitals during the years 1998 to 2010. Data collection was based on the Israeli national trauma registry and the hospital records and included demographic, clinical, and radiologic details of all patients with documented cervical spine injuries. The cohort included 2,267 patients. All of them were secondary to terrorist attacks. SRCC was applied to all the patients at the scene. Nineteen patients (0.83%) had cervical spine fractures. Nine patients (0.088%) had unstable cervical spine injury. All but one had irreversible neurologic deficit on admission. A total of 151 patients (6.6%) had potentially life-threatening penetrating nonskeletal neck injuries. Unstable cervical spine injuries secondary to explosion are extremely rare. The majority of unstable cervical spine fractures were secondary to penetrating injuries, with irreversible neurologic deficits on admission. The application of SRCC did not seem to be of any benefit in these patients and might pose a risk of obscuring other neck injuries. We recommend that SRCC will not be used in the prehospital management of victims of explosions. Prognostic/epidemiologic study, level III.

Lifelong disturbance of serotonin transporter functioning results in fear learning deficits: Reversal by blockade of CRF1 receptors.

PubMed

Bijlsma, Elisabeth Y; Hendriksen, Hendrikus; Baas, Johanna M P; Millan, Mark J; Groenink, Lucianne

2015-10-01

The inability to associate aversive events with relevant cues (i.e. fear learning) may lead to maladaptive anxiety. To further study the role of the serotonin transporter (SERT) in fear learning, classical fear conditioning was studied in SERT knockout rats (SERT(-/-)) using fear potentiation of the startle reflex. Next, fear acquisition and concomitant development of contextual conditioned fear were monitored during training. To differentiate between developmental and direct effects of reduced SERT functioning, effects of acute and chronic SSRI treatment were studied in adult rats. Considering the known interactions between serotonin and corticotropin-releasing factor (CRF), we studied the effect of the CRFR1 antagonist CP154,526 on behavioral changes observed and determined CRF1 receptor levels in SERT(-/-) rats. SERT(-/-) showed blunted fear potentiation and enhanced contextual fear, which resulted from a deficit in fear acquisition. Paroxetine treatment did not affect acquisition or expression of fear-potentiated startle, suggesting that disturbed fear learning in SERT(-/-) results from developmental changes and not from reduced SERT functioning. Although CRF1 receptor levels did not differ significantly between genotypes, CP154,526 treatment normalized both cue- and contextual fear in SERT(-/-) during acquisition, but not expression of fear-potentiated startle. The disrupted fear acquisition and concomitant increase in contextual conditioned fear-potentiated startle fear in SERT(-/-) resembles the associative learning deficit seen in patients with panic disorder and suggests that normal SERT functioning is crucial for the development of an adequate fear neuro-circuitry. Moreover, the normalization of fear acquisition by CP154,526 suggests a role for central CRF signaling in the generalization of fear. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

Molecular mechanisms mediating a deficit in recall of fear extinction in adult mice exposed to cocaine in utero.

PubMed

Kabir, Zeeba D; Katzman, Aaron C; Kosofsky, Barry E

2013-01-01

Prenatal cocaine exposure has been shown to alter cognitive processes of exposed individuals, presumed to be a result of long-lasting molecular alterations in the brain. In adult prenatal cocaine exposed (PCOC) mice we have identified a deficit in recall of fear extinction, a behavior that is dependent on the medial prefrontal cortex (mPFC) and the hippocampus. While we observed no change in the constitutive expression of brain derived neurotrophic factor (BDNF) protein and mRNA in the mPFC and hippocampus of adult PCOC mice, we observed blunted BDNF signaling in the mPFC of adult PCOC mice after fear extinction compared to the control animals. Specifically, during the consolidation phase of the extinction memory, we observed a decrease in BDNF protein and it's phospho-TrkB receptor expression. Interestingly, at this same time point there was a significant increase in total Bdnf mRNA levels in the mPFC of PCOC mice as compared with controls. In the Bdnf gene, we identified decreased constitutive binding of the transcription factors, MeCP2 and P-CREB at the promoters of Bdnf exons I and IV in the mPFC of PCOC mice, that unlike control mice remained unchanged when measured during the behavior. Finally, bilateral infusion of recombinant BDNF protein into the infralimbic subdivision of the mPFC during the consolidation phase of the extinction memory rescued the behavioral deficit in PCOC mice. In conclusion, these findings extend our knowledge of the neurobiologic impact of prenatal cocaine exposure on the mPFC of mice, which may lead to improved clinical recognition and treatment of exposed individuals.

Blunted brain activation in patients with schizophrenia in response to emotional cognitive inhibition: a functional near-infrared spectroscopy study.

PubMed

Egashira, Kazuteru; Matsuo, Koji; Nakashima, Mami; Watanuki, Toshio; Harada, Kenichiro; Nakano, Masayuki; Matsubara, Toshio; Takahashi, Kanji; Watanabe, Yoshifumi

2015-03-01

Patients with schizophrenia (SZ) have deficits of facial emotion processing and cognitive inhibition, but the brain pathophysiology underlying these deficits and their interaction are not clearly understood. We tested brain activity during an emotional face go/no-go task that requires rapid executive control affected by emotional stimuli in patients with SZ using functional near-infrared spectroscopy (fNIRS). Twenty-five patients with SZ and 28 healthy control subjects were studied. We evaluated behavioral performance and used fNIRS to measure oxygenated hemoglobin concentration changes in fronto-temporal areas during the emotional go/no-go task with emotional and non-emotional blocks. Patients with SZ made more errors and had longer reaction times in both test blocks compared with healthy subjects. Significantly greater activation in the inferior, superior, middle, and orbital frontal regions were observed in healthy subjects during the emotional go/no-go block compared to the non-emotional go/no-go block, but this difference was not observed in patients with SZ. Relative to healthy subjects, patients with SZ showed less activation in the superior and orbital frontal and middle temporal regions during the emotional go/no-go block. Our results suggest that fronto-temporal dysfunction in patients with SZ is due to an interaction between abnormal processing of emotional facial expressions with negative valence and cognitive inhibition, especially during the rapid selection of rule-based associations that override automatic emotional response tendencies. They indicate that fronto-temporal dysfunction is involved in the pathophysiology of emotional-cognitive deficits in patients with SZ. Copyright © 2015 Elsevier B.V. All rights reserved.

Cardiovascular responses to static exercise in conscious cats: effects of intracerebroventricular injection of clonidine.

PubMed Central

Ally, A; Hand, G A; Mitchell, J H

1996-01-01

1. Static exercise elicits increases in arterial blood pressure and heart rate (HR) in humans and conscious animals. In this study, the effects of intracerebroventricular (I.C.V.) administration of clonidine, an alpha 2-adrenergic agonist, on these cardiovascular responses were investigated using conscious cats. Four cats were operantly trained to extend a forelimb and press a bar (200-650 g) for 15-60 s. A stainless-steel cannula was inserted into the right lateral ventricle for I.C.V. injection of drugs, and a common carotid artery was catheterized to measure mean arterial pressure (MAP) and HR. The number of exercise trials and changes in MAP, HR and force were pooled for 30 min periods. After the cats exercised for 30 min, either artificial cerebrospinal fluid (CSF) or clonidine (2 or 5 micrograms) were administered intracerebroventricularly. 2. Before clonidine injection, fifty-two exercise trials increased MAP and HR by 15 +/- 3 mmHg and 41 +/- 5 beats min-1, respectively. Administration of clonidine (2 micrograms) did not alter the resting MAP and HR, but attenuated the increases in MAP and HR in response to exercise (0-30 min post-clonidine: n = 81; delta MAP, 6 +/- 3 mmHg; delta HR, 20 +/- 6 beats min-1; 30-60 min post-clonidine: n = 71; delta MAP, 4 +/- 4 mmHg; delta HR, 17 +/- 8 beats min-1). Administration of artificial CSF I.C.V. had no effect on the cardiovascular responses to static exercise. 3. An increased dose of clonidine (5 micrograms) decreased resting MAP and HR by 31 +/- 7 mmHg and 37 +/- 7 beats min-1, respectively, and markedly blunted the cardiovascular responses to exercise (pre-clonidine: n = 52; delta MAP, 17 +/- 3 mmHg; delta HR, 38 +/- 5 beats min-1; post-clonidine 0-30 min: n = 66; delta MAP, 4 +/- 2 mmHg; delta HR, 15 +/- 5 beats min-1; post-clonidine 30-60 min: n = 60; delta MAP, 4 +/- 2 mmHg; delta HR, 14 +/- 6 beats min-1). Pretreatment with the alpha 2-adrenergic antagonist, yohimbine (8 micrograms, I.C.V.), blocked the attenuating effects of I.C.V. administration of clonidine (5 micrograms). 4. These results show that stimulation of central alpha 2-adrenoceptors by clonidine attenuates the cardiovascular responses to static exercise in conscious cats. In addition, this study suggests that alpha 2-adrenoceptors blocked by yohimbine injected I.C.V. do not appear to have a tonic influence on HR and blood pressure. PMID:8866875

Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training

PubMed Central

Roberts, Llion A; Raastad, Truls; Markworth, James F; Figueiredo, Vandre C; Egner, Ingrid M; Shield, Anthony; Cameron-Smith, David; Coombes, Jeff S; Peake, Jonathan M

2015-01-01

Abstract We investigated functional, morphological and molecular adaptations to strength training exercise and cold water immersion (CWI) through two separate studies. In one study, 21 physically active men strength trained for 12 weeks (2 days per week), with either 10 min of CWI or active recovery (ACT) after each training session. Strength and muscle mass increased more in the ACT group than in the CWI group (P < 0.05). Isokinetic work (19%), type II muscle fibre cross-sectional area (17%) and the number of myonuclei per fibre (26%) increased in the ACT group (all P < 0.05), but not the CWI group. In another study, nine active men performed a bout of single-leg strength exercises on separate days, followed by CWI or ACT. Muscle biopsies were collected before and 2, 24 and 48 h after exercise. The number of satellite cells expressing neural cell adhesion molecule (NCAM) (10−30%) and paired box protein (Pax7) (20−50%) increased 24–48 h after exercise with ACT. The number of NCAM+ satellite cells increased 48 h after exercise with CWI. NCAM+- and Pax7+-positive satellite cell numbers were greater after ACT than after CWI (P < 0.05). Phosphorylation of p70S6 kinaseThr421/Ser424 increased after exercise in both conditions but was greater after ACT (P < 0.05). These data suggest that CWI attenuates the acute changes in satellite cell numbers and activity of kinases that regulate muscle hypertrophy, which may translate to smaller long-term training gains in muscle strength and hypertrophy. The use of CWI as a regular post-exercise recovery strategy should be reconsidered. Key points Cold water immersion is a popular strategy to recover from exercise. However, whether regular cold water immersion influences muscle adaptations to strength training is not well understood. We compared the effects of cold water immersion and active recovery on changes in muscle mass and strength after 12 weeks of strength training. We also examined the effects of these two treatments on hypertrophy signalling pathways and satellite cell activity in skeletal muscle after acute strength exercise. Cold water immersion attenuated long term gains in muscle mass and strength. It also blunted the activation of key proteins and satellite cells in skeletal muscle up to 2 days after strength exercise. Individuals who use strength training to improve athletic performance, recover from injury or maintain their health should therefore reconsider whether to use cold water immersion as an adjuvant to their training. PMID:26174323

Does power indicate capacity? 30-s Wingate anaerobic test vs. maximal accumulated O2 deficit.

PubMed

Minahan, C; Chia, M; Inbar, O

2007-10-01

The purpose of this study was to evaluate the relationship between anaerobic power and capacity. Seven men and seven women performed a 30-s Wingate Anaerobic Test on a cycle ergometer to determine peak power, mean power, and the fatigue index. Subjects also cycled at a work rate predicted to elicit 120 % of peak oxygen uptake to exhaustion to determine the maximal accumulated O (2) deficit. Peak power and the maximal accumulated O (2) deficit were significantly correlated (r = 0.782, p = 0.001). However, when the absolute difference in exercise values between groups (men and women) was held constant using a partial correlation, the relationship diminished (r = 0.531, p = 0.062). In contrast, we observed a significant correlation between fatigue index and the maximal accumulated O (2) deficit when controlling for gender (r = - 0.597, p = 0.024) and the relationship remained significant when values were expressed relative to active muscle mass. A higher anaerobic power does not indicate a greater anaerobic capacity. Furthermore, we suggest that the ability to maintain power output during a 30-s cycle sprint is related to anaerobic capacity.

Reassessment of Self-Reported Behavioral Health Habits and Other Issues Among Distributed Common Ground System Intelligence Operators and Non-Combatant Support Personnel

DTIC Science & Technology

2017-10-28

9 4.2 Sleep and Physical Exercise Health Behaviors...excess caffeine, nicotine, and alcohol use, and a deficit in physical fitness activity can further contribute to reduction in overall health . Since...to address key physical and psychological health concerns and to promote resiliency among their designated remote warrior workforces. The purpose

The Effectiveness of Exercise Intervention on Inhibitory Control in Children with Developmental Coordination Disorder: Using a Visuospatial Attention Paradigm as a Model

ERIC Educational Resources Information Center

Tsai, Chia-Liang

2009-01-01

Children with developmental coordination disorder (DCD) have been demonstrated to show a deficit of inhibitory control in volitional shifts of attention. The aim of this study was to use ecological intervention to investigate the efficacy of table-tennis training on treating both problems with attentional networks and motor disorder in children…

Time-dependent solution for axisymmetric flow over a blunt body with ideal gas, CF4, or equilibrium air chemistry

NASA Technical Reports Server (NTRS)

Hamilton, H. H., II; Spall, J. R.

1986-01-01

A time-asymptotic method has been used to obtain steady-flow solutions for axisymmetric inviscid flow over several blunt bodies including spheres, paraboloids, ellipsoids, and spherically blunted cones. Comparisons with experimental data and results of other computational methods have demonstrated that accurate solutions can be obtained using this approach. The method should prove useful as an analysis tool for comparing with experimental data and for making engineering calculations for blunt reentry vehicles.

Time-dependent solution for axisymmetric flow over a blunt body with ideal gas, CF4, or equilibrium air chemistry

NASA Astrophysics Data System (ADS)

Hamilton, H. H., II; Spall, J. R.

1986-07-01

A time-asymptotic method has been used to obtain steady-flow solutions for axisymmetric inviscid flow over several blunt bodies including spheres, paraboloids, ellipsoids, and spherically blunted cones. Comparisons with experimental data and results of other computational methods have demonstrated that accurate solutions can be obtained using this approach. The method should prove useful as an analysis tool for comparing with experimental data and for making engineering calculations for blunt reentry vehicles.

Cervical spine immobilization following blunt trauma: a systematic review of recent literature and proposed treatment algorithm.

PubMed

Lukins, Timothy R; Ferch, Richard; Balogh, Zsolt J; Hansen, Mitchell A

2015-12-01

Management of the cervical spine following blunt trauma is commonplace. In 2013, the American Association of Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS) published practice guidelines drawn from evidence dating to 2011. Since then, further publications have emerged that are reviewed, and a simple management algorithm produced to assist practitioners in Australian trauma centres. These publications attempt to shed light on two controversial scenarios, those being the management of symptomatic patients with negative computed tomography (CT) and management of the obtunded patient. The search strategy mirrored that of the AANS/CNS guidelines. A search of the National Library of Medicine (PubMed) database for manuscripts published between January 2011 and October 2014 was conducted. One reviewer extracted data from studies assessing the performance of various imaging modalities in identifying traumatic cervical spine injuries. In clinical scenarios where little evidence has emerged since the AANS/CNS guidelines, key manuscripts published prior to 2011 were identified from bibliographies. Awake, asymptomatic patients may be 'cleared' without further imaging. Awake, symptomatic patients without pathology on CT and without neurological deficit can safely be 'cleared' without magnetic resonance imaging. There is no longer a role for flexion-extension films. In the obtunded patient, findings remain conflicting. Several of these findings represent a departure from previous practices, including clearance of patients with non-neurological symptoms on the basis of CT and the exclusion of flexion-extension film in detecting injury. Management of the obtunded patient remains controversial. © 2015 Royal Australasian College of Surgeons.

Regulating task-monitoring systems in response to variable reward contingencies and outcomes in cocaine addicts.

PubMed

Morie, Kristen P; De Sanctis, Pierfilippo; Garavan, Hugh; Foxe, John J

2016-03-01

We investigated anticipatory and consummatory reward processing in cocaine addiction. In addition, we set out to assess whether task-monitoring systems were appropriately recalibrated in light of variable reward schedules. We also examined neural measures of task-monitoring and reward processing as a function of hedonic tone, since anhedonia is a vulnerability marker for addiction that is obviously germane in the context of reward processing. High-density event-related potentials were recorded while participants performed a speeded response task that systematically varied anticipated probabilities of reward receipt. The paradigm dissociated feedback regarding task success (or failure) from feedback regarding the value of reward (or loss), so that task-monitoring and reward processing could be examined in partial isolation. Twenty-three active cocaine abusers and 23 age-matched healthy controls participated. Cocaine abusers showed amplified anticipatory responses to reward predictive cues, but crucially, these responses were not as strongly modulated by reward probability as in controls. Cocaine users also showed blunted responses to feedback about task success or failure and did not use this information to update predictions about reward. In turn, they showed clearly blunted responses to reward feedback. In controls and users, measures of anhedonia were associated with reward motivation. In cocaine users, anhedonia was also associated with diminished monitoring and reward feedback responses. Findings imply that reward anticipation and monitoring deficiencies in addiction are associated with increased responsiveness to reward cues but impaired ability to predict reward in light of task contingencies, compounded by deficits in responding to actual reward outcomes.

CT Appearance of Traumatic Inferior Vena Cava Injury.

PubMed

Tsai, Richard; Raptis, Constantine; Schuerer, Douglas J; Mellnick, Vincent M

2016-07-19

CT plays a crucial role in the evaluation of stable patients with blunt and penetrating trauma in the emergency department. Among the more severe injuries that may occur in penetrating and blunt trauma are those to the inferior vena cava (IVC). The purpose of this study was to evaluate and differentiate the CT findings associated with penetrating versus blunt trauma to the IVC to aid the radiologist in diagnosing IVC injuries. Cases of blunt and penetrating IVC injury were retrospectively identified using search queries. Criteria for inclusion were preoperative contrast-enhanced CT and surgically confirmed caval injury or direct findings of caval injury on CT with patient death before surgical confirmation could be obtained. Twelve cases of traumatic IVC injury were identified over a 9-year period: six blunt and six penetrating. The most common finding was a retroperitoneal hematoma, seen in 75% of cases. Eighty-three percent of blunt injuries were associated with hepatic lacerations and contrast material extravasation. Thirty-three percent of penetrating IVC injuries were associated with extravasation. Contour abnormalities were seen in 50% of blunt and 17% of penetrating injuries to the IVC. All three cases of IVC injury resulting in mortality occurred in the retrohepatic segment. Injury to the IVC is frequently fatal in patients with penetrating or blunt trauma. The CT appearance of IVC injury is dichotomous between the two causes, with blunt IVC injury more likely to show extravasation, contour abnormality, and associated hepatic laceration. Injury of the retrohepatic IVC portends a poor outcome. With the continued use of CT for evaluation of trauma patients, the radiologist should be familiar with IVC injury and its different CT appearances.