Human skeletal muscle mitochondrial capacity.

PubMed

Rasmussen, U F; Rasmussen, H N

2000-04-01

Under aerobic work, the oxygen consumption and major ATP production occur in the mitochondria and it is therefore a relevant question whether the in vivo rates can be accounted for by mitochondrial capacities measured in vitro. Mitochondria were isolated from human quadriceps muscle biopsies in yields of approximately 45%. The tissue content of total creatine, mitochondrial protein and different cytochromes was estimated. A number of activities were measured in functional assays of the mitochondria: pyruvate, ketoglutarate, glutamate and succinate dehydrogenases, palmitoyl-carnitine respiration, cytochrome oxidase, the respiratory chain and the ATP synthesis. The activities involved in carbohydrate oxidation could account for in vivo oxygen uptakes of 15-16 mmol O2 min-1 kg-1 or slightly above the value measured at maximal work rates in the knee-extensor model of Saltin and co-workers, i.e. without limitation from the cardiac output. This probably indicates that the maximal oxygen consumption of the muscle is limited by the mitochondrial capacities. The in vitro activities of fatty acid oxidation corresponded to only 39% of those of carbohydrate oxidation. The maximal rate of free energy production from aerobic metabolism of glycogen was calculated from the mitochondrial activities and estimates of the DeltaG or ATP hydrolysis and the efficiency of the actin-myosin reaction. The resultant value was 20 W kg-1 or approximately 70% of the maximal in vivo work rates of which 10-20% probably are sustained by the anaerobic ATP production. The lack of aerobic in vitro ATP synthesis might reflect termination of some critical interplay between cytoplasm and mitochondria.

Effects of N-acetylcysteine on isolated skeletal muscle contractile properties after an acute bout of aerobic exercise.

PubMed

Jannig, Paulo R; Alves, Christiano R R; Voltarelli, Vanessa A; Bozi, Luiz H M; Vieira, Janaina S; Brum, Patricia C; Bechara, Luiz R G

2017-12-15

The current study tested the hypotheses that 1) an acute bout of aerobic exercise impairs isolated skeletal muscle contractile properties and 2) N-acetylcysteine (a thiol antioxidant; NAC) administration can restore the impaired muscle contractility after exercise. At rest or immediately after an acute bout of aerobic exercise, extensor digitorum longus (EDL) and soleus muscles from male Wistar rats were harvested for ex vivo skeletal muscle contraction experiments. Muscles from exercised animals were incubated in Krebs Ringer's buffer in absence or presence of 20mM of NAC. Force capacity and fatigue properties were evaluated. Exercised EDL and soleus displayed lower force production across various stimulation frequencies (p<0.001), indicating that skeletal muscle force production was impaired after an acute bout of exercise. However, NAC treatment restored the loss of force production in both EDL and soleus after fatiguing exercise (p<0.05). Additionally, NAC treatment increased relative force production at different time points during a fatigue-induced protocol, suggesting that NAC treatment mitigates fatigue induced by successive contractions. NAC treatment improves force capacity and fatigue properties in ex vivo skeletal muscle from rats submitted to an acute bout of aerobic exercise. Copyright © 2017 Elsevier Inc. All rights reserved.

Relationships between body fat accumulation, aerobic capacity and insulin resistance in Japanese participants.

PubMed

Yoshimura, Eiichi; Kumahara, Hideaki; Tobina, Takuro; Ayabe, Makoto; Matono, Sakiko; Anzai, Keizo; Higaki, Yasuki; Kiyonaga, Akira; Tanaka, Hiroaki

2011-01-01

This study evaluated the relationships between body fat accumulation, aerobic capacity and insulin resistance (HOMA-IR) in 61 Japanese participants. The participants were middle-aged to elderly (age: 33-73; BMI: 21.6-38.5). Body fat mass (FM) was evaluated by hydrostatic weighing. Computed tomography was used to evaluate visceral and subcutaneous fat areas (VFA and SFA), liver to spleen ratio (L/S), and low-density muscle area (LDMA). To assess aerobic capacity, VO2 at the lactate threshold (VO2@LT) and VO2 peak were measured using a bicycle ergometer. FM, VFA, SFA, LDMA and L/S significantly correlated with HOMA-IR, but VO2@LT and VO2 peak did not. Analysis of covariance after adjustment for VFA or other body fat distribution and aerobic capacity showed that HOMA-IR had a significant linear trend across the tertile groups of L/S. However, for FM, VFA, SFA, LDMA and VO2@LT or VO2 peak, no significant trend was observed between the tertiles and insulin resistance. Ectopic fat deposition in the liver may influence insulin resistance independently of other body fat accumulation and aerobic capacity in Japanese participants. © 2011 Asian Oceanian Association for the Study of Obesity . Published by Elsevier Ltd. All rights reserved.

Lower extremity muscle size and strength and aerobic capacity decrease with caloric restriction but not with exercise-induced weight loss

PubMed Central

Weiss, Edward P.; Racette, Susan B.; Villareal, Dennis T.; Fontana, Luigi; Steger-May, Karen; Schechtman, Kenneth B.; Klein, Samuel; Ehsani, Ali A.; Holloszy, John O.

2015-01-01

Caloric restriction (CR) results in fat loss; however, it may also result in loss of muscle and thereby reduce strength and aerobic capacity (V̇O2 max). These effects may not occur with exercise-induced weight loss (EX) because of the anabolic effects of exercise on heart and skeletal muscle. We tested the hypothesis that CR reduces muscle size and strength and V̇O2 max, whereas EX preserves or improves these parameters. Healthy 50- to 60-yr-old men and women (body mass index of 23.5–29.9 kg/m2) were studied before and after 12 mo of weight loss by CR (n = 18) or EX (n = 16). Lean mass was assessed by dual-energy X-ray absorptiometry, thigh muscle volume by MRI, isometric and isokinetic knee flexor strength by dynamometry, and treadmill V̇O2 max by indirect calorimetry. Both interventions caused significant decreases in body weight (CR: −10.7 ± 1.4%, EX: −9.5 ± 1.5%) and lean mass (CR: −3.5 ± 0.7%, EX: −2.2 ± 0.8%), with no significant differences between groups. Significant decreases in thigh muscle volume (−6.9 ± 0.8%) and composite knee flexion strength (−7.2 ± 3%) occurred in the CR group only. Absolute V̇O2 max decreased significantly in the CR group (−6.8 ± 2.3%), whereas the EX group had significant increases in both absolute (+15.5 ± 2.4%) and relative (+28.3 ± 3.0%) V̇O2 max. These data provide evidence that muscle mass and absolute physical work capacity decrease in response to 12 mo of CR but not in response to a similar weight loss induced by exercise. These findings suggest that, during EX, the body adapts to maintain or even enhance physical performance capacity. PMID:17095635

Low-intensity aerobic exercise training: inhibition of skeletal muscle atrophy in high-fat-diet-induced ovariectomized rats.

PubMed

Kim, Hye Jin; Lee, Won Jun

2017-09-30

Postmenopausal women are highly susceptible to diseases, such as obesity, type 2 diabetes, osteoporosis, or skeletal muscle atrophy and many people recognize the need for regular physical activity. Aerobic exercise training is known to improve the oxidative capacity and insulin sensitivity of skeletal muscles. This study aimed to investigate the role of low-intensity aerobic exercise training on skeletal muscle protein degradation or synthesis in the plantaris muscles of high-fat-fed ovariectomized rats. Ovariectomized female rats were divided into two groups: a high-fat diet-sedentary group (HFD), and a high-fat diet-aerobic exercise group (HFD+EX). The exercise group exercised aerobically on a treadmill 5 days/week for 8 weeks. The rats progressively ran 30 min/day at 15 m/min, up to 40 min/day at 18 m/min, 0% slope, in the last 4 weeks. Although aerobic exercise led to significantly increased AMP-activated protein kinase (AMPK) phosphorylation at Thr172, phosphorylation of the mammalian target of rapamycin (mTOR) substrate Thr389 S6K1 level did not decrease. Additionally, even though Akt activity did not increase at Ser473, the atrogin-1 level significantly decreased in the exercise group compared to the non-exercise group. Immunohistochemical staining revealed that high-fat-induced TSC2 protein expression was eliminated in response to aerobic exercise. These results suggest that aerobic exercise can inhibit skeletal muscle protein degradation, but it cannot increase protein synthesis in the plantaris muscle of high-fat-fed ovariectomized rats. Our findings have implications in understanding skeletal muscle mass maintenance with low intensity aerobic exercise in post-menopausal women. ©2017 The Korean Society for Exercise Nutrition

Intrinsic aerobic capacity correlates with greater inherent mitochondrial oxidative and H2O2 emission capacities without major shifts in myosin heavy chain isoform

PubMed Central

Seifert, Erin L.; Bastianelli, Mark; Aguer, Céline; Moffat, Cynthia; Estey, Carmen; Koch, Lauren G.; Britton, Steven L.

2012-01-01

Exercise capacity and performance strongly associate with metabolic and biophysical characteristics of skeletal muscle, factors that also relate to overall disease risk. Despite its importance, the exact mechanistic features that connect aerobic metabolism with health status are unknown. To explore this, we applied artificial selection of rats for intrinsic (i.e., untrained) aerobic treadmill running to generate strains of low- and high-capacity runners (LCR and HCR, respectively), subsequently shown to diverge for disease risk. Concurrent breeding of LCR and HCR per generation allows the lines to serve as reciprocal controls for unknown environmental changes. Here we provide the first direct evidence in mitochondria isolated from skeletal muscle that intrinsic mitochondrial capacity is higher in HCR rats. Maximal phosphorylating respiration was ∼40% greater in HCR mitochondria, independent of substrate and without altered proton leak or major changes in protein levels or muscle fiber type, consistent with altered control of phosphorylating respiration. Unexpectedly, H2O2 emission was ∼20% higher in HCR mitochondria, due to greater reduction of more harmful reactive oxygen species to H2O2; indeed, oxidative modification of mitochondrial proteins was lower. When the higher mitochondrial yield was considered, phosphorylating respiration and H2O2 emission were 70–80% greater in HCR muscle. Greater capacity of HCR muscle for work and H2O2 signaling may result in enhanced and more immediate cellular repair, possibly explaining lowered disease risks. PMID:22995392

Intrinsic aerobic capacity correlates with greater inherent mitochondrial oxidative and H2O2 emission capacities without major shifts in myosin heavy chain isoform.

PubMed

Seifert, Erin L; Bastianelli, Mark; Aguer, Céline; Moffat, Cynthia; Estey, Carmen; Koch, Lauren G; Britton, Steven L; Harper, Mary-Ellen

2012-11-01

Exercise capacity and performance strongly associate with metabolic and biophysical characteristics of skeletal muscle, factors that also relate to overall disease risk. Despite its importance, the exact mechanistic features that connect aerobic metabolism with health status are unknown. To explore this, we applied artificial selection of rats for intrinsic (i.e., untrained) aerobic treadmill running to generate strains of low- and high-capacity runners (LCR and HCR, respectively), subsequently shown to diverge for disease risk. Concurrent breeding of LCR and HCR per generation allows the lines to serve as reciprocal controls for unknown environmental changes. Here we provide the first direct evidence in mitochondria isolated from skeletal muscle that intrinsic mitochondrial capacity is higher in HCR rats. Maximal phosphorylating respiration was ~40% greater in HCR mitochondria, independent of substrate and without altered proton leak or major changes in protein levels or muscle fiber type, consistent with altered control of phosphorylating respiration. Unexpectedly, H(2)O(2) emission was ~20% higher in HCR mitochondria, due to greater reduction of more harmful reactive oxygen species to H(2)O(2); indeed, oxidative modification of mitochondrial proteins was lower. When the higher mitochondrial yield was considered, phosphorylating respiration and H(2)O(2) emission were 70-80% greater in HCR muscle. Greater capacity of HCR muscle for work and H(2)O(2) signaling may result in enhanced and more immediate cellular repair, possibly explaining lowered disease risks.

Aerobic capacity and its correlates in patients with ankylosing spondylitis.

PubMed

Hsieh, Lin-Fen; Wei, James Cheng-Chung; Lee, Hsin-Yi; Chuang, Chih-Cheng; Jiang, Jiunn-Song; Chang, Kae-Chwen

2016-05-01

To evaluate aerobic capacity in patients with ankylosing spondylitis (AS) and determine possible relationships between aerobic capacity, pulmonary function, and disease-related variables. Forty-two patients with AS and 42 healthy controls were recruited in the study. Descriptive data, disease-related variables (grip strength, lumbosacral mobility, occiput-to-wall distance, chest expansion, finger-to-floor distance, Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Global Score, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and hemoglobin), and chest and thoracic spine x-rays were collected in each patient with AS. All subjects took standard pulmonary function and exercise tolerance tests, and forced vital capacity (FVC) and aerobic capacity were recorded. Both aerobic capacity and FVC in patients with AS were significantly lower than those in normal subjects (P < 0.05). AS patients with BASFI scores of < 3 or BASDI scores of < 4 had a higher aerobic capacity. There was significant correlation between aerobic capacity, vital capacity, chest expansion, Schober's test, cervical range of motion, and BASFI in patients with AS. Neither aerobic capacity nor vital capacity correlated with disease duration, ESR, CRP, and hemoglobin. Significantly reduced aerobic capacity and FVC were observed in patients with AS, and there was significant correlation between aerobic capacity, vital capacity, chest expansion, and BASFI. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

Aerobic metabolism on muscle contraction in porcine gastric smooth muscle.

PubMed

Kanda, Hidenori; Kaneda, Takeharu; Nagai, Yuta; Urakawa, Norimoto; Shimizu, Kazumasa

2018-05-18

Exposure to chronic hypoxic conditions causes various gastric diseases, including gastric ulcers. It has been suggested that gastric smooth muscle contraction is associated with aerobic metabolism. However, there are no reports on the association between gastric smooth muscle contraction and aerobic metabolism, and we have investigated this association in the present study. High K + - and carbachol (CCh)-induced muscle contractions involved increasing O 2 consumption. Aeration with N 2 (hypoxia) and NaCN significantly decreased high K + - and CCh-induced muscle contraction and O 2 consumption. In addition, hypoxia and NaCN significantly decreased creatine phosphate (PCr) contents in the presence of high K + . Moreover, decrease in CCh-induced contraction and O 2 consumption was greater than that of high K + . Our results suggest that hypoxia and NaCN inhibit high K + - and CCh-induced contractions in gastric fundus smooth muscles by decreasing O 2 consumption and intracellular PCr content. However, the inhibition of CCh-induced muscle contraction was greater than that of high K + -induced muscle contraction.

Anthropometry, muscular strength and aerobic capacity up to 5 years after pediatric burns.

PubMed

Disseldorp, Laurien M; Mouton, Leonora J; Van der Woude, Lucas H V; Van Brussel, Marco; Nieuwenhuis, Marianne K

2015-12-01

Physical functioning is of major importance after burns in many areas of life, in both the short and the long term. This cross-sectional study aimed to describe anthropometry, muscular strength and aerobic capacity in children and adolescents between 0.5-5 years after burns over 10% TBSA. Assessments took place in a mobile exercise lab. Demographics, burn characteristics and anthropometrics were recorded. Muscular strength in six muscle groups was measured using hand-held dynamometry and aerobic capacity was measured with a graded cardiopulmonary exercise test. Subjects' scores were compared with Dutch age- and gender-matched norm values and converted to Z-scores. The assessments were completed by 24 subjects with pediatric burns ranging from 10 to 41% TBSA and time after burn from 1 to 5 years (58.3% male; 6-18 years). On group level, no significant differences between the subjects' scores and norm values were found. No trends were seen indicating an effect of extent of burn or time after burn. Individually, eight subjects (33.3%), mostly aged 6 or 7, showed significantly low performance on at least one variable: seven for strength, one for aerobic capacity and one for both. Anthropometry, muscular strength and aerobic capacity are adequate in the majority of Dutch children and adolescents 1-5 years after 10-41% TBSA burns. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Relationship between aerobic capacity and pelvic floor muscles function: a cross-sectional study

PubMed Central

Jürgensen, S.P.; Borghi-Silva, A.; Bastos, A.M.F.G.; Correia, G.N.; Pereira-Baldon, V.S.; Cabiddu, R.; Catai, A.M.; Driusso, P.

2017-01-01

The objective of this study was to evaluate the relationship between aerobic capacity and pelvic floor muscles (PFM) function in adult women. Women aged 18 or over and without urinary dysfunction or other chronic diseases were eligible to participate. They completed the habitual physical activity (HPA) questionnaire, underwent a PFM functional evaluation by palpation and perineometry, and performed a submaximal (between 75 and 85% of maximum heart rate) cardiopulmonary exercise (CPX) test to determine the ventilatory anaerobic threshold (VAT). Forty-one women were included (35±16 years, 75% physically active, 17% very active, and 8% sedentary and 17% presented grade 1 PFM contraction, 31.8% grade 2, 26.8% grade 3, and 24.4% grade 4, according to the modified Oxford Scale). The average PFM contraction pressure obtained by perineometer was 53±26 cmH2O and the average oxygen consumption at VAT (VO2VAT) obtained from CPX was 14±2 mL·kg-1·min-1. Significant correlations were found between PFM contraction pressure and VO2VAT (r=0.55; P<0.001); between PFM contraction pressure and HPA score (r=0.38; P=0.02); between age and VO2VAT (r=-0.25; P=0.049); and between VO2VAT and HPA score (r=0.36; P=0.02). An age-adjusted multiple linear regression equation (R2=0.32) was derived to estimate VO2VAT from the contraction value obtained by perineometer, so that the PFM contraction pressure was able to predict VO2VAT. The equation was validated using data from another group of 20 healthy women (33±12 years; PFM contraction: 49±23 cmH2O) and no significant difference was found between actual VO2VAT and predicted VO2VAT (13.1±1.9 vs 13.8±2.0 mL·kg-1·min-1). In conclusion, PFM function is associated with aerobic capacity in healthy women and PFM contraction pressure may be used to estimate VO2VAT in this population. PMID:28953985

Eight-Week Training Cessation Suppresses Physiological Stress but Rapidly Impairs Health Metabolic Profiles and Aerobic Capacity in Elite Taekwondo Athletes.

PubMed

Liao, Yi-Hung; Sung, Yu-Chi; Chou, Chun-Chung; Chen, Chung-Yu

2016-01-01

Changes in an athlete's physiological and health metabolic profiles after detraining have not been studied in elite Taekwondo (TKD) athletes. To enable a better understanding of these physiological changes to training cessation, this study examined the effects of 8-weeks detraining on the aerobic capacity, body composition, inflammatory status and health metabolic profile in elite TKD athletes. Sixteen elite TKD athletes (age: 21.0 ± 0.8 yrs, BMI: 22.4 ± 3.9 kg/m2; Mean ± SD; 11 males and 5 females) participated in this study. Physical activity level assessment using computerized physical activity logs was performed during the competitive preparation season (i.e. one-week before national competition) and at two week intervals throughout the detraining period. Participant aerobic capacity, body fat, and blood biomarkers were measured before and after detraining, and the blood biomarker analyses included leukocyte subpopulations, blood glucose, insulin, dehydroepiandrosterone-sulfate (DHEA-S), and cortisol. Eight-week detraining increased DHEA-S/cortisol ratio (+57.3%, p = 0.004), increased insulin/cortisol ratio (+59.9%, p = 0.004), reduced aerobic power (-2.43%, p = 0.043), increased body fat accumulation (body fat%: +21.3%, p < 0.001), decreased muscle mass (muscle mass%: -4.04%, p < 0.001), and elevated HOMA-IR (the biomarker of systemic insulin resistance; +34.2%, p = 0.006). The neutrophil-to-lymphocyte ratio (NLR), a systemic inflammatory index, increased by 48.2% (p = 0.005). The change in aerobic capacity was correlated with the increased fat mass (r = -0.429, p = 0.049) but not with muscle loss. An increase in the NLR was correlated to the changes in HOMA-IR (r = 0.44, p = 0.044) and aerobic capacity (r = -0.439, p = 0.045). We demonstrate that 8-week detraining suppresses physiological stress but rapidly results in declines in athletic performance and health metabolic profiles, including reduced aerobic capacity, increased body fat, muscle loss, insulin

The Impact of Aerobic Exercise on the Muscle Stem Cell Response.

PubMed

Joanisse, Sophie; Snijders, Tim; Nederveen, Joshua P; Parise, Gianni

2018-04-16

Satellite cells are indispensable for skeletal muscle repair and regeneration and are associated with muscle growth in humans. Aerobic exercise training results in improved skeletal muscle health also translating to an increase in satellite cell pool activation. We postulate that aerobic exercise improves satellite cell function in skeletal muscle.

Physical Fitness and Mitochondrial Respiratory Capacity in Horse Skeletal Muscle

PubMed Central

Lemieux, Hélène; Mouithys-Mickalad, Ange; Serteyn, Didier

2012-01-01

Background Within the animal kingdom, horses are among the most powerful aerobic athletic mammals. Determination of muscle respiratory capacity and control improves our knowledge of mitochondrial physiology in horses and high aerobic performance in general. Methodology/Principal Findings We applied high-resolution respirometry and multiple substrate-uncoupler-inhibitor titration protocols to study mitochondrial physiology in small (1.0–2.5 mg) permeabilized muscle fibres sampled from triceps brachii of healthy horses. Oxidative phosphorylation (OXPHOS) capacity (pmol O2•s−1•mg−1 wet weight) with combined Complex I and II (CI+II) substrate supply (malate+glutamate+succinate) increased from 77±18 in overweight horses to 103±18, 122±15, and 129±12 in untrained, trained and competitive horses (N = 3, 8, 16, and 5, respectively). Similar to human muscle mitochondria, equine OXPHOS capacity was limited by the phosphorylation system to 0.85±0.10 (N = 32) of electron transfer capacity, independent of fitness level. In 15 trained horses, OXPHOS capacity increased from 119±12 to 134±37 when pyruvate was included in the CI+II substrate cocktail. Relative to this maximum OXPHOS capacity, Complex I (CI)-linked OXPHOS capacities were only 50% with glutamate+malate, 64% with pyruvate+malate, and 68% with pyruvate+malate+glutamate, and ∼78% with CII-linked succinate+rotenone. OXPHOS capacity with glutamate+malate increased with fitness relative to CI+II-supported ETS capacity from a flux control ratio of 0.38 to 0.40, 0.41 and 0.46 in overweight to competitive horses, whereas the CII/CI+II substrate control ratio remained constant at 0.70. Therefore, the apparent deficit of the CI- over CII-linked pathway capacity was reduced with physical fitness. Conclusions/Significance The scope of mitochondrial density-dependent OXPHOS capacity and the density-independent (qualitative) increase of CI-linked respiratory capacity with increased fitness open up new

Aerobic exercise training induces skeletal muscle hypertrophy and age-dependent adaptations in myofiber function in young and older men

PubMed Central

Konopka, Adam R.; Undem, Miranda K.; Hinkley, James M.; Minchev, Kiril; Kaminsky, Leonard A.; Trappe, Todd A.; Trappe, Scott

2012-01-01

To examine potential age-specific adaptations in skeletal muscle size and myofiber contractile physiology in response to aerobic exercise, seven young (YM; 20 ± 1 yr) and six older men (OM; 74 ± 3 yr) performed 12 wk of cycle ergometer training. Muscle biopsies were obtained from the vastus lateralis to determine size and contractile properties of isolated slow [myosin heavy chain (MHC) I] and fast (MHC IIa) myofibers, MHC composition, and muscle protein concentration. Aerobic capacity was higher (P < 0.05) after training in both YM (16 ± 2%) and OM (13 ± 3%). Quadriceps muscle volume, determined via MRI, was 5 ± 1 and 6 ± 1% greater (P < 0.05) after training for YM and OM, respectively, which was associated with an increase in MHC I myofiber cross-sectional area (CSA), independent of age. MHC I peak power was higher (P < 0.05) after training for both YM and OM, while MHC IIa peak power was increased (P < 0.05) with training in OM only. MHC I and MHC IIa myofiber peak and normalized (peak force/CSA) force were preserved with training in OM, while MHC I peak force/CSA and MHC IIa peak force were lower (P < 0.05) after training in YM. The age-dependent adaptations in myofiber function were not due to changes in protein content, as total muscle protein and myofibrillar protein concentration were unchanged (P > 0.05) with training. Training reduced (P < 0.05) the proportion of MHC IIx isoform, independent of age, whereas no other changes in MHC composition were observed. These data suggest relative improvements in muscle size and aerobic capacity are similar between YM and OM, while adaptations in myofiber contractile function showed a general improvement in OM. Training-related increases in MHC I and MHC IIa peak power reveal that skeletal muscle of OM is responsive to aerobic exercise training and further support the use of aerobic exercise for improving cardiovascular and skeletal muscle health in older individuals. PMID:22984247

Effect of Combined Exercise Versus Aerobic-Only Training on Skeletal Muscle Lipid Metabolism in a Rodent Model of Type1 Diabetes.

PubMed

Dotzert, Michelle S; McDonald, Matthew W; Murray, Michael R; Nickels, J Zachary; Noble, Earl G; Melling, C W James

2017-12-04

Abnormal skeletal muscle lipid metabolism is associated with insulin resistance in people with type 1 diabetes. Although lipid metabolism is restored with aerobic exercise training, the risk for postexercise hypoglycemia is increased with this modality. Integrating resistance and aerobic exercise is associated with reduced hypoglycemic risk; however, the effects of this exercise modality on lipid metabolism and insulin resistance remain unknown. We compared the effects of combined (aerobic + resistance) versus aerobic exercise training on oxidative capacity and muscle lipid metabolism in a rat model of type 1 diabetes. Male Sprague-Dawley rats were divided into 4 groups: sedentary control (C), sedentary control + diabetes (CD), diabetes + high-intensity aerobic exercise (DAE) and diabetes + combined aerobic and resistance exercise (DARE). Following diabetes induction (20 mg/kg streptozotocin over five days), DAE rats ran for 12 weeks (5 days/week for 1 hour) on a motorized treadmill (27 m/min at a 6-degree grade), and DARE rats alternated daily between running and incremental weighted ladder climbing. After training, DAE showed reduced muscle CD36 protein content and lipid content compared to CD (p≤0.05). DAE rats also had significantly increased citrate synthase (CS) activity compared to CD (p≤0.05). DARE rats showed reduced CD36 protein content compared to CD and increased CS activity compared to CD and DAE rats (p≤0.05). DARE rats demonstrated increased skeletal muscle lipid staining, elevated lipin-1 protein content and insulin sensitivity (p≤0.05). Integration of aerobic and resistance exercise may exert a synergistic effect, producing adaptations characteristic of the "athlete's paradox," including increased capacity to store and oxidize lipids. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Intrinsic aerobic capacity sets a divide for aging and longevity

PubMed Central

Koch, Lauren Gerard; Kemi, Ole J.; Qi, Nathan; Leng, Sean X.; Bijma, Piter; Gilligan, Lori J.; Wilkinson, John E.; Wisløff, Helene; Høydal, Morten A.; Rolim, Natale; Abadir, Peter M.; Van Grevenhof, Ilse; Smith, Godfrey L.; Burant, Charles F.; Ellingsen, Øyvind; Britton, Steven L.; Wisløff, Ulrik

2011-01-01

Rationale Low aerobic exercise capacity is a powerful predictor of premature morbidity and mortality for healthy adults as well as those with cardiovascular disease For aged populations, poor performance on treadmill or extended walking tests indicates closer proximity to future health declines. Together, these findings suggest a fundamental connection between aerobic capacity and longevity. Objectives Through artificial selective breeding, we developed an animal model system to prospectively test the association between aerobic exercise capacity and survivability (aerobic hypothesis). Methods and Results Laboratory rats of widely diverse genetic backgrounds (N:NIH stock) were selectively bred for low or high intrinsic (inborn) treadmill running capacity. Cohorts of male and female rats from generations 14, 15 and 17 of selection were followed for survivability and assessed for age-related declines in cardiovascular fitness including maximal oxygen uptake (VO2max), myocardial function, endurance performance, and change in body mass. Median lifespan for low exercise capacity rats was 28-45% shorter than high capacity rats (hazard ratio, 0.06; P<.001). VO2max, measured across adulthood was a reliable predictor of lifespan (P<.001). During progression from adult to old age, left ventricular myocardial and cardiomyocyte morphology, contractility, and intracellular Ca2+ handling in both systole and diastole, as well as mean blood pressure, were more compromised in rats bred for low aerobic capacity. Physical activity levels, energy expenditure (VO2), and lean body mass were all better sustained with age in rats bred for high aerobic capacity. Conclusions These data obtained from a contrasting heterogeneous model system provide strong evidence that genetic segregation for aerobic exercise capacity can be linked with longevity and useful for deeper mechanistic exploration. PMID:21921265

Intrinsic aerobic capacity sets a divide for aging and longevity.

PubMed

Koch, Lauren Gerard; Kemi, Ole J; Qi, Nathan; Leng, Sean X; Bijma, Piter; Gilligan, Lori J; Wilkinson, John E; Wisløff, Helene; Høydal, Morten A; Rolim, Natale; Abadir, Peter M; van Grevenhof, Elizabeth M; Smith, Godfrey L; Burant, Charles F; Ellingsen, Oyvind; Britton, Steven L; Wisløff, Ulrik

2011-10-28

Low aerobic exercise capacity is a powerful predictor of premature morbidity and mortality for healthy adults as well as those with cardiovascular disease. For aged populations, poor performance on treadmill or extended walking tests indicates closer proximity to future health declines. Together, these findings suggest a fundamental connection between aerobic capacity and longevity. Through artificial selective breeding, we developed an animal model system to prospectively test the association between aerobic exercise capacity and survivability (aerobic hypothesis). Laboratory rats of widely diverse genetic backgrounds (N:NIH stock) were selectively bred for low or high intrinsic (inborn) treadmill running capacity. Cohorts of male and female rats from generations 14, 15, and 17 of selection were followed for survivability and assessed for age-related declines in cardiovascular fitness including maximal oxygen uptake (VO(2max)), myocardial function, endurance performance, and change in body mass. Median lifespan for low exercise capacity rats was 28% to 45% shorter than high capacity rats (hazard ratio, 0.06; P<0.001). VO(2max), measured across adulthood was a reliable predictor of lifespan (P<0.001). During progression from adult to old age, left ventricular myocardial and cardiomyocyte morphology, contractility, and intracellular Ca(2+) handling in both systole and diastole, as well as mean blood pressure, were more compromised in rats bred for low aerobic capacity. Physical activity levels, energy expenditure (Vo(2)), and lean body mass were all better sustained with age in rats bred for high aerobic capacity. These data obtained from a contrasting heterogeneous model system provide strong evidence that genetic segregation for aerobic exercise capacity can be linked with longevity and are useful for deeper mechanistic exploration of aging.

The use of aerobic exercise training in improving aerobic capacity in individuals with stroke: a meta-analysis

PubMed Central

Pang, Marco YC; Eng, Janice J; Dawson, Andrew S; Gylfadóttir, Sif

2011-01-01

Objective To determine whether aerobic exercise improves aerobic capacity in individuals with stroke. Design A systematic review of randomized controlled trials. Databases searched MEDLINE, CINAHL, EMBASE, Cochrane Database of Systematic Reviews, Physiotherapy Evidence Database were searched. Inclusion criteria Design: randomized controlled trials; Participants: individuals with stroke; Interventions: aerobic exercise training aimed at improving aerobic capacity; Outcomes Primary outcomes: aerobic capacity [peak oxygen consumption (VO2), peak workload); Secondary outcomes: walking velocity, walking endurance. Data Analysis The methodological quality was assessed by the PEDro scale. Meta-analyses were performed for all primary and secondary outcomes. Results Nine articles (seven RCTs) were identified. The exercise intensity ranged from 50% to 80% heart rate reserve. Exercise duration was 20–40 minutes for 3–5 days a week. The total number of subjects included in the studies was 480. All studies reported positive effects on aerobic capacity, regardless of the stage of stroke recovery. Meta-analysis revealed a significant homogeneous standardized effect size (SES) in favour of aerobic exercise to improve peak VO2 (SES, 0.42; 95%CI, 0.15 to 0.69; p=0.001) and peak workload (SES, 0.50; 95%CI, 0.26 to 0.73; p<0.001). There was also a significant homogeneous SES in favour of aerobic training to improve walking velocity (SES, 0.26; 95%CI, 0.05 to 0.48; p=0.008) and walking endurance (SES, 0.30; 95%CI, 0.06to 0.55; p=0.008). Conclusions There is good evidence that aerobic exercise is beneficial for improving aerobic capacity in people with mild and moderate stroke. Aerobic exercise should be an important component of stroke rehabilitation. PMID:16541930

Benefits of aerobic exercise after stroke.

PubMed

Potempa, K; Braun, L T; Tinknell, T; Popovich, J

1996-05-01

The debilitating loss of function after a stroke has both primary and secondary effects on sensorimotor function. Primary effects include paresis, paralysis, spasticity, and sensory-perceptual dysfunction due to upper motor neuron damage. Secondary effects, contractures and disuse muscle atrophy, are also debilitating. This paper presents theoretical and empirical benefits of aerobic exercise after stroke, issues relevant to measuring peak capacity, exercise training protocols, and the clinical use of aerobic exercise in this patient population. A stroke, and resulting hemiparesis, produces physiological changes in muscle fibres and muscle metabolism during exercise. These changes, along with comorbid cardiovascular disease, must be considered when exercising stroke patients. While few studies have measured peak exercise capacity in hemiparetic populations, it has been consistently observed in these studies that stroke patients have a lower functional capacity than healthy populations. Hemiparetic patients have low peak exercise responses probably due to a reduced number of motor units available for recruitment during dynamic exercise, the reduced oxidative capacity of paretic muscle, and decreased overall endurance. Consequently, traditional methods to predict aerobic capacity are not appropriate for use with stroke patients. Endurance exercise training is increasingly recognised as an important component in rehabilitation. An average improvement in maximal oxygen consumption (VO2max) of 13.3% in stroke patients who participated in a 10-week aerobic exercise training programme has been reported compared with controls. This study underscored the potential benefits of aerobic exercise training in stroke patients. In this paper, advantages and disadvantages of exercise modalities are discussed in relation to stroke patients. Recommendations are presented to maximise physical performance and minimise potential cardiac risks during exercise.

Aerobic capacity mediates susceptibility for the transition from steatosis to steatohepatitis.

PubMed

Morris, E Matthew; McCoin, Colin S; Allen, Julie A; Gastecki, Michelle L; Koch, Lauren G; Britton, Steven L; Fletcher, Justin A; Fu, Xiarong; Ding, Wen-Xing; Burgess, Shawn C; Rector, R Scott; Thyfault, John P

2017-07-15

Low intrinsic aerobic capacity is associated with increased all-cause and liver-related mortality in humans. Low intrinsic aerobic capacity in the low capacity runner (LCR) rat increases susceptibility to acute and chronic high-fat/high-sucrose diet-induced steatosis, without observed increases in liver inflammation. Addition of excess cholesterol to a high-fat/high-sucrose diet produced greater steatosis in LCR and high capacity runner (HCR) rats. However, the LCR rat demonstrated greater susceptibility to increased liver inflammatory and apoptotic markers compared to the HCR rat. The progressive non-alcoholic fatty liver disease observed in the LCR rats following western diet feeding was associated with further declines in liver fatty acid oxidation and mitochondrial respiratory capacity compared to HCR rats. Low aerobic capacity increases risk for non-alcoholic fatty liver disease and liver-related disease mortality, but mechanisms mediating these effects remain unknown. We recently reported that rats bred for low aerobic capacity (low capacity runner; LCR) displayed susceptibility to high fat diet-induced steatosis in association with reduced hepatic mitochondrial fatty acid oxidation (FAO) and respiratory capacity compared to high aerobic capacity (high capacity runner; HCR) rats. Here we tested the impact of aerobic capacity on susceptibility for progressive liver disease following a 16-week 'western diet' (WD) high in fat (45% kcal), cholesterol (1% w/w) and sucrose (15% kcal). Unlike previously with a diet high in fat and sucrose alone, the inclusion of cholesterol in the WD induced hepatomegaly and steatosis in both HCR and LCR rats, while producing greater cholesterol ester accumulation in LCR compared to HCR rats. Importantly, WD-fed low-fitness LCR rats displayed greater inflammatory cell infiltration, serum alanine transaminase, expression of hepatic inflammatory markers (F4/80, MCP-1, TLR4, TLR2 and IL-1β) and effector caspase (caspase 3 and 7

High Aerobic Capacity Mitigates Changes in the Plasma Metabolomic Profile Associated with Aging.

PubMed

Falegan, Oluyemi S; Vogel, Hans J; Hittel, Dustin S; Koch, Lauren G; Britton, Steven L; Hepple, Russ T; Shearer, Jane

2017-02-03

Advancing age is associated with declines in maximal oxygen consumption. Declines in aerobic capacity not only contribute to the aging process but also are an independent risk factor for morbidity, cardiovascular disease, and all-cause mortality. Although statistically convincing, the relationships between aerobic capacity, aging, and disease risk remain largely unresolved. To this end, we employed sensitive, system-based metabolomics approach to determine whether enhanced aerobic capacity could mitigate some of the changes seen in the plasma metabolomic profile associated with aging. Metabolomic profiles of plasma samples obtained from young (13 month) and old (26 month) rats bred for low (LCR) or high (HCR) running capacity using proton nuclear magnetic resonance spectroscopy ( 1 H NMR) were examined. Results demonstrated strong profile separation in old and low aerobic capacity rats, whereas young and high aerobic capacity rat models were less predictive. Significantly differential metabolites between the groups include taurine, acetone, valine, and trimethylamine-N-oxide among other metabolites, specifically citrate, succinate, isovalerate, and proline, were differentially increased in older HCR animals compared with their younger counterparts. When interactions between age and aerobic capacity were examined, results demonstrated that enhanced aerobic capacity could mitigate some but not all age-associated alterations in the metabolomic profile.

The Effect of Aerobic or Aerobic-Strength Exercise on Body Composition and Functional Capacity in Patients with BMI ≥35 after Bariatric Surgery: a Randomized Control Trial.

PubMed

Hassannejad, Alireza; Khalaj, Alireza; Mansournia, Mohammad Ali; Rajabian Tabesh, Mastaneh; Alizadeh, Zahra

2017-11-01

Although previous studies suggested that bariatric surgery is the most effective and sustainable treatment method for morbid obesity in long term, but without changing in lifestyle, maintaining optimal weight loss is almost impossible. Sixty morbid obese patients (BMI ≥ 35) were evaluated before and after 12 weeks of bariatric surgery in order to compare the impact of two different exercise programs on body composition and functional capacity outcomes. Participants were divided into three groups: aerobic (A), aerobic-strength (AS), and control (C) group. Aerobic capacity was assessed with 12-min walk-run test (12MWRT). One-repetition maximum (1RM) test was performed to evaluation upper limb muscle strength. Lower extremity functional capacity was assessed by sit-to-stand test. Weight, percent body fat (PBF), and fat mass (FM) reduced greater in the trial groups in comparison to the C group (P < 0.05). In the AS group, the reduction of fat-free mass (FFM) was significantly lower than that in the other groups. Mean changes in 12MWRT increased significantly in the intervention groups. The mean change in the sit-to-stand scores was not statistically significant between the three groups. Comparing the intervention groups showed that mean changes in 1RM variables increased in AS group (P = 0.03). The data suggests a positive effect of exercise on weight and PBF decrease after surgery, and it leads to significant improvement on aerobic capacity. Moreover, doing resisted exercise caused greater preserving of lean mass.

Voluntary Running Aids to Maintain High Body Temperature in Rats Bred for High Aerobic Capacity

PubMed Central

Karvinen, Sira M.; Silvennoinen, Mika; Ma, Hongqiang; Törmäkangas, Timo; Rantalainen, Timo; Rinnankoski-Tuikka, Rita; Lensu, Sanna; Koch, Lauren G.; Britton, Steven L.; Kainulainen, Heikki

2016-01-01

The production of heat, i.e., thermogenesis, is a significant component of the metabolic rate, which in turn affects weight gain and health. Thermogenesis is linked to physical activity (PA) level. However, it is not known whether intrinsic exercise capacity, aging, and long-term voluntary running affect core body temperature. Here we use rat models selectively bred to differ in maximal treadmill endurance running capacity (Low capacity runners, LCR and High capacity Runners, HCR), that as adults are divergent for aerobic exercise capacity, aging, and metabolic disease risk to study the connection between PA and body temperature. Ten high capacity runner (HCR) and ten low capacity runner (LCR) female rats were studied between 9 and 21 months of age. Rectal body temperature of HCR and LCR rats was measured before and after 1-year voluntary running/control intervention to explore the effects of aging and PA. Also, we determined whether injected glucose and spontaneous activity affect the body temperature differently between LCR and HCR rats at 9 vs. 21 months of age. HCRs had on average 1.3°C higher body temperature than LCRs (p < 0.001). Aging decreased the body temperature level of HCRs to similar levels with LCRs. The opportunity to run voluntarily had a significant impact on the body temperature of HCRs (p < 0.001) allowing them to maintain body temperature at a similar level as when at younger age. Compared to LCRs, HCRs were spontaneously more active, had higher relative gastrocnemius muscle mass and higher UCP2, PGC-1α, cyt c, and OXPHOS levels in the skeletal muscle (p < 0.050). These results suggest that higher PA level together with greater relative muscle mass and higher mitochondrial content/function contribute to the accumulation of heat in the HCRs. Interestingly, neither aging nor voluntary training had a significant impact on core body temperature of LCRs. However, glucose injection resulted in a lowering of the body temperature of LCRs (p < 0

Voluntary Running Aids to Maintain High Body Temperature in Rats Bred for High Aerobic Capacity.

PubMed

Karvinen, Sira M; Silvennoinen, Mika; Ma, Hongqiang; Törmäkangas, Timo; Rantalainen, Timo; Rinnankoski-Tuikka, Rita; Lensu, Sanna; Koch, Lauren G; Britton, Steven L; Kainulainen, Heikki

2016-01-01

The production of heat, i.e., thermogenesis, is a significant component of the metabolic rate, which in turn affects weight gain and health. Thermogenesis is linked to physical activity (PA) level. However, it is not known whether intrinsic exercise capacity, aging, and long-term voluntary running affect core body temperature. Here we use rat models selectively bred to differ in maximal treadmill endurance running capacity (Low capacity runners, LCR and High capacity Runners, HCR), that as adults are divergent for aerobic exercise capacity, aging, and metabolic disease risk to study the connection between PA and body temperature. Ten high capacity runner (HCR) and ten low capacity runner (LCR) female rats were studied between 9 and 21 months of age. Rectal body temperature of HCR and LCR rats was measured before and after 1-year voluntary running/control intervention to explore the effects of aging and PA. Also, we determined whether injected glucose and spontaneous activity affect the body temperature differently between LCR and HCR rats at 9 vs. 21 months of age. HCRs had on average 1.3°C higher body temperature than LCRs (p < 0.001). Aging decreased the body temperature level of HCRs to similar levels with LCRs. The opportunity to run voluntarily had a significant impact on the body temperature of HCRs (p < 0.001) allowing them to maintain body temperature at a similar level as when at younger age. Compared to LCRs, HCRs were spontaneously more active, had higher relative gastrocnemius muscle mass and higher UCP2, PGC-1α, cyt c, and OXPHOS levels in the skeletal muscle (p < 0.050). These results suggest that higher PA level together with greater relative muscle mass and higher mitochondrial content/function contribute to the accumulation of heat in the HCRs. Interestingly, neither aging nor voluntary training had a significant impact on core body temperature of LCRs. However, glucose injection resulted in a lowering of the body temperature of LCRs (p < 0

Circulating micrornas as potential biomarkers of aerobic exercise capacity

PubMed Central

Viereck, Janika; Krüger, Karsten; Thum, Thomas

2013-01-01

Purpose microRNAs (miRs) are crucial intracellular mediators of various biological processes, also affecting the cardiovascular system. Recently, it has been shown that miRs circulate extracellularly in the bloodstream and that such circulating miRs change in response to physical activity. Therefore, the purpose of the current study was to investigate heart/muscle specific and inflammation related miRs in plasma of individuals before, directly after, and 24 h after a marathon run and to analyze their relation to conventional biochemical, cardiovascular, and performance indexes. Male endurance athletes (n =14) were recruited for the study after performing a battery of cardiac functional tests. Blood samples were collected before, directly after, and 24 h after a public marathon run. miR-1, miR-133, miR-206, miR-499, miR-208b, miR-21, and miR-155 were measured using individual Taqman assays and normalized to Caenorhabditis elegans miR-39 (cel-39) spike-in control. Moreover, soluble cardiac, inflammatory, and muscle damage markers were determined. As a result, skeletal- and heart muscle-specific miRs showed a significant increase after the marathon. The strongest increase was observed for miR-206. Twenty-four hours after the run, only miR-499 and miR-208b were returned to preexercise levels, whereas the others were still enhanced. In contrast, miR-21 and -155 were not affected by exercise. miR-1, -133a, and -206 correlated to aerobic performance parameters such as maximum oxygen uptake (V̇o2max) and running speed at individual anaerobic lactate threshold (VIAS). miR-1 showed a moderate negative correlation with fractional shortening, whereas miR-133a was positively related to the thickness of intraventricular septum. None of the miRs correlated with cardiac injury markers such as troponin T, troponin I, and pro-brain natriuretic peptide. In conclusion, these findings suggest a potential role for muscle- and heart-specific miRs in cardiovascular adaptation processes

Effects of new sports tennis type exercise on aerobic capacity, follicle stimulating hormone and N-terminal telopeptide in the postmenopausal women.

PubMed

Shin, Hyun-Jae; Lee, Ha-Yan; Cho, Hye-Young; Park, Yun-Jin; Moon, Hyung-Hoon; Lee, Sung-Hwan; Lee, Sung-Ki; Kim, Myung-Ki

2014-04-01

Menopause is characterized by rapid decreases in bone mineral density, aerobic fitness, muscle strength, and balance. In the present study, we investigated the effects of new sports tennis type exercise on aerobic capacity, follicle stimulating hormone (FSH) and N-terminal telopeptide (NTX) in the postmenopausal women. Subjects were consisted of 20 postmenopausal women, who had not menstruated for at least 1 yr and had follicle-stimulating hormone levels > 35 mIU/L, estradiol levels< 40 pg/mL. The subjects were randomly divided into two groups: control group (n= 10), new sports tennis type exercise group (n= 10). New sports tennis type exercise was consisted of warm up (10 min), new sports tennis type exercise (40 min), cool down (10 min) 3 days a per week for 12 weeks. The aerobic capacities were increased by 12 weeks new sports tennis type exercise. New sports tennis type exercise significantly increased FSH and NTx levels, indicating biochemical markers of bone formation and resorption. These findings indicate that 12 weeks of new sports tennis type exercise can be effective in prevention of bone loss and enhancement of aerobic capacity in postmenopausal women.

Muscle irisin response to aerobic vs HIIT in overweight female adolescents.

PubMed

Archundia-Herrera, Carolina; Macias-Cervantes, Maciste; Ruiz-Muñoz, Bernardo; Vargas-Ortiz, Katya; Kornhauser, Carlos; Perez-Vazquez, Victoriano

2017-01-01

Exercise stimulates the production of fibronectin type III domain-containing protein 5 (FNDC5), which is cleaved to release a protein called irisin. This protein induces browning of white adipose tissue resulting in increased thermogenesis. Different studies have measured circulating irisin at baseline and in response to exercise among a wide variety of individuals; yet, regarding the effect of different exercise intensities in obese adolescent girls, limited insight is available. This study compares the effect of acute aerobic exercise of moderate intensity and high-intensity interval training (HIIT) on irisin levels in skeletal muscle and plasma of sedentary overweight or obese female adolescents. The aerobic group (n = 15) and HIIT group (n = 15) underwent anthropometric and metabolic measurements, electrocardiogram, peak oxygen uptake (VO 2peak ), and two vastus lateralis muscle biopsies before and after session of workout. The session of aerobic exercise included cycling at 65% of their peak heart rate (HRpeak) for 40 min. In the HIIT group, exercise included six bouts of 1 min at 85-95% HRpeak separated by 1 min of recovery. Irisin levels were evaluated in samples of skeletal muscle (western blot) and plasma (ELISA). The levels of expression of irisin in skeletal muscle increased significantly after a session of HIIT (p < 0.05), while aerobic exercise no affect irisin levels. No significant differences between the groups in plasma irisin levels were found. The increase in muscle irisin levels was observed only following HIIT session. No increases in plasma irisin concentration were observed.

Effects of small-sided games and high-intensity interval training on aerobic and repeated sprint performance and peripheral muscle oxygenation changes in elite junior basketball players.

PubMed

Delextrat, A; Gruet, M; Bieuzen, F

2018-03-06

The aim of the current study was to compare the effects of 6 weeks of small-sided game (SSG) and high-intensity interval training (HIIT) on aerobic fitness and muscle oxygenation during a repeated sprint (RS) sequence in elite male junior basketball players. Twenty participants (14.3 ± 0.5 years; 176.8 ± 12.5 cm; 74.5 ± 9.8 kg) performed pre- and post-tests interspersed by 6-weeks of SSG or HIIT training. Testing sessions consisted of the 30-15 Intermittent Fitness Test and a RS sequence (two bouts of 15-s). During RS, muscle oxygenation parameters (tissue saturation index (TSI, %), post-sprint muscle reoxygenation rate) were measured by near-infrared spectroscopy (NIRS). The results showed that both training interventions similarly improved maximal aerobic speed (VIFT, 3.4 and 4.1%, respectively for HIIT and SSG, P<0.05) as well as RSA (smaller percentage decrement by 62.5% and 21.6%, respectively for HIIT and SSG, P<0.05). Both training interventions also resulted in a greater ΔTSI during the second sprint (47.8% to 114%, P<0.05) and significant improvements in post-sprints reoxygenation after both sprints (+23.0% to +107.7%). Finally, the variation in muscle reoxygenation after sprint 1 was significantly associated with improvements in aerobic (ΔVIFT, r =0.61, P=0.008) and anaerobic (Δ% Dec during RS, r =-0.487, P=0.028) performances. The current study has observed that SSG and HIIT resulted in similar improvements in aerobic and anaerobic variables and a better muscle oxygenation capacity during RS. Coaches should be aware that both trainings are applicable methodologies to improve in-season aerobic and anaerobic fitness capacities in junior basketball players.

Effects of dominant somatotype on aerobic capacity trainability.

PubMed

Chaouachi, M; Chaouachi, A; Chamari, K; Chtara, M; Feki, Y; Amri, M; Trudeau, F

2005-12-01

This study examined the association between dominant somatotype and the effect on aerobic capacity variables of individualised aerobic interval training. Forty one white North African subjects (age 21.4+/-1.3 years; Vo2max = 52.8+/-5.7 ml kg(-1) min(-1)) performed three exercise tests 1 week apart (i) an incremental test on a cycle ergometer to determine Vo2max and Vo2 at the second ventilatory threshold (VT2); (ii) a VAM-EVAL track test to determine maximal aerobic speed (vVo2max); and (iii) an exhaustive constant velocity test to determine time limit performed at 100% vVo2max (tlim100). Subjects were divided into four somatometric groups: endomorphs-mesomorphs (Endo-meso; n = 9), mesomorphs (Meso; n = 11), mesomorphs-ectomorphs (Meso-ecto; n = 12), and ectomorphs (Ecto; n = 9). Subjects followed a 12 week training program (two sessions/week). Each endurance training session consisted of the maximal number of successive fractions for each subject. Each fraction consisted of one period of exercise at 100% of vVo2max and one of active recovery at 60% of vVo2max. The duration of each period was equal to half the individual tlim100 duration (153.6+/-39.7 s). After the training program, all subjects were re-evaluated for comparison with pre-test results. Pre- and post-training data were grouped by dominant somatotype. Two way ANOVA revealed significant somatotype-aerobic training interaction effects (p<0.001) for improvements in vVo2max, Vo2max expressed classically and according to allometric scaling, and Vo2 at VT2. There were significant differences among groups post-training: the Meso-ecto and the Meso groups showed the greatest improvements in aerobic capacity. The significant somatotype-aerobic training interaction suggests different trainability with intermittent and individualised aerobic training according to somatotype.

Aerobic metabolism on muscle contraction in porcine iris sphincter.

PubMed

Kanda, Hidenori; Kaneda, Takeharu; Kato, Asami; Yogo, Takuya; Harada, Yasuji; Hara, Yasusi; Urakawa, Norimoto; Shimizu, Kazumasa

2016-12-01

Eyes are supplied O 2 through the cornea and vessels of the retina and iris, which are tissues characterized by aerobic metabolism. Meanwhile, there are no reports on the association between iris sphincter contraction and aerobic metabolism. In this paper, we studied the aforementioned association. Eyes from adult pigs of either sex were obtained from a local abattoir. A muscle strip was connected to a transducer to isometrically record the tension. O 2 consumption was measured using a Clark-type polarograph connected to a biological oxygen monitor. Creatine phosphate (PCr) and adenosine triphosphate (ATP) contents were measured in the muscle strips by high-performance liquid chromatography (HPLC). Iris sphincter muscles were measured in resting, contractile or hypoxic phases. Contraction was induced by hyperosmotic 65 mM KCl (H-65K + ) or carbachol (CCh), and hypoxia was induced by aeration with N 2 instead of O 2 or by addition of sodium cyanide (NaCN). H-65K + - and CCh-induced muscle contraction, involved increasing O 2 consumption. Hypoxia and NaCN significantly decreased H-65K + - and CCh-induced muscle contraction and/or O 2 consumption and PCr contents. Our results suggest that the contractile behavior in porcine iris sphincter highly depends on mitogen oxidative metabolism.

Exercise therapy improves aerobic capacity of inpatients with major depressive disorder.

PubMed

Kerling, Arno; von Bohlen, Anne; Kück, Momme; Tegtbur, Uwe; Grams, Lena; Haufe, Sven; Gützlaff, Elke; Kahl, Kai G

2016-06-01

Unipolar depression is one of the most common diseases worldwide and is associated with a higher cardiovascular risk partly due to reduced aerobic capacity. Therefore, the aim of our study was to examine whether a structured aerobic training program can improve aerobic capacity in inpatients with MDD (major depressive disorder). Overall, 25 patients (13 women, 12 men) diagnosed with MDD were included in the study. Parameters of aerobic capacity, such as maximum performance, maximum oxygen consumption, and VAT (ventilatory anaerobic threshold), were assessed on a bicycle ergometer before and 6 weeks after a training period (three times per week for 45 min on two endurance machines). In addition, a constant load test was carried out at 50% of the maximum performance prior to and after the training period. The performance data were compared with 25 healthy controls matched for sex, age, and body mass index before and after the training period. Compared to controls, patients with MDD had significantly lower aerobic capacity. After training, there was a significant improvement in their performance data. A significant difference remained only for VAT between patients with MDD and healthy controls. With regard to the coincidence of MDD with cardiovascular and cardiometabolic disorders, a structured supervised exercise program carried out during hospitalization is a useful supplement for patients with MDD.

Continuous Aerobic Training in Individualized Intensity Avoids Spontaneous Physical Activity Decline and Improves MCT1 Expression in Oxidative Muscle of Swimming Rats.

PubMed

Scariot, Pedro P M; Manchado-Gobatto, Fúlvia de Barros; Torsoni, Adriana S; Dos Reis, Ivan G M; Beck, Wladimir R; Gobatto, Claudio A

2016-01-01

Although aerobic training has been shown to affect the lactate transport of skeletal muscle, there is no information concerning the effect of continuous aerobic training on spontaneous physical activity (SPA). Because every movement in daily life (i.e., SPA) is generated by skeletal muscle, we think that it is possible that an improvement of SPA could affect the physiological properties of muscle with regard to lactate transport. The aim of this study was to evaluate the effect of 12 weeks of continuous aerobic training in individualized intensity on SPA of rats and their gene expressions of monocarboxylate transporters (MCT) 1 and 4 in soleus (oxidative) and white gastrocnemius (glycolytic) muscles. We also analyzed the effect of continuous aerobic training on aerobic and anaerobic parameters using the lactate minimum test (LMT). Sixty-day-old rats were randomly divided into three groups: a baseline group in which rats were evaluated prior to initiation of the study; a control group (Co) in which rats were kept without any treatment during 12 weeks; and a chronic exercise group (Tr) in which rats swam for 40 min/day, 5 days/week at 80% of anaerobic threshold during 12 weeks. After the experimental period, SPA of rats was measured using a gravimetric method. Rats had their expression of MCTs determined by RT-PCR analysis. In essence, aerobic training is effective in maintaining SPA, but did not prevent the decline of aerobic capacity and anaerobic performance, leading us to propose that the decline of SPA is not fully attributed to a deterioration of physical properties. Changes in SPA were concomitant with changes in MCT1 expression in the soleus muscle of trained rats, suggestive of an additional adaptive response toward increased lactate clearance. This result is in line with our observation showing a better equilibrium on lactate production-remotion during the continuous exercise (LMT). We propose an approach to combat the decline of SPA of rats in their home

Circulating microRNAs as potential biomarkers of aerobic exercise capacity.

PubMed

Mooren, Frank C; Viereck, Janika; Krüger, Karsten; Thum, Thomas

2014-02-15

Purpose microRNAs (miRs) are crucial intracellular mediators of various biological processes, also affecting the cardiovascular system. Recently, it has been shown that miRs circulate extracellularly in the bloodstream and that such circulating miRs change in response to physical activity. Therefore, the purpose of the current study was to investigate heart/muscle specific and inflammation related miRs in plasma of individuals before, directly after, and 24 h after a marathon run and to analyze their relation to conventional biochemical, cardiovascular, and performance indexes. Male endurance athletes (n =14) were recruited for the study after performing a battery of cardiac functional tests. Blood samples were collected before, directly after, and 24 h after a public marathon run. miR-1, miR-133, miR-206, miR-499, miR-208b, miR-21, and miR-155 were measured using individual Taqman assays and normalized to Caenorhabditis elegans miR-39 (cel-39) spike-in control. Moreover, soluble cardiac, inflammatory, and muscle damage markers were determined. As a result, skeletal- and heart muscle-specific miRs showed a significant increase after the marathon. The strongest increase was observed for miR-206. Twenty-four hours after the run, only miR-499 and miR-208b were returned to preexercise levels, whereas the others were still enhanced. In contrast, miR-21 and -155 were not affected by exercise. miR-1, -133a, and -206 correlated to aerobic performance parameters such as maximum oxygen uptake (VO(2max)) and running speed at individual anaerobic lactate threshold (VIAS). miR-1 showed a moderate negative correlation with fractional shortening, whereas miR-133a was positively related to the thickness of intraventricular septum. None of the miRs correlated with cardiac injury markers such as troponin T, troponin I, and pro-brain natriuretic peptide. In conclusion, these findings suggest a potential role for muscle- and heart-specific miRs in cardiovascular adaptation processes

REDD1 induction regulates the skeletal muscle gene expression signature following acute aerobic exercise.

PubMed

Gordon, Bradley S; Steiner, Jennifer L; Rossetti, Michael L; Qiao, Shuxi; Ellisen, Leif W; Govindarajan, Subramaniam S; Eroshkin, Alexey M; Williamson, David L; Coen, Paul M

2017-12-01

The metabolic stress placed on skeletal muscle by aerobic exercise promotes acute and long-term health benefits in part through changes in gene expression. However, the transducers that mediate altered gene expression signatures have not been completely elucidated. Regulated in development and DNA damage 1 (REDD1) is a stress-induced protein whose expression is transiently increased in skeletal muscle following acute aerobic exercise. However, the role of this induction remains unclear. Because REDD1 altered gene expression in other model systems, we sought to determine whether REDD1 induction following acute exercise altered the gene expression signature in muscle. To do this, wild-type and REDD1-null mice were randomized to remain sedentary or undergo a bout of acute treadmill exercise. Exercised mice recovered for 1, 3, or 6 h before euthanization. Acute exercise induced a transient increase in REDD1 protein expression within the plantaris only at 1 h postexercise, and the induction occurred in both cytosolic and nuclear fractions. At this time point, global changes in gene expression were surveyed using microarray. REDD1 induction was required for the exercise-induced change in expression of 24 genes. Validation by RT-PCR confirmed that the exercise-mediated changes in genes related to exercise capacity, muscle protein metabolism, neuromuscular junction remodeling, and Metformin action were negated in REDD1-null mice. Finally, the exercise-mediated induction of REDD1 was partially dependent upon glucocorticoid receptor activation. In all, these data show that REDD1 induction regulates the exercise-mediated change in a distinct set of genes within skeletal muscle. Copyright © 2017 the American Physiological Society.

Effects of detraining on anthropometry, aerobic capacity and functional ability in adults with Down syndrome.

PubMed

Boer, P H

2018-01-01

Structured exercise has shown to improve parameters of functional fitness in adults with Down syndrome (DS). However, few, if any, continue to exercise after exercise intervention studies. Consequently, the purpose of this study was to determine the effects of detraining on anthropometry, aerobic capacity and functional ability of adults with DS. In a previous study, forty-two participants either performed 12 weeks of interval training, continuous aerobic training or no training (CON). After 3 months of detraining, the same participants were tested again for anthropometry, aerobic capacity, leg strength and functional ability. Significant reductions in maximal aerobic capacity, time to exhaustion and both functional test items were reported for both exercise groups compared to CON (p < .05). No significant differences were reported between the exercise groups concerning aerobic and functional capacity reductions. Detraining occurred significantly in both exercise groups regarding parameters associated with aerobic and functional capacity. © 2017 John Wiley & Sons Ltd.

Effects of dominant somatotype on aerobic capacity trainability

PubMed Central

Chaouachi, M; Chaouachi, A; Chamari, K; Chtara, M; Feki, Y; Amri, M; Trudeau, F

2005-01-01

Purpose: This study examined the association between dominant somatotype and the effect on aerobic capacity variables of individualised aerobic interval training. Methods: Forty one white North African subjects (age 21.4±1.3 years; V·o2max = 52.8±5.7 ml kg–1 min–1) performed three exercise tests 1 week apart (i) an incremental test on a cycle ergometer to determine V·o2max and V·o2 at the second ventilatory threshold (VT2); (ii) a VAM-EVAL track test to determine maximal aerobic speed (vV·o2max); and (iii) an exhaustive constant velocity test to determine time limit performed at 100% vV·o2max (tlim100). Subjects were divided into four somatometric groups: endomorphs-mesomorphs (Endo-meso; n = 9), mesomorphs (Meso; n = 11), mesomorphs-ectomorphs (Meso-ecto; n = 12), and ectomorphs (Ecto; n = 9). Subjects followed a 12 week training program (two sessions/week). Each endurance training session consisted of the maximal number of successive fractions for each subject. Each fraction consisted of one period of exercise at 100% of vV·o2max and one of active recovery at 60% of vV·o2max. The duration of each period was equal to half the individual tlim100 duration (153.6±39.7 s). After the training program, all subjects were re-evaluated for comparison with pre-test results. Results: Pre- and post-training data were grouped by dominant somatotype. Two way ANOVA revealed significant somatotype-aerobic training interaction effects (p<0.001) for improvements in vV·o2max, V·o2max expressed classically and according to allometric scaling, and V·o2 at VT2. There were significant differences among groups post-training: the Meso-ecto and the Meso groups showed the greatest improvements in aerobic capacity. Conclusion: The significant somatotype-aerobic training interaction suggests different trainability with intermittent and individualised aerobic training according to somatotype. PMID:16306506

Exercise training enhances aerobic capacity in juvenile estuarine crocodiles (Crocodylus porosus).

PubMed

Owerkowicz, Tomasz; Baudinette, Russell V

2008-06-01

Aerobic capacity (VO2max) of endothermic vertebrates is known to increase with exercise training, but this effect has not been found to-date in non-avian reptiles. We exercised juvenile estuarine crocodiles (Crocodylus porosus) to walk at 0.75-0.88 km/h on a treadmill for up to 20 min a day over 16 weeks, and compared their aerobic performance with that of unexercised crocodiles. In the exercised group, VO2max increased from 6.9 to 8.5 mLO2/kg/min (+28%), and locomotor endurance increased from 3.8 to 6.9 min (+82%). Neither VO2max nor endurance changed significantly in the sedentary group. This finding extends the exercise training effect onto another vertebrate clade, and demonstrates that ectothermic amniotes are capable of elevating their aerobic capacity in response to exercise training. We propose that differences in cardiopulmonary structure and function in non-avian reptiles may be responsible for the absence (in squamates) or presence (in crocodilians) of a strong training effect on aerobic capacity.

New insights into the benefits of exercise for muscle health in patients with idiopathic inflammatory myositis.

PubMed

Alemo Munters, Li; Alexanderson, Helene; Crofford, Leslie J; Lundberg, Ingrid E

2014-07-01

With recommended treatment, a majority with idiopathic inflammatory myopathy (IIM) develop muscle impairment and poor health. Beneficial effects of exercise have been reported on muscle performance, aerobic capacity and health in chronic polymyositis and dermatomyositis and to some extent in active disease and inclusion body myositis (IBM). Importantly, randomized controlled trials (RCTs) indicate that improved health and decreased clinical disease activity could be mediated through increased aerobic capacity. Recently, reports seeking mechanisms underlying effects of exercise in skeletal muscle indicate increased aerobic capacity (i.e. increased mitochondrial capacity and capillary density, reduced lactate levels), activation of genes in aerobic phenotype and muscle growth programs, and down regulation in genes related to inflammation. Altogether, exercise contributes to both systemic and within-muscle adaptations demonstrating that exercise is fundamental to improve muscle performance and health in IIM. There is a need for RCTs to study effects of exercise in active disease and IBM.

Effect of aerobic capacity on Lower Body Negative Pressure (LBNP) tolerance in females

NASA Technical Reports Server (NTRS)

Moore, Alan D., Jr.; Fortney, Suzanne M.; Siconolfi, Steven F.

1993-01-01

This investigation determined whether a relationship exists in females between: (1) aerobic capacity and Lower Body Negative Pressure (LBNP); and (2) aerobic capacity and change in LBNP tolerance induced by bed rest. Nine females, age 27-47 (34.6 plus or minus 6.0 (Mean plus or minus SD)), completed a treadmill-graded exercise test to establish aerobic capacity. A presyncopal-limited LBNP test was performed prior to and after 13 days of bed rest at a 6 deg head-down tilt. LBNP tolerance was quantified as: (1) the absolute level of negative pressure (NP) tolerated for greater than or equal to 60 sec; and (2) Luft's Cumulative Stress Index (CSI). Aerobic capacity was 33.3 plus or minus 5.0 mL/kg/min and ranged from 25.7 to 38.7. Bed rest was associated with a decrease in NP tolerance (-9.04 1.6 kPa(-67.8 plus or minus 12.0 mmHg) versus -7.7 1.1 kPa(-57.8 plus or minus 8.33 mmHg); p = 0.028) and in CSI (99.4 27.4 kPa min(745.7 plus or minus 205.4 mmHg min) versus 77.0 16.9 kPa min (577.3 plus or minus mmHg min); p = 0.008). The correlation between aerobic capacity and absolute NP or CSI pre-bed rest did not differ significantly from zero (r = -0.56, p = 0.11 for NP; and r = -0.52, p = 0.16 for CSI). Also, no significant correlation was observed between aerobic and pre- to post-rest change for absolute NP tolerance (r = -0.35, p = 0.35) or CSI (r = -0.32, p = 0.40). Therefore, a significant relationship does not exist between aerobic capacity and orthostatic function or change in orthostatic function induced by bed rest.

Effects of Sesame (Sesamum indicum L.) Supplementation on Creatine Kinase, Lactate Dehydrogenase, Oxidative Stress Markers, and Aerobic Capacity in Semi-Professional Soccer Players

PubMed Central

Barbosa, Carlos V. da Silva; Silva, Alexandre S.; de Oliveira, Caio V. C.; Massa, Nayara M. L.; de Sousa, Yasmim R. F.; da Costa, Whyara K. A.; Silva, Ayice C.; Delatorre, Plínio; Carvalho, Rhayane; Braga, Valdir de Andrade; Magnani, Marciane

2017-01-01

Nutritional intervention with antioxidants rich foods has been considered a strategy to minimize the effects of overtraining in athletes. This experimental, randomized, and placebo-controlled study evaluated the effects of consumption of sesame (Sesamum indicum L.) on muscle damage markers, oxidative stress, systemic inflammation, and aerobic performance in male semi-professional soccer players. Twenty athletes were randomly assigned to groups that received 40 g (two tablespoons) per day of sesame or a placebo during 28 days of regular training (exposed to routine training that includes loads of heavy training in the final half of the season). Before and after intervention, creatine kinase (CK), lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), C-reactive protein (hs-CRP), and aerobic capacity were evaluated. Before intervention, a physiologic imbalance was noted in both groups related to CK and LDH levels. Sesame intake caused a reduction of CK (19%, p < 0.05), LDH (37%, p < 0.05), MDA (55%, p < 0.05) and hs-CRP (53%, p < 0.05) and increased SOD (14%, p < 0.05), vitamin A (25%, p < 0.05), and vitamin E (65%, p < 0.05) in the experimental group. These phenomena were accompanied by increased aerobic capacity (17%, p < 0.05). The placebo group showed an increase in CK (5%, p < 0.05) and no significant change in LDH, SOD or vitamin A. MDA levels decreased (21%, p < 0.05) and vitamin E increased (14%, p < 0.05) in the placebo group, but to a much lesser extent than in the experimental group. These results show that sesame consumption may reduce muscle damage and oxidative stress while improving the aerobic capacity in soccer players. PMID:28408889

Physical Activity, Aerobic Capacity, and Total Antioxidant Capacity in Healthy Men and in Men with Coronary Heart Disease.

PubMed

Gawron-Skarbek, Anna; Chrzczanowicz, Jacek; Kostka, Joanna; Nowak, Dariusz; Drygas, Wojciech; Jegier, Anna; Kostka, Tomasz

2015-01-01

The purpose of the study was to assess total antioxidant capacity (TAC) of blood serum in relation with habitual leisure time physical activity (LTPA) and aerobic capacity in a group of 90 men with coronary heart disease (CHD) aged 34.8-77.0 years and in 90 age-matched peers without CHD. Two spectrophotometric methods were applied to assess TAC: Ferric Reducing Ability of Serum (TAC-FRAS) and 2.2-diphenyl-1-picryl-hydrazyl (TAC-DPPH) tests. Aerobic capacity was expressed as physical working capacity at 85% of the maximal heart rate (PWC(85%HRmax)). CHD patients had higher values of TACFRAS (1.37 ± 0.28 versus 1.27 ± 0.23 mmol FeCl2·L(-1); P < 0.05) but there were no group differences for TAC-DPPH and for uric acid (UA). Negative correlation was found between LTPA (also when calculated per kg of body mass) and TAC-DPPH in CHD patients. In CHD patients, TAC-FRAS and UA were lower in subjects with higher aerobic capacity expressed as PWC(85%HRmax/kg). Those associations were not found in healthy men. We conclude that TAC of blood serum is moderately adversely related to LTPA and aerobic capacity in patients with CHD. UA, as the main determinant of serum TAC, may be partially responsible for those associations.

Physical Activity, Aerobic Capacity, and Total Antioxidant Capacity in Healthy Men and in Men with Coronary Heart Disease

PubMed Central

Gawron-Skarbek, Anna; Kostka, Joanna; Nowak, Dariusz; Drygas, Wojciech; Jegier, Anna; Kostka, Tomasz

2015-01-01

Objective. The purpose of the study was to assess total antioxidant capacity (TAC) of blood serum in relation with habitual leisure time physical activity (LTPA) and aerobic capacity in a group of 90 men with coronary heart disease (CHD) aged 34.8–77.0 years and in 90 age-matched peers without CHD. Methods. Two spectrophotometric methods were applied to assess TAC: Ferric Reducing Ability of Serum (TAC-FRAS) and 2.2-diphenyl-1-picryl-hydrazyl (TAC-DPPH) tests. Aerobic capacity was expressed as physical working capacity at 85% of the maximal heart rate (PWC85%HRmax). Results. CHD patients had higher values of TACFRAS (1.37 ± 0.28 versus 1.27 ± 0.23 mmol FeCl2·L−1; P < 0.05) but there were no group differences for TAC-DPPH and for uric acid (UA). Negative correlation was found between LTPA (also when calculated per kg of body mass) and TAC-DPPH in CHD patients. In CHD patients, TAC-FRAS and UA were lower in subjects with higher aerobic capacity expressed as PWC85%HRmax/kg. Those associations were not found in healthy men. Conclusions. We conclude that TAC of blood serum is moderately adversely related to LTPA and aerobic capacity in patients with CHD. UA, as the main determinant of serum TAC, may be partially responsible for those associations. PMID:26451234

Comparison of normalized maximum aerobic capacity and body composition of sumo wrestlers to athletes in combat and other sports.

PubMed

Beekley, Matthew D; Abe, Takashi; Kondo, Masakatsu; Midorikawa, Taishi; Yamauchi, Taro

2006-01-01

Sumo wrestling is unique in combat sport, and in all of sport. We examined the maximum aerobic capacity and body composition of sumo wrestlers and compared them to untrained controls. We also compared "aerobic muscle quality", meaning VO2max normalized to predicted skeletal muscle mass (SMM) (VO2max /SMM), between sumo wrestlers and controls and among previously published data for male athletes from combat, aerobic, and power sports. Sumo wrestlers, compared to untrained controls, had greater (p < 0.05) body mass (mean ± SD; 117.0 ± 4.9 vs. 56.1 ± 9.8 kg), percent fat (24.0 ± 1.4 vs. 13.3 ± 4.5), fat-free mass (88.9 ± 4.2 vs. 48.4 ± 6.8 kg), predicted SMM (48.2 ± 2.9 vs. 20.6 ± 4.7 kg) and absolute VO2max (3.6 ± 1.3 vs. 2.5 ± 0.7 L·min(-1)). Mean VO2max /SMM (ml·kg SMM(-1)·min(-1)) was significantly different (p < 0.05) among aerobic athletes (164.8 ± 18.3), combat athletes (which was not different from untrained controls; 131.4 ± 9.3 and 128.6 ± 13.6, respectively), power athletes (96.5 ± 5.3), and sumo wrestlers (71.4 ± 5.3). There was a strong negative correlation (r = - 0.75) between percent body fat and VO2max /SMM (p < 0.05). We conclude that sumo wrestlers have some of the largest percent body fat and fat-free mass and the lowest "aerobic muscle quality "(VO2max /SMM), both in combat sport and compared to aerobic and power sport athletes. Additionally, it appears from analysis of the relationship between SMM and absolute VO2max for all sports that there is a "ceiling "at which increases in SMM do not result in additional increases in absolute VO2max. Key PointsSumo wrestlers have a high absolute VO2max compared to untrained controls.However, sumo wrestlers have a low VO2max /kg of skeletal muscle mass compared to other combat sports, other strength/power sports, and untrained controls.The reason for this is unknown, but is probably related to alterations in sumo skeletal muscle compared to other sports.Based on the present and previous

Aerobic exercise deconditioning and countermeasures during bed rest.

PubMed

Lee, Stuart M C; Moore, Alan D; Everett, Meghan E; Stenger, Michael B; Platts, Steven H

2010-01-01

Bed rest is a well-accepted model for spaceflight in which the physiologic adaptations, particularly in the cardiovascular system, are studied and potential countermeasures can be tested. Bed rest without countermeasures results in reduced aerobic capacity and altered submaximal exercise responses. Aerobic endurance and factors which may impact prolonged exercise, however, have not been well studied. The initial loss of aerobic capacity is rapid, occurring in parallel with the loss of plasma volume. Thereafter, the reduction in maximal aerobic capacity proceeds more slowly and is influenced by central and peripheral adaptation. Exercise capacity can be maintained during bed rest and may be improved during recovery with appropriate countermeasures. Plasma volume restoration, resistive exercise, orthostatic stress, aerobic exercise, and aerobic exercise plus orthostatic stress all have been tested with varying levels of success. However, the optimal combination of elements-exercise modality, intensity, duration, muscle groups exercised and frequency of aerobic exercise, orthostatic stress, and supplementary resistive or anaerobic exercise training-has not been systematically evaluated. Currently, frequent (at least 3 days per week) bouts of intense exercise (interval-style and near maximal) with orthostatic stress appears to be the most efficacious method to protect aerobic capacity during bed rest. Further refinement of protocols and countermeasure hardware may be necessary to insure the success of countermeasures in the unique environment of space.

Nordic Walking Can Be Incorporated in the Exercise Prescription to Increase Aerobic Capacity, Strength, and Quality of Life for Elderly: A Systematic Review and Meta-Analysis.

PubMed

Bullo, Valentina; Gobbo, Stefano; Vendramin, Barbara; Duregon, Federica; Cugusi, Lucia; Di Blasio, Andrea; Bocalini, Danilo Sales; Zaccaria, Marco; Bergamin, Marco; Ermolao, Andrea

2018-04-01

The aim of this systematic review and meta-analysis was to summarize and analyze the effects of Nordic Walking on physical fitness, body composition, and quality of life in the elderly. Keyword "Nordic Walking" associated with "elderly" AND/OR "aging" AND/OR "old subjects" AND/OR "aged" AND/OR "older adults" were used in the online database MEDLINE, Embase, PubMed, Scopus, PsycINFO, and SPORTDiscus. Only studies written in English language and published in peer-reviewed journals were considered. A meta-analysis was performed and effect sizes calculated. Fifteen studies were identified; age of participants ranged from 60 to 92 years old. Comparing with a sedentary group, effect sizes showed that Nordic Walking was able to improve dynamic balance (0.30), functional balance (0.62), muscle strength of upper (0.66) and lower limbs (0.43), aerobic capacity (0.92), cardiovascular outcomes (0.23), body composition (0.30), and lipid profile (0.67). It seemed that Nordic Walking had a negative effect on static balance (-0.72). Comparing with a walking (alone) training, effect sizes showed that Nordic Walking improved the dynamic balance (0.30), flexibility of the lower body (0.47), and quality of life (0.53). Walking training was more effective in improving aerobic capacity (-0.21). Comparing Nordic Walking with resistance training, effect sizes showed that Nordic Walking improved dynamic balance (0.33), muscle strength of the lower body (0.39), aerobic capacity (0.75), flexibility of the upper body (0.41), and the quality of life (0.93). Nordic Walking can be considered as a safe and accessible form of aerobic exercise for the elderly population, able to improve cardiovascular outcomes, muscle strength, balance ability, and quality of life.

Comparisons of low-intensity versus moderate-intensity combined aerobic and resistance training on body composition, muscle strength, and functional performance in older women.

PubMed

Shiotsu, Yoko; Yanagita, Masahiko

2018-06-01

This study aimed to examine the effects of exercise order of combined aerobic and low- or moderate-intensity resistance training into the same session on body composition, functional performance, and muscle strength in healthy older women. Furthermore, this study compared the effects of different (low- vs moderate-) intensity combined training. A total of 60 healthy older women (age 61-81 y) were randomly assigned to five groups that performed aerobic exercise before low-intensity resistance training (AR-L, n = 12) or after resistance training (RA-L, n = 12), performed aerobic exercise before moderate-intensity resistance training (AR-M, n = 12) or after resistance training (RA-M, n = 12), or nonintervention control conditions (CON, n = 12). Body composition, functional performance, and muscle strength were evaluated before and after the 10-week training. No effects of exercise order of combined aerobic and low- or moderate-intensity resistance training (AR-L vs RA-L, AR-M vs RA-M) were observed in body composition, functional performance, or muscle strength, whereas the effects of training intensity of combined training (AR-L vs AR-M, RA-L vs RA-M) were observed on functional performance. All combined trainings significantly increased muscle strength and gait ability (P < 0.01, respectively). Functional reach test significantly increased in the AR-M and RA-M groups (P < 0.01, respectively), and there were significant group differences between AR-L and AR-M (P = 0.002), RA-L and RA-M (P = 0.014). Preliminary findings suggest that combined aerobic and low- or moderate-intensity resistance training increases muscle strength and improves gait ability, regardless of the exercise order. Also, greater improvement in dynamic balance capacity, a risk factor associated with falling, is observed in moderate-intensity combined training.

[Aerobic capacity, weight status and self-concept in schoolchildren].

PubMed

Gálvez Casas, Arancha; Rodríguez García, Pedro Luis; Rosa Guillamón, Andrés; García-Cantó, Eliseo; Pérez Soto, Juan José; Tárraga López, Pedro; Tárraga Marcos, Loreto

2016-01-01

To analyze the relationship between self-concept, aerobic capacity and weight status in schoolchildren. Relational descriptive design in which was assessed the weight status and aerobic capacity of 256 schoolchildren among 8-11 years. Aerobic capacity (low vs high) and the body mass index (normal-weight vs overweight-obesity) were categorized using standard criteria. The self-concept was assessed through the Piers Harris self-concept scale for children. Schoolchildren with normal-weight and high fitness level showed better levels of conductual self-concept (P=.030), physical (P<.001), lack of anxiety (P=.048), and global self-concept (P=.002). The schoolchildren with normal-weight show higher levels of conductual self-concpt (P=.016), intellectual (P=.050), physical (P<.001), life satisfaction (P=.036), and global self-concept (P=.001). The schoolchildren with a higher fitness level showed better conductual self-concept (P=.024), physical (P=.004), lack of anxiety (P=.011), social (P=.024), and global (P=.003). The results of the study strengthen the importance to transmit to the educative community the knowledge of the relationship between the variables analyzed aiming to improve the schoolchildren self-concept. Copyright © 2015 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

Relation between aerobic capacity and walking ability in older adults with a lower-limb amputation.

PubMed

Wezenberg, Daphne; van der Woude, Lucas H; Faber, Willemijn X; de Haan, Arnold; Houdijk, Han

2013-09-01

To determine the relative aerobic load, walking speed, and walking economy of older adults with a lower-limb prosthesis, and to predict the effect of an increased aerobic capacity on their walking ability. Cross-sectional. Human motion laboratory at a rehabilitation center. Convenience sample of older adults (n=36) who underwent lower-limb amputation because of vascular deficiency or trauma and able-bodied controls (n=21). Not applicable. Peak aerobic capacity and oxygen consumption while walking were determined. The relative aerobic load and walking economy were assessed as a function of walking speed, and a data-based model was constructed to predict the effect of an increased aerobic capacity on walking ability. People with a vascular amputation walked at a substantially higher (45.2%) relative aerobic load than people with an amputation because of trauma. The preferred walking speed in both groups of amputees was slower than that of able-bodied controls and below their most economical walking speed. We predicted that a 10% increase in peak aerobic capacity could potentially result in a reduction in the relative aerobic load of 9.1%, an increase in walking speed of 17.3% and 13.9%, and an improvement in the walking economy of 6.8% and 2.9%, for people after a vascular or traumatic amputation, respectively. Current findings corroborate the notion that, especially in people with a vascular amputation, the peak aerobic capacity is an important determinant for walking ability. The data provide quantitative predictions on the effect of aerobic training; however, future research is needed to experimentally confirm these predictions. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Low Volume Aerobic Training Heightens Muscle Deoxygenation in Early Post-Angina Pectoris Patients.

PubMed

Takagi, Shun; Murase, Norio; Kime, Ryotaro; Niwayama, Masatsugu; Osada, Takuya; Katsumura, Toshihito

2016-01-01

The aim of this study was to investigate the effect of low volume aerobic exercise training on muscle O2 dynamics during exercise in early post-angina pectoris (AP) patients, as a pilot study. Seven AP patients (age: 72 ± 6 years) participated in aerobic exercise training for 12 weeks. Training consisted of continuous cycling exercise for 30 min at the individual's estimated lactate threshold, and the subjects trained for 15 ± 5 exercise sessions over 12 weeks. Before and after training, the subjects performed ramp cycling exercise until exhaustion. Muscle O2 saturation (SmO2) and relative changes from rest in deoxygenated hemoglobin concentration (∆Deoxy-Hb) and total hemoglobin concentration (∆Total-Hb) were monitored at the vastus lateralis by near infrared spatial resolved spectroscopy during exercise. The SmO2 was significantly lower and ∆Deoxy-Hb was significantly higher after training than before training, while there were no significant changes in ∆Total-Hb. These results indicated that muscle deoxygenation and muscle O2 extraction were potentially heightened by aerobic exercise training in AP patients, even though the exercise training volume was low.

Eight weeks of exercise training increases aerobic capacity and muscle mass and reduces fatigue in patients with cirrhosis.

PubMed

Zenith, Laura; Meena, Neha; Ramadi, Ailar; Yavari, Milad; Harvey, Andrea; Carbonneau, Michelle; Ma, Mang; Abraldes, Juan G; Paterson, Ian; Haykowsky, Mark J; Tandon, Puneeta

2014-11-01

Patients with cirrhosis have reduced exercise tolerance, measured objectively as decreased peak exercise oxygen uptake (peak VO2). Reduced peak VO2 is associated with decreased survival time. The effect of aerobic exercise training on peak VO2 has not been well studied in patients with cirrhosis. We evaluated the safety and efficacy of 8 weeks of supervised exercise on peak VO2, quadriceps muscle thickness, and quality of life. In a prospective pilot study, stable patients (79% male, 57.6 ± 6.7 years old) with Child-Pugh class A or B cirrhosis (mean Model for End-Stage Liver Disease score, 10 ± 2.2) were randomly assigned to groups that received exercise training (n = 9) or usual care (controls, n = 10) at the University of Alberta Hospital in Canada from February through June 2013. Supervised exercise was performed on a cycle ergometer 3 days/week for 8 weeks at 60%-80% of baseline peak VO2. Peak VO2, quadriceps muscle thickness (measured by ultrasound), thigh circumference, answers from Chronic Liver Disease Questionnaires, EQ-visual analogue scales, 6-minute walk distance, and Model for End-Stage Liver Disease scores were evaluated at baseline and at week 8. Analysis of covariance was used to compare variables. At week 8, peak VO2 was 5.3 mL/kg/min higher in the exercise group compared with controls (95% confidence interval, 2.9-7.8; P = .001). Thigh circumference (P = .001), thigh muscle thickness (P = .01), and EQ-visual analogue scale determined self-perceived health status (P = .01) was also significantly higher in the exercise group compared with controls at week 8; fatigue subscores of the Chronic Liver Disease Questionnaires were lower in the exercise group compared with controls (P = .01). No adverse events occurred during cardiopulmonary exercise testing or training. In a controlled prospective pilot trial, 8 weeks of supervised aerobic exercise training increased peak VO2 and muscle mass and reduced fatigue in patients with cirrhosis. No

The effect of estrogen on muscle damage biomarkers following prolonged aerobic exercise in eumenorrheic women.

PubMed

Williams, T; Walz, E; Lane, A R; Pebole, M; Hackney, A C

2015-09-01

This study assessed the influence of estrogen (E2) on muscle damage biomarkers [skeletal muscle - creatine kinase (CK); cardiac muscle - CK-MB] responses to prolonged aerobic exercise. Eumenorrheic women (n=10) who were physically active completed two 60-minute treadmill running sessions at ∼60-65% maximal intensity during low E2 (midfollicular menstrual phase) and high E2 (midluteal menstrual phase) hormonal conditions. Blood samples were collected prior to exercise (following supine rest), immediately post-, 30 min post-, and 24 hours post-exercise to determine changes in muscle biomarkers. Resting blood samples confirmed appropriate E2 hormonal levels Total CK concentrations increased following exercise and at 24 hours post-exercise were higher in the midfollicular low E2 phase (p<0.001). However, CK-MB concentrations were unaffected by E2 level or exercise (p=0.442) resulting in the ratio of CK-MB to total CK being consistently low in subject responses (i.e., indicative of skeletal muscle damage). Elevated E2 levels reduce the CK responses of skeletal muscle, but had no effect on CK-MB responses following prolonged aerobic exercise. These findings support earlier work showing elevated E2 is protective of skeletal muscle from exercise-induced damage associated with prolonged aerobic exercise.

The effect of estrogen on muscle damage biomarkers following prolonged aerobic exercise in eumenorrheic women

PubMed Central

Walz, E; Lane, AR; Pebole, M; Hackney, AC

2015-01-01

This study assessed the influence of estrogen (E2) on muscle damage biomarkers [skeletal muscle - creatine kinase (CK); cardiac muscle - CK-MB] responses to prolonged aerobic exercise. Eumenorrheic women (n=10) who were physically active completed two 60-minute treadmill running sessions at ∼60-65% maximal intensity during low E2 (midfollicular menstrual phase) and high E2 (midluteal menstrual phase) hormonal conditions. Blood samples were collected prior to exercise (following supine rest), immediately post-, 30 min post-, and 24 hours post-exercise to determine changes in muscle biomarkers. Resting blood samples confirmed appropriate E2 hormonal levels Total CK concentrations increased following exercise and at 24 hours post-exercise were higher in the midfollicular low E2 phase (p<0.001). However, CK-MB concentrations were unaffected by E2 level or exercise (p=0.442) resulting in the ratio of CK-MB to total CK being consistently low in subject responses (i.e., indicative of skeletal muscle damage). Elevated E2 levels reduce the CK responses of skeletal muscle, but had no effect on CK-MB responses following prolonged aerobic exercise. These findings support earlier work showing elevated E2 is protective of skeletal muscle from exercise-induced damage associated with prolonged aerobic exercise. PMID:26424921

Relation of systemic and local muscle exercise capacity to skeletal muscle characteristics in men with congestive heart failure

NASA Technical Reports Server (NTRS)

Massie, B. M.; Simonini, A.; Sahgal, P.; Wells, L.; Dudley, G. A.

1996-01-01

patients. None of the skeletal muscle characteristics examined correlated with exercise capacity in control subjects. CONCLUSIONS. These results indicate that congestive heart failure is associated with changes in the characteristics of skeletal muscle and local as well as systemic exercise performance. There are fewer slow twitch fibers, smaller fast twitch fibers and lower succinate dehydrogenase activity. The latter finding suggests that mitochondrial content of muscle is reduced in heart failure and that impaired aerobic-oxidative capacity may play a role in the limitation of systemic exercise capacity.

Integrated Resistance and Aerobic Training Maintains Cardiovascular and Skeletal Muscle Fitness During 14 Days of Bed Rest

NASA Technical Reports Server (NTRS)

Ploutz-Snyder, Lori; Goetchius, Elizabeth; Crowell, Brent; Hackney, Kyle; Wickwire, Jason; Ploutz-Snyder, Robert; Snyder, Scott

2012-01-01

Background: Known incompatibilities exist between resistance and aerobic training. Of particular importance are findings that concurrent resistance and aerobic training reduces the effectiveness of the resistance training and limits skeletal muscle adaptations (example: Dudley & Djamil, 1985). Numerous unloading studies have documented the effectiveness of resistance training alone for the maintenance of skeletal muscle size and strength. However the practical applications of those studies are limited because long ]duration crew members perform both aerobic and resistance exercise throughout missions/spaceflight. To date, such integrated training on the International Space Station (ISS) has not been fully effective in the maintenance of skeletal muscle function. Purpose: The purpose of this study was to evaluate the efficacy of high intensity concurrent resistance and aerobic training for the maintenance of cardiovascular fitness and skeletal muscle strength, power and endurance over 14 days of strict bed rest. Methods: 9 subjects (8 male and 1 female; 34.5 +/- 8.2 years) underwent 14 days of bed rest with concurrent training. Resistance and aerobic training were integrated as shown in table 1. Days that included 2 exercise sessions had a 4-8 hour rest between exercise bouts. The resistance training consisted of 3 sets of 12 repetitions of squat, heel raise, leg press and hamstring curl exercise. Aerobic exercise consisted of periodized interval training that included 30 sec, 2 min and 4 min intervals alternating by day with continuous aerobic exercise.

Aerobic metabolism underlies complexity and capacity

PubMed Central

Koch, Lauren G; Britton, Steven L

2008-01-01

The evolution of biological complexity beyond single-celled organisms was linked temporally with the development of an oxygen atmosphere. Functionally, this linkage can be attributed to oxygen ranking high in both abundance and electronegativity amongst the stable elements of the universe. That is, reduction of oxygen provides for close to the largest possible transfer of energy for each electron transfer reaction. This suggests the general hypothesis that the steep thermodynamic gradient of an oxygen environment was permissive for the development of multicellular complexity. A corollary of this hypothesis is that aerobic metabolism underwrites complex biological function mechanistically at all levels of organization. The strong contemporary functional association of aerobic metabolism with both physical capacity and health is presumably a product of the integral role of oxygen in our evolutionary history. Here we provide arguments from thermodynamics, evolution, metabolic network analysis, clinical observations and animal models that are in accord with the centrality of oxygen in biology. PMID:17947307

Aerobic exercise and respiratory muscle strength in patients with cystic fibrosis.

PubMed

Dassios, Theodore; Katelari, Anna; Doudounakis, Stavros; Dimitriou, Gabriel

2013-05-01

The beneficial role of exercise in maintaining health in patients with cystic fibrosis (CF) is well described. Few data exist on the effect of exercise on respiratory muscle function in patients with CF. Our objective was to compare respiratory muscle function indices in CF patients that regularly exercise with those CF patients that do not. This cross-sectional study assessed nutrition, pulmonary function and respiratory muscle function in 37 CF patients that undertook regular aerobic exercise and in a control group matched for age and gender which consisted of 44 CF patients that did not undertake regular exercise. Respiratory muscle function in CF was assessed by maximal inspiratory pressure (Pimax), maximal expiratory pressure (Pemax) and pressure-time index of the respiratory muscles (PTImus). Median Pimax and Pemax were significantly higher in the exercise group compared to the control group (92 vs. 63 cm H2O and 94 vs. 64 cm H2O respectively). PTImus was significantly lower in the exercise group compared to the control group (0.089 vs. 0.121). Upper arm muscle area (UAMA) and mid-arm muscle circumference were significantly increased in the exercise group compared to the control group (2608 vs. 2178 mm2 and 23 vs. 21 cm respectively). UAMA was significantly related to Pimax in the exercising group. These results suggest that CF patients that undertake regular aerobic exercise maintain higher indices of respiratory muscle strength and lower PTImus values, while increased UAMA values in exercising patients highlight the importance of muscular competence in respiratory muscle function in this population. Copyright © 2013 Elsevier Ltd. All rights reserved.

Muscle quality, aerobic fitness and fat mass predict lower-extremity physical function in community-dwelling older adults.

PubMed

Misic, Mark M; Rosengren, Karl S; Woods, Jeffrey A; Evans, Ellen M

2007-01-01

Muscle mass, strength and fitness play a role in lower-extremity physical function (LEPF) in older adults; however, the relationships remain inadequately characterized. This study aimed to examine the relationships between leg mineral free lean mass (MFLM(LEG)), leg muscle quality (leg strength normalized for MFLM(LEG)), adiposity, aerobic fitness and LEPF in community-dwelling healthy elderly subjects. Fifty-five older adults (69.3 +/- 5.5 years, 36 females, 19 males) were assessed for leg strength using an isokinetic dynamometer, body composition by dual energy X-ray absorptiometry and aerobic fitness via a treadmill maximal oxygen consumption test. LEPF was assessed using computerized dynamic posturography and stair ascent/descent, a timed up-and-go task and a 7-meter walk with and without an obstacle. Muscle strength, muscle quality and aerobic fitness were similarly correlated with static LEPF tests (r range 0.27-0.40, p < 0.05); however, the strength of the independent predictors was not robust with explained variance ranging from 9 to 16%. Muscle quality was the strongest correlate of all dynamic LEPF tests (r range 0.54-0.65, p < 0.001). Using stepwise linear regression analysis, muscle quality was the strongest independent predictor of dynamic physical function explaining 29-42% of the variance (p < 0.001), whereas aerobic fitness or body fat mass explained 5-6% of the variance (p < 0.05) depending on performance measure. Muscle quality is the most important predictor, and aerobic fitness and fat mass are secondary predictors of LEPF in community-dwelling older adults. These findings support the importance of exercise, especially strength training, for optimal body composition, and maintenance of strength and physical function in older adults.

Whey protein with potassium bicarbonate supplement attenuates the reduction in muscle oxidative capacity during 19 days of bed rest.

PubMed

Bosutti, Alessandra; Salanova, Michele; Blottner, Dieter; Buehlmeier, Judith; Mulder, Edwin; Rittweger, Jörn; Yap, Moi Hoon; Ganse, Bergita; Degens, Hans

2016-10-01

The effectiveness of whey protein plus potassium bicarbonate-enriched diet (WP+KHCO 3 ) in mitigating disuse-induced changes in muscle fiber oxidative capacity and capillarization was investigated in a 21-day crossover design bed rest study. Ten healthy men (31 ± 6 yr) once received WP+KHCO 3 and once received a standardized isocaloric diet. Muscle biopsies were taken 2 days before and during the 19th day of bed rest (BR) from the soleus (SOL) and vastus lateralis (VL) muscle. Whole-body aerobic power (V̇o 2 max ), muscle fatigue, and isometric strength of knee extensor and plantar flexor muscles were monitored. Muscle fiber types and capillaries were identified by immunohistochemistry. Fiber oxidative capacity was determined as the optical density (OD) at 660 nm of succinate dehydrogenase (SDH)-stained sections. The product of fiber cross-sectional area and SDH-OD (integrated SDH) indicated the maximal oxygen consumption of that fiber. The maximal oxygen consumption supported by a capillary was calculated as the integrated SDH in its supply area. BR reduced isometric strength of knee extensor muscles (P < 0.05), and the fiber oxidative capacity (P < 0.001) and V̇o 2 max (P = 0.042), but had no significant impact on muscle capillarization or fatigue resistance of thigh muscles. The maximal oxygen consumption supported by a capillary was reduced by 24% in SOL and 16% in VL (P < 0.001). WP+KHCO 3 attenuated the disuse-induced reduction in fiber oxidative capacity in both muscles (P < 0.01). In conclusion, following 19 days of bed rest, the decrement in fiber oxidative capacity is proportionally larger than the loss of capillaries. WP+KHCO 3 appears to attenuate disuse-induced reductions in fiber oxidative capacity. Copyright © 2016 the American Physiological Society.

Aerobic Capacities of Early College High School Students

ERIC Educational Resources Information Center

Loflin, Jerry W.

2014-01-01

The Early College High School Initiative (ECHSI) was introduced in 2002. Since 2002, limited data, especially student physical activity data, have been published pertaining to the ECHSI. The purpose of this study was to examine the aerobic capacities of early college students and compare them to state and national averages. Early college students…

Aerobic capacity over 16 years in patients with rheumatoid arthritis: Relationship to disease activity and risk factors for cardiovascular disease

PubMed Central

Sundström, Björn; Innala, Lena; Rantapää-Dahlqvist, Solbritt; Wållberg-Jonsson, Solveig

2017-01-01

The aim of this study was to analyse the change in aerobic capacity from disease onset of rheumatoid arthritis (RA) over 16.2 years, and its associations with disease activity and cardiovascular risk factors. Twenty-five patients (20 f/5 m), diagnosed with RA 1995-2002 were tested at disease onset and after mean 16.2 years. Parameters measured were: sub-maximal ergometer test for aerobic capacity, functional ability, self-efficacy, ESR, CRP and DAS28. At follow-up, cardiovascular risk factors were assessed as blood lipids, glucose concentrations, waist circumference, body mass index (BMI), body composition, pulse wave analysis and carotid intima-media thickness. Aerobic capacity [median (IQR)] was 32.3 (27.9-42.1) ml O2/kg x min at disease onset, and 33.2 (28.4-38.9) at follow-up (p>0.05). Baseline aerobic capacity was associated with follow-up values of: BMI (rs = -.401, p = .047), waist circumference (rs = -.498, p = .011), peripheral pulse pressure (rs = -.415, p = .039) self-efficacy (rs = .420, p = .037) and aerobic capacity (rs = .557, p = .004). In multiple regression models adjusted for baseline aerobic capacity, disease activity at baseline and over time predicted aerobic capacity at follow-up (AUC DAS28, 0-24 months; β = -.14, p = .004). At follow-up, aerobic capacity was inversely associated with blood glucose levels (rs = -.508, p = .016), BMI (rs = -.434, p = .030), body fat% (rs = -.419, p = .037), aortic pulse pressure (rs = -.405, p = .044), resting heart rate (rs = -.424, p = .034) and self-efficacy (rs = .464, p = .020) at follow-up. We conclude that the aerobic capacity was maintained over 16 years. High baseline aerobic capacity associated with favourable measures of cardiovascular risk factors at follow-up. Higher disease activity in early stages of RA predicted lower aerobic capacity after 16.2 years. PMID:29272303

Aerobic capacity over 16 years in patients with rheumatoid arthritis: Relationship to disease activity and risk factors for cardiovascular disease.

PubMed

Hörnberg, Kristina; Sundström, Björn; Innala, Lena; Rantapää-Dahlqvist, Solbritt; Wållberg-Jonsson, Solveig

2017-01-01

The aim of this study was to analyse the change in aerobic capacity from disease onset of rheumatoid arthritis (RA) over 16.2 years, and its associations with disease activity and cardiovascular risk factors. Twenty-five patients (20 f/5 m), diagnosed with RA 1995-2002 were tested at disease onset and after mean 16.2 years. Parameters measured were: sub-maximal ergometer test for aerobic capacity, functional ability, self-efficacy, ESR, CRP and DAS28. At follow-up, cardiovascular risk factors were assessed as blood lipids, glucose concentrations, waist circumference, body mass index (BMI), body composition, pulse wave analysis and carotid intima-media thickness. Aerobic capacity [median (IQR)] was 32.3 (27.9-42.1) ml O2/kg x min at disease onset, and 33.2 (28.4-38.9) at follow-up (p>0.05). Baseline aerobic capacity was associated with follow-up values of: BMI (rs = -.401, p = .047), waist circumference (rs = -.498, p = .011), peripheral pulse pressure (rs = -.415, p = .039) self-efficacy (rs = .420, p = .037) and aerobic capacity (rs = .557, p = .004). In multiple regression models adjusted for baseline aerobic capacity, disease activity at baseline and over time predicted aerobic capacity at follow-up (AUC DAS28, 0-24 months; β = -.14, p = .004). At follow-up, aerobic capacity was inversely associated with blood glucose levels (rs = -.508, p = .016), BMI (rs = -.434, p = .030), body fat% (rs = -.419, p = .037), aortic pulse pressure (rs = -.405, p = .044), resting heart rate (rs = -.424, p = .034) and self-efficacy (rs = .464, p = .020) at follow-up. We conclude that the aerobic capacity was maintained over 16 years. High baseline aerobic capacity associated with favourable measures of cardiovascular risk factors at follow-up. Higher disease activity in early stages of RA predicted lower aerobic capacity after 16.2 years.

Intermittent hypobaric hypoxia combined with aerobic exercise improves muscle morphofunctional recovery after eccentric exercise to exhaustion in trained rats.

PubMed

Rizo-Roca, D; Ríos-Kristjánsson, J G; Núñez-Espinosa, C; Santos-Alves, E; Gonçalves, I O; Magalhães, J; Ascensão, A; Pagès, T; Viscor, G; Torrella, J R

2017-03-01

damage, fiber morphofunctionality, capillarization, angiogenesis, and the oxidative capacity of damaged soleus muscle. Most of these parameters were improved after a 2-wk protocol of intermittent hypobaric hypoxia combined with aerobic exercise. Copyright © 2017 the American Physiological Society.

Within-Winter Flexibility in Muscle Masses, Myostatin, and Cellular Aerobic Metabolic Intensity in Passerine Birds.

PubMed

Swanson, David L; King, Marisa O; Culver, William; Zhang, Yufeng

Metabolic rates of passerine birds are flexible traits that vary both seasonally and among and within winters. Seasonal variation in summit metabolic rates (M sum = maximum thermoregulatory metabolism) in birds is consistently correlated with changes in pectoralis muscle and heart masses and sometimes with variation in cellular aerobic metabolic intensity, so these traits might also be associated with shorter-term, within-winter variation in metabolic rates. To determine whether these mechanisms are associated with within-winter variation in M sum , we examined the effects of short-term (ST; 0-7 d), medium-term (MT; 14-30 d), and long-term (LT; 30-yr means) temperature variables on pectoralis muscle and heart masses, pectoralis expression of the muscle-growth inhibitor myostatin and its metalloproteinase activators TLL-1 and TLL-2, and pectoralis and heart citrate synthase (CS; an indicator of cellular aerobic metabolic intensity) activities for two temperate-zone resident passerines, house sparrows (Passer domesticus) and dark-eyed juncos (Junco hyemalis). For both species, pectoralis mass residuals were positively correlated with ST temperature variables, suggesting that cold temperatures resulted in increased turnover of pectoralis muscle, but heart mass showed little within-winter variation for either species. Pectoralis mRNA and protein expression of myostatin and the TLLs were only weakly correlated with ST and MT temperature variables, which is largely consistent with trends in muscle masses for both species. Pectoralis and heart CS activities showed weak and variable trends with ST temperature variables in both species, suggesting only minor effects of temperature variation on cellular aerobic metabolic intensity. Thus, neither muscle or heart masses, regulation by the myostatin system, nor cellular aerobic metabolic intensity varied consistently with winter temperature, suggesting that other factors regulate within-winter metabolic variation in these birds.

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.

Reduced anaerobic and aerobic performance in children with primary ciliary dyskinesia.

PubMed

Simsek, Senem; Inal-Ince, Deniz; Cakmak, Aslihan; Emiralioglu, Nagehan; Calik-Kutukcu, Ebru; Saglam, Melda; Vardar-Yagli, Naciye; Ozcelik, Hayriye Ugur; Sonbahar-Ulu, Hazal; Bozdemir-Ozel, Cemile; Kiper, Nural; Arikan, Hulya

2018-05-01

Primary ciliary dyskinesia (PCD) restricts lifestyle and increases morbidity. The aim of the study was to investigate anaerobic and aerobic performance in children with PCD and their healthy counterparts. Thirty-one children with PCD and 29 age- and sex-matched healthy subjects were studied. Pulmonary function, hand grip strength (HGS), quadriceps strength (QMS), physical activity, anaerobic capacity (muscle power sprint test), and aerobic performance (modified shuttle walk test (MSWT)) were determined. Pulmonary function, HGS, QMS, mean anaerobic power (MAP), and MSWT distance in PCD were significantly lower than those of healthy subjects (p < 0.05). In PCD, the MAP was significantly correlated with age, FEV 1 , and the mean kcal for 3 days (p < 0.05), and age was its independent predictor (p < 0.05). The MSWT distance was significantly related to gender and weight (p < 0.05), and gender was selected as its independent predictor (p < 0.05). In healthy controls, the MAP was significantly associated with age, gender, FVC, FEV 1 , HGS, QMS, and the mean kcal for three days (p < 0.05). The MSWT distance was significantly related to weight and body mass index in healthy group (p < 0.05). Anaerobic and aerobic performance is impaired in PCD from the early stages. Age determines anaerobic performance. Gender is the determinant of aerobic performance. Whether skeletal muscle characteristics and sex-related changes in body composition affect anaerobic and aerobic capacity in PCD children warrants further study. What is Known: • Exercise performance is determined by anaerobic and aerobic power. • Few studies have shown that PCD patients have lower aerobic performance which is associated with impaired lung function. What is New: • The present research indicated that both anaerobic and aerobic exercise capacity determined using field testing is impaired in PCD from the early stages. • Anaerobic capacity was found to be independently

Blunted angiogenesis and hypertrophy are associated with increased fatigue resistance and unchanged aerobic capacity in old overloaded mouse muscle.

PubMed

Ballak, Sam B; Busé-Pot, Tinelies; Harding, Peter J; Yap, Moi H; Deldicque, Louise; de Haan, Arnold; Jaspers, Richard T; Degens, Hans

2016-04-01

We hypothesize that the attenuated hypertrophic response in old mouse muscle is (1) partly due to a reduced capillarization and angiogenesis, which is (2) accompanied by a reduced oxidative capacity and fatigue resistance in old control and overloaded muscles, that (3) can be rescued by the antioxidant resveratrol. To investigate this, the hypertrophic response, capillarization, oxidative capacity, and fatigue resistance of m. plantaris were compared in 9- and 25-month-old non-treated and 25-month-old resveratrol-treated mice. Overload increased the local capillary-to-fiber ratio less in old (15 %) than in adult (59 %) muscle (P < 0.05). Although muscles of old mice had a higher succinate dehydrogenase (SDH) activity (P < 0.05) and a slower fiber type profile (P < 0.05), the isometric fatigue resistance was similar in 9- and 25-month-old mice. In both age groups, the fatigue resistance was increased to the same extent after overload (P < 0.01), without a significant change in SDH activity, but an increased capillary density (P < 0.05). Attenuated angiogenesis during overload may contribute to the attenuated hypertrophic response in old age. Neither was rescued by resveratrol supplementation. Changes in fatigue resistance with overload and aging were dissociated from changes in SDH activity, but paralleled those in capillarization. This suggests that capillarization plays a more important role in fatigue resistance than oxidative capacity.

Aerobic capacity and future cardiovascular risk in Indian community from a low-income area in Cauca, Colombia.

PubMed

Ramírez-Vélez, Robinson; Correa-Bautista, Jorge Enrique; Ramos-Sepúlveda, Jeison Alexander; Piñeros-Álvarez, Carlos Andrés; Giraldo, Lorena Isabel; Izquierdo, Mikel; García-Hermoso, Antonio; Rodríguez-Rodríguez, Fernando; Cristi-Montero, Carlos

2017-03-07

Several studies indicates that children's aerobic capacity levels are predictors of the future risk of non-communicable diseases. Therefore, the aim of this study was to establish the proportion of subjects whose aerobic capacity is indicative of future cardiovascular risk in Indian-Nasa community from a low-income area in Cauca, Colombia. We performed a cross-sectional analysis of morphological component (height, weight, body mass index (BMI), waist circumference, triceps skinfold, subscapular skinfold, and body fat percent [BF%]), and the cardiorespiratory component (course-navette 20 m, shuttle run test and estimation of maximal oxygen consumption by indirect VO 2 max) from 576 participants (319 boys and 257 girls) aged 10 to 17.9 years, using the standardized FUPRECOL test battery. We showed that the boys performed better than the girls in cardiorespiratory fitness. The proportion of subjects with an aerobic capacity indicative of future cardiovascular risk was 7.3%. By sex, 3.8% of boys and 11.7% of girls (X 2 p = 0.001) displayed an unhealthy aerobic capacity in this study. The findings of this study that provide the first data on aerobic capacity health for Colombian Nasa Indian children and adolescents aged 10-17.9 years. Although the known loss of aerobic capacity is a serious consequence of the future risk of non-communicable diseases, the deterioration of physical fitness deserves increased attention among indigenous population.

Effects of exercise on functional aerobic capacity in adults with fibromyalgia syndrome: A systematic review of randomized controlled trials.

PubMed

García-Hermoso, Antonio; Saavedra, Jose M; Escalante, Yolanda

2015-01-01

Patients with fibromyalgia present a reduced capacity of upper and lower limb physical performance and affect their independence in performing everyday activities. The purpose of the present systematic review was to summarize evidence for the effectiveness and structure of exercise programs on functional aerobic capacity in patients with fibromyalgia syndrome. Keyword searches were made of seven databases. The systematic review was limited to English language studies of people with FM that evaluated the effects of exercise programs on functional aerobic capacity (6-minute walk test). The criteria for inclusion were satisfied by 12 randomized controlled trial (RCT) studies. The main cumulative evidence indicates that the programs based on aerobic exercise alone and on aquatic exercises have large (effect size = 0.85) and moderate (effect size = 0.44) effects. Aerobic and aquatic exercises at the proper intensity favour the increased functional aerobic capacity of fibromyalgia patients; however, most works do not adequately detail the intensity of the exercises. Moderate intensity exercise (aerobic and aquatic exercise) performed at least two times per week and 30-60 minutes a day is effective for increasing functional aerobic capacity, favouring the daily activities of daily living in this population.

Phylogenetic Analysis Supports the Aerobic-Capacity Model for the Evolution of Endothermy.

PubMed

Nespolo, Roberto F; Solano-Iguaran, Jaiber J; Bozinovic, Francisco

2017-01-01

The evolution of endothermy is a controversial topic in evolutionary biology, although several hypotheses have been proposed to explain it. To a great extent, the debate has centered on the aerobic-capacity model (AC model), an adaptive hypothesis involving maximum and resting rates of metabolism (MMR and RMR, respectively; hereafter "metabolic traits"). The AC model posits that MMR, a proxy of aerobic capacity and sustained activity, is the target of directional selection and that RMR is also influenced as a correlated response. Associated with this reasoning are the assumptions that (1) factorial aerobic scope (FAS; MMR/RMR) and net aerobic scope (NAS; MMR - RMR), two commonly used indexes of aerobic capacity, show different evolutionary optima and (2) the functional link between MMR and RMR is a basic design feature of vertebrates. To test these assumptions, we performed a comparative phylogenetic analysis in 176 vertebrate species, ranging from fish and amphibians to birds and mammals. Using disparity-through-time analysis, we also explored trait diversification and fitted different evolutionary models to study the evolution of metabolic traits. As predicted, we found (1) a positive phylogenetic correlation between RMR and MMR, (2) diversification of metabolic traits exceeding that of random-walk expectations, (3) that a model assuming selection fits the data better than alternative models, and (4) that a single evolutionary optimum best fits FAS data, whereas a model involving two optima (one for ectotherms and another for endotherms) is the best explanatory model for NAS. These results support the AC model and give novel information concerning the mode and tempo of physiological evolution of vertebrates.

Effects of a pulmonary rehabilitation program on physical capacity, peripheral muscle function and inflammatory markers in asthmatic children and adolescents: study protocol for a randomized controlled trial.

PubMed

Reimberg, Mariana Mazzuca; Castro, Rejane Agnelo Silva; Selman, Jessyca Pachi Rodrigues; Meneses, Aline Santos; Politti, Fabiano; Mallozi, Márcia Carvalho; Wandalsen, Gustavo Falbo; Solé, Dirceu; De Angelis, Kátia; Dal Corso, Simone; Lanza, Fernanda Cordoba

2015-08-13

Individuals with chronic lung disease are more susceptible to present reduction in exercise tolerance and muscles strength not only due to pulmonary limitations but also due systemic repercussions of the pulmonary disease. The aim of this study is to assess the physical capacity, peripheral muscle function, physical activity in daily life, and the inflammatory markers in children and adolescents with asthma after pulmonary rehabilitation program. This is a study protocol of randomized controlled trial in asthmatic patients between 6 to 18 years old. The assessments will be conducted in three different days and will be performed at the beginning and at the end of the protocol. First visit: quality of life questionnaire, asthma control questionnaire, pre- and post-bronchodilator spirometry (400 μcg salbutamol), inflammatory assessment (blood collection), and cardiopulmonary exercise test on a cycle ergometer to determine aerobic capacity. Second visit: assessment of strength and endurance of the quadriceps femoris and biceps brachii muscles with concomitant electromyography to assess peripheral muscle strength. Third visit: incremental shuttle walk test (ISWT) and accelerometer to evaluate functional capacity and physical activity in daily life during 7 days. Then, the volunteers will be randomized to receive pulmonary rehabilitation program (intervention group) or chest physiotherapy + stretching exercises (control group). Both groups will have a supervised session, twice a week, each session will have 60 minutes duration, with minimum interval of 24 hours, for a period of 8 weeks. Intervention group: aerobic training (35 minutes) intensity between 60 to 80 % of the maximum workload of cardiopulmonary exercise testing or of ISWT; strength muscle training will be applied to the quadriceps femoris, biceps brachii and deltoid muscles (intensity: 40 to 70 % of maximal repetition, 3 x 8 repetition); finally the oral high-frequency oscillation device (Flutter®) will be

Physical activity, sedentary behavior, and aerobic capacity in persons with multiple sclerosis.

PubMed

Motl, Robert W; Sandroff, Brian M; Pilutti, Lara A; Klaren, Rachel E; Baynard, Tracy; Fernhall, Bo

2017-01-15

There is substantial evidence that exercise training improves aerobic capacity among people with multiple sclerosis (MS), but less is known about the associations between physical activity and sedentary behaviors with aerobic capacity. This study examined if objectively-measured moderate-to-vigorous (MVPA) and light (LPA) physical activity and sedentary behavior were associated with peak aerobic capacity (VO 2 peak) measured using an established protocol for conducting a maximal, incremental exercise test in persons with MS. The study involved a cross-sectional, observational study design and included 49 persons with MS. Participants wore an accelerometer around the waist during the waking hours for a 7-day period as a measure of physical activity and sedentary behaviors, and completed a maximal, incremental exercise test on an electronically-braked, computer-controlled cycle ergometer with open-circuit spirometry for measuring VO 2 peak. VO 2 peak was significantly correlated with MVPA (r=0.53, p<0.001) and LPA (r=0.39, p<0.01), but not sedentary behavior (r=-0.12, p=0.44). Linear regression analysis indicated that MVPA (B=0.19, SE B=0.04, β=0.51, p<0.001) and LPA (B=0.02, SE B=0.01, β=0.30, p<0.05), but not sedentary behavior (B=-0.01, SE B=0.01, β=-0.14, p=0.26), explained significant variance in VO 2 peak (R 2 =0.40). We provide the first evidence that MVPA and LPA represent concurrent correlates of VO 2 peak and both could be targeted for improving aerobic capacity in persons with MS. Copyright © 2016 Elsevier B.V. All rights reserved.

Training modalities: impact on endurance capacity.

PubMed

Flueck, Martin; Eilers, Wouter

2010-03-01

Endurance athletes demonstrate an exceptional resistance to fatigue when exercising at high intensity. Much research has been devoted to the contribution of aerobic capacity for the economy of endurance performance. Important aspects of the fine-tuning of metabolic processes and power output in the endurance athlete have been overlooked. This review addresses how training paradigms exploit bioenergetic pathways in recruited muscle groups to promote the endurance phenotype. A special focus is laid on the genome-mediated mechanisms that underlie the conditioning of fatigue resistance and aerobic performance by training macrocycles and complements. The available data on work-induced muscle plasticity implies that different biologic strategies are exploited in athletic and untrained populations to boost endurance capacity. Olympic champions are probably endowed with a unique constitution that renders the conditioning of endurance capacity for competition particularly efficient. Copyright 2010 Elsevier Inc. All rights reserved.

Aerobic Capacity in Children and Adolescents with Cerebral Palsy

ERIC Educational Resources Information Center

Verschuren, Olaf; Takken, Tim

2010-01-01

This study described the aerobic capacity [VO[subscript 2peak] (ml/kg/min)] in contemporary children and adolescents with cerebral palsy (CP) using a maximal exercise test protocol. Twenty-four children and adolescents with CP classified at Gross Motor Functional Classification Scale (GMFCS) level I or level II and 336 typically developing…

Effects of Aerobic Capacity on Thrombin-Induced Hydrocephalus and White Matter Injury.

PubMed

Ni, Wei; Gao, Feng; Zheng, Mingzhe; Koch, Lauren G; Britton, Steven L; Keep, Richard F; Xi, Guohua; Hua, Ya

2016-01-01

We have previously shown that intracerebral hemorrhage-induced brain injury is less in rats bred for high aerobic capacity (high capacity runners; HCR) compared with those bred for low aerobic capacity (low capacity runners; LCRs). Thrombin, an essential component in the coagulation cascade, is produced after cerebral hemorrhage. Intraventricular injection of thrombin causes significant hydrocephalus and white matter damage. In the present study, we examined the effect of exercise capacity on thrombin-induced hydrocephalus and white matter damage. Mid-aged (13-month-old) female LCRs (n = 13) and HCRs (n = 12) rats were used in this study. Rats received an intraventricular injection of thrombin (3 U, 50 μl). All rats underwent magnetic resonance imaging (MRI) at 24 h and were then euthanized for brain histology and Western blot. The mortalities were 20 % in LCRs and 33 % in HCRs after thrombin injection (p > 0.05). No rats died after saline injection. Intraventricular thrombin injection resulted in hydrocephalus and periventricular white matter damage as determined on MRI. In LCR rats, thrombin induced significant ventricle enlargement (23.0 ± 2.3 vs12.8 ± 1.9 mm(3) in LCR saline group; p < 0.01) and white matter lesion (9.3 ± 7.6 vs 0.6 ± 0.5 mm(3) in LCR saline group, p < 0.05). In comparison, in HCR rats thrombin induced less ventricular enlargement (17.3 ± 3.9 vs 23.0 ± 2.3 mm(3) in LCRs, p < 0.01) and smaller white matter lesions (2.6 ± 1.2 mm(3) vs 9.3 ± 7.6 mm(3) in LCRs, p < 0.05). In LCR rats, there was also upregulation of heat shock protein-32, a stress marker, and microglial activation in the periventricular white matter. These changes were significantly reduced in HCR rats. Intraventricular injection of thrombin caused more white matter damage and hydrocephalus in rats with low aerobic capacity. A differential effect of thrombin may contribute to differences in the effects of cerebral

Intrinsic aerobic capacity impacts susceptibility to acute high-fat diet-induced hepatic steatosis.

PubMed

Morris, E Matthew; Jackman, Matthew R; Johnson, Ginger C; Liu, Tzu-Wen; Lopez, Jordan L; Kearney, Monica L; Fletcher, Justin A; Meers, Grace M E; Koch, Lauren G; Britton, Stephen L; Rector, R Scott; Ibdah, Jamal A; MacLean, Paul S; Thyfault, John P

2014-08-15

Aerobic capacity/fitness significantly impacts susceptibility for fatty liver and diabetes, but the mechanisms remain unknown. Herein, we utilized rats selectively bred for high (HCR) and low (LCR) intrinsic aerobic capacity to examine the mechanisms by which aerobic capacity impacts metabolic vulnerability for fatty liver following a 3-day high-fat diet (HFD). Indirect calorimetry assessment of energy metabolism combined with radiolabeled dietary food was employed to examine systemic metabolism in combination with ex vivo measurements of hepatic lipid oxidation. The LCR, but not HCR, displayed increased hepatic lipid accumulation in response to the HFD despite both groups increasing energy intake. However, LCR rats had a greater increase in energy intake and demonstrated greater daily weight gain and percent body fat due to HFD compared with HCR. Additionally, total energy expenditure was higher in the larger LCR. However, controlling for the difference in body weight, the LCR has lower resting energy expenditure compared with HCR. Importantly, respiratory quotient was significantly higher during the HFD in the LCR compared with HCR, suggesting reduced whole body lipid utilization in the LCR. This was confirmed by the observed lower whole body dietary fatty acid oxidation in LCR compared with HCR. Furthermore, LCR liver homogenate and isolated mitochondria showed lower complete fatty acid oxidation compared with HCR. We conclude that rats bred for low intrinsic aerobic capacity show greater susceptibility for dietary-induced hepatic steatosis, which is associated with a lower energy expenditure and reduced whole body and hepatic mitochondrial lipid oxidation.

Elevated Nicotinamide Phosphoribosyl Transferase in Skeletal Muscle Augments Exercise Performance and Mitochondrial Respiratory Capacity Following Exercise Training

PubMed Central

Brouwers, Bram; Stephens, Natalie A.; Costford, Sheila R.; Hopf, Meghan E.; Ayala, Julio E.; Yi, Fanchao; Xie, Hui; Li, Jian-Liang; Gardell, Stephen J.; Sparks, Lauren M.; Smith, Steven R.

2018-01-01

Mice overexpressing NAMPT in skeletal muscle (NamptTg mice) develop higher exercise endurance and maximal aerobic capacity (VO2max) following voluntary exercise training compared to wild-type (WT) mice. Here, we aimed to investigate the mechanisms underlying by determining skeletal muscle mitochondrial respiratory capacity in NamptTg and WT mice. Body weight and body composition, tissue weight (gastrocnemius, quadriceps, soleus, heart, liver, and epididymal white adipose tissue), skeletal muscle and liver glycogen content, VO2max, skeletal muscle mitochondrial respiratory capacity (measured by high-resolution respirometry), skeletal muscle gene expression (measured by microarray and qPCR), and skeletal muscle protein content (measured by Western blot) were determined following 6 weeks of voluntary exercise training (access to running wheel) in 13-week-old male NamptTg (exercised NamptTg) mice and WT (exercised WT) mice. Daily running distance and running time during the voluntary exercise training protocol were recorded. Daily running distance (p = 0.51) and running time (p = 0.85) were not significantly different between exercised NamptTg mice and exercised WT mice. VO2max was higher in exercised NamptTg mice compared to exercised WT mice (p = 0.02). Body weight (p = 0.92), fat mass (p = 0.49), lean mass (p = 0.91), tissue weight (all p > 0.05), and skeletal muscle (p = 0.72) and liver (p = 0.94) glycogen content were not significantly different between exercised NamptTg mice and exercised WT mice. Complex I oxidative phosphorylation (OXPHOS) respiratory capacity supported by fatty acid substrates (p < 0.01), maximal (complex I+II) OXPHOS respiratory capacity supported by glycolytic (p = 0.02) and fatty acid (p < 0.01) substrates, and maximal uncoupled respiratory capacity supported by fatty acid substrates (p < 0.01) was higher in exercised NamptTg mice compared to exercised WT mice. Transcriptomic analyses revealed differential expression for genes involved in

Identification of serum analytes and metabolites associated with aerobic capacity

USDA-ARS?s Scientific Manuscript database

Studies aimed at identifying serum markers of cellular metabolism (biomarkers) that are associated at baseline with aerobic capacity (V02 max) in young, healthy individuals have yet to be reported. Therefore, the goal of the present study was to use the standard chemistry screen and untargeted mass ...

Aerobic Exercise Attenuates the Loss of Skeletal Muscle during Energy Restriction in Adults with Visceral Adiposity

PubMed Central

Yoshimura, Eiichi; Kumahara, Hideaki; Tobina, Takuro; Matsuda, Takuro; Watabe, Kiwa; Matono, Sakiko; Ayabe, Makoto; Kiyonaga, Akira; Anzai, Keizo; Higaki, Yasuki; Tanaka, Hiroaki

2014-01-01

Objective To evaluate the effects of energy restriction with or without aerobic exercise on thigh muscle mass and quality in adults with visceral adiposity. Methods 75 males and females were randomly assigned to the groups ‘diet only’ (DO; n = 42) or ‘diet plus aerobic exercise’ (D/Ex; n = 33) for 12 weeks. The target energy intake in both groups was 25 kcal/kg of ideal body weight. Subjects in the D/Ex group were instructed to exercise for ≥300 min/week at lactate threshold. Computed tomography was used to measure thigh muscle cross-sectional area (CSA), normal-density muscle area (NDMA), and visceral fat area. Results Total body weight (DO: −6.6 ± 3.6%; D/Ex: −7.3 ± 4.6%) and visceral fat (DO: −16.0 ± 13.8%; D/Ex: −23.1 ± 14.7%) decreased significantly in both groups; however, the changes were not significantly different between the two groups. The decrease in muscle CSA was significantly greater in the DO group (-5.1 ± 4.5%) compared with the D/Ex group (-2.5 ± 5.0%). NDMA decreased significantly in the DO (-4.9 ± 4.9%) but not in the D/Ex group (-1.4 ± 5.0%). Conclusion Aerobic exercise attenuated the loss of skeletal muscle during energy restriction in adults with visceral adiposity. PMID:24457527

Temperature compensation of aerobic capacity and performance in the Antarctic pteropod, Clione antarctica, compared with its northern congener, C. limacina.

PubMed

Dymowska, Agnieszka K; Manfredi, Thomas; Rosenthal, Joshua J C; Seibel, Brad A

2012-10-01

In ectotherms living in cold waters, locomotory performance is constrained by a slower generation of the ATP that is needed to fuel muscle contraction. Both polar and temperate pteropods of the genus Clione, however, are able to swim continuously by flapping their parapodia (wings) at comparable frequencies at their respective habitat temperatures. Therefore, we expected polar species to have increased aerobic capacities in their wing muscles when measured at common temperatures. We investigated muscle and mitochondrial ultrastructure of Clione antarctica from the Southern Ocean (-1.8°C) and populations of a sister species, Clione limacina, from the Arctic (-0.5 to 3°C) and from the North Atlantic (10°C). We also measured oxygen consumption and the activity of the mitochondrial enzyme citrate synthase (CS) in isolated wings of the two species. The Antarctic species showed a substantial up-regulation of the density of oxidative muscle fibers, but at the expense of fast-twitch muscle fibers. Mitochondrial capacity was also substantially increased in the Antarctic species, with the cristae surface density (58.2±1.3μm(2)μm(-3)) more than twice that found in temperate species (34.3±0.8μm(2)μm(-3)). Arctic C. limacina was intermediate between these two populations (43.7±0.5μm(2)μm(-3)). The values for cold-adapted populations are on par with those found in high-performance vertebrates. As a result of oxidative muscle proliferation, CS activity was 4-fold greater in C. antarctica wings than in temperate C. limacina when measured at a common temperature (20°C). Oxygen consumption of isolated wing preparations was comparable in the two species when measured at their respective habitat temperatures. These findings indicate complete compensation of ATP generation in wing muscles across a 10°C temperature range, which supports similar wing-beat frequencies during locomotion at each species' respective temperature. The elevated capacity in the wing muscles is

Physical inactivity and muscle oxidative capacity in humans.

PubMed

Gram, Martin; Dahl, Rannvá; Dela, Flemming

2014-01-01

Physical inactivity is associated with a high prevalence of type 2 diabetes and is an independent predictor of mortality. It is possible that the detrimental effects of physical inactivity are mediated through a lack of adequate muscle oxidative capacity. This short review will cover the present literature on the effects of different models of inactivity on muscle oxidative capacity in humans. Effects of physical inactivity include decreased mitochondrial content, decreased activity of oxidative enzymes, changes in markers of oxidative stress and a decreased expression of genes and contents of proteins related to oxidative phosphorylation. With such a substantial down-regulation, it is likely that a range of adenosine triphosphate (ATP)-dependent pathways such as calcium signalling, respiratory capacity and apoptosis are affected by physical inactivity. However, this has not been investigated in humans, and further studies are required to substantiate this hypothesis, which could expand our knowledge of the potential link between lifestyle-related diseases and muscle oxidative capacity. Furthermore, even though a large body of literature reports the effect of physical training on muscle oxidative capacity, the adaptations that occur with physical inactivity may not always be opposite to that of physical training. Thus, it is concluded that studies on the effect of physical inactivity per se on muscle oxidative capacity in functional human skeletal muscle are warranted.

Aerobic scope explains individual variation in feeding capacity

PubMed Central

Auer, Sonya K.; Salin, Karine; Anderson, Graeme J.; Metcalfe, Neil B.

2015-01-01

Links between metabolism and components of fitness such as growth, reproduction and survival can depend on food availability. A high standard metabolic rate (SMR; baseline energy expenditure) or aerobic scope (AS; the difference between an individual's maximum and SMR) is often beneficial when food is abundant or easily accessible but can be less important or even disadvantageous when food levels decline. While the mechanisms underlying these context-dependent associations are not well understood, they suggest that individuals with a higher SMR or AS are better able to take advantage of high food abundance. Here we show that juvenile brown trout (Salmo trutta) with a higher AS were able to consume more food per day relative to individuals with a lower AS. These results help explain why a high aerobic capacity can improve performance measures such as growth rate at high but not low levels of food availability. PMID:26556902

Aerobic power and flight capacity in birds: a phylogenetic test of the heart-size hypothesis.

PubMed

Nespolo, Roberto F; González-Lagos, César; Solano-Iguaran, Jaiber J; Elfwing, Magnus; Garitano-Zavala, Alvaro; Mañosa, Santiago; Alonso, Juan Carlos; Altimiras, Jordi

2018-01-09

Flight capacity is one of the most important innovations in animal evolution; it only evolved in insects, birds, mammals and the extinct pterodactyls. Given that powered flight represents a demanding aerobic activity, an efficient cardiovascular system is essential for the continuous delivery of oxygen to the pectoral muscles during flight. It is well known that the limiting step in the circulation is stroke volume (the volume of blood pumped from the ventricle to the body during each beat), which is determined by the size of the ventricle. Thus, the fresh mass of the heart represents a simple and repeatable anatomical measure of the aerobic power of an animal. Although several authors have compared heart masses across bird species, a phylogenetic comparative analysis is still lacking. By compiling heart sizes for 915 species and applying several statistical procedures controlling for body size and/or testing for adaptive trends in the dataset (e.g. model selection approaches, phylogenetic generalized linear models), we found that (residuals of) heart size is consistently associated with four categories of flight capacity. In general, our results indicate that species exhibiting continuous hovering flight (i.e. hummingbirds) have substantially larger hearts than other groups, species that use flapping flight and gliding show intermediate values, and that species categorized as poor flyers show the smallest values. Our study reveals that on a broad scale, routine flight modes seem to have shaped the energetic requirements of birds sufficiently to be anatomically detected at the comparative level. © 2018. Published by The Company of Biologists Ltd.

Combined short-arm centrifuge and aerobic exercise training improves cardiovascular function and physical working capacity in humans.

PubMed

Yang, Chang-Bin; Zhang, Shu; Zhang, Yu; Wang, Bing; Yao, Yong-Jie; Wang, Yong-Chun; Wu, Yan-Hong; Liang, Wen-Bin; Sun, Xi-Qing

2010-12-01

Musculoskeletal and cardiovascular deconditioning occurring in long-term spaceflight gives rise to the needs to develop new strategies to counteract these adverse effects. Short-arm centrifuge combined with ergometer has been proposed as a strategy to counteract adverse effects of microgravity. This study sought to investigate whether the combination of short-arm centrifuge and aerobic exercise training have advantages over short-arm centrifuge or aerobic exercise training alone. One week training was conducted by 24 healthy men. They were randomly divided into 3 groups: (1) short-arm centrifuge training, (2) aerobic exercise training, 40 W, and (3) combined short-arm centrifuge and aerobic exercise training. Before and after training, the cardiac pump function represented by stroke volume, cardiac output, left ventricular ejection time, and total peripheral resistance was evaluated. Variability of heart rate and systolic blood pressure were determined by spectral analysis. Physical working capacity was surveyed by near maximal physical working capacity test. The 1-week combined short-arm centrifuge and aerobic exercise training remarkably ameliorated the cardiac pump function and enhanced vasomotor sympathetic nerve modulation and improved physical working capacity by 10.9% (P<.05, n=8). In contrast, neither the short-arm centrifuge nor the aerobic exercise group showed improvements in these functions. These results demonstrate that combined short-arm centrifuge and aerobic exercise training has advantages over short-arm centrifuge or aerobic exercise training alone in influencing several physiologically important cardiovascular functions in humans. The combination of short-arm centrifuge and aerobic exercise offers a promising countermeasure to microgravity.

Associations between Attitudes toward Physical Education and Aerobic Capacity in Hungarian High School Students

ERIC Educational Resources Information Center

Kaj, Mónika; Saint-Maurice, Pedro F.; Karsai, István; Vass, Zoltán; Csányi, Tamás; Boronyai, Zoltán; Révész, László

2015-01-01

Purpose: The purpose of this study was to create a physical education (PE) attitude scale and examine how it is associated with aerobic capacity (AC). Method: Participants (n = 961, aged 15-20 years) were randomly selected from 26 Hungarian high schools. AC was estimated from performance on the Progressive Aerobic Cardiovascular and Endurance Run…

Impact of error self-perception of aerobic capacity in the safety and efficacy of the lifeguards.

PubMed

Prieto, Jose A; Nistal, Paloma; Méndez, David; Abelairas-Gomez, Cristian; Barcala-Furelos, Roberto

2016-01-01

The strong physical demands that are required of lifeguards during rescues also require an accurate self-perception of one's fitness level to be able to regulate the intensity of effort. The aim of this study was to determine the real aerobic capacity (RAC) and to compare it with two self-reported measurements: subjective appraisal of aerobic capacity (SAAC) and appraisal of physical exercise (APE). Fifty-two professional lifeguards were included in the study. For an objective assessment of RAC, the lifeguards' maximum oxygen uptake (VO2max) values were measured during treadmill stress tests. A fitness assessment questionnaire was used to obtain the SAAC and APE values. We found a statistically significant association between the APE and RAC variables in the contingency analysis (p < 0.001). In total, 93.7% of the lifeguards who obtained a VO2max value below 43 ml kg(-1) min(-1) considered their aerobic capacity to be high or very high. This self-perception error of true aerobic capacity could lead to premature fatigue during a rescue, endangering both the lifeguard's life and the life of the victim. These data may help lifeguards and beach managers to become aware of the need to know lifeguards' true physical conditions through testing and structured training programs.

Effect of single-session aerobic exercise with varying intensities on lipid peroxidation and muscle-damage markers in sedentary males.

PubMed

Moflehi, Daruosh; Kok, Lian-Yee; Tengku-Kamalden, Tengku-Fadilah; Amri, Saidon

2012-05-23

This study was conducted to evaluate the effect of the different intensity levels of single-session aerobic exercise on serum levels of lipid peroxidation and muscle damage markers in sedentary males. Fifty one sedentary healthy males aged 21.76±1.89 years were randomly divided into four groups, with one control (n=10) and three treatment groups that attended single-session aerobic exercise with low (n=14), moderate (n=14), and high (n=13) intensities. The serum levels of malondialdehyde (MDA) and creatine kinase (CK) were measured. Data analysis revealed a significant effect by the intensity levels of aerobic exercise on MDA (P=0.001) and CK (P=0.003) post-test when the participants in the treatment groups were compared with the control. When the intensity of aerobic exercise was increased, the amount of MDA and CK was also found to be increased. Single-session aerobic exercise can increase the amount of MDA and CK, suggesting that low intensity level of aerobic exercise should be utilized for more adaptation, and to prevent lipid peroxidation and muscle damage in sedentary males.

FES-assisted Cycling Improves Aerobic Capacity and Locomotor Function Postcerebrovascular Accident.

PubMed

Aaron, Stacey E; Vanderwerker, Catherine J; Embry, Aaron E; Newton, Jennifer H; Lee, Samuel C K; Gregory, Chris M

2018-03-01

After a cerebrovascular accident (CVA) aerobic deconditioning contributes to diminished physical function. Functional electrical stimulation (FES)-assisted cycling is a promising exercise paradigm designed to target both aerobic capacity and locomotor function. This pilot study aimed to evaluate the effects of an FES-assisted cycling intervention on aerobic capacity and locomotor function in individuals post-CVA. Eleven individuals with chronic (>6 months) post-CVA hemiparesis completed an 8-wk (three times per week; 24 sessions) progressive FES-assisted cycling intervention. V˙O2peak, self-selected, and fastest comfortable walking speeds, gait, and pedaling symmetry, 6-min walk test (6MWT), balance, dynamic gait movements, and health status were measured at baseline and posttraining. Functional electrical stimulation-assisted cycling significantly improved V˙O2peak (12%, P = 0.006), self-selected walking speed (SSWS, 0.05 ± 0.1 m·s, P = 0.04), Activities-specific Balance Confidence scale score (12.75 ± 17.4, P = 0.04), Berg Balance Scale score (3.91 ± 4.2, P = 0.016), Dynamic Gait Index score (1.64 ± 1.4, P = 0.016), and Stroke Impact Scale participation/role domain score (12.74 ± 16.7, P = 0.027). Additionally, pedal symmetry, represented by the paretic limb contribution to pedaling (paretic pedaling ratio [PPR]) significantly improved (10.09% ± 9.0%, P = 0.016). Although step length symmetry (paretic step ratio [PSR]) did improve, these changes were not statistically significant (-0.05% ± 0.1%, P = 0.09). Exploratory correlations showed moderate association between change in SSWS and 6-min walk test (r = 0.74), and moderate/strong negative association between change in PPR and PSR. These results support FES-assisted cycling as a means to improve both aerobic capacity and locomotor function. Improvements in SSWS, balance, dynamic walking movements, and participation in familial and societal roles are important targets for rehabilitation of individuals

Aerobic Capacity and Anaerobic Power Levels of the University Students

ERIC Educational Resources Information Center

Taskin, Cengiz

2016-01-01

The aim of study was to analyze aerobic capacity and anaerobic power levels of the university students. Total forty university students who is department physical education and department business (age means; 21.15±1.46 years for male and age means; 20.55±1.79 years for female in department physical education), volunteered to participate in this…

Aerobic Capacity and Cognitive Control in Elementary School-Age Children

PubMed Central

Scudder, Mark R.; Lambourne, Kate; Drollette, Eric S.; Herrmann, Stephen; Washburn, Richard; Donnelly, Joseph E.; Hillman, Charles H.

2014-01-01

Purpose The current study examined the relationship between children’s performance on the Progressive Aerobic Cardiovascular Endurance Run (PACER) subtest of the FitnessGram® and aspects of cognitive control that are believed to support academic success. Methods Hierarchical linear regression analyses were conducted on a sample of 2nd and 3rd grade children (n = 397) who completed modified versions of a flanker task and spatial n-back task to assess inhibitory control and working memory, respectively. Results Greater aerobic fitness was significantly related to shorter reaction time and superior accuracy during the flanker task, suggesting better inhibitory control and the facilitation of attention in higher fit children. A similar result was observed for the n-back task such that higher fit children exhibited more accurate target detection and discrimination performance when working memory demands were increased. Conclusion These findings support the positive association between aerobic fitness and multiple aspects of cognitive control in a large sample of children, using a widely implemented and reliable field estimate of aerobic capacity. Importantly, the current results suggest that this relationship is consistent across methods used to assess fitness, which may have important implications for extending this research to more representative samples of children in a variety of experimental contexts. PMID:24743109

The Longitudinal Impact of NFL PLAY 60 Programming on Youth Aerobic Capacity and BMI.

PubMed

Bai, Yang; Saint-Maurice, Pedro F; Welk, Gregory J; Russell, Daniel W; Allums-Featherston, Kelly; Candelaria, Norma

2017-03-01

The NFL PLAY 60 campaign has actively promoted physical activity and healthy eating in youth through programs such as the PLAY 60 Challenge and Fuel Up to PLAY 60. The purpose of the study was to evaluate the impact of NFL PLAY 60 programming on longitudinal trajectories of youth aerobic capacity and BMI. Data were from the NFL PLAY 60 FitnessGram Partnership Project, a large participatory research project designed to promote physical activity and healthy eating among Kindergarten through 12th grade children and adolescents. The programming was led by teachers in school settings across 32 NFL franchise markets. A range of 50,000-100,000 students from 497 schools completed FitnessGram assessments annually starting in 2011 and continuing through 2015. The analysis was conducted in 2015. Adoption of NFL PLAY 60 programming was encouraged but not required and the program implementation was evaluated each year. The adoption was evaluated through self-reported annual survey. School assessments of aerobic capacity and BMI were evaluated using FitnessGram standards to calculate the percentage of students meeting the Healthy Fitness Zone for each test. Growth curve modeling was used to estimate the longitudinal trajectories. About 19% of schools were classified as programming schools. Annual improvements in aerobic capacity were significantly greater in schools that participated in the programs for both girls (3.0%, p<0.01) and boys (2.9%, p<0.01) compared with non-programming schools. The annual improvements in BMI Healthy Fitness Zone achievement were also higher in girls (1.3%, p<0.05) and in boys (1.2%, p<0.05) from schools that participated in the programs versus non-participating schools. Schools that implemented the programs for the entire 4-year period tended to have better improvements in aerobic capacity than schools enrolled for only 2 or 3 years (p<0.05). The results of these longitudinal analyses support the utility of the NFL PLAY 60 physical activity

Hypercholesterolemia Impairs Exercise Capacity in Mice

PubMed Central

Maxwell, Andrew J.; Niebauer, Josef; Lin, Patrick S.; Tsao, Philip S.; Bernstein, Daniel; Cooke, John P.

2011-01-01

Objective We previously reported an attenuation of both exercise hyperemia and measures of aerobic capacity in hypercholesterolemic mice. In this study we expanded upon the previous findings by examining the temporal and quantitative relationship of hypercholesterolemia to aerobic and anaerobic capacity and by exploring several potential mechanisms of dysfunction. Methods Eight-week old wild type (n=123) and apoE knockout (n=79) C57BL/6J mice were divided into groups with distinct cholesterol levels by feeding regular or high fat diets. At various ages the mice underwent treadmill ergospirometry. To explore mechanisms, aortic ring vasodilator function and nitrate (NOx) activity, urinary excretion of NOx, running muscle microvascular density and citrate synthase activity, as well as myocardial mass and histologic evidence of ischemia were measured. Results At 8 weeks of age, all mice had similar measures of exercise capacity. All indices of aerobic exercise capacity progressively declined at 12 and 20 weeks of age in the hypercholesterolemic mice as cholesterol levels increased while indices of anaerobic capacity remained unaffected. Across the 4 cholesterol groups, the degree of aerobic dysfunction was related to serum cholesterol levels; a relationship that was maintained after correcting for confounding factors. Associated with the deterioration in exercise capacity was a decline in measures of nitric oxide-mediated vascular function while there was no evidence of aberrations in functional or oxidative capacities or in other components of transport capacity. Conclusion Aerobic exercise dysfunction is observed in murine models of genetic and diet-induced hypercholesterolemia and is associated with a reduction in vascular nitric oxide production. PMID:19651675

2014 Bone and Muscle Risks Standing Review Panel

NASA Technical Reports Server (NTRS)

Steinberg, Susan; Glowacki, Julie; Gregor, Robert; Cullen, Diane; Drake, Almond; Enoka, Roger; Hanley, Edward Jr.; Kraemer, William; Raven, Peter; Sumner, Rick, D.

2014-01-01

The 2014 Bone and Muscle Risks Standing Review Panel (from here on referred to as the SRP) met for a site visit in Houston, TX on December 17 - 18, 2014. The SRP reviewed the updated research plans for the Risk of Impaired Performance Due to Reduced Muscle Mass, Strength and Endurance (Muscle Risk) and the Risk of Reduced Physical Performance Capabilities Due to Reduced Aerobic Capacity (Aerobic Risk). The SRP also received a status update on the Risk of Bone Fracture (Bone Risk), the Risk of Early Onset Osteoporosis Due To Spaceflight (Osteo Risk), the Risk of Intervertebral Disc Damage (IVD Risk), and the Risk of Renal Stone Formation (Renal Risk).

Aerobic Exercise Training Prevents Heart Failure-Induced Skeletal Muscle Atrophy by Anti-Catabolic, but Not Anabolic Actions

PubMed Central

Souza, Rodrigo W. A.; Piedade, Warlen P.; Soares, Luana C.; Souza, Paula A. T.; Aguiar, Andreo F.; Vechetti-Júnior, Ivan J.; Campos, Dijon H. S.; Fernandes, Ana A. H.; Okoshi, Katashi; Carvalho, Robson F.; Cicogna, Antonio C.; Dal-Pai-Silva, Maeli

2014-01-01

Background Heart failure (HF) is associated with cachexia and consequent exercise intolerance. Given the beneficial effects of aerobic exercise training (ET) in HF, the aim of this study was to determine if the ET performed during the transition from cardiac dysfunction to HF would alter the expression of anabolic and catabolic factors, thus preventing skeletal muscle wasting. Methods and Results We employed ascending aortic stenosis (AS) inducing HF in Wistar male rats. Controls were sham-operated animals. At 18 weeks after surgery, rats with cardiac dysfunction were randomized to 10 weeks of aerobic ET (AS-ET) or to an untrained group (AS-UN). At 28 weeks, the AS-UN group presented HF signs in conjunction with high TNF-α serum levels; soleus and plantaris muscle atrophy; and an increase in the expression of TNF-α, NFκB (p65), MAFbx, MuRF1, FoxO1, and myostatin catabolic factors. However, in the AS-ET group, the deterioration of cardiac function was prevented, as well as muscle wasting, and the atrophy promoters were decreased. Interestingly, changes in anabolic factor expression (IGF-I, AKT, and mTOR) were not observed. Nevertheless, in the plantaris muscle, ET maintained high PGC1α levels. Conclusions Thus, the ET capability to attenuate cardiac function during the transition from cardiac dysfunction to HF was accompanied by a prevention of skeletal muscle atrophy that did not occur via an increase in anabolic factors, but through anti-catabolic activity, presumably caused by PGC1α action. These findings indicate the therapeutic potential of aerobic ET to block HF-induced muscle atrophy by counteracting the increased catabolic state. PMID:25330387

ASC Methylation and Interleukin-1β Are Associated with Aerobic Capacity in Heart Failure.

PubMed

Butts, Brittany; Butler, Javed; Dunbar, Sandra B; Corwin, Elizabeth J; Gary, Rebecca A

2017-06-01

Aerobic capacity, as measured by peak oxygen uptake (V˙O2), is one of the most powerful predictors of prognosis in heart failure (HF). Inflammation is a key factor contributing to alterations in aerobic capacity, and interleukin (IL)-1 cytokines are implicated in this process. The adaptor protein ASC is necessary for inflammasome activation of IL-1β and IL-18. ASC expression is controlled through epigenetic modification; lower ASC methylation is associated with worse outcomes in HF. The purpose of this study is to examine the relationships between ASC methylation, IL-1β, and IL-18 with V˙O2peak in persons with HF. This study examined the relationship between ASC methylation, IL-1β, and IL-18 with V˙O2peak in 54 stable outpatients with HF. All participants were NYHA class II or III, not engaged in an exercise program, and physically able to complete an exercise treadmill test. Mean V˙O2peak was 16.68 ± 4.7 mL·kg·min. V˙O2peak was positively associated with mean percent ASC methylation (r = 0.47, P = 0.001) and negatively associated with IL-1β (r = -0.38, P = 0.007). Multiple linear regression models demonstrated that V˙O2peak increased by 2.30 mL·kg·min for every 1% increase in ASC methylation and decreased by 1.91 mL·kg·min for every 1 pg·mL increase in plasma IL-1β. Mean percent ASC methylation and plasma IL-1β levels are associated with clinically meaningful differences in V˙O2peak in persons with HF. Inflammasome activation may play a mechanistic role in determining aerobic capacity. ASC methylation is a potentially modifiable mechanism for reducing the inflammatory response, thereby improving aerobic capacity in HF.

In vivo low-level light therapy increases cytochrome oxidase in skeletal muscle.

PubMed

Hayworth, Christopher R; Rojas, Julio C; Padilla, Eimeira; Holmes, Genevieve M; Sheridan, Eva C; Gonzalez-Lima, F

2010-01-01

Low-level light therapy (LLLT) increases survival of cultured cells, improves behavioral recovery from neurodegeneration and speeds wound healing. These beneficial effects are thought to be mediated by upregulation of mitochondrial proteins, especially the respiratory enzyme cytochrome oxidase. However, the effects of in vivo LLLT on cytochrome oxidase in intact skeletal muscle have not been previously investigated. We used a sensitive method for enzyme histochemistry of cytochrome oxidase to examine the rat temporalis muscle 24 h after in vivo LLLT. The findings showed for the first time that in vivo LLLT induced a dose- and fiber type-dependent increase in cytochrome oxidase in muscle fibers. LLLT was particularly effective at enhancing the aerobic capacity of intermediate and red fibers. The findings suggest that LLLT may enhance the oxidative energy metabolic capacity of different types of muscle fibers, and that LLLT may be used to enhance the aerobic potential of skeletal muscle.

Evaluating pulmonary function, aerobic capacity, and pediatric quality of life following a 10-week aerobic exercise training in school-aged asthmatics: a randomized controlled trial.

PubMed

Abdelbasset, Walid K; Alsubaie, Saud F; Tantawy, Sayed A; Abo Elyazed, Tamer I; Kamel, Dalia M

2018-01-01

It has been documented that aerobic exercise may increase pulmonary functions and aerobic capacity, but limited data has evaluated a child's satisfaction and pediatric quality of life (PQoL) with exercise training. This study aimed to investigate the effects of moderate-intensity exercise training on asthmatic school-aged children. This study included 38 school-aged children with asthma (23 males and 15 females) aged between 8-12 years. They were randomly assigned to two groups, aerobic exercise (AE) and conventional treatment (Con ttt) groups. The AE group received a program of moderate-intensity aerobic exercise for 10 weeks with asthma medications and the Con ttt group received only asthma medications without exercise intervention. A home respiratory exercise was recommended for the two groups. Aerobic capacity was investigated using maximal oxygen uptake (VO 2max ), 6-minute walk test (6MWT), and fatigue index. PQoL was evaluated using Pediatric Quality of Life Questionnaire (PQoLQ). Also, pulmonary function tests were performed, and the results recorded. The findings of this study showed significant improvements in pulmonary functions and VO 2max in the two groups; however, this improvement was significantly higher in the AE group than in the Con ttt group ( p <0.05). The 6MWT and fatigue index improved in the AE group ( p <0.05) but not in the Con ttt group ( p >0.05). All dimensions of PQoL significantly improved in the AE group ( p <0.05), but there was no significant improvement in the Con ttt group after the 10-week intervention period ( p >0.05). Ten weeks of physical exercise had beneficial effects on pulmonary functions, aerobic capacity, and PQoL in school-aged children with asthma. Effort and awareness should be dedicated to encouraging the active lifestyle among different populations, especially asthmatic children.

Augmentation of aerobic respiration and mitochondrial biogenesis in skeletal muscle by hypoxia preconditioning with cobalt chloride

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

Saxena, Saurabh; Shukla, Dhananjay; Bansal, Anju, E-mail: anjubansaldipas@gmail.com

High altitude/hypoxia training is known to improve physical performance in athletes. Hypoxia induces hypoxia inducible factor-1 (HIF-1) and its downstream genes that facilitate hypoxia adaptation in muscle to increase physical performance. Cobalt chloride (CoCl{sub 2}), a hypoxia mimetic, stabilizes HIF-1, which otherwise is degraded in normoxic conditions. We studied the effects of hypoxia preconditioning by CoCl{sub 2} supplementation on physical performance, glucose metabolism, and mitochondrial biogenesis using rodent model. The results showed significant increase in physical performance in cobalt supplemented rats without (two times) or with training (3.3 times) as compared to control animals. CoCl{sub 2} supplementation in rats augmentedmore » the biological activities of enzymes of TCA cycle, glycolysis and cytochrome c oxidase (COX); and increased the expression of glucose transporter-1 (Glut-1) in muscle showing increased glucose metabolism by aerobic respiration. There was also an increase in mitochondrial biogenesis in skeletal muscle observed by increased mRNA expressions of mitochondrial biogenesis markers which was further confirmed by electron microscopy. Moreover, nitric oxide production increased in skeletal muscle in cobalt supplemented rats, which seems to be the major reason for peroxisome proliferator activated receptor-gamma coactivator-1α (PGC-1α) induction and mitochondrial biogenesis. Thus, in conclusion, we state that hypoxia preconditioning by CoCl{sub 2} supplementation in rats increases mitochondrial biogenesis, glucose uptake and metabolism by aerobic respiration in skeletal muscle, which leads to increased physical performance. The significance of this study lies in understanding the molecular mechanism of hypoxia adaptation and improvement of work performance in normal as well as extreme conditions like hypoxia via hypoxia preconditioning. -- Highlights: ► We supplemented rats with CoCl{sub 2} for 15 days along with training. �

Extensive Functional Evaluations to Monitor Aerobic Training in Becker Muscular Dystrophy: A Case Report.

PubMed

Tramonti, Caterina; Rossi, Bruno; Chisari, Carmelo

2016-06-13

Low-intensity aerobic training seems to have positive effects on muscle strength, endurance and fatigue in Becker Muscular Dystrophy (BMD) patients. We describe the case of a 33-year old BMD man, who performed a four-week aerobic training. Extensive functional evaluations were executed to monitor the efficacy of the rehabilitative treatment. Results evidenced an increased force exertion and an improvement in muscle contraction during sustained exercise. An improvement of walk velocity, together with agility, endurance capacity and oxygen consumption during exercise was observed. Moreover, an enhanced metabolic efficiency was evidenced, as shown by reduced lactate blood levels after training. Interestingly, CK showed higher levels after the training protocol, revealing possible muscle damage. In conclusion, aerobic training may represent an effective method improving exercise performance, functional status and metabolic efficiency. Anyway, a careful functional assessment should be taken into account as a useful approach in the management of the disease's rehabilitative treatment.

Effects of lower extremity injuries on aerobic exercise capacity, anaerobic power, and knee isokinetic muscular function in high school soccer players.

PubMed

Ko, Kwang-Jun; Ha, Gi-Chul; Kim, Dong-Woo; Kang, Seol-Jung

2017-10-01

[Purpose] The study investigated the effects of lower extremity injuries on aerobic exercise capacity, anaerobic power, and knee isokinetic muscular function in high school soccer players. [Subjects and Methods] The study assessed U High School soccer players (n=40) in S area, South Korea, divided into 2 groups: a lower extremity injury group (n=16) comprising those with knee and ankle injuries and a control group (n=24) without injury. Aerobic exercise capacity, anaerobic power, and knee isokinetic muscular function were compared and analyzed. [Results] Regarding the aerobic exercise capacity test, significant differences were observed in maximal oxygen uptake and anaerobic threshold between both groups. For the anaerobic power test, no significant difference was observed in peak power and average power between the groups; however, a significant difference in fatigue index was noted. Regarding the knee isokinetic muscular test, no significant difference was noted in knee flexion, extension, and flexion/extension ratio between both groups. [Conclusion] Lower extremity injury was associated with reduced aerobic exercise capacity and a higher fatigue index with respect to anaerobic exercise capacity. Therefore, it seems necessary to establish post-injury training programs that improve aerobic and anaerobic exercise capacity for soccer players who experience lower extremity injury.

Aerobic capacity and peak power output of elite quadriplegic games players

PubMed Central

Goosey‐Tolfrey, V; Castle, P; Webborn, N

2006-01-01

Background Participation in wheelchair sports such as tennis and rugby enables people with quadriplegia to compete both individually and as a team at the highest level. Both sports are dominated by frequent, intermittent, short term power demands superimposed on a background of aerobic activity. Objective To gain physiological profiles of highly trained British quadriplegic athletes, and to examine the relation between aerobic and sprint capacity. Methods Eight male quadriplegic athletes performed an arm crank exercise using an ergometer fitted with a Schoberer Rad Messtechnik (SRM) powermeter. The sprint test consisted of three maximum‐effort sprints of five seconds duration against a resistance of 2%, 3%, and 4% of body mass. The highest power output obtained was recorded (PPO). Peak oxygen consumption (V̇o2peak), peak heart rate (HRpeak), and maximal power output (POaer) were determined. Results Mean POaer was 67.7 (16.2) W, mean V̇o2peak was 0.96 (0.17) litres/min, and HRpeak was 134 (19) beats/min for the group. There was high variability among subjects. Peak power over the five second sprint for the group was 220 (62) W. There was a significant correlation between V̇o2peak (litres/min) and POaer (W) (r  =  0.74, p<0.05). Conclusions These British quadriplegic athletes have relatively high aerobic fitness when compared with the available literature. Moreover, the anaerobic capacity of these athletes appeared to be relatively high compared with paraplegic participants. PMID:16611721

Immunological parameters in elderly women: correlations with aerobic power, muscle strength and mood state.

PubMed

Raso, Vagner; Natale, Valéria Maria; Duarte, Alberto José da Silva; Greve, Júlia Maria D'Andrea; Shephard, Roy J

2012-05-01

Our objective was to relate immunological data for healthy but sedentary elderly women to aerobic power, strength, and mood state. We measured peak aerobic power and one-repetition maximum strength along with mood (depression and fatigue), quality of life and carbohydrate intake on 42 women aged 60-77 years. Standard immunological techniques determined natural killer cell count and cytotoxic activity (NKCA), proliferative responses to phytohemaglutinin and OKT(3), various lymphocyte subpopulations (CD3(+), CD3(-)CD19(+), CD56(+), CD4(+), CD8(+), CD56(dim) and CD56(bright)), and markers of activation, maturation, down-regulation and susceptibility to apoptosis (CD25(+), CD28(+), CD45RA(+), CD45RO(+), CD69(+), CD95(+), HLA-DR(+)). Correlations of immune parameters with aerobic power and strength were very similar for absolute and relative immunological data. In the group as a whole, the only correlation with aerobic power was -0.35 (relative CD4(+)CD69(+) count), but in subjects with values <22.6 mL kg(-1)min(-1) correlations ranged from -0.57 (relative CD4(+)CD45RO(+)) to 0.92 (absolute CD56(dim)HLA-DR(+)). In terms of muscle strength, univariate correlation coefficients ranged from -0.34 (relative and absolute CD3(+)CD4(+)CD8(+)) to +0.48 (absolute CD3(+)HLA-DR(+)) and +0.50 (absolute CD8(+)CD45RA(+)CD45RO(+)). Neither NKCA nor lymphocyte proliferation were correlated with aerobic power or muscle strength. Although mood state and quality of life can sometimes be influenced by an individual's fitness level, our multivariate analyses suggested that depression, fatigue and quality of life were more important determinants of immune profile than our fitness measures. Psychological changes associated with aging may have a substantial adverse effect upon the immune system, and immunological function may be enhanced more by addressing these issues than by focusing upon aerobic or resistance training. Copyright © 2012 Elsevier Inc. All rights reserved.

Muscle-strengthening and aerobic activities and mortality among 3+ year cancer survivors in the U.S.

PubMed

Tarasenko, Yelena N; Linder, Daniel F; Miller, Eric A

2018-05-01

This study examined the association between adherence to American College of Sports Medicine and American Cancer Society guidelines on aerobic and muscle-strengthening activities and mortality risks among 3+ year cancer survivors in the U.S. The observational study was based on 1999-2009 National Health Interview Survey Linked Mortality Files with follow-up through 2011. After applying exclusion criteria, there were 13,997 observations. The hazard ratios (HRs) for meeting recommendations on muscle-strengthening activities only, on aerobic activities only, and on both types of physical activity (i.e., adhering to complete guidelines) were calculated using a reference group of cancer survivors engaging in neither. Unadjusted and adjusted HRs of all-cause, cancer-specific, and cardiovascular disease-specific mortalities were estimated using Cox proportional hazards models. In all models, compared to the reference group, cancer survivors adhering to complete guidelines had significantly decreased all-cause, cancer-specific, and cardiovascular disease-specific mortalities (HRs ranged from 0.37 to 0.64, p's < 0.05). There were no statistically significant differences between hazard rates of cancer survivors engaging in recommended levels of muscle-strengthening activities only and the reference group (HRs ranged from 0.76 to 0.94, p's > 0.05). Wald test statistics suggested a significant dose-response relationship between levels of adherence to complete guidelines and cancer-specific mortality. While muscle-strengthening activities by themselves do not appear to reduce mortality risks, such activities may provide added cancer-specific survival benefits to 3+ year cancer survivors who are already aerobically active.

Plasticity of muscle function in a thermoregulating ectotherm (Crocodylus porosus): biomechanics and metabolism.

PubMed

Seebacher, Frank; James, Rob S

2008-03-01

Thermoregulation and thermal sensitivity of performance are thought to have coevolved so that performance is optimized within the selected body temperature range. However, locomotor performance in thermoregulating crocodiles (Crocodylus porosus) is plastic and maxima shift to different selected body temperatures in different thermal environments. Here we test the hypothesis that muscle metabolic and biomechanical parameters are optimized at the body temperatures selected in different thermal environments. Hence, we related indices of anaerobic (lactate dehydrogenase) and aerobic (cytochrome c oxidase) metabolic capacities and myofibrillar ATPase activity to the biomechanics of isometric and work loop caudofemoralis muscle function. Maximal isometric stress (force per muscle cross-sectional area) did not change with thermal acclimation, but muscle work loop power output increased with cold acclimation as a result of shorter activation and relaxation times. The thermal sensitivity of myofibrillar ATPase activity decreased with cold acclimation in caudofemoralis muscle. Neither aerobic nor anaerobic metabolic capacities were directly linked to changes in muscle performance during thermal acclimation, although there was a negative relationship between anaerobic capacity and isometric twitch stress in cold-acclimated animals. We conclude that by combining thermoregulation with plasticity in biomechanical function, crocodiles maximize performance in environments with highly variable thermal properties.

Preseason Aerobic Capacity Is an Independent Predictor of In-Season Injury in Collegiate Soccer Players.

PubMed

Watson, Andrew; Brindle, Jacob; Brickson, Stacey; Allee, Tyler; Sanfilippo, Jennifer

2017-05-01

To determine whether preseason aerobic capacity is independently associated with in-season injury among collegiate soccer players. Prospective cohort study. University athletic department. Forty-three NCAA Division I soccer athletes (male = 23). Gender and preseason lean body mass (LBM), body fat percentage (BF%), and maximal aerobic capacity (V[Combining Dot Above]O2max). In-season injuries were recorded during the season, and body composition and fitness variables were compared between injured and uninjured players. Multivariate regression models were developed to predict injury during the entire season and during the first 4 weeks of the season. Thirty-five injuries among 25 players were recorded during the season. Players injured at any point during the season had lower V[Combining Dot Above]O2max (57.7 vs 63.4 mL·kg·min, P = 0.014) and Tmax (15.8 vs 17.2 minutes, P = 0.035), compared with uninjured players, but no differences were noted in age, gender, LBM, or BF%. Players injured during the first 4 weeks of the season had lower LBM (49.7 vs 56.0 kg, P = 0.038) and Tmax (15.1 vs 16.7 minutes, P = 0.043) than uninjured players. For injuries occurring throughout the entire season, V[Combining Dot Above]O2max was an independent predictor of injury (P = 0.043), whereas gender, LBM, and BF% were not. During the first 4 weeks of the season, V[Combining Dot Above]O2max (P = 0.035) and LBM (P = 0.049) were related to injury, whereas gender and BF% were not. Aerobic fitness is an independent predictor of in-season injury. Early-season injuries are related to aerobic fitness and LBM. Efforts to increase aerobic capacity and LBM among soccer players in the off-season may help reduce in-season injury.

Twelve-week combined resistance and aerobic training confers greater benefits than aerobic training alone in nondialysis CKD.

PubMed

Watson, Emma L; Gould, Douglas W; Wilkinson, Thomas J; Xenophontos, Soteris; Clarke, Amy L; Vogt, Barbara Perez; Viana, João L; Smith, Alice C

2018-06-01

There is a growing consensus that patients with chronic kidney disease (CKD) should engage in regular exercise, but there is a lack of formal guidelines. In this report, we determined whether combined aerobic and resistance exercise would elicit superior physiological gains, in particular muscular strength, compared with aerobic training alone in nondialysis CKD. Nondialysis patients with CKD stages 3b-5 were randomly allocated to aerobic exercise {AE, n = 21; 9 men; median age 63 [interquartile range (IQR) 58-71] yr; median estimated glomerular filtration rate (eGFR) 24 (IQR 20-30) ml·min -1 ·1.73 m -2 } or combined exercise [CE, n = 20, 9 men, median age 63 (IQR 51-69) yr, median eGFR 27 (IQR 22-32) ml·min -1 ·1.73 m -2 ], preceded by a 6-wk run-in control period. Patients then underwent 12 wk of supervised AE (treadmill, rowing, or cycling exercise) or CE training (as AE plus leg extension and leg press exercise) performed three times per week. Outcome assessments of knee extensor muscle strength, quadriceps muscle volume, exercise capacity, and central hemodynamics were performed at baseline, following the 6-wk control period, and at the end of the intervention. AE and CE resulted in significant increases in knee extensor strength of 16 ± 19% (mean ± SD; P = 0.001) and 48 ± 37% ( P < 0.001), respectively, which were greater after CE ( P = 0.02). AE and CE resulted in 5 ± 7% ( P = 0.04) and 9 ± 7% ( P < 0.001) increases in quadriceps volume, respectively ( P < 0.001), which were greater after CE ( P = 0.01). Both AE and CE increased distance walked in the incremental shuttle walk test [28 ± 44 m ( P = 0.01) and 32 ± 45 m ( P = 0.01), respectively]. In nondialysis CKD, the addition of resistance exercise to aerobic exercise confers greater increases in muscle mass and strength than aerobic exercise alone.

Resistance to Aerobic Exercise Training Causes Metabolic Dysfunction and Reveals Novel Exercise-Regulated Signaling Networks

PubMed Central

Lessard, Sarah J.; Rivas, Donato A.; Alves-Wagner, Ana B.; Hirshman, Michael F.; Gallagher, Iain J.; Constantin-Teodosiu, Dumitru; Atkins, Ryan; Greenhaff, Paul L.; Qi, Nathan R.; Gustafsson, Thomas; Fielding, Roger A.; Timmons, James A.; Britton, Steven L.; Koch, Lauren G.; Goodyear, Laurie J.

2013-01-01

Low aerobic exercise capacity is a risk factor for diabetes and a strong predictor of mortality, yet some individuals are “exercise-resistant” and unable to improve exercise capacity through exercise training. To test the hypothesis that resistance to aerobic exercise training underlies metabolic disease risk, we used selective breeding for 15 generations to develop rat models of low and high aerobic response to training. Before exercise training, rats selected as low and high responders had similar exercise capacities. However, after 8 weeks of treadmill training, low responders failed to improve their exercise capacity, whereas high responders improved by 54%. Remarkably, low responders to aerobic training exhibited pronounced metabolic dysfunction characterized by insulin resistance and increased adiposity, demonstrating that the exercise-resistant phenotype segregates with disease risk. Low responders had impaired exercise-induced angiogenesis in muscle; however, mitochondrial capacity was intact and increased normally with exercise training, demonstrating that mitochondria are not limiting for aerobic adaptation or responsible for metabolic dysfunction in low responders. Low responders had increased stress/inflammatory signaling and altered transforming growth factor-β signaling, characterized by hyperphosphorylation of a novel exercise-regulated phosphorylation site on SMAD2. Using this powerful biological model system, we have discovered key pathways for low exercise training response that may represent novel targets for the treatment of metabolic disease. PMID:23610057

Digestive capacities, inbreeding and growth capacities in juvenile Arctic charr Salvelinus alpinus.

PubMed

Ditlecadet, D; Blier, P U; Le François, N R; Dufresne, F

2009-12-01

Genetic variation in growth performance was estimated in 26 families from two commercial strains of Arctic charr Salvelinus alpinus. Physiological determinants of growth and metabolic capacities were also assessed through enzymatic assays. A relatedness coefficient was attributed to each family using parental genotypes at seven microsatellite loci. After 15 months of growth, faster growing families had significantly lower relatedness coefficients than slower growing families, suggesting their value as indicators of growth potential. Individual fish that exhibited higher trypsin activity also displayed higher growth rate, suggesting that superior protein digestion capacities can be highly advantageous at early stages. Capacities to use amino acids as expressed by glutamate dehydrogenase (GDH) activities were lower in the liver of fast-growing fish (13-20%), whereas white muscle of fast-growing fish showed higher activities than that of slow-growing fish for amino acid metabolism and aerobic capacity [22-32% increase for citrate synthase (CS), aspartate aminotransferase (AAT) and GDH]. The generally higher glycolytic capacities (PK and LDH) in white muscle of fast-growing fish indicated higher burst swimming capacities and hence better access to food.

Lung function profiles and aerobic capacity of adult cigarette and hookah smokers after 12 weeks intermittent training.

PubMed

Koubaa, Abdessalem; Triki, Moez; Trabelsi, Hajer; Masmoudi, Liwa; Zeghal, Khaled N; Sahnoun, Zouhair; Hakim, Ahmed

2015-01-01

Introduction Pulmonary function is compromised in most smokers. Yet it is unknown whether exercise training improves pulmonary function and aerobic capacity in cigarette and hookah smokers and whether these smokers respond in a similar way as do non-smokers. Aim To evaluate the effects of an interval exercise training program on pulmonary function and aerobic capacity in cigarette and hookah smokers. Methods Twelve cigarette smokers, 10 hookah smokers, and 11 non-smokers participated in our exercise program. All subjects performed 30 min of interval exercise (2 min of work followed by 1 min of rest) three times a week for 12 weeks at an intensity estimated at 70% of the subject's maximum aerobic capacity ([Formula: see text]). Pulmonary function was measured using spirometry, and maximum aerobic capacity was assessed by maximal exercise testing on a treadmill before the beginning and at the end of the exercise training program. Results As expected, prior to the exercise intervention, the cigarette and hookah smokers had significantly lower pulmonary function than the non-smokers. The 12-week exercise training program did not significantly affect lung function as assessed by spirometry in the non-smoker group. However, it significantly increased both forced expiratory volume in 1 second and peak expiratory flow (PEF) in the cigarette smoker group, and PEF in the hookah smoker group. Our training program had its most notable impact on the cardiopulmonary system of smokers. In the non-smoker and cigarette smoker groups, the training program significantly improved [Formula: see text] (4.4 and 4.7%, respectively), v [Formula: see text] (6.7 and 5.6%, respectively), and the recovery index (7.9 and 10.5%, respectively). Conclusions After 12 weeks of interval training program, the increase of [Formula: see text] and the decrease of recovery index and resting heart rate in the smoking subjects indicated better exercise tolerance. Although the intermittent training program

Lung function profiles and aerobic capacity of adult cigarette and hookah smokers after 12 weeks intermittent training.

PubMed

Koubaa, Abdessalem; Triki, Moez; Trabelsi, Hajer; Masmoudi, Liwa; Zeghal, Khaled N; Sahnoun, Zouhair; Hakim, Ahmed

2015-01-01

Pulmonary function is compromised in most smokers. Yet it is unknown whether exercise training improves pulmonary function and aerobic capacity in cigarette and hookah smokers and whether these smokers respond in a similar way as do non-smokers. To evaluate the effects of an interval exercise training program on pulmonary function and aerobic capacity in cigarette and hookah smokers. Twelve cigarette smokers, 10 hookah smokers, and 11 non-smokers participated in our exercise program. All subjects performed 30 min of interval exercise (2 min of work followed by 1 min of rest) three times a week for 12 weeks at an intensity estimated at 70% of the subject's maximum aerobic capacity (VO2max). Pulmonary function was measured using spirometry, and maximum aerobic capacity was assessed by maximal exercise testing on a treadmill before the beginning and at the end of the exercise training program. As expected, prior to the exercise intervention, the cigarette and hookah smokers had significantly lower pulmonary function than the non-smokers. The 12-week exercise training program did not significantly affect lung function as assessed by spirometry in the non-smoker group. However, it significantly increased both forced expiratory volume in 1 second and peak expiratory flow (PEF) in the cigarette smoker group, and PEF in the hookah smoker group. Our training program had its most notable impact on the cardiopulmonary system of smokers. In the non-smoker and cigarette smoker groups, the training program significantly improved VO2max (4.4 and 4.7%, respectively), v VO2max (6.7 and 5.6%, respectively), and the recovery index (7.9 and 10.5%, respectively). After 12 weeks of interval training program, the increase of VO2max and the decrease of recovery index and resting heart rate in the smoking subjects indicated better exercise tolerance. Although the intermittent training program altered pulmonary function only partially, both aerobic capacity and life quality were improved

Aerobic training and l-arginine supplementation promotes rat heart and hindleg muscles arteriogenesis after myocardial infarction.

PubMed

Ranjbar, Kamal; Rahmani-Nia, Farhad; Shahabpour, Elham

2016-09-01

Arteriogenesis is a main defense mechanism to prevent heart and local tissues dysfunction in occlusive artery disease. TGF-β and angiostatin have a pivotal role in arteriogenesis. We tested the hypothesis that aerobic training and l-arginine supplementation promotes cardiac and skeletal muscles arteriogenesis after myocardial infarction (MI) parallel to upregulation of TGF-β and downregulation of angiostatin. For this purpose, 4 weeks after LAD occlusion, 50 male Wistar rats were randomly distributed into five groups: (1) sham surgery without MI (sham, n = 10), (2) control-MI (Con-MI, n = 10), (3) l-arginine-MI (La-MI, n = 10), (4) exercise training-MI (Ex-MI, n = 10), and (5) exercise and l-arginine-MI (Ex + La-MI). Exercise training groups running on a treadmill for 10 weeks with moderate intensity. Rats in the l-arginine-treated groups drank water containing 4 % l-arginine. Arteriolar density with different diameters (11-25, 26-50, 51-75, and 76-150 μm), TGF-β, and angiostatin gene expression were measured in cardiac (area at risk) and skeletal (soleus and gastrocnemius) muscles. Smaller arterioles decreased in cardiac after MI. Aerobic training and l-arginine increased the number of cardiac arterioles with 11-25 and 26-50 μm diameters parallel to TGF-β overexpression. In gastrocnemius muscle, the number of arterioles/mm(2) was only increased in the 11 to 25 μm in response to training with and without l-arginine parallel to angiostatin downregulation. Soleus arteriolar density with different size was not different between experimental groups. Results showed that 10 weeks aerobic exercise training and l-arginine supplementation promotes arteriogenesis of heart and gastrocnemius muscles parallel to overexpression of TGF-β and downregulation of angiostatin in MI rats.

Appropriate interpretation of aerobic capacity: allometric scaling in adult and young soccer players

PubMed Central

Chamari, K; Moussa-Chamari, I; Boussaidi, L; Hachana, Y; Kaouech, F; Wisloff, U

2005-01-01

Objective: To compare aerobic capacity of young and adult elite soccer players using appropriate scaling procedures. Methods: Twenty four male adult (mean (SD) age 24 (2) years, weight 75.7 (7.2) kg, VO2MAX 66.6 (5.2) ml/lbm/min, where lbm is lean body mass in kg) and 21 youth (14 (0.4) years, 60.2 (7.3) kg, 66.5 (5.9) ml/lbm/min) elite soccer players took part in the study. Allometric equations were used to determine the relation between maximal and submaximal oxygen cost of running (running economy) and body mass. Results: Maximal and submaximal oxygen uptake increased in proportion to body mass raised to the power of 0.72 (0.04) and 0.60 (0.06) respectively. The VO2MAX of adult players was similar to that of the youth players when expressed in direct proportion to body mass—that is, ml/kg/min—but 5% higher (p<0.05) when expressed using appropriate procedures for scaling. Conversely, compared with seniors, youth players had 13% higher (p<0.001) energy cost of running—that is, poorer running economy—when expressed as ml/kg/min but not when expressed according to the scaling procedures. Conclusions: Compared with the youth soccer players, VO2MAX in the seniors was underestimated and running economy overestimated when expressed traditionally as ml/lbm/min. The study clearly shows the pitfalls in previous studies when aerobic capacity was evaluated in subjects with different body mass. It further shows that the use of scaling procedures can affect the evaluation of, and the resultant training programme to improve, aerobic capacity. PMID:15665205

Overweight female rats selectively breed for low aerobic capacity exhibit increased myocardial fibrosis and diastolic dysfunction

PubMed Central

Johnson, Megan S.; Ma, Lixin; Pulakat, Lakshmi; Mugerfeld, Irina; Hayden, Melvin R.; Garro, Mona; Knight, William; Britton, Steven L.; Koch, Lauren G.; Sowers, James R.

2012-01-01

The statistical association between endurance exercise capacity and cardiovascular disease suggests that impaired aerobic metabolism underlies the cardiovascular disease risk in men and women. To explore this connection, we applied divergent artificial selection in rats to develop low-capacity runner (LCR) and high-capacity runner (HCR) rats and found that disease risks segregated strongly with low running capacity. Here, we tested if inborn low aerobic capacity promotes differential sex-related cardiovascular effects. Compared with HCR males (HCR-M), LCR males (LCR-M) were overweight by 34% and had heavier retroperitoneal, epididymal, and omental fat pads; LCR females (LCR-F) were 20% heavier than HCR females (HCR-F), and their retroperitoneal, but not perireproductive or omental, fat pads were heavier as well. Unlike HCR-M, blood pressure was elevated in LCR-M, and this was accompanied by left ventricular (LV) hypertrophy. Like HCR-F, LCR-F exhibited normal blood pressure and LV weight as well as increased spontaneous cage activity compared with males. Despite normal blood pressures, LCR-F exhibited increased myocardial interstitial fibrosis and diastolic dysfunction, as indicated by increased LV stiffness, a decrease in the initial filling rate, and an increase in diastolic relaxation time. Although females exhibited increased arterial stiffness, ejection fraction was normal. Increased interstitial fibrosis and diastolic dysfunction in LCR-F was accompanied by the lowest protein levels of phosphorylated AMP-actived protein kinase [phospho-AMPK (Thr172)] and silent information regulator 1. Thus, the combination of risk factors, including female sex, intrinsic low aerobic capacity, and overweightness, promote myocardial stiffness/fibrosis sufficient to induce diastolic dysfunction in the absence of hypertension and LV hypertrophy. PMID:22345570

Calcineurin-NFAT Signaling and Neurotrophins Control Transformation of Myosin Heavy Chain Isoforms in Rat Soleus Muscle in Response to Aerobic Treadmill Training.

PubMed

Liu, Wenfeng; Chen, Gan; Li, Fanling; Tang, Changfa; Yin, Dazhong

2014-12-01

This study elucidated the role of CaN-NFAT signaling and neurotrophins on the transformation of myosin heavy chain isoforms in the rat soleus muscle fiber following aerobic exercise training. To do so, we examined the content and distribution of myosin heavy chain (MyHC) isoforms in the rat soleus muscle fiber, the activity of CaN and expression of NFATc1 in these fibers, and changes in the expression of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neutrophin-3 (NT-3) in the soleus and striatum following high-and medium-intensity aerobic treadmill training. Specific pathogen-free 2 month old male Sprague-Dawley (SD) rats were randomly divided into three groups: Control group (Con, n = 8), moderate-intensity aerobic exercise group (M-Ex, n = 8) and high-intensity aerobic exercise group (H-Ex, n = 8). We used ATPase staining to identify the muscle fiber type I and II, SDS-PAGE to separate and analyze the isoforms MyHCI, MyHCIIA, MyHCIIB and MyHCIIx, and performed western blots to determine the expression of NFATc1, NGF, BDNF and NT-3. CaN activity was measured using a colorimetric assay. In the soleus muscle, 8 weeks of moderate-intensity exercise can induce transformation of MyHC IIA and MyHC IIB to MyHC IIX and MyHC I (p < 0.01), while high-intensity treadmill exercise can induce transform MyHC IIx to MyHC IIB, MyHC IIA and MyHC I (p < 0.01). In comparison to the control group, CaN activity and NFATcl protein level were significantly increased in both the M-Ex and H-Ex groups (p < 0.05, p < 0.01), with a more pronounced upregulation in the M-Ex group (p < 0.05). Eight weeks of moderate- and high-intensity aerobic exercise induced the expression of NGF, BDNF and NT-3 in the soleus muscle and the striatum (p < 0.01), with the most significant increase in the H-Ex group (p < 0.01). In the rat soleus muscle, (1) CaN-NFATcl signaling contributes to the conversion of MyHC I isoform in response to moderate-intensity exercise; (2) Neurotrophins

Anthropometric and Cardio-Respiratory Indices and Aerobic Capacity of Male and Female Students

ERIC Educational Resources Information Center

Czajkowska, Anna; Mazurek, Krzysztof; Lutoslawska, Grazyna; Zmijewski, Piotr

2009-01-01

Study aim: To assess the relations between anthropometric and cardio-respiratory indices, and aerobic capacity of students, differing in the level of physical activity, under resting and exercise conditions. Material and methods: A group of 87 male and 75 female students volunteered to participate in the study. Their physical activity was…

The Relationship between Aerobic Capacity and Physical Activity in Blind and Sighted Adolescents.

ERIC Educational Resources Information Center

Kobberling, G.; And Others

1991-01-01

This study investigated the relationship between habitual physical activity and aerobic capacity in 30 blind and 30 sighted adolescents. Both physical activity and maximal oxygen consumption were significantly higher among the sighted adolescents. A minimum of 30 minutes of daily activity at a minimal oxygen consumption of 8 METs (resting…

Effects of body fat and dominant somatotype on explosive strength and aerobic capacity trainability in prepubescent children.

PubMed

Marta, Carlos C; Marinho, Daniel A; Barbosa, Tiago M; Carneiro, André L; Izquierdo, Mikel; Marques, Mário C

2013-12-01

The purpose of this study was to analyze the influence of body fat and somatotype on explosive strength and aerobic capacity trainability in the prepubertal growth spurt, marked by rapid changes in body size, shape, and composition, all of which are sexually dimorphic. One hundred twenty-five healthy children (58 boys, 67 girls), aged 10-11 years (10.8 ± 0.4 years), who were self-assessed in Tanner stages 1-2, were randomly assigned into 2 experimental groups to train twice a week for 8 weeks: strength training group (19 boys, 22 girls), endurance training group (21 boys, 24 girls), and a control group (18 boys, 21 girls). Evaluation of body fat was carried out using the method described by Slaughter. Somatotype was computed according to the Heath-Carter method. Increased endomorphy reduced the likelihood of vertical jump height improvement (odds ratio [OR], 0.10; 95% confidence interval [CI], 0.01-0.85), increased mesomorphy (OR, 6.15; 95% CI, 1.52-24.88) and ectomorphy (OR, 6.52; 95% CI, 1.71-24.91) increased the likelihood of sprint performance, and increased ectomorphy (OR, 3.84; 95% CI, 1.20-12.27) increased the likelihood of aerobic fitness gains. Sex did not affect the training-induced changes in strength or aerobic fitness. These data suggest that somatotype has an effect on explosive strength and aerobic capacity trainability, which should not be disregarded. The effect of adiposity on explosive strength, musculoskeletal magnitude on running speed, and relative linearity on running speed and aerobic capacity seem to be crucial factors related to training-induced gains in prepubescent boys and girls.

Childhood Fitness and Academic Performance: An Investigation into the Effect of Aerobic Capacity on Academic Test Scores

ERIC Educational Resources Information Center

Hobbs, Mark

2014-01-01

The purpose of this quantitate ve study was to determine whether or not students in fifth grade who meet the healthy fitness zone (HFZ) for aerobic capacity on the fall 2013 FITNESSGRAM® Test scored higher on the math portion of the 2013 fall Measures of Academic Progress (MAP) test, than students that failed to reach the HFZ for aerobic capacity…

Effects of of habitats and pesticides on aerobic capacity and survival of soil fauna.

PubMed

Tripathi, G; Sharma, B M

2005-06-01

Faunal health is largely dependent on their soil environment and available litter quality. So the effects of different soil habitats and pesticides on citrate synthase (CS) activity of soil fauna and its population were studied. The soil animals were collected from different pedoecosystems for habitat study. Whereas Vigna radiata based system was selected for pesticidal observations. The field was divided into five equal plots for control and treatment of gamma-BHC, quinalphos, carbaryl and cypermethrin. Soil fauna was collected by quadrat method and extracted by Tullgren funnel. Individuals of a species having similar sizes were collected for the estimation of CS activity. They were homogenized and fractions were obtained by differential centrifugation. The activity of CS was assayed spectrophotometrically. Citrate synthase (CS) activity of beetle (Rasphytus fregi), woodlouse (Porcellio laevis) and centipede (Scolopendra morsitans) varied significantly with respect to changes in different soil habitats. Though the CS activity of R. fregi, P. laevis, and S. morsitans differed among themselves but the highest activity of CS in these animals was in V. radiata and lowest in A. nilotica based pedoecosystem. The aerobic capacity of centipede was maximum followed by woodlouse and beetle. The treatment of gamma-BHC, quinalphos, carbaryl and cypermethrin significantly reduced the CS activity of these animals. Gamma-BHC showed maximum reduction in CS activity indicating highly toxic effect of organochlorine on aerobic metabolism of soil fauna. However, minimum reduction was observed in response to carbaryl (in beetle) or cypermethrin (in woodlouse/centipede) leading to impairment of aerobic capacity. The differences in pesticide effects might be assigned to the differences in chemical nature of pesticides and their interactions with below-ground fauna. Treatment of gamma-BHC and quinalphos reduced the population of Acari, Coleoptera, Collembola, other arthropods as well as

Aerobic Exercise Training in Post-Polio Syndrome: Process Evaluation of a Randomized Controlled Trial.

PubMed

Voorn, Eric L; Koopman, Fieke S; Brehm, Merel A; Beelen, Anita; de Haan, Arnold; Gerrits, Karin H L; Nollet, Frans

2016-01-01

To explore reasons for the lack of efficacy of a high intensity aerobic exercise program in post-polio syndrome (PPS) on cardiorespiratory fitness by evaluating adherence to the training program and effects on muscle function. A process evaluation using data from an RCT. Forty-four severely fatigued individuals with PPS were randomized to exercise therapy (n = 22) or usual care (n = 22). Participants in the exercise group were instructed to exercise 3 times weekly for 4 months on a bicycle ergometer (60-70% heart rate reserve). The attendance rate was high (median 89%). None of the participants trained within the target heart rate range during >75% of the designated time. Instead, participants exercised at lower intensities, though still around the anaerobic threshold (AT) most of the time. Muscle function did not improve in the exercise group. Our results suggest that severely fatigued individuals with PPS cannot adhere to a high intensity aerobic exercise program on a cycle ergometer. Despite exercise intensities around the AT, lower extremity muscle function nor cardiorespiratory fitness improved. Improving the aerobic capacity in PPS is difficult through exercise primarily focusing on the lower extremities, and may require a more individualized approach, including the use of other large muscle groups instead. Netherlands National Trial Register NTR1371.

[Effects of a high intensity interval training on the aerobic capacity of adolescents].

PubMed

Huerta Ojeda, Álvaro; Galdames Maliqueo, Sergio; Cataldo Guerra, Marianela; Barahona Fuentes, Guillermo; Rozas Villanueva, Tania; Cáceres Serrano, Pablo

2017-08-01

If aerobic capacity is stimulated early in life, maximal oxygen consumption during adulthood is assured. To analyze the effects of a high intensity interval training (HIIT) in adolescents on the maximal oxygen consumption (VO2max) measured using the 20-m shuttle run test (20mSRT). Twenty eight teenagers aged 13 ± 0.6 years were divided in two groups of 14 subjects each. One group was to a 16 sessions of HIIT interval training based on their individual maximal aerobic speed and the other continued with their usual exercise done at school. At baseline and the end of the intervention VO2max was measured using the 20mSTR. At the end of the intervention, the trained teenagers significantly improved their VO2max and the time spent in the 20mSTR. A HIIT program based on the individual maximal aerobic speed improves VO2max in adolescents.

Effects of integrated treatment with LED and microcurrent on muscle tone and stiffness in the calf muscle during moderate aerobic exercise.

PubMed

Han, Sang-Wan; Lee, Jeong-Woo

2018-06-01

[Purpose] This study aimed to investigate the effects of the therapeutic device combined with LED and microcurrent (MC) on muscle tone and stiffness in the calf muscle after its application during moderate aerobic exercise. [Subjects and Methods] Twenty healthy adult subjects were randomized to either the test group of the therapeutic device combined with LED and MC or the control group, and they walked on a 10%-sloped treadmill with a 5 km/hr speed for 30 minutes. Each of the subjects in the test group performed treadmill exercise with the therapeutic device attached to the edge of his or her calf muscle. After the exercise, the muscle tone and stiffness at the edge of the calf muscle were measured. [Results] With respect to the muscle tone, a statistically significant difference was found between the two groups only 5 minutes after the exercise. Concerning muscle stiffness, significant differences were shown between the two groups right after the exercise and 5 minutes after the exercise. [Conclusion] Integrated treatment with LED and MC on is considered helpful for lowering the muscle tone 5 minutes after the exercise, and for lowering the muscle stiffness right after the exercise and 5 minutes after the exercise.

Ventilatory threshold may be a more specific measure of aerobic capacity than peak oxygen consumption rate in persons with stroke.

PubMed

Boyne, Pierce; Reisman, Darcy; Brian, Michael; Barney, Brian; Franke, Ava; Carl, Daniel; Khoury, Jane; Dunning, Kari

2017-03-01

After stroke, aerobic deconditioning can have a profound impact on daily activities. This is usually measured by the peak oxygen consumption rate achieved during exercise testing (VO2-peak). However, VO2-peak may be distorted by motor function. The oxygen uptake efficiency slope (OUES) and VO2 at the ventilatory threshold (VO2-VT) could more specifically assess aerobic capacity after stroke, but this has not been tested. To assess the differential influence of motor function on three measures of aerobic capacity (VO2-peak, OUES, and VO2-VT) and to evaluate the inter-rater reliability of VO2-VT determination post-stroke. Among 59 persons with chronic stroke, cross-sectional correlations with motor function (comfortable gait speed [CGS] and lower extremity Fugl-Meyer [LEFM]) were compared between the different aerobic capacity measures, after adjustment for covariates, in order to isolate any distorting effect of motor function. Reliability of VO2-VT determination between three raters was assessed with intra-class correlation (ICC). CGS was moderately correlated with VO2-peak (r = 0.52, p < 0.0001) and weakly correlated with OUES (r = 0.41, p = 0.002) and VO2-VT (r = 0.37, p = 0.01). LEFM was weakly correlated with VO2-peak (r = 0.26, p = 0.055) and very weakly correlated with OUES (r = 0.19, p = 0.17) and VO2-VT (r = 0.14, p = 0.31). Compared to VO2-peak, VO2-VT was significantly less correlated with CGS (r difference = -0.16, p = 0.02). Inter-rater reliability of VO2-VT determination was high (ICC: 0.93, 95% CI: 0.89-0.96). Motor dysfunction appears to artificially lower measured aerobic capacity. VO2-VT seemed to be less distorted than VO2-peak and had good inter-rater reliability, so it may provide more specific assessment of aerobic capacity post-stroke.

Aerobic capacity in speed-power athletes aged 20-90 years vs endurance runners and untrained participants.

PubMed

Kusy, K; Zieliński, J

2014-02-01

We studied relationships between age and aerobic capacity in three groups of subjects adhering to different exercise modalities. A total of 203 men aged 20-90 years were examined: 52 speed-power track and field athletes (SP), 89 endurance runners (ER) and 62 untrained individuals (UT). Maximal exercise characteristics were obtained during a graded treadmill test until exhaustion: oxygen uptake (VO2max), heart rate (HRmax), oxygen pulse (O2 Pulsemax) and maximal distance (Distmax). Information about training history and weekly training amount was collected. A linear model of regression was adopted. VO2max in SP was lower than in ER, but significantly higher than in UT. The cross-sectional rates of decline in body mass-adjusted VO2max and Distmax were significantly smaller in SP than in ER and UT. About 80 years of age, the levels of VO2max and Distmax reached similar values in SP and ER. The decline in HRmax, but not in O2 Pulsemax was suggested as a cardiac adaptation accounting for between-group differences in VO2max loss. Weekly training volume was a significant positive predictor of age-related changes in aerobic capacity. In conclusion, not only endurance, but also speed-power exercise appears adequate to ensure an elevated aerobic capacity at old age. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of high-intensity interval cycling performed after resistance training on muscle strength and hypertrophy.

PubMed

Tsitkanou, S; Spengos, K; Stasinaki, A-N; Zaras, N; Bogdanis, G; Papadimas, G; Terzis, G

2017-11-01

Aim of the study was to investigate whether high-intensity interval cycling performed immediately after resistance training would inhibit muscle strength increase and hypertrophy expected from resistance training per se. Twenty-two young men were assigned into either resistance training (RE; N = 11) or resistance training plus high-intensity interval cycling (REC; N = 11). Lower body muscle strength and rate of force development (RFD), quadriceps cross-sectional area (CSA) and vastus lateralis muscle architecture, muscle fiber type composition and capillarization, and estimated aerobic capacity were evaluated before and after 8 weeks of training (2 times per week). Muscle strength and quadriceps CSA were significantly and similarly increased after both interventions. Fiber CSA increased significantly and similarly after both RE (type I: 13.6 ± 3.7%, type IIA: 17.6 ± 4.4%, type IIX: 23.2 ± 5.7%, P < 0.05) and REC (type I: 10.0 ± 2.7%, type IIA: 14.8 ± 4.3% type IIX: 20.8 ± 6.0%, P < 0.05). In contrast, RFD decreased and fascicle angle increased (P < 0.05) only after REC. Capillary density and estimated aerobic capacity increased (P < 0.05) only after REC. These results suggest that high-intensity interval cycling performed after heavy-resistance exercise may not inhibit resistance exercise-induced muscle strength/hypertrophy after 2 months of training, while it prompts aerobic capacity and muscle capillarization. The addition of high-intensity cycling after heavy-resistance exercise may decrease RFD partly due to muscle architectural changes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Isometric muscle strength and mobility capacity in children with cerebral palsy.

PubMed

Dallmeijer, Annet J; Rameckers, Eugene A; Houdijk, Han; de Groot, Sonja; Scholtes, Vanessa A; Becher, Jules G

2017-01-01

To determine the relationship between isometric leg muscle strength and mobility capacity in children with cerebral palsy (CP) compared to typically developing (TD) peers. Participants were 62 children with CP (6-13 years), able to walk with (n = 10) or without (n = 52) walking aids, and 47 TD children. Isometric muscle strength of five muscle groups of the leg was measured using hand-held dynamometry. Mobility capacity was assessed with the 1-min walk, the 10-m walk, sit-to-stand, lateral-step-up and timed-stair tests. Isometric strength of children with CP was reduced to 36-82% of TD. When adjusted for age and height, the percentage of variance in mobility capacity that was explained by isometric strength of the leg muscles was 21-24% (walking speed), 25% (sit-to-stand), 28% (lateral-step-up) and 35% (timed-stair) in children with CP. Hip abductors and knee flexors had the largest contribution to the explained variance, while knee extensors showed the weakest correlation. Weak or no associations were found between strength and mobility capacity in TD children. Isometric strength, especially hip abductor and knee flexor strength, is moderately related to mobility capacity in children with CP, but not in TD children. To what extent training of these muscle groups will lead to better mobility capacity needs further study. Implications for Rehabilitation Strength training in children with cerebral palsy (CP) may be targeted more specifically at hip abductors and knee flexors. The moderate associations imply that large improvements in mobility capacity may not be expected when strength increases.

Exercise capacity, muscle strength and fatigue in sarcoidosis.

PubMed

Marcellis, R G J; Lenssen, A F; Elfferich, M D P; De Vries, J; Kassim, S; Foerster, K; Drent, M

2011-09-01

The aim of this case-control study was to investigate the prevalence of exercise intolerance, muscle weakness and fatigue in sarcoidosis patients. Additionally, we evaluated whether fatigue can be explained by exercise capacity, muscle strength or other clinical characteristics (lung function tests, radiographic stages, prednisone usage and inflammatory markers). 124 sarcoidosis patients (80 males) referred to the Maastricht University Medical Centre (Maastricht, the Netherlands) were included (mean age 46.6±10.2 yrs). Patients performed a 6-min walk test (6MWT) and handgrip force (HGF), elbow flexor muscle strength (EFMS), quadriceps peak torque (QPT) and hamstring peak torque (HPT) tests. Maximal inspiratory pressure (P(I,max)) was recorded. All patients completed the Fatigue Assessment Scale (FAS) questionnaire. The 6MWT was reduced in 45% of the population, while HGF, EFMS, QPT and HPT muscle strength were reduced in 15, 12, 27 and 18%, respectively. P(I,max) was reduced in 43% of the population. The majority of the patients (81%) reported fatigue (FAS ≥22). Patients with reduced peripheral muscle strength of the upper and/or lower extremities were more fatigued and demonstrated impaired lung functions, fat-free mass, P(I,max), 6MWT and quality of life. Fatigue was neither predicted by exercise capacity, nor by muscle strength. Besides fatigue, exercise intolerance and muscle weakness are frequent problems in sarcoidosis. We therefore recommend physical tests in the multidisciplinary management of sarcoidosis patients, even in nonfatigued patients.

Inverse relationship between exercise economy and oxidative capacity in muscle.

PubMed

Hunter, Gary R; Bamman, Marcas M; Larson-Meyer, D Enette; Joanisse, Denis R; McCarthy, John P; Blaudeau, Tamilane E; Newcomer, Bradley R

2005-08-01

An inverse relationship has been shown between running and cycling exercise economy and maximum oxygen uptake (VO2max). The purposes were: 1) determine the relationship between walking economy and VO2max; and 2) determine the relationship between muscle metabolic economy and muscle oxidative capacity and fiber type. Subjects were 77 premenopausal normal weight women. Walking economy (1/VO2max) was measured at 3 mph and VO2max during graded treadmill test. Muscle oxidative phosphorylation rate (OxPhos), and muscle metabolic economy (force/ATP) were measured in calf muscle using 31P MRS during isometric plantar flexion at 70 and 100% of maximum force, (HI) and (MI) respectively. Muscle fiber type and citrate synthase activity were determined in the lateral gastrocnemius. Significant inverse relationships (r from -0.28 to -0.74) were observed between oxidative metabolism measures and exercise economy (walking and muscle). Type IIa fiber distribution was inversely related to all measures of exercise economy (r from -0.51 to -0.64) and citrate synthase activity was inversely related to muscle metabolic economy at MI (r = -0.56). In addition, Type IIa fiber distribution and citrate synthase activity were positively related to VO2max and muscle OxPhos at HI and MI (r from 0.49 to 0.70). Type I fiber distribution was not related to any measure of exercise economy or oxidative capacity. Our results support the concept that exercise economy and oxidative capacity are inversely related. We have demonstrated this inverse relationship in women both by indirect calorimetry during walking and in muscle tissue by 31P MRS.

Aerobic and resistance training dependent skeletal muscle plasticity in the colon-26 murine model of cancer cachexia.

PubMed

Khamoui, Andy V; Park, Bong-Sup; Kim, Do-Houn; Yeh, Ming-Chia; Oh, Seung-Lyul; Elam, Marcus L; Jo, Edward; Arjmandi, Bahram H; Salazar, Gloria; Grant, Samuel C; Contreras, Robert J; Lee, Won Jun; Kim, Jeong-Su

2016-05-01

The appropriate mode of exercise training for cancer cachexia is not well-established. Using the colon-26 (C26) mouse model of cancer cachexia, we defined and compared the skeletal muscle responses to aerobic and resistance training. Twelve-month old Balb/c mice were initially assigned to control, aerobic training (AT; wheel running), or resistance training (RT; ladder climbing) (n=16-17/group). After 8weeks of training, half of each group was injected with C26 tumor cells, followed by 3 additional weeks of training. Body composition and neuromuscular function was evaluated pre- and post-training. Muscles were collected post-training and analyzed for fiber cross-sectional area (CSA), Akt-mTOR signaling, and expression of insulin-like growth factor-I (IGF-I) and myogenic regulatory factors. Total body mass decreased (p<0.05) in C26 (-8%), AT+C26 (-18%), and RT+C26 (-15%) but not control. Sensorimotor function declined (p<0.05) in control (-16%), C26 (-13%), and RT+C26 (-23%) but not AT+C26. Similarly, strength/body weight decreased (p<0.05) in control (-7%), C26 (-21%), and RT+C26 (-10%) but not AT+C26. Gastrocnemius mass/body weight tended to be greater in AT+C26 vs. C26 (+6%, p=0.09). Enlargement of the spleen was partially corrected in AT+C26 (-27% vs. C26, p<0.05). Fiber CSA was lower in all C26 groups vs. control (-32% to 46%, p<0.05); however, the effect size calculated from C26 and AT+C26 was large (+24%, d=1.04). Phosphorylated levels of mTOR in AT+C26 exceeded C26 (+32%, p<0.05). RT+C26 showed greater mRNA expression (p<0.05) of IGF-IEa (+79%) and myogenin (+126%) with a strong tendency for greater IGF-IEb (+127%, p=0.069) vs. Aerobic or resistance training was unable to prevent tumor-induced body weight loss. However, aerobic training may have preserved function, reduced the inflammatory response of the spleen, and marginally rescued muscle mass possibly through activation of mTOR. Aerobic training may therefore have therapeutic value for patients with

The Effect of β-Hydroxy-β-Methylbutyrate on Aerobic Capacity and Body Composition in Trained Athletes.

PubMed

Durkalec-Michalski, Krzysztof; Jeszka, Jan

2016-09-01

Durkalec-Michalski, K and Jeszka, J. The effect of β-hydroxy-β-methylbutyrate on aerobic capacity and body composition in trained athletes. J Strength Cond Res 30(9): 2617-2626, 2016-The aim of this study was to investigate whether supplementation with β-hydroxy-β-methylbutyrate (HMB) affects body composition, aerobic capacity, or intramuscular enzymes activity, as well as in anabolic and/or catabolic hormones and lactate concentrations. A cohort of 58 highly trained males was subjected to 12-week supplementation with HMB (3 × 1 gHMB·d) and a placebo (PLA) in randomized, PLA controlled, double-blind crossover trials, with a 10-day washout period. Body composition and aerobic capacity were recorded, whereas the levels of creatine kinase, lactate dehydrogenase, testosterone, cortisol, and lactate, as well as the T/C ratio, in blood samples were measured. After HMB supplementation, fat-free mass increased (+0.2 kgHMB vs. -1.0 kgPLA, p = 0.021), with a simultaneous reduction of fat mass (-0.8 kgHMB vs. +0.8 kgPLA, p < 0.001). In turn, after HMB supplementation, in comparison to PLA, maximal oxygen uptake (V[Combining Dot Above][Combining Dot Above]O2max: +0.102 L·minHMB vs. -0.063 L·minPLA, p = 0.013), time to reach ventilatory threshold (VT) (TVT: +1.0 minHMB vs. -0.4 minPLA, p < 0.0001), threshold load at VT (WVT: +20 WHMB vs. -7 WPLA, p = 0.001), and the threshold heart rate at VT (HRVT: +8 b·minHMB vs. -1 b·minPLA, p < 0.0001) increased significantly. Analysis of the tested biochemical markers shows significant differences only in relation to the initial concentration. In HMB group, testosterone levels increased (p = 0.047) and in both groups (HMB: p = 0.008; PLA: p = 0.008) higher cortisol levels were observed. The results indicate that supplying HMB promotes advantageous changes in body composition and stimulates an increase in aerobic capacity, although seeming not to significantly affect the levels of the analyzed blood markers.

Assessing effects of aerobic and anaerobic conditions on phosphorus sorption and retention capacity of water treatment residuals.

PubMed

Oliver, Ian W; Grant, Cameron D; Murray, Robert S

2011-03-01

Water treatment residuals (WTRs) are the by-products of drinking water clarification processes, whereby chemical flocculants such as alum or ferric chloride are added to raw water to remove suspended clay particles, organic matter and other materials and impurities. Previous studies have identified a strong phosphorus (P) fixing capacity of WTRs which has led to experimentation with their use as P-sorbing materials for controlling P discharges from agricultural and forestry land. However, the P-fixing capacity of WTRs and its capacity to retain sorbed P under anaerobic conditions have yet to be fully demonstrated, which is an issue that must be addressed for WTR field applications. This study therefore examined the capacity of WTRs to retain sorbed P and sorb further additional P from aqueous solution under both aerobic and anaerobic conditions. An innovative, low cost apparatus was constructed and successfully used to rapidly establish anoxic conditions in anaerobic treatments. The results showed that even in treatments with initial solution P concentrations set at 100 mg l(-1), soluble reactive P concentrations rapidly fell to negligible levels (due to sorption by WTRs), while total P (i.e. dissolved + particulate and colloidal P) was less than 3 mg l(-1). This equated to an added P retention rate of >98% regardless of anaerobic or aerobic status, indicating that WTRs are able to sorb and retain P in both aerobic and anaerobic conditions. Copyright © 2010 Elsevier Ltd. All rights reserved.

Mangiferin protects against adverse skeletal muscle changes and enhances muscle oxidative capacity in obese rats

PubMed Central

Acevedo, Luz M.; Raya, Ana I.; Martínez-Moreno, Julio M.

2017-01-01

Obesity-related skeletal muscle changes include muscle atrophy, slow-to-fast fiber-type transformation, and impaired mitochondrial oxidative capacity. These changes relate with increased risk of insulin resistance. Mangiferin, the major component of the plant Mangifera indica, is a well-known anti-inflammatory, anti-diabetic, and antihyperlipidemic agent. This study tested the hypothesis that mangiferin treatment counteracts obesity-induced fiber atrophy and slow-to-fast fiber transition, and favors an oxidative phenotype in skeletal muscle of obese rats. Obese Zucker rats were fed gelatin pellets with (15 mg/kg BW/day) or without (placebo group) mangiferin for 8 weeks. Lean Zucker rats received the same gelatin pellets without mangiferin and served as non-obese and non-diabetic controls. Lesser diameter, fiber composition, and histochemical succinic dehydrogenase activity (an oxidative marker) of myosin-based fiber-types were assessed in soleus and tibialis cranialis muscles. A multivariate discriminant analysis encompassing all fiber-type features indicated that obese rats treated with mangiferin displayed skeletal muscle phenotypes significantly different compared with both lean and obese control rats. Mangiferin significantly decreased inflammatory cytokines, preserved skeletal muscle mass, fiber cross-sectional size, and fiber-type composition, and enhanced muscle fiber oxidative capacity. These data demonstrate that mangiferin attenuated adverse skeletal muscle changes in obese rats. PMID:28253314

Mangiferin protects against adverse skeletal muscle changes and enhances muscle oxidative capacity in obese rats.

PubMed

Acevedo, Luz M; Raya, Ana I; Martínez-Moreno, Julio M; Aguilera-Tejero, Escolástico; Rivero, José-Luis L

2017-01-01

Obesity-related skeletal muscle changes include muscle atrophy, slow-to-fast fiber-type transformation, and impaired mitochondrial oxidative capacity. These changes relate with increased risk of insulin resistance. Mangiferin, the major component of the plant Mangifera indica, is a well-known anti-inflammatory, anti-diabetic, and antihyperlipidemic agent. This study tested the hypothesis that mangiferin treatment counteracts obesity-induced fiber atrophy and slow-to-fast fiber transition, and favors an oxidative phenotype in skeletal muscle of obese rats. Obese Zucker rats were fed gelatin pellets with (15 mg/kg BW/day) or without (placebo group) mangiferin for 8 weeks. Lean Zucker rats received the same gelatin pellets without mangiferin and served as non-obese and non-diabetic controls. Lesser diameter, fiber composition, and histochemical succinic dehydrogenase activity (an oxidative marker) of myosin-based fiber-types were assessed in soleus and tibialis cranialis muscles. A multivariate discriminant analysis encompassing all fiber-type features indicated that obese rats treated with mangiferin displayed skeletal muscle phenotypes significantly different compared with both lean and obese control rats. Mangiferin significantly decreased inflammatory cytokines, preserved skeletal muscle mass, fiber cross-sectional size, and fiber-type composition, and enhanced muscle fiber oxidative capacity. These data demonstrate that mangiferin attenuated adverse skeletal muscle changes in obese rats.

Differences in Sustained Attention Capacity as a Function of Aerobic Fitness.

PubMed

Luque-Casado, Antonio; Perakakis, Pandelis; Hillman, Charles H; Kao, Shih-Chun; Llorens, Francesc; Guerra, Pedro; Sanabria, Daniel

2016-05-01

We investigated the relationship between aerobic fitness and sustained attention capacity by comparing task performance and brain function, by means of event-related potentials (ERP), in high- and low-fit young adults. Two groups of participants (22 higher-fit and 20 lower-fit) completed a 60-min version of the Psychomotor Vigilance Task (PVT). Behavioral (i.e., reaction time) and electrophysiological (ERP) (i.e., contingent negative variation and P3) were obtained and analyzed as a function of time-on-task. A submaximal cardiorespiratory fitness test confirmed the between-groups difference in terms of aerobic fitness. The results revealed shorter reaction time in higher-fit than in lower-fit participants in the first 36 min of the task. This was accompanied by larger contingent negative variation amplitude in the same period of the task in higher-fit than in lower-fit group. Crucially, higher-fit participants maintained larger P3 amplitude throughout the task compared to lower-fit, who showed a reduction in the P3 magnitude over time. Higher fitness was related to neuroelectric activity suggestive of better overall sustained attention demonstrating a better ability to allocate attentional resources over time. Moreover, higher fitness was related to enhanced response preparation in the first part of the task. Taken together, the current data set demonstrated a positive association between aerobic fitness, sustained attention, and response preparation.

Aerobic Exercise Training in Post-Polio Syndrome: Process Evaluation of a Randomized Controlled Trial

PubMed Central

Voorn, Eric L.; Koopman, Fieke S.; Brehm, Merel A.; Beelen, Anita; de Haan, Arnold; Gerrits, Karin H. L.; Nollet, Frans

2016-01-01

Objective To explore reasons for the lack of efficacy of a high intensity aerobic exercise program in post-polio syndrome (PPS) on cardiorespiratory fitness by evaluating adherence to the training program and effects on muscle function. Design A process evaluation using data from an RCT. Patients Forty-four severely fatigued individuals with PPS were randomized to exercise therapy (n = 22) or usual care (n = 22). Methods Participants in the exercise group were instructed to exercise 3 times weekly for 4 months on a bicycle ergometer (60–70% heart rate reserve). Results The attendance rate was high (median 89%). None of the participants trained within the target heart rate range during >75% of the designated time. Instead, participants exercised at lower intensities, though still around the anaerobic threshold (AT) most of the time. Muscle function did not improve in the exercise group. Conclusion Our results suggest that severely fatigued individuals with PPS cannot adhere to a high intensity aerobic exercise program on a cycle ergometer. Despite exercise intensities around the AT, lower extremity muscle function nor cardiorespiratory fitness improved. Improving the aerobic capacity in PPS is difficult through exercise primarily focusing on the lower extremities, and may require a more individualized approach, including the use of other large muscle groups instead. Trial Registration Netherlands National Trial Register NTR1371 PMID:27419388

[Regeneration capacity of skeletal muscle].

PubMed

Wernig, A

2003-07-01

The organotypic stem cell of skeletal muscle has previously been known as satellite cell. They allow muscle fiber growth during ontogenesis, enable fiber hypertrophy and are responsible for the very efficient repair of muscle fibers. This efficient apparatus is to some degree counterbalanced by an enormous use of the satellite cell pool: fiber atrophy probably is accompanied by loss of myonuclei such that every reversal of atrophy is bound to use new myonuclei i.e. satellite cells. How often in life does this occur? Hard to say. Moreover, the potent repair capacity is challenged by an unexpected vulnerability of skeletal muscle fibers: Passive stretching of contracted muscles may cause multiple "microdamage," disruption of contractile elements or tiny areas of true necrosis (focal necrosis). How often does this happen? Well, for many of us at least once per year when we go up and down mountains during vacation time, followed by sour muscles. Others may decide to change his/her (locomotor) behaviour by severe onset of jogging; it may happen that they suffer kidney failure on Monday due to muscle microdamage and the transfer of myoproteins into the serum over weekend. Also 20 minutes of stepping up and down something like a chair will do: There is a remarkable increase in kreatin kinase and other muscle derived proteins which lasts for days and is bound to reflect some muscle damage. How about sportsmen and worker who repeatedly use their muscles in such a way? We don't have answers yet to most of these questions, but considerable amount of information has been collected over the last years both in animal and--less--in human. What is common in all cases of growth and repair is the proliferation of the satellite cells and their consequent incorporation and fusion with the parent fiber. This way focal damage is repaired often without visible reminders. We would run out of satellite cells were they not stem cells: After division one daughter remains a satellite cell

24-weeks Pilates-aerobic and educative training to improve body fat mass in elderly Serbian women.

PubMed

Ruiz-Montero, Pedro Jesús; Castillo-Rodriguez, Alfonso; Mikalački, Milena; Nebojsa, Cokorilo; Korovljev, Darinka

2014-01-01

The purpose of this study was to examine the differences in anthropometric measurements using an aerobic and Pilates exercise program which lasted 24 weeks. This was a clinical intervention study of 303 women over the age of 60 living in Novi Sad, Serbia. Changes in body mass index and skinfold thickness were estimated through height, weight, and anthropometric measurements. The program comprised Pilates exercises for upper- and lower-body strength, agility, and aerobic capacity. Fat mass (FM) improved significantly (pre-test, 32.89%, 8.65; post-test, 28.25%, 6.58; P<0.01). Bone diameters and muscle perimeters showed no significant changes pre- and post-test (P>0.05), but there was a higher correlation between FM (%) and waist-hip ratio (rho, 0.80; P<0.01). A mixed program of aerobics and Pilates, controls and improves baseline muscle mass and decreases FM values, without causing deterioration during practice and follow-up exercises.

Day-to-Day Changes in Muscle Protein Synthesis in Recovery From Resistance, Aerobic, and High-Intensity Interval Exercise in Older Men.

PubMed

Bell, Kirsten E; Séguin, Christopher; Parise, Gianni; Baker, Steven K; Phillips, Stuart M

2015-08-01

Resistance exercise (RE) and aerobic exercise are recommended for older adults for fitness and strength. High-intensity interval exercise (HIIT) is an understudied but potent potential alternative to aerobic exercise. This study aimed to determine how each mode of exercise affected the integrated day-to-day response of muscle protein synthesis. Sedentary men (n = 22; 67±4 years; body mass index: 27.0±2.6 kg m(-) (2) [mean ± SEM]) were randomly assigned to perform RE, aerobic exercise, or HIIT. Participants consumed a stable isotope tracer (D2O) for 9 days. Daily saliva samples were taken to measure tracer incorporation in body water. Muscle biopsies were obtained on Days 5-8 of D2O consumption to measure tracer incorporation into muscle at rest, 24 hours, and 48 hours following each exercise bout: RE (3 × 10 repetitions: leg extensor and press, 95% 10RM), HIIT (10 × 1 minute, 95% maximal heart rate [HRmax]), or aerobic exercise (30 minutes, 55%-60% HRmax). Myofibrillar protein fractional synthetic rate was elevated, relative to rest, at 24 and 48 hours following RE and HIIT. The increase in myofibrillar fractional synthetic rate was greater following RE versus HIIT at both time points. HIIT was the only mode of exercise to increase sarcoplasmic protein fractional synthetic rate 24-hour postexercise (2.30±0.34% d(-) (1) vs 1.83±0.21% d(-) (1)). This study shows that in older men, changes in muscle protein synthesis in response to certain exercises are long lasting and that HIIT significantly increases myofibrillar and sarcoplasmic fractional synthetic rate in this population. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Inspiratory Muscle Training and Functional Capacity in Patients Undergoing Cardiac Surgery.

PubMed

Cordeiro, André Luiz Lisboa; de Melo, Thiago Araújo; Neves, Daniela; Luna, Julianne; Esquivel, Mateus Souza; Guimarães, André Raimundo França; Borges, Daniel Lago; Petto, Jefferson

2016-04-01

Cardiac surgery is a highly complex procedure which generates worsening of lung function and decreased inspiratory muscle strength. The inspiratory muscle training becomes effective for muscle strengthening and can improve functional capacity. To investigate the effect of inspiratory muscle training on functional capacity submaximal and inspiratory muscle strength in patients undergoing cardiac surgery. This is a clinical randomized controlled trial with patients undergoing cardiac surgery at Instituto Nobre de Cardiologia. Patients were divided into two groups: control group and training. Preoperatively, were assessed the maximum inspiratory pressure and the distance covered in a 6-minute walk test. From the third postoperative day, the control group was managed according to the routine of the unit while the training group underwent daily protocol of respiratory muscle training until the day of discharge. 50 patients, 27 (54%) males were included, with a mean age of 56.7±13.9 years. After the analysis, the training group had significant increase in maximum inspiratory pressure (69.5±14.9 vs. 83.1±19.1 cmH2O, P=0.0073) and 6-minute walk test (422.4±102.8 vs. 502.4±112.8 m, P=0.0031). We conclude that inspiratory muscle training was effective in improving functional capacity submaximal and inspiratory muscle strength in this sample of patients undergoing cardiac surgery.

Effect of Aerobic Exercise Training on Ventilatory Efficiency and Respiratory Drive in Obese Subjects.

PubMed

Chlif, Mehdi; Chaouachi, Anis; Ahmaidi, Said

2017-07-01

Obese patients show a decline in exercise capacity and diverse degrees of dyspnea in association with mechanical abnormalities, increased ventilatory requirements secondary to the increased metabolic load, and a greater work of breathing. Consequently, obese patients may be particularly predisposed to the development of respiratory muscle fatigue during exercise. The aim of this study was to assess inspiratory muscle performance during incremental exercise in 19 obese male subjects (body mass index 41 ± 6 kg/m 2 ) after aerobic exercise training using the noninvasive, inspiratory muscle tension-time index (T T0.1 ). Measurements performed included anthropometric parameters, lung function assessed by spirometry, rate of perceived breathlessness with the modified Borg dyspnea scale (0-10), breathing pattern, maximal exercise capacity, and inspiratory muscle performance with a breath-by-breath automated exercise metabolic system during an incremental exercise test. T T0.1 was calculated using the equation, T T0.1 = P 0.1 /P Imax × T I /T tot (where P 0.1 represents mouth occlusion pressure, P Imax is maximal inspiratory pressure, and T I /T tot is the duty cycle). At rest, there was no statistically significant difference for spirometric parameters and cardiorespiratory parameters between pre- and post-training. At maximal exercise, the minute ventilation, the rate of exchange ratio, the rate of perceived breathlessness, and the respiratory muscle performance parameters were not significantly different pre- and post-training; in contrast, tidal volume ( P = .037, effect size = 1.51), breathing frequency ( P = .049, effect size = 0.97), power output ( P = .048, effect size = 0.79), peak oxygen uptake ( P = .02, effect size = 0.92) were significantly higher after training. At comparable work load, training induces lower minute ventilation, mouth occlusion pressure, ratio of occlusion pressure to maximal inspiratory pressure, T T0.1 , and rate of perceived

Leanness and heightened nonresting energy expenditure: role of skeletal muscle activity thermogenesis

PubMed Central

Mukherjee, Sromona; Shukla, Charu; Britton, Steven L.; Koch, Lauren G.; Shi, Haifei; Novak, Colleen M.

2014-01-01

A high-calorie diet accompanied by low levels of physical activity (PA) accounts for the widespread prevalence of obesity today, and yet some people remain lean even in this obesogenic environment. Here, we investigate the cause for this exception. A key trait that predicts high PA in both humans and laboratory rodents is intrinsic aerobic capacity. Rats artificially selected as high-capacity runners (HCR) are lean and consistently more physically active than their low-capacity runner (LCR) counterparts; this applies to both males and females. Here, we demonstrate that HCR show heightened total energy expenditure (TEE) and hypothesize that this is due to higher nonresting energy expenditure (NREE; includes activity EE). After matching for body weight and lean mass, female HCR consistently had heightened nonresting EE, but not resting EE, compared with female LCR. Because of the dominant role of skeletal muscle in nonresting EE, we examined muscle energy use. We found that lean female HCR had higher muscle heat dissipation during activity, explaining their low economy of activity and high activity EE. This may be due to the amplified skeletal muscle expression levels of proteins involved in EE and reduced expression levels of proteins involved in energy conservation in HCR relative to LCR. This is also associated with an increased sympathetic drive to skeletal muscle in HCR compared with LCR. We find little support for the hypothesis that resting metabolic rate is correlated with maximal aerobic capacity if body size and composition are fully considered; rather, the critical factor appears to be activity thermogenesis. PMID:24398400

Effects of Detraining on Anthropometry, Aerobic Capacity and Functional Ability in Adults with Down Syndrome

ERIC Educational Resources Information Center

Boer, P. H.

2018-01-01

Background: Structured exercise has shown to improve parameters of functional fitness in adults with Down syndrome (DS). However, few, if any, continue to exercise after exercise intervention studies. Consequently, the purpose of this study was to determine the effects of detraining on anthropometry, aerobic capacity and functional ability of…

Short-term water-based aerobic training promotes improvements in aerobic conditioning parameters of mature women.

PubMed

Costa, Rochelle Rocha; Reichert, Thais; Coconcelli, Leandro; Simmer, Nicole Monticelli; Bagatini, Natália Carvalho; Buttelli, Adriana Cristine Koch; Bracht, Cláudia Gomes; Stein, Ricardo; Kruel, Luiz Fernando Martins

2017-08-01

Aging is accompanied by a decrease in aerobic capacity. Therefore, physical training has been recommended to soften the effects of advancement age. The aim of this study was to assess the effects of a short-term water-based aerobic training on resting heart rate (HR rest ), heart rate corresponding to anaerobic threshold (HR AT ), peak heart rate (HR peak ), percentage value of HR AT in relation to HR peak and test duration (TD) of mature women. Twenty-two women (65.91 ± 4.83 years) were submitted to a five-week water-based interval aerobic training. Aerobic capacity parameters were evaluated through an aquatic incremental test. After training, there was an increase in TD (16%) and HR AT percentage in relation to HR peak (4.68%), and a reduction of HR rest (9%). It is concluded that a water-based aerobic interval training prescribed through HR AT of only five weeks is able to promote improvements in aerobic capacity of mature women. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of space capacities of the respiratory muscles during hypokinesia

NASA Astrophysics Data System (ADS)

Baranov, V. M.; Aleksandrova, N. P.; Tikhonov, M. A.

2005-08-01

Nowdays, the phenomenon of physical performance degradation after a long period of motor restraint or microgravity is universally interpreted as a result of deconditioning of the cardiovascular system and anti- gravity skeletal muscles.Yet, deconditioning affects not only the skeletal but also respiratory muscles exhaustion of which by relative hypoventilation brings about hypercapnia, hypoxia and pulmonary acidosis conducive to the sensations of painful breathlessness impacting the capacity for physical work. It should be emphasized that these developments are little known in spite of their theoretical and practical significance; therefore, our purpose was to study the functional state and spare capacity of the respiratory muscles in laboratory animals (Wistar rats) following 3-wk tail-suspension.The experiment strengthened the hypothesis according to which simulation of the physiological effects of motor restraint and microgravity leads to fatigue and deconditioning of the respiratory muscles.

Leisure-time aerobic physical activity, muscle-strengthening activity and mortality risks among US adults: the NHANES linked mortality study.

PubMed

Zhao, Guixiang; Li, Chaoyang; Ford, Earl S; Fulton, Janet E; Carlson, Susan A; Okoro, Catherine A; Wen, Xiao Jun; Balluz, Lina S

2014-02-01

Regular physical activity elicits multiple health benefits in the prevention and management of chronic diseases. We examined the mortality risks associated with levels of leisure-time aerobic physical activity and muscle-strengthening activity based on the 2008 Physical Activity Guidelines for Americans among US adults. We analysed data from the 1999 to 2004 National Health and Nutrition Examination Survey with linked mortality data obtained through 2006. Cox proportional HRs with 95% CIs were estimated to assess risks for all-causes and cardiovascular disease (CVD) mortality associated with aerobic physical activity and muscle-strengthening activity. Of 10 535 participants, 665 died (233 deaths from CVD) during an average of 4.8-year follow-up. Compared with participants who were physically inactive, the adjusted HR for all-cause mortality was 0.64 (95% CI 0.52 to 0.79) among those who were physically active (engaging in ≥150 min/week of the equivalent moderate-intensity physical activity) and 0.72 (95% CI 0.54 to 0.97) among those who were insufficiently active (engaging in >0 to <150 min/week of the equivalent moderate-intensity physical activity). The adjusted HR for CVD mortality was 0.57 (95% CI 0.34 to 0.97) among participants who were insufficiently active and 0.69 (95% CI 0.43 to 1.12) among those who were physically active. Among adults who were insufficiently active, the adjusted HR for all-cause mortality was 44% lower by engaging in muscle-strengthening activity ≥2 times/week. Engaging in aerobic physical activity ranging from insufficient activity to meeting the 2008 Guidelines reduces the risk of premature mortality among US adults. Engaging in muscle-strengthening activity ≥2 times/week may provide additional benefits among insufficiently active adults.

Feedback-controlled robotics-assisted treadmill exercise to assess and influence aerobic capacity early after stroke: a proof-of-concept study.

PubMed

Stoller, Oliver; Schindelholz, Matthias; Bichsel, Lukas; Schuster, Corina; de Bie, Rob A; de Bruin, Eling D; Hunt, Kenneth J

2014-07-01

The majority of post-stroke individuals suffer from low exercise capacity as a secondary reaction to immobility. The aim of this study was to prove the concept of feedback-controlled robotics-assisted treadmill exercise (RATE) to assess aerobic capacity and guide cardiovascular exercise in severely impaired individuals early after stroke. Subjects underwent constant load and incremental exercise testing using a human-in-the-loop feedback system within a robotics-assisted exoskeleton (Lokomat, Hocoma AG, CH). Inclusion criteria were: stroke onset ≤8 weeks, stable medical condition, non-ambulatory status, moderate motor control of the lower limbs and appropriate cognitive function. Outcome measures included oxygen uptake kinetics, peak oxygen uptake (VO2peak), gas exchange threshold (GET), peak heart rate (HRpeak), peak work rate (Ppeak) and accuracy of reaching target work rate (P-RMSE). Three subjects (18-42 d post-stroke) were included. Oxygen uptake kinetics during constant load ranged from 42.0 to 60.2 s. Incremental exercise testing showed: VO2peak range 19.7-28.8 ml/min/kg, GET range 11.6-12.7 ml/min/kg, and HRpeak range 115-161 bpm. Ppeak range was 55.2-110.9 W and P-RMSE range was 3.8-7.5 W. The concept of feedback-controlled RATE for assessment of aerobic capacity and guidance of cardiovascular exercise is feasible. Further research is warranted to validate the method on a larger scale. Aerobic capacity is seriously reduced in post-stroke individuals as a secondary reaction to immobility. Robotics-assisted walking devices may have substantial clinical relevance regarding assessment and improvement of aerobic capacity early after stroke. Feedback-controlled robotics-assisted treadmill exercise represents a new concept for cardiovascular assessment and intervention protocols for severely impaired individuals.

The interrelationship between muscle oxygenation, muscle activation, and pulmonary oxygen uptake to incremental ramp exercise: influence of aerobic fitness.

PubMed

Boone, Jan; Barstow, Thomas J; Celie, Bert; Prieur, Fabrice; Bourgois, Jan

2016-01-01

We investigated whether muscle and ventilatory responses to incremental ramp exercise would be influenced by aerobic fitness status by means of a cross-sectional study with a large subject population. Sixty-four male students (age: 21.2 ± 3.2 years) with a heterogeneous peak oxygen uptake (51.9 ± 6.3 mL·min(-1)·kg(-1), range 39.7-66.2 mL·min(-1)·kg(-1)) performed an incremental ramp cycle test (20-35 W·min(-1)) to exhaustion. Breath-by-breath gas exchange was recorded, and muscle activation and oxygenation were measured with surface electromyography and near-infrared spectroscopy, respectively. The integrated electromyography (iEMG), mean power frequency (MPF), deoxygenated [hemoglobin and myoglobin] (deoxy[Hb+Mb]), and total[Hb+Mb] responses were set out as functions of work rate and fitted with a double linear function. The respiratory compensation point (RCP) was compared and correlated with the breakpoints (BPs) (as percentage of peak oxygen uptake) in muscle activation and oxygenation. The BP in total[Hb+Mb] (83.2% ± 3.0% peak oxygen uptake) preceded (P < 0.001) the BP in iEMG (86.7% ± 4.0% peak oxygen uptake) and MPF (86.3% ± 4.1% peak oxygen uptake), which in turn preceded (P < 0.01) the BP in deoxy[Hb+Mb] (88.2% ± 4.5% peak oxygen uptake) and RCP (87.4% ± 4.5% peak oxygen uptake). Furthermore, the peak oxygen uptake was significantly (P < 0.001) positively correlated to the BPs and RCP, indicating that the BPs in total[Hb+Mb] (r = 0.66; P < 0.001), deoxy[Hb+Mb] (r = 0.76; P < 0.001), iEMG (r = 0.61; P < 0.001), MPF (r = 0.63; P < 0.001), and RCP (r = 0.75; P < 0.001) occurred at a higher percentage of peak oxygen uptake in subjects with a higher peak oxygen uptake. In this study a close relationship between muscle oxygenation, activation, and pulmonary oxygen uptake was found, occurring in a cascade of events. In subjects with a higher aerobic fitness level this cascade occurred at a higher relative intensity.

Weight-to-height ratio and aerobic capacity in 15-year-old male taekwondo martial artists.

PubMed

Poliszczuk, Tatiana; Jankowska, Ewa; Poliszczuk, Dmytro

2013-01-01

Martial arts are growing in popularity throughout the whole world. Their beneficial influence on physical development and fitness is noteworthy. Martial arts are an attractive form of physical recreation, constitute a perfect means for combating stress, and have a positive effect on general health, including during rehabilitation. The aim of this study is to assess physical development and aerobic capacity in boys who practice taekwondo and to determine the relationships between results of a fitness test and particular parameters of physical development. Study participants comparised 51 boys aged 15 years who practiced taekwondo (with training experience ranging from 1 to 6 years). Volkov´s modification of the Harvard Step Test was used to assess body height and body mass. BMI was also calculated. Centile charts were used to assess weight-to-height ratio and the level of measured parameters. BMI was analyzed according to the Cole classification system. Dispersion was calculated using a coefficient of variation. The Pearson product-moment correlation coefficient between selected parameters was also calculated. Most study participants had normal BMI, but 30% showed overweight and 13% showed underweight or emaciation. Weight-to-height ratio differed significantly from the norm in 33% of the boys when compared to centile charts. All participants had average aerobic capacity. However, when weight-to-height ratio was compared to the results of the Harvard Step Test, boys with normal body proportions performed much better in the test than boys with abnormal body mass (p<0.05). Study participants showed abnormal weight-to-height ratio mainly in terms of overweight. The boys had greater body height and body mass compared to the general Polish population. Aerobic capacity differed considerably between participants.

Short-term low-intensity blood flow restricted interval training improves both aerobic fitness and muscle strength.

PubMed

de Oliveira, M F M; Caputo, F; Corvino, R B; Denadai, B S

2016-09-01

The present study aimed to analyze and compare the effects of four different interval-training protocols on aerobic fitness and muscle strength. Thirty-seven subjects (23.8 ± 4 years; 171.7 ± 9.5 cm; 70 ± 11 kg) were assigned to one of four groups: low-intensity interval training with (BFR, n = 10) or without (LOW, n = 7) blood flow restriction, high-intensity interval training (HIT, n = 10), and combined HIT and BFR (BFR + HIT, n = 10, every session performed 50% as BFR and 50% as HIT). Before and after 4 weeks training (3 days a week), the maximal oxygen uptake (VO2max ), maximal power output (Pmax ), onset blood lactate accumulation (OBLA), and muscle strength were measured for all subjects. All training groups were able to improve OBLA (BFR, 16%; HIT, 25%; HIT + BFR, 22%; LOW, 6%), with no difference between groups. However, VO2max and Pmax improved only for BFR (6%, 12%), HIT (9%, 15%) and HIT + BFR (6%, 11%), with no difference between groups. Muscle strength gains were only observed after BFR training (11%). This study demonstrates the advantage of short-term low-intensity interval BFR training as the single mode of training able to simultaneously improve aerobic fitness and muscular strength. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Perm1 enhances mitochondrial biogenesis, oxidative capacity, and fatigue resistance in adult skeletal muscle

PubMed Central

Cho, Yoshitake; Hazen, Bethany C.; Gandra, Paulo G.; Ward, Samuel R.; Schenk, Simon; Russell, Aaron P.; Kralli, Anastasia

2016-01-01

Skeletal muscle mitochondrial content and oxidative capacity are important determinants of muscle function and whole-body health. Mitochondrial content and function are enhanced by endurance exercise and impaired in states or diseases where muscle function is compromised, such as myopathies, muscular dystrophies, neuromuscular diseases, and age-related muscle atrophy. Hence, elucidating the mechanisms that control muscle mitochondrial content and oxidative function can provide new insights into states and diseases that affect muscle health. In past studies, we identified Perm1 (PPARGC1- and ESRR-induced regulator, muscle 1) as a gene induced by endurance exercise in skeletal muscle, and regulating mitochondrial oxidative function in cultured myotubes. The capacity of Perm1 to regulate muscle mitochondrial content and function in vivo is not yet known. In this study, we use adeno-associated viral (AAV) vectors to increase Perm1 expression in skeletal muscles of 4-wk-old mice. Compared to control vector, AAV1-Perm1 leads to significant increases in mitochondrial content and oxidative capacity (by 40–80%). Moreover, AAV1-Perm1–transduced muscles show increased capillary density and resistance to fatigue (by 33 and 31%, respectively), without prominent changes in fiber-type composition. These findings suggest that Perm1 selectively regulates mitochondrial biogenesis and oxidative function, and implicate Perm1 in muscle adaptations that also occur in response to endurance exercise.—Cho, Y., Hazen, B. C., Gandra, P. G., Ward, S. R., Schenk, S., Russell, A. P., Kralli, A. Perm1 enhances mitochondrial biogenesis, oxidative capacity, and fatigue resistance in adult skeletal muscle. PMID:26481306

Label-Free LC-MS Profiling of Skeletal Muscle Reveals Heart-Type Fatty Acid Binding Protein as a Candidate Biomarker of Aerobic Capacity.

PubMed

Malik, Zulezwan Ab; Cobley, James N; Morton, James P; Close, Graeme L; Edwards, Ben J; Koch, Lauren G; Britton, Steven L; Burniston, Jatin G

2013-12-01

Two-dimensional gel electrophoresis provides robust comparative analysis of skeletal muscle, but this technique is laborious and limited by its inability to resolve all proteins. In contrast, orthogonal separation by SDS-PAGE and reverse-phase liquid chromatography (RPLC) coupled to mass spectrometry (MS) affords deep mining of the muscle proteome, but differential analysis between samples is challenging due to the greater level of fractionation and the complexities of quantifying proteins based on the abundances of their tryptic peptides. Here we report simple, semi-automated and time efficient ( i.e ., 3 h per sample) proteome profiling of skeletal muscle by 1-dimensional RPLC electrospray ionisation tandem MS. Solei were analysed from rats (n = 5, in each group) bred as either high- or low-capacity runners (HCR and LCR, respectively) that exhibited a 6.4-fold difference (1,625 ± 112 m vs . 252 ± 43 m, p < 0.0001) in running capacity during a standardized treadmill test. Soluble muscle proteins were extracted, digested with trypsin and individual biological replicates (50 ng of tryptic peptides) subjected to LC-MS profiling. Proteins were identified by triplicate LC-MS/MS analysis of a pooled sample of each biological replicate. Differential expression profiling was performed on relative abundances (RA) of parent ions, which spanned three orders of magnitude. In total, 207 proteins were analysed, which encompassed almost all enzymes of the major metabolic pathways in skeletal muscle. The most abundant protein detected was type I myosin heavy chain (RA = 5,843 ± 897) and the least abundant protein detected was heat shock 70 kDa protein (RA = 2 ± 0.5). Sixteen proteins were significantly ( p < 0.05) more abundant in HCR muscle and hierarchal clustering of the profiling data highlighted two protein subgroups, which encompassed proteins associated with either the respiratory chain or fatty acid oxidation. Heart-type fatty acid binding protein (FABPH) was 1

Aerobic capacity explains physical functioning and participation in patients with multiple sclerosis-related fatigue.

PubMed

Rosalie Driehuis, Emma; van den Akker, Lizanne Eva; de Groot, Vincent; Beckerman, Heleen

2018-02-13

To investigate whether aerobic capacity explains the level of self-reported physical activity, physical functioning, and participation and autonomy in daily living in persons with multiple sclerosis-related fatigue. A cross-sectional study. Sixty-two participants with multiple sclerosis-related fatigue. Aerobic capacity was measured with a leg ergometer and was expressed as maximal oxygen uptake (VO2max, in ml/kg/min). Physical activity was measured with the Physical Activity Scale for Individuals with Physical Disabilities (PASIPD), physical functioning with the Short Form 36 - physical functioning (SF36-pf), and participation and autonomy in daily living with the Impact on Participation and Autonomy questionnaire (IPA). Multiple regression analyses were performed, adjusted for potential confounders (gender, age, body mass index, educational level, and employment status). Mean maximal oxygen uptake (VO2max) was 23.9 ml/kg/min (standard deviation (SD) 6.3 ml/kg/min). There was no significant relationship between VO2max and physical activity (PASIPD): β = 0.320, 95% confidence interval (95% CI) = -0.109 to 0.749, R2 = 10.8%. Higher VO2max correlated with better physical functioning (SF36-pf): β = 1.527, 95% CI = 0.820-2.234, R2 = 25.9%, and was significantly related to IPA domains "autonomy indoors" (β = -0.043, 95% CI = -0.067 to -0.020, R2 = 20.6%), "autonomy outdoors" (β = -0.037, 95% CI = -0.062 to -0.012, R2 = 18.2%) and "social life and relationships" (β=-0.033, 95% CI = -0.060 to -0.007, R2 = 21.3%). Maximum aerobic capacity was severely reduced in persons with multiple sclerosis-related fatigue. This partly explains the limited physical functioning and restrictions in participation and autonomy indoors, outdoors and in social life and relationships in these persons.

Sprint interval and moderate-intensity cycling training differentially affect adiposity and aerobic capacity in overweight young-adult women.

PubMed

Higgins, Simon; Fedewa, Michael V; Hathaway, Elizabeth D; Schmidt, Michael D; Evans, Ellen M

2016-11-01

The purpose of the study was to examine the effects of sprint interval training (SIT) and moderate-intensity continuous cycle training (MICT), with equal estimated energy expenditure during training on body composition and aerobic capacity. Body composition measured via dual-energy X-ray absorptiometry and aerobic capacity were assessed following 6 weeks of training in previously inactive overweight/obese young women (n = 52; age, 20.4 ± 1.5 years; body mass index, 30.3 ± 4.5 kg·m -2 , 67.3% white). Training was performed in a group-exercise format that mimicked cycling classes offered by commercial fitness facilities, and included 3 weekly sessions of either 30-s "all-out" sprints followed by 4 min of active recovery (SIT), or continuous cycling at 60%-70% heart rate reserve to expend a similar amount of energy. Participants were randomized to SIT or MICT, attended a similar number of sessions (15.0 ± 1.5 sessions vs. 15.8 ± 1.9 sessions, P = 0.097) and expended a similar amount of energy (541.8 ± 104.6 kJ·session -1 vs. 553.5 ± 138.1 kJ·session -1 , P = 0.250). Without significant changes in body mass (P > 0.05), greater relative reductions occurred in SIT than in MICT in total fat mass (3.6% ± 5.6% vs. 0.6% ± 3.9%, P = 0.007), and android fat mass (6.6% ± 6.9% vs. 0.7% ± 6.5%, P = 0.002). Aerobic capacity (mL·kg -1 ·min -1 ) increased significantly following both interventions (P < 0.05), but the relative increase was 2-fold greater in SIT than in MICT (14.09% ± 10.31% vs. 7.06% ± 7.81%, P < 0.001). In conclusion, sprint-interval cycling reduces adiposity and increases aerobic capacity more than continuous moderate-intensity cycling of equal estimated energy expenditure in overweight/obese young women.

BAIBA Does Not Regulate UCP-3 Expression in Human Skeletal Muscle as a Response to Aerobic Exercise.

PubMed

Morales, Flor E; Forsse, Jeffrey S; Andre, Thomas L; McKinley-Barnard, Sarah K; Hwang, Paul S; Anthony, Ian G; Tinsley, Grant M; Spillane, Mike; Grandjean, Peter W; Ramirez, Alejandro; Willoughby, Darryn S

2017-01-01

β-Aminoisobutyric acid (BAIBA) has shown to modulate uncoupling protein (UCP)-1 expression, which is mainly expressed in white adipose tissue; however, no studies to date have analyzed its potential effect on the main uncoupling protein of skeletal muscle, UCP-3. The main goal of this study was to assess the potential effect of acute aerobic exercise on serum BAIBA and skeletal muscle UCP-3. The secondary goal was to assess the potential involvement of the transcription factors proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and peroxisome proliferator-activated receptor alpha (PPARα), as well as free fatty acids (FFAs) in UCP-3 expression. A tertiary goal of the study was to evaluate the potential effect of consuming a preexercise meal on the outcome of the first 2 objectives. In a randomized crossover design, untrained participants performed 2 acute cycling sessions (350 kcal at 70% of their VO 2peak ) after 2 experimental conditions: (1) consumption of a multi-macronutrient shake and (2) a fasting period of 8 hours. Blood samples were taken at baseline, preexercise, postexercise, 1 hour, and 4 hours postexercise, and muscle biopsies were taken at the last 4 time points. UCP-3 protein concentration and expression, as well as the mRNA expression of PGC-1α and PPARα, were measured in muscle, and BAIBA, glucose, and FFA were measured in serum. Aerobic exercise failed to induce a significant effect on serum BAIBA, PGC-1α, and PPARα regardless on the feeding condition. Despite the lack of effect of exercise on the previous variables, UCP-3 expression and protein concentration significantly increased in the shake condition. The expression of human skeletal muscle UCP-3 as a result of exercise might be controlled by factors other than BAIBA.

Muscle Adaptations Following Short-Duration Bed Rest with Integrated Resistance, Interval, and Aerobic Exercise

NASA Technical Reports Server (NTRS)

Hackney, Kyle J.; Scott, Jessica M.; Buxton, Roxanne; Redd-Goetchius, Elizabeth; Crowell, J. Brent; Everett, Meghan E.; Wickwire, Jason; Ryder, Jeffrey W.; Bloomberg, Jacob J.; Ploutz-Snyder, Lori L.

2011-01-01

Unloading of the musculoskeletal system during space flight results in deconditioning that may impair mission-related task performance in astronauts. Exercise countermeasures have been frequently tested during bed rest (BR) and limb suspension; however, high-intensity, short-duration exercise prescriptions have not been fully explored. PURPOSE: To determine if a high intensity resistance, interval, and aerobic exercise program could protect against muscle atrophy and dysfunction when performed during short duration BR. METHODS: Nine subjects (1 female, 8 male) performed a combination of supine exercises during 2 weeks of horizontal BR. Resistance exercise (3 d / wk) consisted of squat, leg press, hamstring curl, and heel raise exercises (3 sets, 12 repetitions). Aerobic (6 d / wk) sessions alternated continuous (75% VO2 peak) and interval exercise (30 s, 2 min, and 4 min) and were completed on a supine cycle ergometer and vertical treadmill, respectively. Muscle volumes of the upper leg were calculated pre, mid, and post-BR using magnetic resonance imaging. Maximal isometric force (MIF), rate of force development (RFD), and peak power of the lower body extensors were measured twice before BR (averaged to represent pre) and once post BR. ANOVA with repeated measures and a priori planned contrasts were used to test for differences. RESULTS: There were no changes to quadriceps, hamstring, and adductor muscle volumes at mid and post BR time points compared to pre BR (Table 1). Peak power increased significantly from 1614 +/- 372 W to 1739 +/- 359 W post BR (+7.7%, p = 0.035). Neither MIF (pre: 1676 +/- 320 N vs. post: 1711 +/- 250 N, +2.1%, p = 0.333) nor RFD (pre: 7534 +/- 1265 N/ms vs. post: 6951 +/- 1241 N/ms, -7.7%, p = 0.136) were significantly impaired post BR.

Five months of physical exercise in hemodialysis patients: effects on aerobic capacity, physical function and self-rated health.

PubMed

Molsted, Stig; Eidemak, Inge; Sorensen, Helle Tauby; Kristensen, Jens Halkjaer

2004-01-01

The number of chronic renal failure patients treated by hemodialysis (HD) is continuously increasing. Most patients have reduced physical capacity and have a high risk of cardiac and vascular diseases. The aim of this study was to determine the effects of 5 months physical exercise of HD patients' physical capacity, self-rated health and risk factors for cardiovascular disease. 33 HD patients were included in the study. HD for more than 3 months, age >18 years. Diabetes mellitus, symptomatic cardiovascular disease, musculoskeletal limitations, severe peripheral polyneuropathy, inability to speak Danish or English, dementia or other mental disorders. The patients were randomly assigned to an exercise group (EG, n = 22) or a control group (CG, n = 11). Prior to randomization, baseline testing was performed. The effects were measured by aerobic capacity, '2-min stair climbing', 'squat test', self-rated health (SF36), blood pressure and lipids. All tests were carried out by blinded testers. The intervention consisted of 1 h of physical exercise twice a week for 5 months. 20 patients completed the intervention. Attendance was 74% of all sessions. There were no dropouts caused by complications related to the intervention. The EG had a significant increase in aerobic capacity, 'squat test' and Physical Function and Physical Component Scale (SF36). No significant changes were observed in any of the parameters in the CG. Physical exercise twice a week for 5 months increases physical function and aerobic capacity in HD patients. An exercise program with only two exercise sessions per week seems easy to implement in clinical practice with high attendance among participants. Further investigation is needed to determine the effects on blood pressure and lipids. There were no medical complications related to the exercise program. Copyright 2004 S. Karger AG, Basel

Aerobic capacity and hepatic mitochondrial lipid oxidation alters susceptibility for chronic high-fat diet-induced hepatic steatosis.

PubMed

Morris, E Matthew; Meers, Grace M E; Koch, Lauren G; Britton, Steven L; Fletcher, Justin A; Fu, Xiaorong; Shankar, Kartik; Burgess, Shawn C; Ibdah, Jamal A; Rector, R Scott; Thyfault, John P

2016-10-01

Rats selectively bred for high capacity running (HCR) or low capacity running (LCR) display divergence for intrinsic aerobic capacity and hepatic mitochondrial oxidative capacity, both factors associated with susceptibility for nonalcoholic fatty liver disease. Here, we tested if HCR and LCR rats display differences in susceptibility for hepatic steatosis after 16 wk of high-fat diets (HFD) with either 45% or 60% of kcals from fat. HCR rats were protected against HFD-induced hepatic steatosis, whereas only the 60% HFD induced steatosis in LCR rats, as marked by a doubling of liver triglycerides. Hepatic complete fatty acid oxidation (FAO) and mitochondrial respiratory capacity were all lower in LCR compared with HCR rats. LCR rats also displayed lower hepatic complete and incomplete FAO in the presence of etomoxir, suggesting a reduced role for noncarnitine palmitoyltransferase-1-mediated lipid catabolism in LCR versus HCR rats. Hepatic complete FAO and mitochondrial respiration were largely unaffected by either chronic HFD; however, 60% HFD feeding markedly reduced 2-pyruvate oxidation, a marker of tricarboxylic acid (TCA) cycle flux, and mitochondrial complete FAO only in LCR rats. LCR rats displayed lower levels of hepatic long-chain acylcarnitines than HCR rats but maintained similar levels of hepatic acetyl-carnitine levels, further supporting lower rates of β-oxidation, and TCA cycle flux in LCR than HCR rats. Finally, only LCR rats displayed early reductions in TCA cycle genes after the acute initiation of a HFD. In conclusion, intrinsically high aerobic capacity confers protection against HFD-induced hepatic steatosis through elevated hepatic mitochondrial oxidative capacity.

Aerobic capacity and hepatic mitochondrial lipid oxidation alters susceptibility for chronic high-fat diet-induced hepatic steatosis

PubMed Central

Morris, E. Matthew; Meers, Grace M. E.; Koch, Lauren G.; Britton, Steven L.; Fletcher, Justin A.; Fu, Xiaorong; Shankar, Kartik; Burgess, Shawn C.; Ibdah, Jamal A.; Rector, R. Scott

2016-01-01

Rats selectively bred for high capacity running (HCR) or low capacity running (LCR) display divergence for intrinsic aerobic capacity and hepatic mitochondrial oxidative capacity, both factors associated with susceptibility for nonalcoholic fatty liver disease. Here, we tested if HCR and LCR rats display differences in susceptibility for hepatic steatosis after 16 wk of high-fat diets (HFD) with either 45% or 60% of kcals from fat. HCR rats were protected against HFD-induced hepatic steatosis, whereas only the 60% HFD induced steatosis in LCR rats, as marked by a doubling of liver triglycerides. Hepatic complete fatty acid oxidation (FAO) and mitochondrial respiratory capacity were all lower in LCR compared with HCR rats. LCR rats also displayed lower hepatic complete and incomplete FAO in the presence of etomoxir, suggesting a reduced role for noncarnitine palmitoyltransferase-1-mediated lipid catabolism in LCR versus HCR rats. Hepatic complete FAO and mitochondrial respiration were largely unaffected by either chronic HFD; however, 60% HFD feeding markedly reduced 2-pyruvate oxidation, a marker of tricarboxylic acid (TCA) cycle flux, and mitochondrial complete FAO only in LCR rats. LCR rats displayed lower levels of hepatic long-chain acylcarnitines than HCR rats but maintained similar levels of hepatic acetyl-carnitine levels, further supporting lower rates of β-oxidation, and TCA cycle flux in LCR than HCR rats. Finally, only LCR rats displayed early reductions in TCA cycle genes after the acute initiation of a HFD. In conclusion, intrinsically high aerobic capacity confers protection against HFD-induced hepatic steatosis through elevated hepatic mitochondrial oxidative capacity. PMID:27600823

Mitochondria-specific antioxidant supplementation does not influence endurance exercise training-induced adaptations in circulating angiogenic cells, skeletal muscle oxidative capacity or maximal oxygen uptake.

PubMed

Shill, Daniel D; Southern, W Michael; Willingham, T Bradley; Lansford, Kasey A; McCully, Kevin K; Jenkins, Nathan T

2016-12-01

Reducing excessive oxidative stress, through chronic exercise or antioxidants, can decrease the negative effects induced by excessive amounts of oxidative stress. Transient increases in oxidative stress produced during acute exercise facilitate beneficial vascular training adaptations, but the effects of non-specific antioxidants on exercise training-induced vascular adaptations remain elusive. Circulating angiogenic cells (CACs) are an exercise-inducible subset of white blood cells that maintain vascular integrity. We investigated whether mitochondria-specific antioxidant (MitoQ) supplementation would affect the response to 3 weeks of endurance exercise training in CACs, muscle mitochondrial capacity and maximal oxygen uptake in young healthy men. We show that endurance exercise training increases multiple CAC types, an adaptation that is not altered by MitoQ supplementation. Additionally, MitoQ does not affect skeletal muscle or whole-body aerobic adaptations to exercise training. These results indicate that MitoQ supplementation neither enhances nor attenuates endurance training adaptations in young healthy men. Antioxidants have been shown to improve endothelial function and cardiovascular outcomes. However, the effects of antioxidants on exercise training-induced vascular adaptations remain elusive. General acting antioxidants combined with exercise have not impacted circulating angiogenic cells (CACs). We investigated whether mitochondria-specific antioxidant (MitoQ) supplementation would affect the response to 3 weeks of endurance exercise training on CD3 + , CD3 + /CD31 + , CD14 + /CD31 + , CD31 + , CD34 + /VEGFR2 + and CD62E + peripheral blood mononuclear cells (PBMCs), muscle mitochondrial capacity, and maximal oxygen uptake (VO2 max ) in healthy men aged 22.1 ± 0.7 years, with a body mass index of 26.9 ± 0.9 kg m -2 , and 24.8 ± 1.3% body fat. Analysis of main effects revealed that training induced 33, 105 and 285% increases in CD14 + /CD31

Mitochondria‐specific antioxidant supplementation does not influence endurance exercise training‐induced adaptations in circulating angiogenic cells, skeletal muscle oxidative capacity or maximal oxygen uptake

PubMed Central

Shill, Daniel D.; Southern, W. Michael; Willingham, T. Bradley; Lansford, Kasey A.; McCully, Kevin K.

2016-01-01

Key points Reducing excessive oxidative stress, through chronic exercise or antioxidants, can decrease the negative effects induced by excessive amounts of oxidative stress. Transient increases in oxidative stress produced during acute exercise facilitate beneficial vascular training adaptations, but the effects of non‐specific antioxidants on exercise training‐induced vascular adaptations remain elusive.Circulating angiogenic cells (CACs) are an exercise‐inducible subset of white blood cells that maintain vascular integrity.We investigated whether mitochondria‐specific antioxidant (MitoQ) supplementation would affect the response to 3 weeks of endurance exercise training in CACs, muscle mitochondrial capacity and maximal oxygen uptake in young healthy men.We show that endurance exercise training increases multiple CAC types, an adaptation that is not altered by MitoQ supplementation. Additionally, MitoQ does not affect skeletal muscle or whole‐body aerobic adaptations to exercise training.These results indicate that MitoQ supplementation neither enhances nor attenuates endurance training adaptations in young healthy men. Abstract Antioxidants have been shown to improve endothelial function and cardiovascular outcomes. However, the effects of antioxidants on exercise training‐induced vascular adaptations remain elusive. General acting antioxidants combined with exercise have not impacted circulating angiogenic cells (CACs). We investigated whether mitochondria‐specific antioxidant (MitoQ) supplementation would affect the response to 3 weeks of endurance exercise training on CD3+, CD3+/CD31+, CD14+/CD31+, CD31+, CD34+/VEGFR2+ and CD62E+ peripheral blood mononuclear cells (PBMCs), muscle mitochondrial capacity, and maximal oxygen uptake (VO2 max ) in healthy men aged 22.1 ± 0.7 years, with a body mass index of 26.9 ± 0.9 kg m–2, and 24.8 ± 1.3% body fat. Analysis of main effects revealed that training induced 33, 105 and 285% increases

Multivariate statistical assessment of predictors of firefighters' muscular and aerobic work capacity.

PubMed

Lindberg, Ann-Sofie; Oksa, Juha; Antti, Henrik; Malm, Christer

2015-01-01

Physical capacity has previously been deemed important for firefighters physical work capacity, and aerobic fitness, muscular strength, and muscular endurance are the most frequently investigated parameters of importance. Traditionally, bivariate and multivariate linear regression statistics have been used to study relationships between physical capacities and work capacities among firefighters. An alternative way to handle datasets consisting of numerous correlated variables is to use multivariate projection analyses, such as Orthogonal Projection to Latent Structures. The first aim of the present study was to evaluate the prediction and predictive power of field and laboratory tests, respectively, on firefighters' physical work capacity on selected work tasks. Also, to study if valid predictions could be achieved without anthropometric data. The second aim was to externally validate selected models. The third aim was to validate selected models on firefighters' and on civilians'. A total of 38 (26 men and 12 women) + 90 (38 men and 52 women) subjects were included in the models and the external validation, respectively. The best prediction (R2) and predictive power (Q2) of Stairs, Pulling, Demolition, Terrain, and Rescue work capacities included field tests (R2 = 0.73 to 0.84, Q2 = 0.68 to 0.82). The best external validation was for Stairs work capacity (R2 = 0.80) and worst for Demolition work capacity (R2 = 0.40). In conclusion, field and laboratory tests could equally well predict physical work capacities for firefighting work tasks, and models excluding anthropometric data were valid. The predictive power was satisfactory for all included work tasks except Demolition.

Muscle Glycogen, Fiber Type, Aerobic Fitness, and Anaerobic Capacity of West Coast U.S. Navy Sea-Air-Land Personnel (SEALS).

DTIC Science & Technology

1992-07-01

traininig and nutritional intake histories for the 36-48 hours preceding the biopsy. Aerobic Fitness Test. Aerobic endurance performance was evaluated...running, cycling, soccer, volleyball, Versiclimber®, calisthenics, and weightlifting . These activities are consistent with the training habits of a...success of missions requiring time-dependent coordination of unit movements. Achieving a greater degree of nutritional homogeneity and physical/mission

Responses to LBNP in men with varying profiles of strength and aerobic capacity: Implications for flight crews

NASA Technical Reports Server (NTRS)

Convertino, Victor A.; Mathes, Karen L.; Lasley, Mary L.; Tomaselli, Clare Marie; Frey, Mary Anne Bassett; Hoffler, G. Wyckliffe

1993-01-01

Hemodynamic and hormonal responses to lower-body negative pressure (LBNP) were examined in 24 healthy men to test the hypothesis that responsiveness of reflex control of blood pressure during orthostatic stress is associated with strength and/or aerobic capacity. Subjects underwent treadmill tests to determine peak oxygen uptake (peak VO2) and isokinetic dynamo meter tests to determine leg strength. Based on predetermined criteria, the subjects were classified into one of four fitness profiles of six subjects each matched for age, height, and weight: (1) low strength/low aerobic fitness; (2) low strength/high aerobic fitness; (3) high strength/low aerobic fitness; and (4) high strength/high aerobic fitness. Following 90 min of 6 degree head-down tilt (HDT), each subject underwent graded LBNP through -50 mmHg or presyncope, with maximal duration 15 min. All groups exhibited typical hemodynamic, hormonal, and fluid shift responses during LBNP, with no intergroup differences except for catecholamines. Seven subjects, distributed among the four fitness profiles, became presyncopal. Subjects who showed greatest reduction in mean arterial pressure (MAP) during LBNP had greater elevations in vasopressin and lesser increases in heart rate and peripheral resistance. Peak VO2 nor leg strength were correlated with fall in MAP or with syncopal episodes. We conclude that neither aerobic nor strength fitness characteristics are good predictors of responses to LBNP stress.

[Impact of exercise on the body composition and aerobic capacity of elderly with obesity through three models of intervention].

PubMed

Prieto, Jose Antonio; Del Valle, Miguel; Nistal, Paloma; Méndez, David; Abelairas-Gómez, Cristian; Barcala-Furelos, Roberto

2014-12-17

The objective of this study was to analyze the influence of aerobic exercise on body composition and aerobic capacity of a sample of older, sedentary adults with obesity rates by three different models of intervention (recommendation, prescription at home and monitoring). A total of 76 older adults with a mean age 67.1+/-1.2 years, sedentary, with a BMI> 30 kg/ m2 were randomized in to four groups: Control (CON) recommendation (REC), prescription home (PRES) and monitoring in a sports center (MON). The same program of aerobic exercise for groups of home and sports center for 24 weeks, 3 days a week was developed. It was determined before and after the intervention BMI, Waist- Hip-index (ICC), the% fat ( Σ folds) and aerobic capacity (T6M) throughout the sample. MON and PRES groups showed significant improvements in the ICC, Σ folds and T 6M variables, not the case in BMI. However the MON group presented significant differences from group PRES between-group analysis (p <0.001). The recommendation did not get positive effects. Monitoring is the most effective exercise programs in adults with obesity methodology. However the exercise prescription at home since early intervention is an important approach for people with physical and/ or psychological reasons such as obesity cannot access the sports centers to participate in activities led by a monitor. Unknowns of aerobic exercise are cleared in the home that are of great impact for social policies regarding the health of the elderly population. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Substrate oxidation capacity in rodent skeletal muscle: effects of exposure to zero gravity

NASA Technical Reports Server (NTRS)

Baldwin, K. M.; Herrick, R. E.; McCue, S. A.

1993-01-01

A study was conducted, as part of the integrated National Aeronautics and Space Administration Space Life Sciences 1 mission flown in June of 1991, to ascertain the effects of 9 days of exposure to zero gravity on the capacity of rodent skeletal muscle fiber types to oxidize either [14C]pyruvate or [14C]palmitate under state 3 metabolic conditions, i.e., nonlimiting amounts of substrate and cofactors. In addition, activity levels of marker enzymes of the tricarboxylic acid cycle, malate shuttle, and beta-oxidation were measured. Results showed that significant differences in muscle weight occurred in both the predominantly slow vastus intermedius and predominantly fast vastus lateralis of flight vs. control groups (P < 0.05). Total protein content of the muscle samples was similar between groups. Both pyruvate oxidation capacity and the marker oxidative enzymes were not altered in the flight relative to control animals. However, the capacity to oxidize long-chain fatty acids was significantly reduced by 37% in both the high- and low-oxidative regions of the vastus muscle (P < 0.05). Although these findings of a selective reduction in fatty acid oxidation capacity in response to spaceflight are surprising, they are consistent with previous findings showing 1) an increased capacity to take up glucose and upregulate glucose transporter proteins and 2) a marked accumulation of triglycerides in the skeletal muscles of rats subjected to states of unloading. Thus, skeletal muscle of animals exposed to non-weight-bearing environments undergo subcellular transformations that may preferentially bias energy utilization to carbohydrates.

The 12-week progressive quadriceps resistance training improves muscle strength, exercise capacity and quality of life in patients with stable chronic heart failure.

PubMed

Jankowska, Ewa A; Wegrzynowska, Kinga; Superlak, Malgorzata; Nowakowska, Katarzyna; Lazorczyk, Malgorzata; Biel, Bartosz; Kustrzycka-Kratochwil, Dorota; Piotrowska, Katarzyna; Banasiak, Waldemar; Wozniewski, Marek; Ponikowski, Piotr

2008-10-30

Abnormalities in the skeletal musculature underlie exercise intolerance in chronic heart failure (CHF). We investigated, whether in CHF selective resistance training without accompanying aerobic regime favourably affects muscle strength, muscle mass and improves exercise capacity. Ten patients with stable ischaemic CHF in NYHA class III (9 men, age: 70+/-6 years [mean+/-SD], left ventricular ejection fraction: 30+/-5%, peak oxygen consumption [peak VO(2)]: 12.4+/-3.0 mL/min/kg) underwent the rehabilitation programme which consisted of a 12-week training phase (progressive resistance exercises restricted to the quadriceps muscles) followed by a 12-week detraining phase. All subjects completed a training phase of the programme with no adverse events. Resistance training markedly increased quadriceps strength (right leg: 260+/-34 vs. 352+/-28 N, left leg: 264+/-38 vs. 342+/-30 N, both p<0.01 - all comparisons: baseline vs. after training), but did not affect lean tissue mass of lower extremities (both p>0.2). It was accompanied by an improvement in clinical status (all NYHA III vs. all NYHA II, p<0.01), quality of life (Minnesota questionnaire: 44+/-15 vs. 33+/-18 points, p<0.05), exercise capacity assessed using a distance during 6-minute walk test (6MWT: 362+/-83 vs. 455+/-71 m, p<0.01), but not peak VO(2) (p>0.2). Plasma NT-proBNP remained unchanged during the training. At the end of detraining phase, only a partial improvement in quadriceps strength (p<0.05), a 6MWT distance (p<0.05) and NYHA class (p=0.07 vs. baseline) persisted. Applied resistance quadriceps training is safe in patients with CHF. It increases muscle strength, improves clinical status, exercise capacity, and quality of life.

Comparison of the effects of weight loss from a high-protein versus standard-protein energy-restricted diet on strength and aerobic capacity in overweight and obese men.

PubMed

Wycherley, Thomas P; Buckley, Jonathan D; Noakes, Manny; Clifton, Peter M; Brinkworth, Grant D

2013-02-01

To compare the effects of two low-fat, hypoenergetic diets differing in carbohydrate-to-protein ratio, on strength and aerobic capacity measures in overweight and obese men. In a parallel design, 56 men (age, 45.5 ± 8.7 years; BMI, 33.6 ± 3.9 kg/m(2)) were randomly assigned to a low-fat, energy-restricted diet (7,000 kJ/day) with either high protein (HP: protein/carbohydrate/fat % energy, 35:40:25) or standard protein (SP, 17:58:25). Body weight, body composition, muscle strength and aerobic capacity were assessed at baseline and after 12 weeks. Forty-two participants completed the study (HP, n = 21; SP, n = 21). Both groups experienced similar reductions in body weight (HP, -10.7 ± 5.3 kg [-9.8%]; SP, -8.7 ± 3.5 kg [-8.4%]) and fat-free mass (HP, -2.8 ± 3.6 kg; SP, -3.2 ± 2.7 kg; P < 0.001 time; P > 0.14 time × group interaction). There was a trend for a greater reduction in fat mass in the HP diet group, (-7.7 ± 4.3 kg [-21.2%] vs. -5.4 ± 3.3 kg [-15.1%]; P < 0.001 time; P = 0.06 time × group interaction). Absolute peak oxygen uptake did not change in either group (P = 0.39 time; P = 0.50 time × group interaction). Overall, in both groups, relative peak oxygen uptake increased (2.9 ± 2.8 ml kg(-1) min(-1) [8.9%]), peak isometric knee extensor strength increased (14.1 ± 35.7 Nm [7.1%]) and peak handgrip strength decreased (-1.6 ± 4.1 kg [-3%]) (P ≤ 0.02 time for all), with no diet effect (P ≤ 0.23 time × group interaction). In overweight and obese men, both a HP and SP diet reduced body weight and improved body composition with similar effects on strength and aerobic capacity.

Regenerative capacity of mdx mouse muscles after repeated applications of myo-necrotic bupivacaine.

PubMed

Itagaki, Y; Saida, K; Iwamura, K

1995-01-01

We injected bupivacaine (BPVC), which produces muscle fiber necrosis, repeatedly into the soleus muscles of mdx mice, which represent a model of human Duchenne muscular dystrophy, over a 12-month period. Cytological and morphometric analysis revealed that the regenerative capacity of repeatedly BPVC-injected mdx muscles was almost equal to that of the saline-injected mdx muscles. At 9 months of age the endomysial collagen content of mdx muscles was 4.6 times that of control mice muscles, and was 7.2 times that of control mice muscle at 12 months. These results suggest that the regenerative capacity of the mdx muscle is quite large and that myo-necrosis induced by an extrinsic cause, such as BPVC, may not be an important factor in the disease progress. However, endomysial collagen, for which the mechanism of increase may be related to the defect of dystrophin, may play an important role in gradual decline of regeneration.

Factors affecting the colour of lamb meat from the longissimus muscle during display: the influence of muscle weight and muscle oxidative capacity.

PubMed

Calnan, H B; Jacob, R H; Pethick, D W; Gardner, G E

2014-02-01

Spectrophotometric measures were used to determine the redness:browness (R630/R580) of 4238 lamb longissimus muscle after 3 days under simulated display. The results were analysed using linear mixed effects models. Environmental factors represented by effects such as kill group and site of production produced the greatest variation of up to 2.76 units in R630/R580. Isocitrate dehydrogenase activity, reflecting muscle oxidative capacity, reduced R630/R580 by 0.5 units. Selection for high muscling sires increased R630/R580 by 0.27 units, likely due to changes in muscle oxidative capacity. Lamb carcass weight also increased R630/R580 by 0.5 units. Analysis of genotypic factors influencing lamb size and growth rate such as sire type and dam breed further supported that increased growth rate improves meat R630/R580. Our findings suggest that breeding for increased growth rate and increased muscle weight could result in Australian lamb meat retaining its red colour for extended periods whilst on display. © 2013.

Combined Training Enhances Skeletal Muscle Mitochondrial Oxidative Capacity Independent of Age

PubMed Central

Lanza, Ian R.; Henderson, Gregory C.; Rao, Rajesh R.; Spiegelman, Bruce M.

2015-01-01

Context: Skeletal muscle from sedentary older adults exhibits reduced mitochondrial abundance and oxidative capacity. Objective: The primary objective was to determine whether 8 weeks of combined training (CT) has a more robust effect than endurance training (ET) or resistance training (RT) on mitochondrial physiology in healthy young (18–30 years) and older (≥65 years) adults. Intervention: Thirty-four young and 31 older adults were randomly assigned to 8 weeks of ET, RT, and control/CT. Control subjects completed 8 weeks of no exercise (control) followed by 8 weeks of CT. Body composition, skeletal muscle strength, and peak oxygen uptake were measured before and after the intervention. Vastus lateralis muscle biopsy samples were obtained before and 48 hours after the intervention. Mitochondrial physiology was evaluated by high-resolution respirometry and expression of mitochondrial proteins and transcription factors by quantitative PCR and immunoblotting. Results: ET and CT significantly increased oxidative capacity and expression of mitochondrial proteins and transcription factors. All training modalities improved body composition, cardiorespiratory fitness, and skeletal muscle strength. CT induced the most robust improvements in mitochondria-related outcomes and physical characteristics despite lower training volumes for the ET and RT components. Importantly, most of the adaptations to training occurred independent of age. Conclusion: Collectively, these results demonstrate that both ET and CT increase muscle mitochondrial abundance and capacity although CT induced the most robust improvements in the outcomes measured. In conclusion, CT provides a robust exercise regimen to improve muscle mitochondrial outcomes and physical characteristics independent of age. PMID:25599385

Aerobic fitness in women and responses to lower body negative pressure.

PubMed

Frey, M A; Mathes, K L; Hoffler, G W

1987-12-01

High aerobic fitness may be associated with impaired responsiveness to orthostatic challenge. This could be detrimental to astronauts returning from spaceflight. Thus, we examined the cardiovascular responses of a group of 45 healthy women to graded lower body negative pressure (LBNP) through 5 min at -50 mm Hg or until they become presyncopal. The ages (range = 23-43 years, mean = 30.4) and peak aerobic capacities (range = 23.0-55.3 ml.kg-1.min-1, mean = 37.8) of these subjects paralleled those of the women astronauts. We monitored heart rate, stroke volume, cardiac output, Heather index of contractility, arterial pressure, peripheral resistance, change in calf circumference, and thoracic impedance (ZO)--a measure of fluid in the chest. The women in this study exhibited the same response pattern to LBNP as previously reported for male subjects. VO2peak of the six subjects who became presyncopal was not different from VO2peak of the tolerant subjects. At rest, only systolic and mean arterial pressures were significantly correlated with VO2peak. Percent changes in calf circumference (i.e. fluid accumulation in the legs) at -30 and -40 mm Hg were the only responses to LBNP significantly related to VO2peak. The greater pooling of blood in the legs during LBNP by women with higher aerobic fitness, and lower percent body fat may be related to more muscle tissue and vasculature in the legs of the more fit subjects. These data indicated that orthostatic tolerance is not related to aerobic capacity in women, and orthostatic tolerance need not be a concern to aerobically fit women astronauts.

Comparison of aerobic capacity in annually certified and uncertified volunteer firefighters.

PubMed

Hammer, Rodney L; Heath, Edward M

2013-05-01

The leading cause of mortality among firefighters has been cardiac arrest precipitated by stress and overexertion with volunteer firefighters having double the death rate from this cause compared with career firefighters. In an attempt to reduce on-duty sudden cardiac deaths, annual fitness testing, and certification, has been widely instigated in wildland firefighters, who have half the cardiac arrest death rate of structural firefighters. The hypothesis was that annual fitness testing would serve as motivation to produce higher cardiorespiratory fitness. This study compared predicted aerobic capacity in annually certified and uncertified volunteer firefighters. Each firefighter performed a submaximal treadmill test to predict V[Combining Dot Above]O2max. Certified volunteer firefighters, who participated in annual fitness testing, had a predicted V[Combining Dot Above]O2max of 39.9 ± 8.4 ml·kg·min. Uncertified volunteer firefighters had a predicted V[Combining Dot Above]O2max of 37.8 ± 8.5 ml·kg·min. Annual fitness testing during the certification process did not contribute to statistically higher (F2,78 = 0.627, p = 0.431) V[Combining Dot Above]O2max levels in certified volunteer firefighters. Although there was no significant difference in predicted V[Combining Dot Above]O2max values for certified and uncertified volunteer firefighters, it was reported that 30% of volunteer firefighters had predicted aerobic capacities below the recommended minimum V[Combining Dot Above]O2max level of 33.5 ml·kg·min. Current annual fitness testing for volunteer firefighters does not seem to be effective. Thus, the study emphasizes the need of a higher priority for firefighter fitness programs to best ensure the safety of firefighters and the public.

Analysis of Reaction Times and Aerobic Capacities of Soccer Players According to Their Playing Positions

ERIC Educational Resources Information Center

Taskin, Cengiz; Karakoc, Onder; Taskin, Mine; Dural, Murat

2016-01-01

70 soccer players in Gaziantep amateur league voluntarily participated in this study, (average of their ages 19,17±1,34years, average of their heights 181,28±5,06 cm, average of their body weights 76,75±4,43 kg and average of their sports experiences 3,78±0,95 years) to analyze visual and auditory reaction times and aerobic capacities of amateur…

Demonstration of a day-night rhythm in human skeletal muscle oxidative capacity.

PubMed

van Moorsel, Dirk; Hansen, Jan; Havekes, Bas; Scheer, Frank A J L; Jörgensen, Johanna A; Hoeks, Joris; Schrauwen-Hinderling, Vera B; Duez, Helene; Lefebvre, Philippe; Schaper, Nicolaas C; Hesselink, Matthijs K C; Staels, Bart; Schrauwen, Patrick

2016-08-01

A disturbed day-night rhythm is associated with metabolic perturbations that can lead to obesity and type 2 diabetes mellitus (T2DM). In skeletal muscle, a reduced oxidative capacity is also associated with the development of T2DM. However, whether oxidative capacity in skeletal muscle displays a day-night rhythm in humans has so far not been investigated. Lean, healthy subjects were enrolled in a standardized living protocol with regular meals, physical activity and sleep to reflect our everyday lifestyle. Mitochondrial oxidative capacity was examined in skeletal muscle biopsies taken at five time points within a 24-hour period. Core-body temperature was lower during the early night, confirming a normal day-night rhythm. Skeletal muscle oxidative capacity demonstrated a robust day-night rhythm, with a significant time effect in ADP-stimulated respiration (state 3 MO, state 3 MOG and state 3 MOGS, p < 0.05). Respiration was lowest at 1 PM and highest at 11 PM (state 3 MOGS: 80.6 ± 4.0 vs. 95.8 ± 4.7 pmol/mg/s). Interestingly, the fluctuation in mitochondrial function was also observed in whole-body energy expenditure, with peak energy expenditure at 11 PM and lowest energy expenditure at 4 AM (p < 0.001). In addition, we demonstrate rhythmicity in mRNA expression of molecular clock genes in human skeletal muscle. Our results suggest that the biological clock drives robust rhythms in human skeletal muscle oxidative metabolism. It is tempting to speculate that disruption of these rhythms contribute to the deterioration of metabolic health associated with circadian misalignment.

A randomized controlled trial on the effects of combined aerobic-resistance exercise on muscle strength and fatigue, glycemic control and health-related quality of life of type 2 diabetes patients.

PubMed

Tomas-Carus, Pablo; Ortega-Alonso, Alfredo; Pietilainen, Kirsi H; Santos, Vitoria; Goncalves, Helena; Ramos, Jorge; Raimundo, Armando

2016-05-01

The aim of this paper was to evaluate the effects of a 12-weeks combined aerobic-resistance exercise therapy on fatigue and isokinetic muscle strength, glycemic control and health-related quality of life (HRQoL) in moderately affected type 2 diabetes (T2DM) patients. A randomized controlled trial design was employed. Forty-three T2DM patients were assigned to an exercise group (N.=22), performing 3 weekly sessions of 60 minutes of combined aerobic-resistance exercise for 12-weeks; or a no exercise control group (N.=21). Both groups were evaluated at a baseline and after 12-weeks of exercise therapy for: 1) muscle strength and fatigue by isokinetic dynamometry; 2) plasma glycated hemoglobin A1C (HbA1C); and 3) HRQoL utilizing the SF-36 questionnaire. The exercise therapy led to improvements in muscle fatigue in knee extensors (-55%) and increased muscle strength in knee flexors and extensors (+15 to +30%), while HbA1C decreased (-18%). In addition, the exercising patients showed sizeable improvements in HRQoL: physical function (+53%), vitality (+21%) and mental health (+40%). Twelve-weeks of combined aerobic-resistance exercise was highly effective to improve muscle strength and fatigue, glycemic control and several aspects of HRQoL in T2DM patients. These data encourage the use of aerobic and resistance exercise in the good clinical care of T2DM.

Aerobic Exercise: Top 10 Reasons to Get Physical

MedlinePlus

... can help you live longer and healthier. Need motivation? See how aerobic exercise affects your heart, lungs and blood flow. Then get moving and start reaping the rewards. During aerobic activity, you repeatedly move large muscles ...

Comparison of abdominal muscle activity and peak expiratory flow between forced vital capacity and fast expiration exercise.

PubMed

Ishida, Hiroshi; Suehiro, Tadanobu; Watanabe, Susumu

2017-04-01

[Purpose] The purpose of this investigation was to compare the activities of the abdominal muscles and peak expiratory flow between forced vital capacity and fast expiration exercise. [Subjects and Methods] Fifteen healthy male participated in this study. Peak expiratory flow and electromyographic activities of the rectus abdominis, external oblique, and internal oblique/transversus abdominis muscles were measured during forced vital capacity and fast expiration exercise and then peak amplitude and its appearance time were obtained. [Results] Peak expiratory flow values were significantly higher during fast expiration exercise than during forced vital capacity. The internal oblique/transversus abdominis muscles showed significantly higher peak amplitude during fast expiration exercise than during forced vital capacity. However, there were no significant differences between forced vital capacity and fast expiration exercise in the rectus abdominis and external oblique muscles. There was no difference in the appearance time of the peak amplitude between forced vital capacity and fast expiration exercise in any muscle. [Conclusion] Fast expiration exercise might be beneficial for increasing expiratory speed and neuromuscular activation of the internal oblique/transversus abdominis muscles compared to forced vital capacity. These findings could be considered when recommending a variation of expiratory muscle strength training as part of pulmonary rehabilitation programs.

Relationship between peripheral muscle structure and function in patients with chronic obstructive pulmonary disease with different nutritional status.

PubMed

Malaguti, Carla; Napolis, Lara M; Villaça, Débora; Neder, José A; Nery, Luiz E; Dal Corso, Simone

2011-07-01

The purpose of this study was to investigate the relationships between peripheral muscle structure (mass) and function (strength, endurance, and maximal aerobic capacity) in patients with chronic obstructive pulmonary disease (COPD) with different nutritional states. Thirty-nine patients (31 male) with moderate-severe COPD (63.5 ± 7.3 [SD] years) and 17 controls (14 male; 64.7 ± 5.5 [SD] years) underwent isokinetic (peak torque [PT]), isometric (isometric torque [IT]), and endurance strength (total work [TW]) measurements of the knee extensor muscles and a maximal cardiopulmonary exercise test to evaluate the maximal aerobic capacity (peak oxygen uptake [VO(2)] peak). Muscle mass (MM) was determined using dual-energy x-ray absorptiometry. Patients with COPD presented with reduced muscle function as compared with the healthy controls: PT (105.9 ± 33.9 vs. 134.3 ± 30.9, N·m(-1), respectively, p < 0.05), TW (1,446.3 ± 550.8 vs. 1,792.9 ± 469.1 kJ, respectively, p < 0.05), and VO(2)peak (68.1 ± 15.1 vs. 93.7 ± 14.5, % pred, respectively, p < 0.05). Significant relationships were found between muscle structure and function (strength and endurance) in the patient subgroup with preserved MM and in the control group: PT·MM(r(2) = 0.36; p = 0.01 vs. r(2) = 0.32; p = 0.01, respectively) and TW·MM (r(2) = 0.32; p = 0.01 vs. r(2) = 0.22; p = 0.05, respectively). Strength corrected for mass normalized this function in both patient subgroups, whereas endurance was normalized only in the patient subgroup without muscle depletion. Maximal aerobic capacity remained reduced, despite the correction, in both patient subgroups (depleted or nondepleted) compared with the healthy controls (VO(2)peak.MM: 9.1 ± 3.7 vs. 21.8 ± 4.9 vs. 28.5 ± 4.2 ml·min·kg, respectively, with p < 0.01 among groups). Muscle atrophy seems to be the main determinant of strength reduction among patients with moderate-severe COPD, whereas endurance reduction seems to be more related to imbalance

[Sub-maximal aerobic capacity and quality of life of patients with rheumatoid arthritis].

PubMed

Lataoui, S; Belghali, S; Zeglaoui, H; Bouajina, E; Ben Saad, H

2017-01-01

Studies about sub-maximal aerobic capacity of patients with rheumatoid arthritis are scarce. To assess the sub-maximal aerobic capacity of these patients through the 6-min walk test, estimated age of the "muscular and cardiorespiratory" chain. Thirty-seven consecutive patients (aged 20 to 60 years) with newly diagnosed rheumatoid arthritis will be included. Non-inclusion criteria will be: use of drugs (e.g.; methotrexate, beta-blockers), orthopaedic or rheumatologic conditions (other than rheumatoid arthritis) that may alter walking ability and recent infections. Exclusion criteria will be: 6-min walking test contra-indications and imperfect performance of the required lung function and walking maneuvers. Signs of walking intolerance will be: test interruption, distance ≤lower limit of normal, dyspnea score ≥5/10 (visual analogue scale) at the end of the test, haemoglobin oxygen saturation (SpO 2 ) drop ≥5%, cardiac frequency at the end of the test ≤60% of maximum predicted. An estimated "muscular and cardiorespiratory chain" age higher than the chronological one will be considered as a sign of accelerated ageing. A high percentage of patients suffering from rheumatoid arthritis would show evidences of walking limitation and accelerated "muscular and cardiorespiratory chain" ageing. There would be a significant correlation between the walking test and clinical, biological, radiological and pulmonary function data and the patients' quality-of-life status. Copyright © 2016 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Feed restriction and a diet's caloric value: The influence on the aerobic and anaerobic capacity of rats

PubMed Central

2012-01-01

Background The influence of feed restriction and different diet's caloric value on the aerobic and anaerobic capacity is unclear in the literature. Thus, the objectives of this study were to determine the possible influences of two diets with different caloric values and the influence of feed restriction on the aerobic (anaerobic threshold: AT) and anaerobic (time to exhaustion: Tlim) variables measured by a lactate minimum test (LM) in rats. Methods We used 40 adult Wistar rats. The animals were divided into four groups: ad libitum commercial Purina® diet (3028.0 Kcal/kg) (ALP), restricted commercial Purina® diet (RAP), ad libitum semi-purified AIN-93 diet (3802.7 Kcal/kg) (ALD) and restricted semi-purified AIN-93 diet (RAD). The animals performed LM at the end of the experiment, 48 h before euthanasia. Comparisons between groups were performed by analysis of variance (p < 0,05). Results At the end of the experiment, the weights of the rats in the groups with the restricted diets were significantly lower than those in the groups with ad libitum diet intakes. In addition, the ALD group had higher amounts of adipose tissue. With respect to energetic substrates, the groups subjected to diet restriction had significantly higher levels of liver and muscle glycogen. There were no differences between the groups with respect to AT; however, the ALD group had lower lactatemia at the AT intensity and higher Tlim than the other groups. Conclusions We conclude that dietary restriction induces changes in energetic substrates and that ad libitum intake of a semi-purified AIN-93 diet results in an increase in adipose tissue, likely reducing the density of the animals in water and favouring their performance during the swimming exercises. PMID:22448911

Effects of resistance training on muscle strength, exercise capacity, and mobility in middle-aged and elderly patients with coronary artery disease: A meta-analysis.

PubMed

Yamamoto, Shuhei; Hotta, Kazuki; Ota, Erika; Mori, Rintaro; Matsunaga, Atsuhiko

2016-08-01

Resistance training (RT) is a core component of cardiac rehabilitation. We investigated the effects of RT on exercise capacity, muscle strength, and mobility in middle-aged and elderly patients with coronary artery disease (CAD). We searched for randomized controlled trials of RT versus usual care, or combined RT and aerobic training (AT) versus AT alone, and identified 440 trials in total from inception to January 2014. Participants who had myocardial infarction, coronary revascularization, angina pectoris or CAD were included in the analysis. Those who had heart failure, heart transplants with either cardiac resynchronization therapy or implantable defibrillators were excluded. Twenty-two trials totaling 1095 participants were analyzed. We performed random-effects meta-analysis. In middle-aged participants, RT increased lower extremity muscle strength [standardized mean difference (SMD): 0.65, 95% confidence interval (CI): 0.35 to 0.95], upper extremity muscle strength (SMD: 0.73, 95% CI: 0.48 to 0.99) and peak oxygen consumption (VO2) [weight mean difference (WMD): 0.92mL/kg/min, 95% CI: 0.12 to 1.72], but did not improve mobility compared with the control. In elderly participants, RT increased lower extremity muscle strength (SMD: 0.63, 95% CI: 0.05 to 1.21), upper extremity muscle strength (SMD: 1.18, 95% CI: 0.56 to 1.80), and peak VO2 (WMD: 0.70mL/kg/min, 95% CI: 0.03 to 1.37), and improved mobility (SMD: 0.61, 95% CI: 0.21 to 1.01) compared with the control. Resistance training could increase exercise capacity and muscle strength in middle-aged and elderly patients, and mobility in elderly patients, with CAD. Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Restoration of Muscle Glycogen and Functional Capacity: Role of Post-Exercise Carbohydrate and Protein Co-Ingestion

PubMed Central

Alghannam, Abdullah F.; Betts, James A.

2018-01-01

The importance of post-exercise recovery nutrition has been well described in recent years, leading to its incorporation as an integral part of training regimes in both athletes and active individuals. Muscle glycogen depletion during an initial prolonged exercise bout is a main factor in the onset of fatigue and so the replenishment of glycogen stores may be important for recovery of functional capacity. Nevertheless, nutritional considerations for optimal short-term (3–6 h) recovery remain incompletely elucidated, particularly surrounding the precise amount of specific types of nutrients required. Current nutritional guidelines to maximise muscle glycogen availability within limited recovery are provided under the assumption that similar fatigue mechanisms (i.e., muscle glycogen depletion) are involved during a repeated exercise bout. Indeed, recent data support the notion that muscle glycogen availability is a determinant of subsequent endurance capacity following limited recovery. Thus, carbohydrate ingestion can be utilised to influence the restoration of endurance capacity following exhaustive exercise. One strategy with the potential to accelerate muscle glycogen resynthesis and/or functional capacity beyond merely ingesting adequate carbohydrate is the co-ingestion of added protein. While numerous studies have been instigated, a consensus that is related to the influence of carbohydrate-protein ingestion in maximising muscle glycogen during short-term recovery and repeated exercise capacity has not been established. When considered collectively, carbohydrate intake during limited recovery appears to primarily determine muscle glycogen resynthesis and repeated exercise capacity. Thus, when the goal is to optimise repeated exercise capacity following short-term recovery, ingesting carbohydrate at an amount of ≥1.2 g kg body mass−1·h−1 can maximise muscle glycogen repletion. The addition of protein to carbohydrate during post-exercise recovery may be

Functional Capacity in Adults With Cerebral Palsy: Lower Limb Muscle Strength Matters.

PubMed

Gillett, Jarred G; Lichtwark, Glen A; Boyd, Roslyn N; Barber, Lee A

2018-05-01

To investigate the relation between lower limb muscle strength, passive muscle properties, and functional capacity outcomes in adults with cerebral palsy (CP). Cross-sectional study. Tertiary institution biomechanics laboratory. Adults with spastic-type CP (N=33; mean age, 25y; range, 15-51y; mean body mass, 70.15±21.35kg) who were either Gross Motor Function Classification System (GMFCS) level I (n=20) or level II (n=13). Not applicable. Six-minute walk test (6MWT) distance (m), lateral step-up (LSU) test performance (total repetitions), timed up-stairs (TUS) performance (s), maximum voluntary isometric strength of plantar flexors (PF) and dorsiflexors (DF) (Nm.kg -1 ), and passive ankle joint and muscle stiffness. Maximum isometric PF strength independently explained 61% of variance in 6MWT performance, 57% of variance in LSU test performance, and 50% of variance in TUS test performance. GMFCS level was significantly and independently related to all 3 functional capacity outcomes, and age was retained as a significant independent predictor of LSU and TUS test performance. Passive medial gastrocnemius muscle fascicle stiffness and ankle joint stiffness were not significantly related to functional capacity measures in any of the multiple regression models. Low isometric PF strength was the most important independent variable related to distance walked on the 6MWT, fewer repetitions on the LSU test, and slower TUS test performance. These findings suggest lower isometric muscle strength contributes to the decline in functional capacity in adults with CP. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Visual Impairment does not Limit Training Effects in Development of Aerobic and Anaerobic Capacity in Tandem Cyclists

PubMed Central

Malwina, Kamelska Anna; Krzysztof, Mazurek; Piotr, Zmijewski

2015-01-01

The study aimed to investigate the differences in the effects of 7-month training on aerobic and anaerobic capacity in tandem cycling athletes with and without visual impairment. In this study, Polish elite (n=13) and sub-elite (n=13) visually impaired (VI) (n=13; 40.8 ±12.8 years) and properly sighted (PS) (n=13; 36.7 ±12.2 years) tandem-cycling athletes participated voluntarily in 7-month routine training. The following pre-/post-training measurements were conducted on separate days: maximal oxygen uptake (VO2max) was estimated with age correction using the Physical Working Capacity test on a bicycle ergometer according to the Astrand-Ryhming method. Maximal power output (Pmax) was evaluated using the Quebec test on a bicycle ergometer. At baseline, VO2max (47.8 ±14.1 vs 42.0 ±8.3 ml/kg/min, respectively) and Pmax (11.5 ±1.5 vs 11.5 ±1.0 W/kg) did not differ significantly between PS and VI cyclists. However, differences in aerobic capacity were considered as clinically significant. Two-way ANOVA revealed that after 7 month training, there were statistically significant increases in VO2max (p=0.003) and Pmax (p=0.009) among VI (VO2max, +9.1%; Pmax, +6.3%) and PS (VO2max, +9.1%; Pmax, +11.7%) cyclists, however, no time × visual impairment interaction effect was found (VO2max, p=0.467; Pmax, p=0.364). After training, VO2max (p=0.03), but not Pmax (p=0.13), was significantly greater in elite compared to sub-elite tandem cyclists. VI and PS tandem cyclists showed similar rates of improvement in VO2max and Pmax after 7-month training. VO2max was a significant determinant of success in tandem cycling. This is one of the first studies providing reference values for aerobic and anaerobic capacity in visually impaired cyclists. PMID:26834877

Comparison of basic physical fitness, aerobic capacity, and isokinetic strength between national and international level high school freestyle swimmers

PubMed Central

Bae, Young-Hyeon; Yu, Jae-Ho; Lee, Suk Min

2016-01-01

[Purpose] This study aimed to compare basic physical fitness, aerobic capacity, and isokinetic strength between international and national level freestyle high school student swimmers. [Subjects and Methods] A total of 28 participants (14 international level swimmers and 14 national level freestyle high school student swimmers) with no known pathology were included. We used a cross-sectional study to examine three variables: basic physical fitness, aerobic capacity, and isokinetic strength. [Results] The mean values of these variables in the international level swimmers were higher than those in the national level swimmers. Swimmers are generally physically fit with a good competition record. [Conclusion] An appropriate training program, which considers specific individual characteristics is likely to have a positive impact on the improvement of total physical fitness, and subsequently, on the performance of the freestyle high school swimmer. PMID:27134379

Trade-off between aerobic capacity and locomotor capability in an Antarctic pteropod

PubMed Central

Rosenthal, Joshua J. C.; Seibel, Brad A.; Dymowska, Agnieszka; Bezanilla, Francisco

2009-01-01

At −1.8 °C, the waters of Antarctica pose a formidable physiological barrier for most ectotherms. The few taxa that inhabit this zone have presumably made specific adjustments to their neuromuscular function and have enhanced their metabolic capacity. However, support for this assertion is equivocal and the details of specific compensations are largely unknown. This can generally be attributed to the fact that most Antarctic organisms are either too distantly related to their temperate relatives to permit direct comparisons (e.g., notothenioid fishes) or because they are not amenable to neuromuscular recording. Here, as a comparative model, we take advantage of 2 pelagic molluscs in the genus Clione to conduct a broadly integrative investigation on neuromuscular adaptation to the extreme cold. We find that for the Antarctic congener aerobic capacity is enhanced, but at a cost. To support a striking proliferation of mitochondria, the Antarctic species has shed a 2-gear swim system and the associated specialized neuromuscular components, resulting in greatly reduced scope for locomotor activity. These results suggest that polar animals have undergone substantial tissue-level reorganizations to accommodate their environment, which may reduce their capacity to acclimate to a changing climate. PMID:19325127

Enzymatic capacities of skeletal muscle - Effects of different types of training

NASA Technical Reports Server (NTRS)

Booth, F. W.; Hugman, G. R.

1981-01-01

Long-term adaptation mechanisms to maintain homeostasis at increased levels of exertion such as those caused by regular exercise are described. Mitochondrial changes have been found to be a result of endurance exercises, while mitochondrial responses to other types of exercise are small. Further discussion is devoted to long-term changes in glucose transport, hexokinase, phosphofructokinase, pyruvate kinase, and the increased sensitivity of an endurance trained muscle to insulin. Less lactate has been found to be produced by the skeletal muscles at the same work rate after adaptation to endurance exercise training, and the capacity for the flux of the two-carbon acetyl chain through the citric acid cycle increases in skeletal muscles in response to endurance training. Finally, endurance training is noted to result in glycogen sparing and an increase in the capacity to utilize fatty acids.

Effects of ovariectomy and intrinsic aerobic capacity on tissue-specific insulin sensitivity

PubMed Central

Park, Young-Min; Rector, R. Scott; Thyfault, John P.; Zidon, Terese M.; Padilla, Jaume; Welly, Rebecca J.; Meers, Grace M.; Morris, Matthew E.; Britton, Steven L.; Koch, Lauren G.; Booth, Frank W.; Kanaley, Jill A.

2015-01-01

High-capacity running (HCR) rats are protected against the early (i.e., ∼11 wk postsurgery) development of ovariectomy (OVX)-induced insulin resistance (IR) compared with low-capacity running (LCR) rats. The purpose of this study was to utilize the hyperinsulinemic euglycemic clamp to determine whether 1) HCR rats remain protected from OVX-induced IR when the time following OVX is extended to 27 wk and 2) tissue-specific glucose uptake differences are responsible for the protection in HCR rats under sedentary conditions. Female HCR and LCR rats (n = 40; aged ∼22 wk) randomly received either OVX or sham (SHM) surgeries and then underwent the clamp 27 wk following surgeries. [3-3H]glucose was used to determine glucose clearance, whereas 2-[14C]deoxyglucose (2-DG) was used to assess glucose uptake in skeletal muscle, brown adipose tissue (BAT), subcutaneous white adipose tissue (WAT), and visceral WAT. OVX decreased the glucose infusion rate and glucose clearance in both lines, but HCR had better insulin sensitivity than LCR (P < 0.05). In both lines, OVX significantly reduced glucose uptake in soleus and gastrocnemius muscles; however, HCR showed ∼40% greater gastrocnemius glucose uptake compared with LCR (P < 0.05). HCR also exhibited greater glucose uptake in BAT and visceral WAT compared with LCR (P < 0.05), yet these tissues were not affected by OVX in either line. In conclusion, OVX impairs insulin sensitivity in both HCR and LCR rats, likely driven by impairments in insulin-mediated skeletal muscle glucose uptake. HCR rats have greater skeletal muscle, BAT, and WAT insulin-mediated glucose uptake, which may aid in protection against OVX-associated insulin resistance. PMID:26646101

Effect of aerobic recovery intensity on delayed-onset muscle soreness and strength.

PubMed

Tufano, James J; Brown, Lee E; Coburn, Jared W; Tsang, Kavin K W; Cazas, Vanessa L; LaPorta, Joe W

2012-10-01

Because of the performance decrements associated with delayed-onset muscle soreness (DOMS), a treatment to alleviate its symptoms is of great interest. The purpose of this study was to investigate the effect of low vs. moderate-intensity aerobic recovery on DOMS and strength. Twenty-six women (22.11 ± 2.49 years; 60.33 ± 8.37 kg; and 163.83 ± 7.29 cm) were split into 3 different groups and performed a DOMS-inducing protocol of 60 eccentric actions of the knee extensors followed by 1 of three 20-minute recovery interventions: moderate-intensity cycling (n = 10), low-intensity cycling (LIC; n = 10), or seated rest (CON; n = 6) after the eccentric protocol. Pain scale (PS), isometric strength (ISO), and dynamic strength (PT) were recorded before (PRE), immediately post (IP), 24- (24h), 48- (48h), 72- (72h), and 96- (96h) hours after exercise. For PT, PRE, 48h, 72h, and 96h were significantly (p < 0.05) greater than IP values but not different from 24h. For PS, IP (4.83 ± 0.36) was greater than that for all other time periods, whereas 24h (2.91 ± 0.42), 48h (2.62 ± 0.53), and 72h (1.97 ± 0.49) were all greater than PRE (0.44 ± 0.19) values. Also, 24h and 48h were not different but were both greater than 72h and 96h (1.13 ± 0.32), whereas 72h was >96h. For ISO, neither CON nor LIC showed any significant difference across time. Moderate-intensity cycling showed no difference between PRE (189.88 ± 40.68), IP (193.75 ± 47.24), 24h (186.52 ± 53.55), or 48h (195.36 ± 55.06), but 72h (210.05 ± 53.57) and 96h (207.78 ± 59.99) were significantly >24h. The 72h was also greater than IP. Therefore, moderate-intensity aerobic recovery may be suggested after eccentric muscle actions.

Extrapulmonary features of bronchiectasis: muscle function, exercise capacity, fatigue, and health status.

PubMed

Ozalp, Ozge; Inal-Ince, Deniz; Calik, Ebru; Vardar-Yagli, Naciye; Saglam, Melda; Savci, Sema; Arikan, Hulya; Bosnak-Guclu, Meral; Coplu, Lutfi

2012-06-11

There are limited number of studies investigating extrapulmonary manifestations of bronchiectasis. The purpose of this study was to compare peripheral muscle function, exercise capacity, fatigue, and health status between patients with bronchiectasis and healthy subjects in order to provide documented differences in these characteristics for individuals with and without bronchiectasis. Twenty patients with bronchiectasis (43.5 ± 14.1 years) and 20 healthy subjects (43.0 ± 10.9 years) participated in the study. Pulmonary function, respiratory muscle strength (maximal expiratory pressure - MIP - and maximal expiratory pressure - MEP), and dyspnea perception using the Modified Medical Research Council Dyspnea Scale (MMRC) were determined. A six-minute walk test (6MWT) was performed. Quadriceps muscle, shoulder abductor, and hand grip strength (QMS, SAS, and HGS, respectively) using a hand held dynamometer and peripheral muscle endurance by a squat test were measured. Fatigue perception and health status were determined using the Fatigue Severity Scale (FSS) and the Leicester Cough Questionnaire (LCQ), respectively. Number of squats, 6MWT distance, and LCQ scores as well as lung function testing values and respiratory muscle strength were significantly lower and MMRC and FSS scores were significantly higher in patients with bronchiectasis than those of healthy subjects (p < 0.05). In bronchiectasis patients, QMS was significantly associated with HGS, MIP and MEP (p < 0.05). The 6MWT distance was significantly correlated to LCQ psychological score (p < 0.05). The FSS score was significantly associated with LCQ physical and total and MMRC scores (p < 0.05). The LCQ psychological score was significantly associated with MEP and 6MWT distance (p < 0.05). Peripheral muscle endurance, exercise capacity, fatigue and health status were adversely affected by the presence of bronchiectasis. Fatigue was associated with dyspnea and health status

Impact of Aerobic and Resistance Exercise on the Health of HIV-Infected Persons.

PubMed

Hand, Gregory A; Lyerly, G William; Jaggers, Jason R; Dudgeon, Wesley D

2009-11-01

Individuals infected with HIV experience numerous comorbidities caused by the disease progression and medications, lack of (or inability to perform) physical activity, malnutrition, or a combination of these causes. Common symptoms include loss of muscle mass, fatigue, lypodystrophy, lypoatrophy, and decreases in strength, functional capacity, and overall quality of life. Studies have shown that exercise is a potential treatment of many of these symptoms. Research suggests that exercise may produce beneficial physiological changes in the HIV-infected population such as improved body composition and increases in both strength and endurance. In addition, psychological conditions such as depression and anxiety have been shown to be positively affected by exercise. The purpose of this review is to examine the literature regarding effects of aerobic, resistance, and combined aerobic and resistance exercise training on HIV-infected individuals.

Combined aerobic and resistance training improves physical capacity in women treated for gynecological cancer.

PubMed

Hausmann, F; Iversen, V V; Kristoffersen, M; Gundersen, H; Johannsson, E; Vika, M

2018-04-14

The purpose of this study was to evaluate the effects of 16 weeks combined aerobic and resistance training, twice a week, on the physical performance in women treated for gynecological cancer. Sixty women (56.9 ± 13.3 years) who had completed curative treatment for gynecological cancer were divided into two groups: a physical training group (PT) (n = 29) or a control group (C) (n = 31). The PT group performed two sessions of combined aerobic and resistance training weekly for 16 weeks. Peak oxygen consumption (V̇O 2peak ) and one repetition maximum (1RM) of leg press, leg extension, and chest press were measured before group assignment, after 16 weeks and at the 1-year follow-up. A significant increase in V̇O 2peak (ml min -1  kg -1 ) (29.7 ± 8.0 vs. 31.3 ± 8.3, p = .009), leg press (kg) (113.0 ± 27.3 vs. 116.7 ± 29.2, p = .047), leg extension (kg) (44.2 ± 10.1 vs. 48.0 ± 10.6, p < .001), and chest press (kg) (24.5 ± 7.5 vs. 26.9 ± 8.2, p = .001) was seen in the PT group from pre- to post-measurement. The PT group maintained the improved aerobic condition and muscle strength 1 year after the training intervention. In the C group, there were no significant differences between pre- and post-measurements, but a significant decrease (28.2 ± 7.5 vs. 27.0 ± 7.3, p = .040) in the V̇O 2peak from post to 1-year follow-up measurements. Combined aerobic and resistance training twice a week in 16 weeks improves V̇O 2peak and maximal strength in women treated for gynecological cancer. The training effects were sustained after 1 year in the PT group.

Changes in mRNA levels for brain-derived neurotrophic factor after wheel running in rats selectively bred for high- and low-aerobic capacity

PubMed Central

Groves-Chapman, Jessica L.; Murray, Patrick S.; Stevens, Kristin L.; Monroe, Derek; Koch, Lauren G.; Britton, Steven L.; Holmes, Philip V.

2012-01-01

We evaluated levels of exercise-induced brain-derived neurotrophic factor (BDNF) messenger RNA (mRNA) within the hippocampal formation in rats selectively bred for 1) high intrinsic (i.e., untrained) aerobic capacity (High Capacity Runners, HCR), 2) low intrinsic aerobic capacity (Low Capacity Runners, LCR), and 3) unselected Sprague-Dawley (SD) rats with or without free access to running wheels for three weeks. The specific aim of the study was to determine whether a dose-response relationship exists between cumulative running distance and levels of BDNF mRNA. No additional treatments or behavioral manipulations were used. HCR, LCR, and SD rats were grouped by strain and randomly assigned to sedentary or activity (voluntary access to activity wheel) conditions. Animals were killed after 21 days of exposure to the assigned conditions. Daily running distances (mean ± standard deviation meters/d) during week three were: HCR (4726 ± 3220), SD (2293 ± 3461), LCR (672 ± 323). Regardless of strain, levels of BDNF mRNA in CA1 were elevated in wheel runners compared to sedentary rats and this difference persisted after adjustment for age (p=0.040). BDNF mRNA was not affected by intrinsic aerobic capacity and was not related to total running distance. The results support that BDNF mRNA expression is increased by unlimited access to activity wheel running for 3 weeks but is not dependent upon accumulated running distance. PMID:22024546

Morphometry, ultrastructure, myosin isoforms, and metabolic capacities of the "mini muscles" favoured by selection for high activity in house mice.

PubMed

Guderley, Helga; Houle-Leroy, Philippe; Diffee, Gary M; Camp, Dana M; Garland, Theodore

2006-07-01

Prolonged selective breeding of mice (Mus musculus) for high levels of voluntary wheel running has favoured an unusual phenotype ("mini muscles"), apparently caused by a single Mendelian recessive allele, in which most hind-limb muscles are markedly reduced in mass, but have increased mass-specific activities of mitochondrial enzymes. We examined whether these changes reflect changes in fibre size, number or ultrastructure in normal and "mini-muscle" mice within the two (of four) selectively bred lines (lab designations L3 and L6) that exhibit the phenotype at generations 26 and 27. In both lines, the gastrocnemius and plantaris muscles are smaller in mass (by >50% and 20%, respectively) in affected individuals. The mass-specific activities of mitochondrial enzymes in the gastrocnemius and plantaris muscles were increased in the mini phenotype in both lines, with stronger effects in the gastrocnemius muscle. In the gastrocnemius, the % myosin heavy chain (MHC) IIb was reduced by 50% in L3 and by 30% in L6, whereas the % MHC IIa and I were higher, particularly in L3. Fibre number in the plantaris muscle did not significantly differ between mini and normal muscles, although muscle mass was a significant positive correlate of fibre number. Small fibres were more abundant in mini than normal muscles in L3. Mitochondrial volume density was significantly higher in mini than normal muscle fibres in L3, but not in L6. Microscopy revealed a surprising attribute of the mini muscles: an abundance of small, minimally differentiated, myofibril-containing cells positioned in a disorderly fashion, particularly in the surface layer. We hypothesise that these unusual cells may be satellite cells or type IIb fibres that did not complete their differentiation. Together, these observations suggest that mice with the mini phenotype have reduced numbers of type IIb fibres in many of their hind-limb muscles, leading to a decrease in mass and an increase in mass-specific aerobic capacity

Influence of exercise training on the oxidative capacity of rat abdominal muscles

NASA Technical Reports Server (NTRS)

Uribe, J. M.; Stump, C. S.; Tipton, C. M.; Fregosi, R. F.

1992-01-01

Our purpose was to determine if endurance exercise training would increase the oxidative capacity of the abdominal expiratory muscles of the rat. Accordingly, 9 male rats were subjected to an endurance training protocol (1 h/day, 6 days/week, 9 weeks) and 9 litter-mates served as controls. Citrate synthase (CS) activity was used as an index of oxidative capacity, and was determined in the following muscles: soleus, plantaris, costal diaphragm, crural diaphragm, and in all four abdominal muscles: rectus abdominis, transversus abdominis, external oblique, and internal oblique. Compared to their non-trained litter-mates, the trained rats had higher peak whole body oxygen consumption rates (+ 16%) and CS activities in plantaris (+34%) and soleus (+36%) muscles. Thus, the training program caused substantial systemic and locomotor muscle adaptations. The CS activity of costal diaphragm was 20% greater in the trained animals, but no difference was observed in crural diaphragm. The CS activity in the abdominal muscles was less than one-half of that in locomotor and diaphragm muscles, and there were no significant changes with training except in the rectus abdominis where a 26% increase was observed. The increase in rectus abdominis CS activity may reflect its role in postural support and/or locomotion, as none of the primary expiratory pumping muscles adapted to the training protocol. The relatively low levels of CS activity in the abdominal muscles suggests that they are not recruited frequently at rest, and the lack of an increase with training indicates that these muscles do not contribute significantly to the increased ventilatory activity accompanying exercise in the rat.

Assessment of Maximum Aerobic Capacity and Anaerobic Threshold of Elite Ballet Dancers.

PubMed

Wyon, Matthew A; Allen, Nick; Cloak, Ross; Beck, Sarah; Davies, Paul; Clarke, Frances

2016-09-01

An athlete's cardiorespiratory profile, maximal aerobic capacity, and anaerobic threshold is affected by training regimen and competition demands. The present study aimed to ascertain whether there are company rank differences in maximal aerobic capacity and anaerobic threshold in elite classical ballet dancers. Seventy-four volunteers (M 34, F 40) were recruited from two full-time professional classical ballet companies. All participants completed a continuous incremental treadmill protocol with a 1-km/hr speed increase at the end of each 1-min stage until termination criteria had been achieved (e.g., voluntary cessation, respiratory exchange ratio <1.15, HR ±5 bpm of estimated HRmax). Peak VO2 (5-breathe smooth) was recorded and anaerobic threshold calculated using ventilatory curve and ventilatory equivalents methods. Statistical analysis reported between-subject effects for gender (F1,67=35.18, p<0.001) and rank (F1,67=8.67, p<0.001); post hoc tests reported soloists (39.5±5.15 mL/kg/min) as having significantly lower VO2 peak than artists (45.9±5.75 mL/kg/min, p<0.001) and principal dancers (48.07±3.24 mL/kg/min, p<0.001). Significant differences in anaerobic threshold were reported for age (F1,67=7.68, p=0.008) and rank (F1,67=3.56, p=0.034); post hoc tests reported artists (75.8±5.45%) having significantly lower anaerobic threshold than soloists (80.9±5.71, p<0.01) and principals (84.1±4.84%, p<0.001). The observed differences in VO2 peak and anaerobic threshold between the ranks in ballet companies are probably due to the different rehearsal and performance demands.

Effect of increasing maximal aerobic exercise on serum muscles enzymes in professional field hockey players.

PubMed

Hazar, Muhsin; Otag, Aynur; Otag, Ilhan; Sezen, Mehmet; Sever, Ozan

2014-11-04

Exercise results in oxidative enzyme increase and micro-injuries in skeletal muscles. The aim of this study was to investigate the effect of maximal aerobic exercise on serum muscle enzymes in professional field hockey players. This study aims to determine the effect of increasing maximal aerobic exercise on creatine kinase (CK), creatine kinase-MB (CK-MB), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) serum levels. 31 young professional field hockey players (13 female and 18 male players) volunteered for this study. All participants underwent the shuttle run test. Blood samples were taken from each participant before the shuttle run test. Post test blood samples were taken immediately after exercise and one hour after respectively. Pre and post test CK, CK-MB, AST and ALT values were measured by means of auto analyzer using original kits. The acute post test measure of the CK level increased in male (p=0.002) and female (p=0.00) sportsmen. CK-MB values obtained one hour after the exercise was lower than those before the exercise in males (p=0.02). In females (p=0.017) and males (p=0.05) AST activity significantly increased immediately after exercise and decreased to resting activity 1 h recovery. ALT significantly increased immediately after exercise in female (p=0.03) and male (p=0.00) athletes and after 1 h recovery ALT activities decreased below resting values. The timing and severity of exercise used in our study increased CK values, decreased CK-MB values and AST, ALT values increased in female and male field hockey players.

Comparison of the effects on dynamic balance and aerobic capacity between objective and subjective methods of high-intensity robot-assisted gait training in chronic stroke patients: a randomized controlled trial.

PubMed

Bae, Young-Hyeon; Lee, Suk Min; Ko, Mansoo

2017-05-01

Robot-assisted gait training (RAGT) is effective for improving dynamic balance and aerobic capacity, but previous RAGT method does not set suitable training intensity. Recently, high-intensity treadmill gait training at 70% of heart rate reserve (HRR) was used for improving aerobic capacity and dynamic balance. This study was designed to compare the effectiveness between objective and subjective methods of high-intensity RAGT for improving dynamic balance and aerobic capacity in chronic stroke. Subjects were randomly allocated into experimental (n = 17) and control (n = 17) groups. The experimental group underwent high-intensity RAGT at 70% of HRR, whereas the control group underwent high-intensity RAGT at an RPE of 15. Both groups received their assigned training for 30 min per session, 3 days per week for 6 weeks. All subjects also received an additional 30 min of conventional physical therapy. Before and after each of the 18 sessions, the dynamic balance and aerobic capacity of all subjects were evaluated by a blinded examiner. After training, Berg Balance Scale (BBS) and Timed Up and Go Test scores, VO 2 max, and VO 2 max/kg were significantly increased in both groups (p < 0.05). These variables in experimental group were significantly greater than control group. However, the BBS score was not significantly different between both groups. All subjects completed high-intensity RAGT. No adverse effect of training was observed in both groups. High-intensity RAGT at 70% of HRR significantly improved dynamic balance and aerobic capacity more than RAGT at RPE of 15. These results suggest that high-intensity RAGT at 70% of HRR is safe and effective for improving dynamic balance and aerobic capacity in chronic stroke.

Does Aerobic Exercise Influence Intrinsic Brain Activity? An Aerobic Exercise Intervention among Healthy Old Adults

PubMed Central

Flodin, Pär; Jonasson, Lars S.; Riklund, Katrin; Nyberg, Lars; Boraxbekk, C. J.

2017-01-01

Previous studies have indicated that aerobic exercise could reduce age related decline in cognition and brain functioning. Here we investigated the effects of aerobic exercise on intrinsic brain activity. Sixty sedentary healthy males and females (64–78 years) were randomized into either an aerobic exercise group or an active control group. Both groups recieved supervised training, 3 days a week for 6 months. Multimodal brain imaging data was acquired before and after the intervention, including 10 min of resting state brain functional magnetic resonance imaging (rs-fMRI) and arterial spin labeling (ASL). Additionally, a comprehensive battery of cognitive tasks assessing, e.g., executive function and episodic memory was administered. Both the aerobic and the control group improved in aerobic capacity (VO2-peak) over 6 months, but a significant group by time interaction confirmed that the aerobic group improved more. Contrary to our hypothesis, we did not observe any significant group by time interactions with regard to any measure of intrinsic activity. To further probe putative relationships between fitness and brain activity, we performed post hoc analyses disregarding group belongings. At baseline, VO2-peak was negativly related to BOLD-signal fluctuations (BOLDSTD) in mid temporal areas. Over 6 months, improvements in aerobic capacity were associated with decreased connectivity between left hippocampus and contralateral precentral gyrus, and positively to connectivity between right mid-temporal areas and frontal and parietal regions. Independent component analysis identified a VO2-related increase in coupling between the default mode network and left orbitofrontal cortex, as well as a decreased connectivity between the sensorimotor network and thalamus. Extensive exploratory data analyses of global efficiency, connectome wide multivariate pattern analysis (connectome-MVPA), as well as ASL, did not reveal any relationships between aerobic fitness and intrinsic

Does Aerobic Exercise Influence Intrinsic Brain Activity? An Aerobic Exercise Intervention among Healthy Old Adults.

PubMed

Flodin, Pär; Jonasson, Lars S; Riklund, Katrin; Nyberg, Lars; Boraxbekk, C J

2017-01-01

Previous studies have indicated that aerobic exercise could reduce age related decline in cognition and brain functioning. Here we investigated the effects of aerobic exercise on intrinsic brain activity. Sixty sedentary healthy males and females (64-78 years) were randomized into either an aerobic exercise group or an active control group. Both groups recieved supervised training, 3 days a week for 6 months. Multimodal brain imaging data was acquired before and after the intervention, including 10 min of resting state brain functional magnetic resonance imaging (rs-fMRI) and arterial spin labeling (ASL). Additionally, a comprehensive battery of cognitive tasks assessing, e.g., executive function and episodic memory was administered. Both the aerobic and the control group improved in aerobic capacity (VO 2 -peak) over 6 months, but a significant group by time interaction confirmed that the aerobic group improved more. Contrary to our hypothesis, we did not observe any significant group by time interactions with regard to any measure of intrinsic activity. To further probe putative relationships between fitness and brain activity, we performed post hoc analyses disregarding group belongings. At baseline, VO 2 -peak was negativly related to BOLD-signal fluctuations (BOLD STD ) in mid temporal areas. Over 6 months, improvements in aerobic capacity were associated with decreased connectivity between left hippocampus and contralateral precentral gyrus, and positively to connectivity between right mid-temporal areas and frontal and parietal regions. Independent component analysis identified a VO 2 -related increase in coupling between the default mode network and left orbitofrontal cortex, as well as a decreased connectivity between the sensorimotor network and thalamus. Extensive exploratory data analyses of global efficiency, connectome wide multivariate pattern analysis (connectome-MVPA), as well as ASL, did not reveal any relationships between aerobic fitness and

Inspiratory muscle training improves respiratory muscle strength, functional capacity and quality of life in patients with chronic kidney disease: a systematic review.

PubMed

de Medeiros, Ana Irene Carlos; Fuzari, Helen Kerlen Bastos; Rattesa, Catarina; Brandão, Daniella Cunha; de Melo Marinho, Patrícia Érika

2017-04-01

Does inspiratory muscle training improve respiratory muscle strength, functional capacity, lung function and quality of life of patients with chronic kidney disease? Does inspiratory muscle training improve these outcomes more than breathing exercises? Systematic review and meta-analysis of randomised trials. People with chronic kidney disease undergoing dialysis treatment. The primary outcomes were: maximal inspiratory pressure, maximal expiratory pressure, and distance covered on the 6-minute walk test. The secondary outcomes were: forced vital capacity, forced expiratory volume in the first second (FEV 1 ), and quality of life. The search identified four eligible studies. The sample consisted of 110 participants. The inspiratory muscle training used a Threshold ® or PowerBreathe ® device, with a load ranging from 30 to 60% of the maximal inspiratory pressure and lasting from 6 weeks to 6 months. The studies showed moderate to high risk of bias, and the quality of the evidence was rated low or very low, due to the studies' methodological limitations. The meta-analysis showed that inspiratory muscle training significantly improved maximal inspiratory pressure (MD 23 cmH 2 O, 95% CI 16 to 29) and the 6-minute walk test distance (MD 80m, 95% CI 41 to 119) when compared with controls. Significant benefits in lung function and quality of life were also identified. When compared to breathing exercises, significant benefits were identified in maximal expiratory pressure (MD 6 cmH 2 O, 95% CI 2 to 10) and FEV 1 (MD 0.24litres 95% CI 0.14 to 0.34), but not maximal inspiratory pressure or forced vital capacity. In patients with chronic renal failure on dialysis, inspiratory muscle training with a fixed load significantly improves respiratory muscle strength, functional capacity, lung function and quality of life. The evidence for these benefits may be influenced by some sources of bias. PROSPERO (CRD 42015029986). [de Medeiros AIC, Fuzari HKB, Rattesa C, Brandão DC, de

Changes in aerobic capacity and glycaemic control in response to reduced-exertion high-intensity interval training (REHIT) are not different between sedentary men and women.

PubMed

Metcalfe, Richard S; Tardif, Nicolas; Thompson, Dylan; Vollaard, Niels B J

2016-11-01

Previously it has been reported that reduced-exertion high-intensity interval training (REHIT; total training time of 3 × 10 min per week) improves maximal aerobic capacity in both sedentary men and women, but improves insulin sensitivity in men only. The aim of the present study was to determine whether there is a true sex difference in response to REHIT, or that these findings can be explained by the large interindividual variability in response inherent to all exercise training. Thirty-five sedentary participants (18 women; mean ± SD age for men and women, respectively: age, 33 ± 9 and 36 ± 9 years; body mass index, 25.1 ± 2.1 and 24.1 ± 3.5 kg·m -2 ; maximal aerobic capacity, 38.6 ± 8.3 and 31.6 ± 4.6 mL·kg -1 ·min -1 ) completed a 6-week REHIT programme consisting of eighteen 10-min unloaded cycling sessions with 1 (first session) or 2 (all other sessions) "all-out" 10-20-s sprints against a resistance of 5% of body mass. Maximal aerobic capacity and oral glucose tolerance test-derived insulin sensitivity were determined before and after training. REHIT was associated with an increase in maximal aerobic capacity (2.54 ± 0.65 vs. 2.78 ± 0.68 L·min -1 , main effect of time: p < 0.01), a trend toward reduced plasma insulin area-under-the-curve (AUC; 6.7 ± 4.8 vs. 6.1 ± 4.0 IU·min -1 ·mL -1 , p = 0.096), but no significant change in plasma glucose AUC or the Cederholm index of insulin sensitivity. Substantial interindividual variability in response to REHIT was observed for all variables, but there was no significant effect of sex. In conclusion, REHIT improves the key health marker of aerobic capacity within a minimal total training time-commitment. There is large interindividual variability in responses to REHIT, but sex differences in the responses are not apparent.

Maternal obesity reduces oxidative capacity in fetal skeletal muscle of Japanese macaques

PubMed Central

McCurdy, Carrie E.; Hetrick, Byron; Houck, Julie; Drew, Brian G.; Kaye, Spencer; Lashbrook, Melanie; Bergman, Bryan C.; Takahashi, Diana L.; Dean, Tyler A.; Gertsman, Ilya; Hansen, Kirk C.; Philp, Andrew; Hevener, Andrea L.; Chicco, Adam J.; Aagaard, Kjersti M.; Grove, Kevin L.; Friedman, Jacob E.

2016-01-01

Maternal obesity is proposed to alter the programming of metabolic systems in the offspring, increasing the risk for developing metabolic diseases; however, the cellular mechanisms remain poorly understood. Here, we used a nonhuman primate model to examine the impact of a maternal Western-style diet (WSD) alone, or in combination with obesity (Ob/WSD), on fetal skeletal muscle metabolism studied in the early third trimester. We find that fetal muscle responds to Ob/WSD by upregulating fatty acid metabolism, mitochondrial complex activity, and metabolic switches (CPT-1, PDK4) that promote lipid utilization over glucose oxidation. Ob/WSD fetuses also had reduced mitochondrial content, diminished oxidative capacity, and lower mitochondrial efficiency in muscle. The decrease in oxidative capacity and glucose metabolism was persistent in primary myotubes from Ob/WSD fetuses despite no additional lipid-induced stress. Switching obese mothers to a healthy diet prior to pregnancy did not improve fetal muscle mitochondrial function. Lastly, while maternal WSD alone led only to intermediary changes in fetal muscle metabolism, it was sufficient to increase oxidative damage and cellular stress. Our findings suggest that maternal obesity or WSD, alone or in combination, leads to programmed decreases in oxidative metabolism in offspring muscle. These alterations may have important implications for future health. PMID:27734025

2014 Bone and Muscle Risks Standing Review Panel

NASA Technical Reports Server (NTRS)

Steinberg, Susan; Glowacki, Julie; Gregor, Robert; Cullen, Diane; Drake, Almond; Enoka, Roger; Hanley, Edward, Jr.; Kraemer, William; Raven, Peter; Sumner, D. Rick

2015-01-01

The 2014 Bone and Muscle Risks Standing Review Panel (from here on referred to as the SRP) met for a site visit in Houston, TX on December 17 - 18, 2014. The SRP reviewed the updated Evidence Reports for the Risk of Impaired Performance Due to Reduced Muscle Mass, Strength and Endurance and (from here on referred to as the 2014 Muscle Evidence Report) and the Risk of Reduced Physical Performance Capabilities Due to Reduced Aerobic Capacity (from here on referred to as the 2014 Aerobic Evidence Report), as well as the Research Plans for these Risks. The SRP agreed the Evidence Reports were comprehensive and described a logical sequence of steps taken by NASA and the scientific community to address the risk of impaired performance as a result of muscle atrophy, i.e., reduced muscle mass, loss of strength and loss of endurance in a microgravity environment. The interdependence of the three physiological systems represented by this SRP (i.e., skeletal, muscular and cardiovascular) supports a level of discussion on system integration that is now appreciated by the Chief Scientist of the Human Research Program (HRP). The Evidence Reports cover the effects of microgravity on muscle, ranging from the cellular and molecular levels to whole muscle function. The reports also addressed other factors related to muscle (e.g., neural influences, insulin resistance, heat stress, and nutrition) that will serve as a basis for future discussions on the integration of physiological systems and the response to microgravity. The SRP agreed the Evidence Reports were balanced, provided insight to muscle function, and laid the foundation for the integrated approach now taken by the SRP.

Glutamate Impairs Mitochondria Aerobic Respiration Capacity and Enhances Glycolysis in Cultured Rat Astrocytes.

PubMed

Yan, Xu; Shi, Zhong Fang; Xu, Li Xin; Li, Jia Xin; Wu, Min; Wang, Xiao Xuan; Jia, Mei; Dong, Li Ping; Yang, Shao Hua; Yuan, Fang

2017-01-01

To study the effect of glutamate on metabolism, shifts in glycolysis and lactate release in rat astrocytes. After 10 days, secondary cultured astrocytes were treated with 1 mmol/L glutamate for 1 h, and the oxygen consumption rates (OCR) and extra cellular acidification rate (ECAR) was analyzed using a Seahorse XF 24 Extracellular Flux Analyzer. Cell viability was then evaluated by MTT assay. Moreover, changes in extracellular lactate concentration induced by glutamate were tested with a lactate detection kit. Compared with the control group, treatment with 1 mmol/L glutamate decreased the astrocytes' maximal respiration and spare respiratory capacity but increased their glycolytic capacity and glycolytic reserve. Further analysis found that 1-h treatment with different concentrations of glutamate (0.1-1 mmol/L) increased lactate release from astrocytes, however the cell viability was not affected by the glutamate treatment. The current study provided direct evidence that exogenous glutamate treatment impaired the mitochondrial respiration capacity of astrocytes and enhanced aerobic glycolysis, which could be involved in glutamate injury or protection mechanisms in response to neurological disorders. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Capacity of small groups of muscles to accomplish precision grasping tasks.

PubMed

Towles, Joseph D; Valero-Cuevas, Francisco J; Hentz, Vincent R

2013-01-01

An understanding of the capacity or ability of various muscle groups to generate endpoint forces that enable grasping tasks could provide a stronger biomechanical basis for the design of reconstructive surgery or rehabilitation for the treatment of the paralyzed or paretic hand. We quantified two-dimensional endpoint force distributions for every combination of the muscles of the index finger, in cadaveric specimens, to understand the capability of muscle groups to produce endpoint forces that accomplish three common types of grasps-tripod, tip and lateral pinch-characterized by a representative level of Coulomb friction. We found that muscle groups of 4 or fewer muscles were capable of generating endpoint forces that enabled performance of each of the grasping tasks examined. We also found that flexor muscles were crucial to accomplish tripod pinch; intrinsic muscles, tip pinch; and the dorsal interosseus muscle, lateral pinch. The results of this study provide a basis for decision making in the design of reconstructive surgeries and rehabilitation approaches that attempt to restore the ability to perform grasping tasks with small groups of muscles.

Systemic oxidative-nitrosative-inflammatory stress during acute exercise in hypoxia; implications for microvascular oxygenation and aerobic capacity.

PubMed

Woodside, John D S; Gutowski, Mariusz; Fall, Lewis; James, Philip E; McEneny, Jane; Young, Ian S; Ogoh, Shigehiko; Bailey, Damian M

2014-12-01

Exercise performance in hypoxia may be limited by a critical reduction in cerebral and skeletal tissue oxygenation, although the underlying mechanisms remain unclear. We examined whether increased systemic free radical accumulation during hypoxia would be associated with elevated microvascular deoxygenation and reduced maximal aerobic capacity (V̇O2 max ). Eleven healthy men were randomly assigned single-blind to an incremental semi-recumbent cycling test to determine V̇O2 max in both normoxia (21% O2) and hypoxia (12% O2) separated by a week. Continuous-wave near-infrared spectroscopy was employed to monitor concentration changes in oxy- and deoxyhaemoglobin in the left vastus lateralis muscle and frontal cerebral cortex. Antecubital venous blood samples were obtained at rest and at V̇O2 max to determine oxidative (ascorbate radical by electron paramagnetic resonance spectroscopy), nitrosative (nitric oxide metabolites by ozone-based chemiluminescence and 3-nitrotyrosine by enzyme-linked immunosorbent assay) and inflammatory stress biomarkers (soluble intercellular/vascular cell adhesion 1 molecules by enzyme-linked immunosorbent assay). Hypoxia was associated with increased cerebral and muscle tissue deoxygenation and lower V̇O2 max (P < 0.05 versus normoxia). Despite an exercise-induced increase in oxidative-nitrosative-inflammatory stress, hypoxia per se did not have an additive effect (P > 0.05 versus normoxia). Consequently, we failed to observe correlations between any metabolic, haemodynamic and cardiorespiratory parameters (P > 0.05). Collectively, these findings suggest that altered free radical metabolism cannot explain the elevated microvascular deoxygenation and corresponding lower V̇O2 max in hypoxia. Further research is required to determine whether free radicals when present in excess do indeed contribute to the premature termination of exercise in hypoxia. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

Water-based aerobic and combined training in elderly women: Effects on functional capacity and quality of life.

PubMed

Silva, Mariana Ribeiro; Alberton, Cristine Lima; Portella, Elisa Gouvêa; Nunes, Gabriela Neves; Martin, Daniela Gomez; Pinto, Stephanie Santana

2018-06-01

This study aimed to investigate the effects of two water-based training programs (aerobic and combined) and a non-periodized physical activity program on functional capacity and quality of life (QoL) of elderly women. Forty-one elderly female volunteers (65 ± 4 years) were divided into three groups: aerobic training group (WBA, n = 13), combined training (sequence: resistance/aerobic; WBC; n = 11) and a control group of non-periodized physical activity program (CG, n = 9). The participants performed the water-based trainings twice a week for 12 weeks. The resistance training sets were performed at maximal effort and the aerobic training was performed in the percentage of the heart rate corresponding to the anaerobic threshold (85-110%) determined in an aquatic progressive test. Assessments of QoL perception (WHOQOL-BREF) and functional tests 30-Second Chair Stand, 6-Minute Walk and 8-Foot Up-and-go were performed before and after training. The data were analyzed using Generalized Estimating Equations (GEE), and Bonferroni post-hoc test (α = 0.05). In CG, QoL perception in the physical domain decreased (12 ± 10%) and there was no difference in the other domains. On the other hand, QoL perception was significantly increased in the water-based training groups after the training period in the physical (WBC: 13 ± 16%), psychological (WBA: 9 ± 16%; WBC: 10 ± 11%), social relationships (WBA: 19 ± 42%; WBC: 16 ± 21%) and environmental (WBA: 10 ± 17%; WBC: 16 ± 28%) domains and overall QoL (WBA: 17 ± 22%). No significant difference was observed in the physical domain for WBA and in the overall for WBC. Significant improvements were observed for all groups in the functional tests 30-Second Chair Stand (WBA: 32 ± 11%; WBC: 24 ± 14%; CG: 20 ± 9), 6-Minute Walk (WBA: 10 ± 7%; WBC: 7 ± 6%; CG: 7 ± 5%) and 8-Foot Up-and-go (WBA: 11 ± 5%; WBC: 10 ± 9%; CG: 10 ± 6

Effects of a hydrotherapy programme on symbolic and complexity dynamics of heart rate variability and aerobic capacity in fibromyalgia patients.

PubMed

Zamunér, Antonio Roberto; Andrade, Carolina P; Forti, Meire; Marchi, Andrea; Milan, Juliana; Avila, Mariana Arias; Catai, Aparecida Maria; Porta, Alberto; Silva, Ester

2015-01-01

To evaluate the effects of a hydrotherapy programme on aerobic capacity and linear and non-linear dynamics of heart rate variability (HRV) in women with fibromyalgia syndrome (FMS). 20 women with FMS and 20 healthy controls (HC) took part in the study. The FMS group was evaluated at baseline and after a 16-week hydrotherapy programme. All participants underwent cardiopulmonary exercise testing on a cycle ergometer and RR intervals recording in supine and standing positions. The HRV was analysed by linear and non-linear methods. The current level of pain, the tender points, the pressure pain threshold and the impact of FMS on quality of life were assessed. The FMS patients presented higher cardiac sympathetic modulation, lower vagal modulation and lower complexity of HRV in supine position than the HC. Only the HC decreased the complexity indices of HRV during orthostatic stimulus. After a 16-week hydrotherapy programme, the FMS patients increased aerobic capacity, decreased cardiac sympathetic modulation and increased vagal modulation and complexity dynamics of HRV in supine. The FMS patients also improved their cardiac autonomic adjustments to the orthostatic stimulus. Associations between improvements in non-linear dynamics of HRV and improvements in pain and in the impact of FMS on quality of life were found. A 16-week hydrotherapy programme proved to be effective in ameliorating symptoms, aerobic functional capacity and cardiac autonomic control in FMS patients. Improvements in the non-linear dynamics of HRV were related to improvements in pain and in the impact of FMS on quality of life.

Caffeine stimulates voluntary wheel running in mice without increasing aerobic capacity.

PubMed

Claghorn, Gerald C; Thompson, Zoe; Wi, Kristianna; Van, Lindsay; Garland, Theodore

2017-03-01

The "energy drink" Red Bull and the "sports drink" Gatorade are often marketed to athletes, with claims that they cause performance gains. However, both are high in sugars, and also consumed by non-athletes. Few studies have addressed the effects of these drinks or their biologically active components in rodent exercise models. We used three experiments to test effects on both voluntary exercise behavior and maximal aerobic capacity in lines of mice known to differ in "athletic" traits. Mice from four replicate High Runner (HR) lines have been selectively bred for voluntary running on wheels, and run approximately three times as many revolutions per day as do mice from four non-selected Control (C) lines. HR mice also have higher endurance and maximal oxygen consumption (VO 2 max) during forced treadmill exercise. In Experiment 1, we tested the hypothesis that Gatorade or Red Bull might cause or allow mice to increase their voluntary wheel running. On days 5 and 6 of 6days of wheel access, as is used to select breeders, HR mice ran 3.3-fold more than C, and females ran 1.2-fold more than males, with no linetype by sex interaction. On day 7, mice were administered Gatorade, Red Bull or tap water. During the subsequent 19-hour period, Gatorade had no statistical effect on running, but Red Bull significantly increased distance run by both sexes and in both HR and C lines. The increase in distance run caused by Red Bull was attributable to time spent running, not an increase in mean (or maximum) speed. As previous studies have found that sucrose alone does not generally increase wheel running, we tested two other active ingredients in Red Bull, caffeine and taurine, in Experiment 2. With a similar testing protocol, caffeine alone and caffeine+taurine increased running by about half the magnitude of Red Bull. In Experiment 3, we tested the hypothesis that Red Bull or caffeine alone can increase physiological performance ability during aerobic exercise, measured as VO 2

Gut microbiota are linked to increased susceptibility to hepatic steatosis in low-aerobic-capacity rats fed an acute high-fat diet.

PubMed

Panasevich, Matthew R; Morris, E M; Chintapalli, S V; Wankhade, U D; Shankar, K; Britton, S L; Koch, L G; Thyfault, J P; Rector, R S

2016-07-01

Poor aerobic fitness is linked to nonalcoholic fatty liver disease and increased all-cause mortality. We previously found that rats with a low capacity for running (LCR) that were fed an acute high-fat diet (HFD; 45% kcal from fat) for 3 days resulted in positive energy balance and increased hepatic steatosis compared with rats that were highly aerobically fit with a high capacity for running (HCR). Here, we tested the hypothesis that poor physiological outcomes in LCR rats following acute HFD feeding are associated with alterations in cecal microbiota. LCR rats exhibited greater body weight, feeding efficiency, 3 days of body weight change, and liver triglycerides after acute HFD feeding compared with HCR rats. Furthermore, compared with HCR rats, LCR rats exhibited reduced expression of intestinal tight junction proteins. Cecal bacterial 16S rDNA revealed that LCR rats had reduced cecal Proteobacteria compared with HCR rats. Microbiota of HCR rats consisted of greater relative abundance of Desulfovibrionaceae and unassigned genera within this family, suggesting increased reduction of endogenous mucins and proteins. Although feeding rats an acute HFD led to reduced Firmicutes in both strains, short-chain fatty acid-producing Phascolarctobacterium was reduced in LCR rats. In addition, Ruminococcae and Ruminococcus were negatively correlated with energy intake in the LCR/HFD rats. Predicted metagenomic function suggested that LCR rats had a greater capacity to metabolize carbohydrate and energy compared with HCR rats. Overall, these data suggest that the populations and metabolic capacity of the microbiota in low-aerobically fit LCR rats may contribute to their susceptibility to acute HFD-induced hepatic steatosis and poor physiologic outcomes.

Gut microbiota are linked to increased susceptibility to hepatic steatosis in low-aerobic-capacity rats fed an acute high-fat diet

PubMed Central

Panasevich, Matthew R.; Morris, E. M.; Chintapalli, S. V.; Wankhade, U. D.; Shankar, K.; Britton, S. L.; Koch, L. G.; Thyfault, J. P.

2016-01-01

Poor aerobic fitness is linked to nonalcoholic fatty liver disease and increased all-cause mortality. We previously found that rats with a low capacity for running (LCR) that were fed an acute high-fat diet (HFD; 45% kcal from fat) for 3 days resulted in positive energy balance and increased hepatic steatosis compared with rats that were highly aerobically fit with a high capacity for running (HCR). Here, we tested the hypothesis that poor physiological outcomes in LCR rats following acute HFD feeding are associated with alterations in cecal microbiota. LCR rats exhibited greater body weight, feeding efficiency, 3 days of body weight change, and liver triglycerides after acute HFD feeding compared with HCR rats. Furthermore, compared with HCR rats, LCR rats exhibited reduced expression of intestinal tight junction proteins. Cecal bacterial 16S rDNA revealed that LCR rats had reduced cecal Proteobacteria compared with HCR rats. Microbiota of HCR rats consisted of greater relative abundance of Desulfovibrionaceae and unassigned genera within this family, suggesting increased reduction of endogenous mucins and proteins. Although feeding rats an acute HFD led to reduced Firmicutes in both strains, short-chain fatty acid-producing Phascolarctobacterium was reduced in LCR rats. In addition, Ruminococcae and Ruminococcus were negatively correlated with energy intake in the LCR/HFD rats. Predicted metagenomic function suggested that LCR rats had a greater capacity to metabolize carbohydrate and energy compared with HCR rats. Overall, these data suggest that the populations and metabolic capacity of the microbiota in low-aerobically fit LCR rats may contribute to their susceptibility to acute HFD-induced hepatic steatosis and poor physiologic outcomes. PMID:27288420

Effect of glycine propionyl-L-carnitine on aerobic and anaerobic exercise performance.

PubMed

Smith, Webb A; Fry, Andrew C; Tschume, Lesley C; Bloomer, Richard J

2008-02-01

The purpose of this study was to evaluate the effect of glycine propionyl-L-carnitine (GPLC) supplementation and endurance training for 8 wk on aerobic- and anaerobic-exercise performance in healthy men and women (age 18-44 yr). Participants were randomly assigned to 1 of 3 groups: placebo (n=9), 1 g/d GPLC (n=11), or 3 g/d GPLC (n=12), in a double-blind fashion. Muscle carnitine (vastus lateralis), VO(2peak), exercise time to fatigue, anaerobic threshold, anaerobic power, and total work were measured at baseline and after an 8-wk aerobic-training program. There were no statistical differences (p> .05) between or within the 3 groups for any performance-related variable or muscle carnitine concentrations after 8 wk of supplementation and training. These results suggest that up to 3 g/d GPLC for 8 wk in conjunction with aerobic-exercise training is ineffective for increasing muscle carnitine content and has no significant effects on aerobic- or anaerobic-exercise performance.

Vegetarians have a reduced skeletal muscle carnitine transport capacity.

PubMed

Stephens, Francis B; Marimuthu, Kanagaraj; Cheng, Yi; Patel, Nitin; Constantin, Despina; Simpson, Elizabeth J; Greenhaff, Paul L

2011-09-01

Ninety-five percent of the body carnitine pool resides in skeletal muscle where it plays a vital role in fuel metabolism. However, vegetarians obtain negligible amounts of carnitine from their diet. We tested the hypothesis that muscle carnitine uptake is elevated in vegetarians compared with that in nonvegetarians to maintain a normal tissue carnitine content. Forty-one young (aged ≈22 y) vegetarian and nonvegetarian volunteers participated in 2 studies. The first study consisted of a 5-h intravenous infusion of l-carnitine while circulating insulin was maintained at a physiologically high concentration (≈170 mU/L; to stimulate muscle carnitine uptake) or at a fasting concentration (≈6 mU/L). The second study consisted of oral ingestion of 3 g l-carnitine. Basal plasma total carnitine (TC) concentration, 24-h urinary TC excretion, muscle TC content, and muscle carnitine transporter [organic cation transporter 2 (OCTN2)] messenger RNA and protein expressions were 16% (P < 0.01), 58% (P < 0.01), 17% (P < 0.05), 33% (P < 0.05), and 37% (P = 0.09) lower, respectively, in vegetarian volunteers. However, although nonvegetarians showed a 15% increase (P < 0.05) in muscle TC during l-carnitine infusion with hyperinsulinemia, l-carnitine infusion in the presence or absence of hyperinsulinemia had no effect on muscle TC content in vegetarians. Nevertheless, 24-h urinary TC excretion was 55% less in vegetarians after l-carnitine ingestion. Vegetarians have a lower muscle TC and reduced capacity to transport carnitine into muscle than do nonvegetarians, possibly because of reduced muscle OCTN2 content. Thus, the greater whole-body carnitine retention observed after a single dose of l-carnitine in vegetarians was not attributable to increased muscle carnitine storage.

Muscle dysfunction in chronic obstructive pulmonary disease: update on causes and biological findings

PubMed Central

Pascual, Sergi; Casadevall, Carme; Orozco-Levi, Mauricio; Barreiro, Esther

2015-01-01

Respiratory and/or limb muscle dysfunction, which are frequently observed in chronic obstructive pulmonary disease (COPD) patients, contribute to their disease prognosis irrespective of the lung function. Muscle dysfunction is caused by the interaction of local and systemic factors. The key deleterious etiologic factors are pulmonary hyperinflation for the respiratory muscles and deconditioning secondary to reduced physical activity for limb muscles. Nonetheless, cigarette smoke, systemic inflammation, nutritional abnormalities, exercise, exacerbations, anabolic insufficiency, drugs and comorbidities also seem to play a relevant role. All these factors modify the phenotype of the muscles, through the induction of several biological phenomena in patients with COPD. While respiratory muscles improve their aerobic phenotype (percentage of oxidative fibers, capillarization, mitochondrial density, enzyme activity in the aerobic pathways, etc.), limb muscles exhibit the opposite phenotype. In addition, both muscle groups show oxidative stress, signs of damage and epigenetic changes. However, fiber atrophy, increased number of inflammatory cells, altered regenerative capacity; signs of apoptosis and autophagy, and an imbalance between protein synthesis and breakdown are rather characteristic features of the limb muscles, mostly in patients with reduced body weight. Despite that significant progress has been achieved in the last decades, full elucidation of the specific roles of the target biological mechanisms involved in COPD muscle dysfunction is still required. Such an achievement will be crucial to adequately tackle with this relevant clinical problem of COPD patients in the near-future. PMID:26623119

Physical demands in working life and individual physical capacity.

PubMed

Karlqvist, L; Leijon, O; Härenstam, A

2003-08-01

The purpose of this study was to investigate the prevalence of the excess of metabolic level (metabolic demands in work exceeding one-third of the individual's aerobic capacity) of working men and women today and to describe the population whose metabolic level is exceeded. A second aim was to explore how externally assessed metabolic demands match with the physical function and capacity of working men and women in jobs with the lowest and the highest demands. The aerobic power of each individual (94 men and 94 women) was estimated from heart rate and workload in sub-maximal tests from dynamic legwork on a cycle ergometer. Physical activity was assessed using a task-oriented interview technique. Physical function was measured by tests of muscle endurance in arms, abdomen and legs, handgrip pressure, balance and coordination. The calculation of individual metabolic demands during a "typical working day" showed that 27% of the men and 22% of the women exceeded their metabolic level. The results indicate that the physical fitness is low or somewhat low for two-thirds of the 94 men and for more than one-half of the 94 women. Women in the group with the highest job demands had significantly lower muscle endurance in the abdomen and legs and worse coordination than women in the group with the lowest job demands. Metabolic demands in working life today remain high. This is reflected in a mismatch between individual physical capacity and the physical demands of work for 25% of the population.

Neuromuscular electrical stimulation and inspiratory muscle training as potential adjunctive rehabilitation options for patients with heart failure.

PubMed

Arena, Ross; Pinkstaff, Sherry; Wheeler, Emma; Peberdy, Mary Ann; Guazzi, Marco; Myers, Jonathan

2010-01-01

Aerobic and resistance exercise training programs produce an abundance of physiologic and clinical benefits in patients with heart failure (HF). Improved maximal aerobic capacity, submaximal aerobic endurance, muscle force production, perceived quality of life, and skeletal muscle characteristics are among the more established outcomes resulting from these rehabilitation techniques. Moreover, both aerobic and resistance exercise training appear to portend a low risk to patients with HF when appropriate exercise prescription methods are followed. While the aforementioned training techniques will undoubtedly continue to be at the center of a well-formulated rehabilitation program, other adjunctive interventions, which are presently underutilized in clinical practice, may prove beneficial in patients with HF. Specifically, both neuromuscular electrical stimulation (NMES) and inspiratory muscle training (IMT) appear to significantly improve several physiologic, exercise, symptomatologic, and quality-of-life parameters. NMES targets skeletal muscle abnormalities, whereas IMT primarily targets the weakened respiratory musculature, both often encountered in patients with HF. A PubMed search using relevant key words identified 19 original investigations examining the impact of NMES (13 studies) and IMT (6 studies) training programs in patients with HF. The resultant review (1) provides a summary of the original research outcomes of both NMES and IMT in patients with HF; (2) addresses current research gaps, providing a direction for future investigations; and (3) provides clinical scenarios where NMES and IMT may prove to be beneficial during the rehabilitation of patients with HF.

Ovariectomy results in differential shifts in gut microbiota in low versus high aerobic capacity rats

PubMed Central

Cox-York, Kimberly A; Sheflin, Amy M; Foster, Michelle T; Gentile, Christopher L; Kahl, Amber; Koch, Lauren G; Britton, Steven L; Weir, Tiffany L

2015-01-01

The increased risk for cardiometabolic disease with the onset of menopause is widely studied and likely precipitated by the decline in endogenous estradiol (E2), yet the precise mechanisms are unknown. The gut microbiome is involved in estrogen metabolism and has been linked to metabolic disease, suggesting its potential involvement in the postmenopausal phenotype. Furthermore, menopause-associated risk factors, as well as gut ecology, are altered with exercise. Therefore, we studied microbial changes in an ovariectomized (OVX vs. Sham) rat model of high (HCR) and low (LCR) intrinsic aerobic capacity (n = 8–10/group) in relation to changes in body weight/composition, glucose tolerance, and liver triglycerides (TG). Nine weeks after OVX, HCR rats were moderately protected against regional adipose tissue gain and liver TG accumulation (P < 0.05 for both). Microbial diversity and number of the Bacteroidetes phylum were significantly increased in LCR with OVX, but unchanged in HCR OVX relative to Sham. Plasma short-chain fatty acids (SCFA), produced by bacteria in the gut and recognized as metabolic signaling molecules, were significantly greater in HCR Sham relative to LCR Sham rats (P = 0.05) and were decreased with OVX in both groups. These results suggest that increased aerobic capacity may be protective against menopause-associated cardiometabolic risk and that gut ecology, and production of signaling molecules such as SCFA, may contribute to the mediation. PMID:26265751

The Individual, Joint, and Additive Interaction Associations of Aerobic-Based Physical Activity and Muscle Strengthening Activities on Metabolic Syndrome.

PubMed

Dankel, Scott J; Loenneke, Jeremy P; Loprinzi, Paul D

2016-12-01

Previous research has demonstrated that physical activity and muscle strengthening activities are independently and inversely associated with metabolic syndrome. Despite a number of studies examining the individual associations, only a few studies have examined the joint associations, and to our knowledge, no previous studies have examined the potential additive interaction of performing muscle strengthening activities and aerobic-based physical activity and their association with metabolic syndrome. Using data from the 2003 to 2006 National Health and Nutrition Examination Survey (NHANES), we computed three separate multivariable logistic regression models to examine the individual, combined, and additive interaction of meeting guidelines for accelerometer-assessed physical activity and self-reported muscle strengthening activities, and their association with metabolic syndrome. We found that individuals meeting physical activity and muscle strengthening activity guidelines, respectively, were at 61 and 25 % lower odds of having metabolic syndrome. Furthermore, individuals meeting both guidelines had the lowest odds of having metabolic syndrome (70 %), in part due to the additive interaction of performing both modes of exercise. In this national sample, accelerometer-assessed physical activity and muscle strengthening activities were synergistically associated with metabolic syndrome.

Sarcopenia and age-related changes in body composition and functional capacity.

PubMed

Evans, W J; Campbell, W W

1993-02-01

Advancing adult age is associated with profound changes in body composition. One of the most prominent of these changes is sarcopenia, defined as the age-related loss in skeletal muscle mass, which results in decreased strength and aerobic capacity and thus functional capacity. Sarcopenia is also closely linked to age-related losses in bone mineral, basal metabolic rate and increased body fat content. Through physical exercise and training, especially resistance training, it may be possible to prevent sarcopenia and the remarkable array of associated abnormalities, such as type II diabetes, coronary artery disease, hypertension, osteoporosis and obesity. Using an exercise program of sufficient frequency, intensity and duration, it is quite possible to increase muscle strength and endurance at any age. There is no pharmacological intervention that holds a greater promise of improving health and promoting independence in the elderly than does exercise.

Effect of 12-week-long aerobic training programme on body composition, aerobic capacity, complete blood count and blood lipid profile among young women.

PubMed

Kostrzewa-Nowak, Dorota; Nowak, Robert; Jastrzębski, Zbigniew; Zarębska, Aleksandra; Bichowska, Marta; Drobnik-Kozakiewicz, Izabela; Radzimiński, Łukasz; Leońska-Duniec, Agata; Ficek, Krzysztof; Cięszczyk, Paweł

2015-01-01

Numerous data suggest that aerobic-type exercise improves lipoprotein-lipid profiles, cardiorespiratory fitness and body composition in young women. The aim of this study was to evaluate the biological response to high-low impact aerobic fitness among young women. Thirty-four young women aged 22 (19-24) years were divided into three groups: underweight (N=10), normal weight (N=12) and overweight (N=12). Aerobic capacity, anthropometry and body composition together with complete blood count and lipid profile were determined before and after completion of a 12-week-long training period. The training programme caused a significant decrease in weight (by 4.3 kg, P=0.003), body mass index (by 1.3 kg/m2, P=0.003), free fat mass (by 2.1 kg, P=0.002), total body water (by 0.4 kg, P=0.036), percentage of fat (by 3 percent points, P=0.002), all analyzed skinfolds thicknesses, as well as the lipid profile in overweight group, and no changes in normal weight group. Significant changes in weight (by 4.2 kg, P=0.005), body mass index (by 0.9 kg/m2, P=0.005), crus skinfold thickness (by 3.3 mm, P=0.028), and in maximum oxygen uptake (by 2.49 mL/kg/min; P=0.047) were observed among underweight women. No change in total blood count was observed in all groups. Twelve-week-long fitness training programme of two alternating styles (low and high impact) has a beneficial effect on overweight young women.

Regulation of skeletal muscle capillary growth in exercise and disease.

PubMed

Haas, Tara L; Nwadozi, Emmanuel

2015-12-01

Capillaries, which are the smallest and most abundant type of blood vessel, form the primary site of gas, nutrient, and waste transfer between the vascular and tissue compartments. Skeletal muscle exhibits the capacity to generate new capillaries (angiogenesis) as an adaptation to exercise training, thus ensuring that the heightened metabolic demand of the active muscle is matched by an improved capacity for distribution of gases, nutrients, and waste products. This review summarizes the current understanding of the regulation of skeletal muscle capillary growth. The multi-step process of angiogenesis is coordinated through the integration of a diverse array of signals associated with hypoxic, metabolic, hemodynamic, and mechanical stresses within the active muscle. The contributions of metabolic and mechanical factors to the modulation of key pro- and anti-angiogenic molecules are discussed within the context of responses to a single aerobic exercise bout and short-term and long-term training. Finally, the paradoxical lack of angiogenesis in peripheral artery disease and diabetes and the implications for disease progression and muscle health are discussed. Future studies that emphasize an integrated analysis of the mechanisms that control skeletal muscle capillary growth will enable development of targeted exercise programs that effectively promote angiogenesis in healthy individuals and in patient populations.

Pro-inflammatory capacity of classically activated monocytes relates positively to muscle mass and strength.

PubMed

Beenakker, Karel G M; Westendorp, Rudi G J; de Craen, Anton J M; Slagboom, Pieternella E; van Heemst, Diana; Maier, Andrea B

2013-08-01

In mice, monocytes that exhibit a pro-inflammatory profile enter muscle tissue after muscle injury and are crucial for clearance of necrotic tissue and stimulation of muscle progenitor cell proliferation and differentiation. The aim of this study was to test if pro-inflammatory capacity of classically activated (M1) monocytes relates to muscle mass and strength in humans. This study included 191 male and 195 female subjects (mean age 64.2 years (SD 6.4) and 61.9 ± 6.4, respectively) of the Leiden Longevity Study. Pro-inflammatory capacity of M1 monocytes was assessed by ex vivo stimulation of whole blood with Toll-like receptor (TLR) 4 agonist lipopolysaccharide (LPS) and TLR-2/1 agonist tripalmitoyl-S-glycerylcysteine (Pam₃Cys-SK₄), both M1 phenotype activators. Cytokines that stimulate M1 monocyte response (IFN-γ and GM-CSF) as well as cytokines that are secreted by M1 monocytes (IL-6, TNF-α, IL-12, and IL-1β) were measured. Analyses were adjusted for age, height, and body fat mass. Upon stimulation with LPS, the cytokine production capacity of INF-γ, GM-CSF, and TNF-α was significantly positively associated with lean body mass, appendicular lean mass and handgrip strength in men, but not in women. Upon stimulation with Pam₃Cys-SK₄, IL-6; TNF-α; and Il-1β were significantly positively associated with lean body mass and appendicular lean in women, but not in men. Taken together, this study shows that higher pro-inflammatory capacity of M1 monocytes upon stimulation is associated with muscle characteristics and sex dependent. © 2013 John Wiley & Sons Ltd and the Anatomical Society.

WISE 2005: Aerobic and resistive countermeasures prevent paraspinal muscle deconditioning during 60-day bed rest in women.

PubMed

Holt, Jacquelyn A; Macias, Brandon R; Schneider, Suzanne M; Watenpaugh, Donald E; Lee, Stuart M C; Chang, Douglas G; Hargens, Alan R

2016-05-15

Microgravity-induced lumbar paraspinal muscle deconditioning may contribute to back pain commonly experienced by astronauts and may increase the risk of postflight injury. We hypothesized that a combined resistive and aerobic exercise countermeasure protocol that included spinal loading would mitigate lumbar paraspinal muscle deconditioning during 60 days of bed rest in women. Sixteen women underwent 60-day, 6° head-down-tilt bed rest (BR) and were randomized into control and exercise groups. During bed rest the control group performed no exercise. The exercise group performed supine treadmill exercise within lower body negative pressure (LBNP) for 3-4 days/wk and flywheel resistive exercise for 2-3 days/wk. Paraspinal muscle cross-sectional area (CSA) was measured using a lumbar spine MRI sequence before and after BR. In addition, isokinetic spinal flexion and extension strengths were measured before and after BR. Data are presented as means ± SD. Total lumbar paraspinal muscle CSA decreased significantly more in controls (10.9 ± 3.4%) than in exercisers (4.3 ± 3.4%; P < 0.05). The erector spinae was the primary contributor (76%) to total lumbar paraspinal muscle loss. Moreover, exercise attenuated isokinetic spinal extension loss (-4.3 ± 4.5%), compared with controls (-16.6 ± 11.2%; P < 0.05). In conclusion, LBNP treadmill and flywheel resistive exercises during simulated microgravity mitigate decrements in lumbar paraspinal muscle structure and spine function. Therefore spaceflight exercise countermeasures that attempt to reproduce spinal loads experienced on Earth may mitigate spinal deconditioning during long-duration space travel.

Two-loads Method for Distinguishing among the Muscle Force, Velocity, and Power Producing Capacities

PubMed Central

Jaric, Slobodan

2016-01-01

It has been generally accepted that muscles could have different mechanical capacities, such as those for producing high force (F), velocity (V), and power (P) outputs. Nevertheless, the standard procedures of the evaluation of muscle function both in research and routine testing are typically conducted under a single mechanical condition, such as under a single external load. Therefore, the observed outcomes do not allow for distinguishing among the different muscle capacities. As a result, the outcomes of most of the routine testing procedures have been of limited informational value, while a number of debated issues in research have originated from arbitrarily interpreted experimental findings regarding specific muscle capacities. A solution for the discussed problem could be based on the approximately linear and exceptionally strong F-V relationship typically observed from various functional tasks performed under different external loads. These findings allow for the 'two-loads method' proposed in this Current Opinion: the functional movement tasks (e.g., maximum jumping, cycling, running, pushing, lifting, or throwing) should be tested against just 2 distinctive external loads. Namely, the F-V relationship determined by 2 pairs of the F and V data could provide the parameters depicting the maximum F (i.e., the F-intercept), V (V-intercept), and P (calculated from the product of F and V) output of the tested muscles. Therefore, the proposed two-loads method applied in both research and routine testing could provide a deeper insight into the mechanical properties and function of the tested muscles and resolve a number of debated issues in the literature. PMID:27075326

Exercise-Induced Hypertrophic and Oxidative Signaling Pathways and Myokine Expression in Fast Muscle of Adult Zebrafish

PubMed Central

Rovira, Mireia; Arrey, Gerard; Planas, Josep V.

2017-01-01

Skeletal muscle is a plastic tissue that undergoes cellular and metabolic adaptations under conditions of increased contractile activity such as exercise. Using adult zebrafish as an exercise model, we previously demonstrated that swimming training stimulates hypertrophy and vascularization of fast muscle fibers, consistent with the known muscle growth-promoting effects of exercise and with the resulting increased aerobic capacity of this tissue. Here we investigated the potential involvement of factors and signaling mechanisms that could be responsible for exercise-induced fast muscle remodeling in adult zebrafish. By subjecting zebrafish to swimming-induced exercise, we observed an increase in the activity of mammalian target of rapamycin (mTOR) and Mef2 protein levels in fast muscle. We also observed an increase in the protein levels of the mitotic marker phosphorylated histone H3 that correlated with an increase in the protein expression levels of Pax7, a satellite-like cell marker. Furthermore, the activity of AMP-activated protein kinase (AMPK) was also increased by exercise, in parallel with an increase in the mRNA expression levels of pgc1α and also of pparda, a β-oxidation marker. Changes in the mRNA expression levels of slow and fast myosin markers further supported the notion of an exercise-induced aerobic phenotype in zebrafish fast muscle. The mRNA expression levels of il6, il6r, apln, aplnra and aplnrb, sparc, decorin and igf1, myokines known in mammals to be produced in response to exercise and to signal through mTOR/AMPK pathways, among others, were increased in fast muscle of exercised zebrafish. These results support the notion that exercise increases skeletal muscle growth and myogenesis in adult zebrafish through the coordinated activation of the mTOR-MEF2 and AMPK-PGC1α signaling pathways. These results, coupled with altered expression of markers for oxidative metabolism and fast-to-slow fiber-type switch, also suggest improved aerobic

Influence of aerobic exercise intensity on myofibrillar and mitochondrial protein synthesis in young men during early and late postexercise recovery.

PubMed

Di Donato, Danielle M; West, Daniel W D; Churchward-Venne, Tyler A; Breen, Leigh; Baker, Steven K; Phillips, Stuart M

2014-05-01

Aerobic exercise is typically associated with expansion of the mitochondrial protein pool and improvements in muscle oxidative capacity. The impact of aerobic exercise intensity on the synthesis of specific skeletal muscle protein subfractions is not known. We aimed to study the effect of aerobic exercise intensity on rates of myofibrillar (MyoPS) and mitochondrial (MitoPS) protein synthesis over an early (0.5-4.5 h) and late (24-28 h) period during postexercise recovery. Using a within-subject crossover design, eight males (21 ± 1 yr, Vo2peak 46.7 ± 2.0 ml·kg(-1)·min(-1)) performed two work-matched cycle ergometry exercise trials (LOW: 60 min at 30% Wmax; HIGH: 30 min at 60% Wmax) in the fasted state while undergoing a primed constant infusion of l-[ring-(13)C6]phenylalanine. Muscle biopsies were obtained at rest and 0.5, 4.5, 24, and 28 h postexercise to determine both the "early" and "late" response of MyoPS and MitoPS and the phosphorylation status of selected proteins within both the Akt/mTOR and MAPK pathways. Over 24-28 h postexercise, MitoPS was significantly greater after the HIGH vs. LOW exercise trial (P < 0.05). Rates of MyoPS were increased equivalently over 0.5-4.5 h postexercise recovery (P < 0.05) but remained elevated at 24-28 h postexercise only following the HIGH trial. In conclusion, an acute bout of high- but not low-intensity aerobic exercise in the fasted state resulted in a sustained elevation of both MitoPS and MyoPS at 24-28 h postexercise recovery.

WISE-2005: LBNP/Treadmill and Resistive Exercise Countermeasures Maintain Aerobic Capacity during a 60-d Bed Rest

NASA Technical Reports Server (NTRS)

Schneider, Suzanne M.; Lee, Stuart M. C.; Watenpaugh, Donald E.; Macias, Brandon R.; Hargens, Alan R.

2006-01-01

We have previously documented that supine treadmill exercise within lower body negative pressure (LBNPex) performed 6 sessions (raised dot) wk(sup -1) during 15- and 30-day bed rests (BR) maintained upright aerobic capacity (VO2pk). In the present study, ure are evaluating whether aerobic capacity is maintained during a 60-d BR when the LBNPex frequency is reduced to 2-4 sessions (raised dot) wk(sup -1) and resistance exercise (REX) is added 2-3 sessions (raised dot) wk(sup -1). Eight healthy women (32 plus or minus 4 yrs; 56.4 plus or minus 3.6 kg; 164 plus or minus 8 cm; mean plus or minus SD) performed maximal-exertion, graded treadmill tests before and 3 days after a 60-d, 6 deg. head-down tilt BR. (Earliest day the medical monitors would permit a maximal exercise test post-BR). During BR, four subjects performed no exercise (CON), while four other subjects (EX) performed LBNPex and REX on separate days. The LBNPex countermeasure employed an intermittent (40-80% pre-BR VO2pk), 40-min protocol against an LBNP pressure (-49 plus or minus 3 mmHg) applied to provide a footward force equivalent to 1.0-1.2 body weight. REX consisted of maximal concentric and eccentric supine leg press and heel raise exercises using a gravity-independent flywheel ergometer. Comparisons were performed using paired (within-group) or non-paired (between-group) t-tests. Three days post-BR, VO2pk of the CON group was reduced significantly from pre-BR (Pre:37.2 plus or minus 1.2, Post: 29.4 plus or minus 2 ml (raised dot) kg(sup -1) (raised dot) min(sup -1), P less than 0.05), while the VO2pk of the EX group was not significantly reduced (Pre: 39.6 plus or minus 1.9, Post: 38.0 plus or minus 0.6 ml (raised dot) kg(sup -1) (raised dot) min(sup -1)). Peak heart rate, ventilation, rating of perceived exertion, and respiratory exchange ratio were not significantly different between the two groups pre- and post-BR. These preliminary results suggest that the combined LBNPex and REX

Female rats selectively bred for high intrinsic aerobic fitness are protected from ovariectomy-associated metabolic dysfunction

PubMed Central

Padilla, Jaume; Park, Young-Min; Welly, Rebecca J.; Scroggins, Rebecca J.; Britton, Steven L.; Koch, Lauren G.; Jenkins, Nathan T.; Crissey, Jacqueline M.; Zidon, Terese; Morris, E. Matthew; Meers, Grace M. E.; Thyfault, John P.

2015-01-01

Ovariectomized rodents model human menopause in that they rapidly gain weight, reduce spontaneous physical activity (SPA), and develop metabolic dysfunction, including insulin resistance. How contrasting aerobic fitness levels impacts ovariectomy (OVX)-associated metabolic dysfunction is not known. Female rats selectively bred for high and low intrinsic aerobic fitness [high-capacity runners (HCR) and low-capacity runners (LCR), respectively] were maintained under sedentary conditions for 39 wk. Midway through the observation period, OVX or sham (SHM) operations were performed providing HCR-SHM, HCR-OVX, LCR-SHM, and LCR-OVX groups. Glucose tolerance, energy expenditure, and SPA were measured before and 4 wk after surgery, while body composition via dual-energy X-ray absorptiometry and adipose tissue distribution, brown adipose tissue (BAT), and skeletal muscle phenotype, hepatic lipid content, insulin resistance via homeostatic assessment model of insulin resistance and AdipoIR, and blood lipids were assessed at death. Remarkably, HCR were protected from OVX-associated increases in adiposity and insulin resistance, observed only in LCR. HCR rats were ∼30% smaller, had ∼70% greater spontaneous physical activity (SPA), consumed ∼10% more relative energy, had greater skeletal muscle proliferator-activated receptor coactivator 1-alpha, and ∼40% more BAT. OVX did not increase energy intake and reduced SPA to the same extent in both HCR and LCR. LCR were particularly affected by an OVX-associated reduction in resting energy expenditure and experienced a reduction in relative BAT; resting energy expenditure correlated positively with BAT across all animals (r = 0.6; P < 0.001). In conclusion, despite reduced SPA following OVX, high intrinsic aerobic fitness protects against OVX-associated increases in adiposity and insulin resistance. The mechanism may involve preservation of resting energy expenditure. PMID:25608751

The Effects of Intermittent Hypoxic Training on Aerobic Capacity and Endurance Performance in Cyclists

PubMed Central

Czuba, Milosz; Waskiewicz, Zbigniew; Zajac, Adam; Poprzecki, Stanislaw; Cholewa, Jaroslaw; Roczniok, Robert

2011-01-01

The aim of the present study was to evaluate the efficacy of intermittent hypoxic training (IHT) with 95 % of lactate threshold workload (WRLT) on aerobic capacity and endurance performance in well-trained cyclists. Twenty male elite cyclists, randomly divided into a hypoxia (H) group (n=10; age 22 ± 2.7years; VO2max 67.8 ± 2.5 ml·kg-1·min-1; body height (BH) 1.78 ± 0.05 m; body mass (BM) 66.7 ± 5.4kg; fat free mass (FFM) 59.3 ± 5.1kg; fat content (FAT%) 11.3 ± 2.1%), and a control (C) group (n = 10; age 23.5 ± 3. 5years; VO2max 67.7 ± 2.0 ml·kg-1·min-1; BH 1.79 ± 3.2 m; BM 69.2 ± 5.5 kg; FFM 63.6 ± 4.8 kg; FAT% 7.9 ± 1.94 %) took part in the research project. The training program used during the experiment was the same for the both groups. For three weeks, the subjects in H group performed 3 training sessions per week in normobaric hypoxia environment (IHT - O2 = 15. 2%). During the elemental core of the IHT session, the intensity was set at 95% WRLT for 30-min in 1st microcycle, 35-min in 2nd microcycle and 40-min in 3rd microcycle. The same training procedure was provided in C group, yet the intensity of the main sessions were set at 100% WRLT in the normoxia environment. The results indicate a significant (p < 0.05) increase in VO2max,VO2LT, WRmax, WRLT and change in lactate concentration (∆LA) during incremental test in H group. Also a significant (p < 0.05) decrease in time of the time trial was seen, associated with a significant increase (p < 0.05) in average generated power (Pavg) and average speed (Vavg) during the time trial. The intermittent hypoxic training (IHT) applied in this research did not significantly affect the hematological variables considered: number of erythrocytes (RBC), hemoglobin concentration (HGB) and haematocrit value (HCT). Significant blood value increases (p < 0.05) were only observed in MCV in H group. This data suggests that intermittent hypoxic training at lactate threshold intensity and medium duration (30

Biomimetic engineered muscle with capacity for vascular integration and functional maturation in vivo

PubMed Central

Juhas, Mark; Engelmayr, George C.; Fontanella, Andrew N.; Palmer, Gregory M.; Bursac, Nenad

2014-01-01

Tissue-engineered skeletal muscle can serve as a physiological model of natural muscle and a potential therapeutic vehicle for rapid repair of severe muscle loss and injury. Here, we describe a platform for engineering and testing highly functional biomimetic muscle tissues with a resident satellite cell niche and capacity for robust myogenesis and self-regeneration in vitro. Using a mouse dorsal window implantation model and transduction with fluorescent intracellular calcium indicator, GCaMP3, we nondestructively monitored, in real time, vascular integration and the functional state of engineered muscle in vivo. During a 2-wk period, implanted engineered muscle exhibited a steady ingrowth of blood-perfused microvasculature along with an increase in amplitude of calcium transients and force of contraction. We also demonstrated superior structural organization, vascularization, and contractile function of fully differentiated vs. undifferentiated engineered muscle implants. The described in vitro and in vivo models of biomimetic engineered muscle represent enabling technology for novel studies of skeletal muscle function and regeneration. PMID:24706792

Influence of racial origin and skeletal muscle properties on disease prevalence and physical performance.

PubMed

Suminski, Richard R; Mattern, Craig O; Devor, Steven T

2002-01-01

Skeletal muscle properties are related to disease (e.g. obesity) and physical performance. For example, a predominance of type I muscle fibres is associated with better performance in endurance sports and a lower risk of obesity. Disease and physical performance also differ among certain racial groups. African Americans are more likely than Caucasians to develop obesity, diabetes mellitus and hypertension. Empirical studies indicate that aerobic capacity is lower in African Americans than Caucasians. Because genetics is a partial determinant of skeletal muscle properties, it is reasonable to assume that skeletal muscle properties vary as a function of race. As such, genetically determined and race-specific skeletal muscle properties may partially explain racial disparities in disease and physical performance. However, additional research is needed in this area to enable the development of more definitive conclusions.

Combined effect of aerobic interval training and selenium nanoparticles on expression of IL-15 and IL-10/TNF-α ratio in skeletal muscle of 4T1 breast cancer mice with cachexia.

PubMed

Molanouri Shamsi, M; Chekachak, S; Soudi, S; Quinn, L S; Ranjbar, K; Chenari, J; Yazdi, M H; Mahdavi, M

2017-02-01

Cancer cachexia is characterized by inflammation, loss of skeletal muscle and adipose tissue mass, and functional impairment. Oxidative stress and inflammation are believed to regulate pathways controlling skeletal muscle wasting. The aim of this study was to determine the effects of aerobic interval training and the purported antioxidant treatment, selenium nanoparticle supplementation, on expression of IL-15 and inflammatory cytokines in 4T1 breast cancer-bearing mice with cachexia. Selenium nanoparticle supplementation accelerated cachexia symptoms in tumor-bearing mice, while exercise training prevented muscle wasting in tumor-bearing mice. Also, aerobic interval training enhanced the anti-inflammatory indices IL-10/TNF-α ratio and IL-15 expression in skeletal muscle in tumor-bearing mice. However, combining exercise training and antioxidant supplementation prevented cachexia and muscle wasting and additionally decreased tumor volume in 4T1 breast cancer mice. These finding suggested that combining exercise training and antioxidant supplementation could be a strategy for managing tumor volume and preventing cachexia in breast cancer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gut microbiota are linked to increased susceptibility to hepatic steatosis in low aerobic capacity rats fed an acute high fat diet

USDA-ARS?s Scientific Manuscript database

Poor aerobic fitness is linked to nonalcoholic fatty liver disease and increased all-cause mortality. We previously found that low capacity running (LCR) rats fed acute high fat diet (HFD; 45% kcal from fat) for 3 days resulted in positive energy balance and increased hepatic steatosis compared with...

The relationship of aerobic capacity, anaerobic peak power and experience to performance in CrossFit exercise.

PubMed

Bellar, D; Hatchett, A; Judge, L W; Breaux, M E; Marcus, L

2015-11-01

CrossFit is becoming increasingly popular as a method to increase fitness and as a competitive sport in both the Unites States and Europe. However, little research on this mode of exercise has been performed to date. The purpose of the present investigation involving experienced CrossFit athletes and naïve healthy young men was to investigate the relationship of aerobic capacity and anaerobic power to performance in two representative CrossFit workouts: the first workout was 12 minutes in duration, and the second was based on the total time to complete the prescribed exercise. The participants were 32 healthy adult males, who were either naïve to CrossFit exercise or had competed in CrossFit competitions. Linear regression was undertaken to predict performance on the first workout (time) with age, group (naïve or CrossFit athlete), VO2max and anaerobic power, which were all significant predictors (p < 0.05) in the model. The second workout (repetitions), when examined similarly using regression, only resulted in CrossFit experience as a significant predictor (p < 0.05). The results of the study suggest that a history of participation in CrossFit competition is a key component of performance in CrossFit workouts which are representative of those performed in CrossFit, and that, in at least one these workouts, aerobic capacity and anaerobic power are associated with success.

The relationship of aerobic capacity, anaerobic peak power and experience to performance in CrossFit exercise

PubMed Central

Hatchett, A; Judge, LW; Breaux, ME; Marcus, L

2015-01-01

CrossFit is becoming increasingly popular as a method to increase fitness and as a competitive sport in both the Unites States and Europe. However, little research on this mode of exercise has been performed to date. The purpose of the present investigation involving experienced CrossFit athletes and naïve healthy young men was to investigate the relationship of aerobic capacity and anaerobic power to performance in two representative CrossFit workouts: the first workout was 12 minutes in duration, and the second was based on the total time to complete the prescribed exercise. The participants were 32 healthy adult males, who were either naïve to CrossFit exercise or had competed in CrossFit competitions. Linear regression was undertaken to predict performance on the first workout (time) with age, group (naïve or CrossFit athlete), VO2max and anaerobic power, which were all significant predictors (p < 0.05) in the model. The second workout (repetitions), when examined similarly using regression, only resulted in CrossFit experience as a significant predictor (p < 0.05). The results of the study suggest that a history of participation in CrossFit competition is a key component of performance in CrossFit workouts which are representative of those performed in CrossFit, and that, in at least one these workouts, aerobic capacity and anaerobic power are associated with success. PMID:26681834

Long-chain acyl-CoA synthetase 6 regulates lipid synthesis and mitochondrial oxidative capacity in human and rat skeletal muscle.

PubMed

Teodoro, Bruno G; Sampaio, Igor H; Bomfim, Lucas H M; Queiroz, André L; Silveira, Leonardo R; Souza, Anderson O; Fernandes, Anna M A P; Eberlin, Marcos N; Huang, Tai-Yu; Zheng, Donghai; Neufer, P Darrell; Cortright, Ronald N; Alberici, Luciane C

2017-02-01

Long-chain acyl-CoA synthetase 6 (ACSL6) mRNA is present in human and rat skeletal muscle, and is modulated by nutritional status: exercise and fasting decrease ACSL6 mRNA, whereas acute lipid ingestion increase its expression. ACSL6 genic inhibition in rat primary myotubes decreased lipid accumulation, as well as activated the higher mitochondrial oxidative capacity programme and fatty acid oxidation through the AMPK/PGC1-α pathway. ACSL6 overexpression in human primary myotubes increased phospholipid species and decreased oxidative metabolism. Long-chain acyl-CoA synthetases (ACSL 1 to 6) are key enzymes regulating the partitioning of acyl-CoA species toward different metabolic fates such as lipid synthesis or β-oxidation. Despite our understanding of ecotopic lipid accumulation in skeletal muscle being associated with metabolic diseases such as obesity and type II diabetes, the role of specific ACSL isoforms in lipid synthesis remains unclear. In the present study, we describe for the first time the presence of ACSL6 mRNA in human skeletal muscle and the role that ACSL6 plays in lipid synthesis in both rodent and human skeletal muscle. ACSL6 mRNA was observed to be up-regulated by acute high-fat meal ingestion in both rodents and humans. In rats, we also demonstrated that fasting and chronic aerobic training negatively modulated the ACSL6 mRNA and other genes of lipid synthesis. Similar results were obtained following ACSL6 knockdown in rat myotubes, which was associated with a decreased accumulation of TAGs and lipid droplets. Under the same knockdown condition, we further demonstrate an increase in fatty acid content, p-AMPK, mitochondrial content, mitochondrial respiratory rates and palmitate oxidation. These results were associated with increased PGC-1α, UCP2 and UCP3 mRNA and decreased reactive oxygen species production. In human myotubes, ACSL6 overexpression reduced palmitate oxidation and PGC-1α mRNA. In conclusion, ACSL6 drives acyl-CoA toward lipid

Maintained peak leg and pulmonary VO2 despite substantial reduction in muscle mitochondrial capacity.

PubMed

Boushel, R; Gnaiger, E; Larsen, F J; Helge, J W; González-Alonso, J; Ara, I; Munch-Andersen, T; van Hall, G; Søndergaard, H; Saltin, B; Calbet, J A L

2015-12-01

We recently reported the circulatory and muscle oxidative capacities of the arm after prolonged low-intensity skiing in the arctic (Boushel et al., 2014). In the present study, leg VO2 was measured by the Fick method during leg cycling while muscle mitochondrial capacity was examined on a biopsy of the vastus lateralis in healthy volunteers (7 male, 2 female) before and after 42 days of skiing at 60% HR max. Peak pulmonary VO2 (3.52 ± 0.18 L.min(-1) pre vs 3.52 ± 0.19 post) and VO2 across the leg (2.8 ± 0.4L.min(-1) pre vs 3.0 ± 0.2 post) were unchanged after the ski journey. Peak leg O2 delivery (3.6 ± 0.2 L.min(-1) pre vs 3.8 ± 0.4 post), O2 extraction (82 ± 1% pre vs 83 ± 1 post), and muscle capillaries per mm(2) (576 ± 17 pre vs 612 ± 28 post) were also unchanged; however, leg muscle mitochondrial OXPHOS capacity was reduced (90 ± 3 pmol.sec(-1) .mg(-1) pre vs 70 ± 2 post, P < 0.05) as was citrate synthase activity (40 ± 3 μmol.min(-1) .g(-1) pre vs 34 ± 3 vs P < 0.05). These findings indicate that peak muscle VO2 can be sustained with a substantial reduction in mitochondrial OXPHOS capacity. This is achieved at a similar O2 delivery and a higher relative ADP-stimulated mitochondrial respiration at a higher mitochondrial p50. These findings support the concept that muscle mitochondrial respiration is submaximal at VO2max , and that mitochondrial volume can be downregulated by chronic energy demand. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of Exercise Rehab on Male Asthmatic Patients: Aerobic Verses Rebound Training

PubMed Central

Zolaktaf, Vahid; Ghasemi, Gholam A; Sadeghi, Morteza

2013-01-01

Background: There are some auspicious records on applying aerobic exercise for asthmatic patients. Recently, it is suggested that rebound exercise might even increase the gains. This study was designed to compare the effects of rebound therapy to aerobic training in male asthmatic patients. Methods: Sample included 37 male asthmatic patients (20-40 years) from the same respiratory clinic. After signing the informed consent, subjects volunteered to take part in control, rebound, or aerobic groups. There was no change in the routine medical treatment of patients. Supervised exercise programs continued for 8 weeks, consisting of two sessions of 45 to 60 minutes per week. Criteria measures were assessed pre- and post exercise program. Peak exercise capacity (VO2peak) was estimated by modified Bruce protocol, Forced vital capacity (FVC), Forced expiratory volume in 1 second (FEV1), and FEV1% were measured by spirometer. Data were analyzed by repeated measure analysis of variance (ANOVA). Results: Significant interactions were observed for all 4 criteria measures (P < 0.01), meaning that both the exercise programs were effective in improving FVC, FEV1, FEV1%, and VO2peak. Rebound exercise produced more improvement in FEV1, FEV1%, and VO2peak. Conclusions: Regular exercise strengthens the respiratory muscles and improves the cellular respiration. At the same time, it improves the muscular, respiratory, and cardio-vascular systems. Effects of rebound exercise seem to be promising. Findings suggest that rebound exercise is a useful complementary means for asthmatic male patients. PMID:23717762

Aerobic anti-gravity exercise in patients with Charcot-Marie-Tooth disease types 1A and X: A pilot study.

PubMed

Knak, Kirsten L; Andersen, Linda K; Vissing, John

2017-12-01

Charcot-Marie-Tooth (CMT) disease is a hereditary neuropathy associated with impaired walking capacity. Some patients are too weak in the lower extremity muscles to walk at gravity with sufficient intensity or duration to gain benefit. The aim was to investigate the effect of aerobic anti-gravity exercise in weak patients with CMT 1A and X. Five adult patients performed moderate-intensity aerobic anti-gravity exercise 3/week for 10 weeks. There was a significant positive difference in Berg balance scale and postural stability test between test occasions, and walking distance in the 6-min walk test trended to increase. The study indicates that the anti-gravity treadmill training of patients with CMT should be pursued in larger CMT cohorts.

Local capillary supply in muscle is not determined by local oxidative capacity.

PubMed

Bosutti, Alessandra; Egginton, Stuart; Barnouin, Yoann; Ganse, Bergita; Rittweger, Jörn; Degens, Hans

2015-11-01

It is thought that the prime determinant of global muscle capillary density is the mean oxidative capacity. However, feedback control during maturational growth or adaptive remodelling of local muscle capillarisation is likely to be more complex than simply matching O2 supply and demand in response to integrated tissue function. We tested the hypothesis that the maximal oxygen consumption (MO2,max) supported by a capillary is relatively constant, and independent of the volume of tissue supplied (capillary domain). We demonstrate that local MO2,max assessed by succinate dehydrogenase histochemistry: (1) varied more than 100-fold between individual capillaries and (2) was positively correlated to capillary domain area in both human vastus lateralis (R=0.750, P<0.001) and soleus (R=0.697, P<0.001) muscles. This suggests that, in contrast to common assumptions, capillarisation is not primarily dictated by local oxidative capacity, but rather by factors such as fibre size, or consequences of differences in fibre size such as substrate delivery and metabolite removal. © 2015. Published by The Company of Biologists Ltd.

Eccentric Torque-Producing Capacity is Influenced by Muscle Length in Older Healthy Adults.

PubMed

Melo, Ruth C; Takahashi, Anielle C M; Quitério, Robison J; Salvini, Tânia F; Catai, Aparecida M

2016-01-01

Considering the importance of muscle strength to functional capacity in the elderly, the study investigated the effects of age on isokinetic performance and torque production as a function of muscle length. Eleven younger (24.2 ± 2.9 years) and 16 older men (62.7 ± 2.5 years) were subjected to concentric and eccentric isokinetic knee extension/flexion at 60 and 120° · s(-1) through a functional range of motion. The older group presented lower peak torque (in newton-meters) than the young group for both isokinetic contraction types (age effect, p < 0.001). Peak torque deficits in the older group were near 30 and 29% for concentric and eccentric contraction, respectively. Concentric peak torque was lower at 120° · s(-1) than at 60° · s(-1) for both groups (angular velocity effect, p < 0.001). Eccentric knee extension torque was the only exercise tested that showed an interaction effect between age and muscle length (p < 0.001), which suggested different torque responses to the muscle length between groups. Compared with the young group, the eccentric knee extension torque was 22-56% lower in the older group, with the deficits being lower in the shortened muscle length (22-27%) and higher (33-56%) in the stretched muscle length. In older men, the production of eccentric knee strength seems to be dependent on the muscle length. At more stretched positions, older subjects lose the capacity to generate eccentric knee extension torque. More studies are needed to assess the mechanisms involved in eccentric strength preservation with aging and its relationship with muscle length.

Multimodal high-intensity interval training increases muscle function and metabolic performance in females.

PubMed

Buckley, Stephanie; Knapp, Kelly; Lackie, Amy; Lewry, Colin; Horvey, Karla; Benko, Chad; Trinh, Jason; Butcher, Scotty

2015-11-01

High-intensity interval training (HIIT) is a time-efficient method of improving aerobic and anaerobic power and capacity. In most individuals, however, HIIT using modalities such as cycling, running, and rowing does not typically result in increased muscle strength, power, or endurance. The purpose of this study is to compare the physiological outcomes of traditional HIIT using rowing (Row-HIIT) with a novel multimodal HIIT (MM-HIIT) circuit incorporating multiple modalities, including strength exercises, within an interval. Twenty-eight recreationally active women (age 24.7 ± 5.4 years) completed 6 weeks of either Row-HIIT or MM-HIIT and were tested on multiple fitness parameters. MM-HIIT and Row-HIIT resulted in similar improvements (p < 0.05 for post hoc pre- vs. post-training increases for each group) in maximal aerobic power (7% vs. 5%), anaerobic threshold (13% vs. 12%), respiratory compensation threshold (7% vs. 5%), anaerobic power (15% vs. 12%), and anaerobic capacity (18% vs. 14%). The MM-HIIT group had significant (p < 0.01 for all) increases in squat (39%), press (27%), and deadlift (18%) strength, broad jump distance (6%), and squat endurance (280%), whereas the Row-HIIT group had no increase in any muscle performance variable (p values 0.33-0.90). Post-training, 1-repetition maximum (1RM) squat (64.2 ± 13.6 vs. 45.8 ± 16.2 kg, p = 0.02), 1RM press (33.2 ± 3.8 vs. 26.0 ± 9.6 kg, p = 0.01), and squat endurance (23.9 ± 12.3 vs. 10.2 ± 5.6 reps, p < 0.01) were greater in the MM-HIIT group than in the Row-HIIT group. MM-HIIT resulted in similar aerobic and anaerobic adaptations but greater muscle performance increases than Row-HIIT in recreationally active women.

Prediction of functional aerobic capacity without exercise testing

NASA Technical Reports Server (NTRS)

Jackson, A. S.; Blair, S. N.; Mahar, M. T.; Wier, L. T.; Ross, R. M.; Stuteville, J. E.

1990-01-01

The purpose of this study was to develop functional aerobic capacity prediction models without using exercise tests (N-Ex) and to compare the accuracy with Astrand single-stage submaximal prediction methods. The data of 2,009 subjects (9.7% female) were randomly divided into validation (N = 1,543) and cross-validation (N = 466) samples. The validation sample was used to develop two N-Ex models to estimate VO2peak. Gender, age, body composition, and self-report activity were used to develop two N-Ex prediction models. One model estimated percent fat from skinfolds (N-Ex %fat) and the other used body mass index (N-Ex BMI) to represent body composition. The multiple correlations for the developed models were R = 0.81 (SE = 5.3 ml.kg-1.min-1) and R = 0.78 (SE = 5.6 ml.kg-1.min-1). This accuracy was confirmed when applied to the cross-validation sample. The N-Ex models were more accurate than what was obtained from VO2peak estimated from the Astrand prediction models. The SEs of the Astrand models ranged from 5.5-9.7 ml.kg-1.min-1. The N-Ex models were cross-validated on 59 men on hypertensive medication and 71 men who were found to have a positive exercise ECG. The SEs of the N-Ex models ranged from 4.6-5.4 ml.kg-1.min-1 with these subjects.(ABSTRACT TRUNCATED AT 250 WORDS).

Exercise capacity and muscle strength and risk of vascular disease and arrhythmia in 1.1 million young Swedish men: cohort study.

PubMed

Andersen, Kasper; Rasmussen, Finn; Held, Claes; Neovius, Martin; Tynelius, Per; Sundström, Johan

2015-09-16

To investigate the associations of exercise capacity and muscle strength in late adolescence with risk of vascular disease and arrhythmia. Cohort study. General population in Sweden. 1.1 million men who participated in mandatory military conscription between 1 August 1972 and 31 December 1995, at a median age of 18.2 years. Participants were followed until 31 December 2010. Associations between exercise capacity and muscle strength with risk of vascular disease and subgroups (ischaemic heart disease, heart failure, stroke, and cardiovascular death) and risk of arrhythmia and subgroups (atrial fibrillation or flutter, bradyarrhythmia, supraventricular tachycardia, and ventricular arrhythmia or sudden cardiac death). Maximum exercise capacity was estimated by the ergometer bicycle test, and muscle strength was measured as handgrip strength by a hand dynamometer. High exercise capacity or muscle strength was deemed as above the median level. During a median follow-up of 26.3 years, 26 088 vascular disease events and 17 312 arrhythmia events were recorded. Exercise capacity was inversely associated with risk of vascular disease and its subgroups. Muscle strength was also inversely associated with vascular disease risk, driven by associations of higher muscle strength with lower risk of heart failure and cardiovascular death. Exercise capacity had a U shaped association with risk of arrhythmia, driven by a direct association with risk of atrial fibrillation and a U shaped association with bradyarrhythmia. Higher muscle strength was associated with lower risk of arrhythmia (specifically, lower risk of bradyarrhythmia and ventricular arrhythmia). The combination of high exercise capacity and high muscle strength was associated with a hazard ratio of 0.67 (95% confidence interval 0.65 to 0.70) for vascular events and 0.92 (0.88 to 0.97) for arrhythmia compared with the combination of low exercise capacity and low muscle strength. Exercise capacity and muscle strength

Proof of Concept to Isolate and Culture Primary Muscle Cells from Northern Elephant Seals to Study the Mechanisms that Maintain Aerobic Metabolism Under the Hypoxic Conditions of Breath-hold Diving

DTIC Science & Technology

2013-09-30

Cells from Northern Elephant Seals to Study the Mechanisms that Maintain Aerobic Metabolism Under the Hypoxic Conditions of Breath-hold Diving...Muscle Cells from Northern Elephant Seals to Study the Mechanisms that Maintain Aerobic Metabolism Under the Hypoxic Conditions of Breath-hold Diving 5a...two day period in September, 2012. The first major huddle to the study was to determine the effect of the overnight shipping of the viability of

Proof of Concept to Isolate and Culture Primary Muscle Cells from Northern Elephant Seals to Study the Mechanisms that Maintain Aerobic Metabolism Under the Hypoxic Conditions of Breath-Hold Diving

DTIC Science & Technology

2014-09-30

that are too small have less effective results with mechanical trituration that follows digestion). 5. Move dish and sample into the cell culture...Cells from Northern Elephant Seals to Study the Mechanisms that Maintain Aerobic Metabolism Under the Hypoxic Conditions of Breath-Hold Diving...Muscle Cells from Northern Elephant Seals to Study the Mechanisms that Maintain Aerobic Metabolism Under the Hypoxic Conditions of Breath-Hold Diving 5a

Cardioprotective Properties of Aerobic and Resistance Training Against Myocardial Infarction.

PubMed

Barboza, C A; Souza, G I H; Oliveira, J C M F; Silva, L M; Mostarda, C T; Dourado, P M M; Oyama, L M; Lira, F S; Irigoyen, M C; Rodrigues, B

2016-06-01

We evaluated the effects of aerobic and resistance exercise training on ventricular morphometry and function, physical capacity, autonomic function, as well as on ventricular inflammatory status in trained rats prior to myocardial infarction. Male Wistar rats were divided into the following groups: sedentary+Sham, sedentary+myocardial infarction, aerobic trained+myocardial infarction, and resistance trained+myocardial infarction. Sham and myocardial infarction were performed after training periods. In the days following the surgeries, evaluations were performed. Aerobic training prevents aerobic (to a greater extent) and resistance capacity impairments, ventricular dysfunction, baroreflex sensitivity and autonomic disorders (vagal tonus decrease and sympathetic tonus increase) triggered by myocardial infarction. Resistance training was able to prevent negative changes to aerobic and resistance capacity (to a greater extent) but not to ventricular dysfunction, and it prevented cardiovascular sympathetic increments. Additionally, both types of training reduced left ventricle inflammatory cytokine concentration. Our results suggest that aerobic and, for the first time, dynamic resistance training were able to reduce sympathetic tonus to the heart and vessels, as well as preventing the increase in pro-inflammatory cytokine concentrations in the left ventricle of trained groups. These data emphasizes the positive effects of aerobic and dynamic resistance training on the prevention of the negative changes triggered by myocardial infarction. © Georg Thieme Verlag KG Stuttgart · New York.

Nutritional status, functional capacity and exercise rehabilitation in end-stage renal disease.

PubMed

Mercer, T H; Koufaki, P; Naish, P F

2004-05-01

A significant percentage of patients with end-stage renal disease are malnourished and/or muscle wasted. Uremia is associated with decreased protein synthesis and increased protein degradation. Fortunately, nutritional status has been shown to be a modifiable risk factor in the dialysis population. It has long been proposed that exercise could positively alter the protein synthesis-degradation balance. Resistance training had been considered as the only form of exercise likely to induce anabolism in renal failure patients. However, a small, but growing, body of evidence indicates that for some dialysis patients, favourable improvements in muscle atrophy and fibre hypertrophy can be achieved via predominantly aerobic exercise training. Moreover, some studies tentatively suggest that nutritional status, as measured by SGA, can also be modestly improved by modes and patterns of exercise training that have been shown to also increase muscle fibre cross-sectional area and improve functional capacity. Functional capacity tests can augment the information content of basic nutritional status assessments of dialysis patients and as such are recommended for routine inclusion as a feature of all nutritional status assessments.

Aerobic fitness does not modify the effect of FTO variation on body composition traits.

PubMed

Huuskonen, Antti; Lappalainen, Jani; Oksala, Niku; Santtila, Matti; Häkkinen, Keijo; Kyröläinen, Heikki; Atalay, Mustafa

2012-01-01

Poor physical fitness and obesity are risk factors for all cause morbidity and mortality. We aimed to clarify whether common genetic variants of key energy intake determinants in leptin (LEP), leptin receptor (LEPR), and fat mass and obesity-associated (FTO) are associated with aerobic and neuromuscular performance, and whether aerobic fitness can alter the effect of these genotypes on body composition. 846 healthy Finnish males of Caucasian origin were genotyped for FTO (rs8050136), LEP (rs7799039) and LEPR (rs8179183 and rs1137101) single nucleotide polymorphisms (SNPs), and studied for associations with maximal oxygen consumption, body fat percent, serum leptin levels, waist circumference and maximal force of leg extensor muscles. Genotype AA of the FTO SNP rs8050136 associated with higher BMI and greater waist circumference compared to the genotype CC. In general linear model, no significant interaction for FTO genotype-relative VO(2)max (mL·kg(-1)·min(-1)) or FTO genotype-absolute VO(2)max (L·min(-1)) on BMI or waist circumference was found. Main effects of aerobic performance on body composition traits were significant (p<0.001). Logistic regression modelling found no significant interaction between aerobic fitness and FTO genotype. LEP SNP rs7799039, LEPR SNPs rs8179183 and rs1137101 did not associate with any of the measured variables, and no significant interactions of LEP or LEPR genotype with aerobic fitness were observed. In addition, none of the studied SNPs associated with aerobic or neuromuscular performance. Aerobic fitness may not modify the effect of FTO variation on body composition traits. However, relative aerobic capacity associates with lower BMI and waist circumference regardless of the FTO genotype. FTO, LEP and LEPR genotypes unlikely associate with physical performance.

[Age-associated peculiarities of microcirculation system in skeletal muscles and their role in muscle work capacity in human aging (author's transl)].

PubMed

Korkusko, O V; Sarkisov, K G; Frajfel'd, V E

1982-01-01

The muscle blood flow was investigated at rest (MBFR) and after physical load under ischemia conditions (maximal muscle blood flow--MMBF) in 87 practically healthy persons (45 women and 42 men) aged 20--90. The state of muscle blood flow was evaluated by means of the clearance of 133xenon injected into M. tibialis anterior. The data obtained showed a decrease of MBFR and MMBF in older people as compared with younger subjects. In realization of this phenomenon a decrease in muscle capillarisation and a reduction in reactivity of microcirculatory link of vascular system plays an increasingly greater role with aging. The reduction in muscle blood flow forms a circulatory component of the age-associated hypoxia. This fact results in a decrease of muscle blood flow and limits the functional capacity of skeletal muscle under conditions of activity.

[Insight into the training of patients with idiopathic inflammatory myopathy].

PubMed

Váncsa, Andrea

2016-09-01

Using current recommended treatment, a majority of patients with idiopathic inflammatory myopathy develop muscle impairment and poor health. Beneficial effects of exercise have been reported on muscle performance, aerobic capacity and health in chronic polymyositis and dermatomyositis, as well as in active disease and inclusion body myositis to some extent. Importantly, randomized controlled trials indicate that improved health and decreased clinical disease activity could be mediated through increased aerobic capacity. Recently, reports seeking pathomechanisms of the underlying effects of exercise on skeletal muscle indicate increased aerobic capacity (i.e. increased mitochondrial capacity and capillary density, reduced lactate levels), activation of genes of aerobic phenotype and muscle growth programs and down regulation of genes related to inflammation. Exercise contributes to both systemic and within-muscle adaptations demonstrating that it is fundamental for improving muscle performance and health in patients with idiopathic inflammatory myopathy. There is a need for randomized controlled trials to study the effects of exercise in patients with active disease and inclusion body myositis. Orv. Hetil., 2016, 157(39), 1557-1562.

Influence of aerobic exercise intensity on myofibrillar and mitochondrial protein synthesis in young men during early and late postexercise recovery

PubMed Central

Di Donato, Danielle M.; West, Daniel W. D.; Churchward-Venne, Tyler A.; Breen, Leigh; Baker, Steven K.

2014-01-01

Aerobic exercise is typically associated with expansion of the mitochondrial protein pool and improvements in muscle oxidative capacity. The impact of aerobic exercise intensity on the synthesis of specific skeletal muscle protein subfractions is not known. We aimed to study the effect of aerobic exercise intensity on rates of myofibrillar (MyoPS) and mitochondrial (MitoPS) protein synthesis over an early (0.5–4.5 h) and late (24–28 h) period during postexercise recovery. Using a within-subject crossover design, eight males (21 ± 1 yr, V̇o2peak 46.7 ± 2.0 ml·kg−1·min−1) performed two work-matched cycle ergometry exercise trials (LOW: 60 min at 30% Wmax; HIGH: 30 min at 60% Wmax) in the fasted state while undergoing a primed constant infusion of l-[ring-13C6]phenylalanine. Muscle biopsies were obtained at rest and 0.5, 4.5, 24, and 28 h postexercise to determine both the “early” and “late” response of MyoPS and MitoPS and the phosphorylation status of selected proteins within both the Akt/mTOR and MAPK pathways. Over 24–28 h postexercise, MitoPS was significantly greater after the HIGH vs. LOW exercise trial (P < 0.05). Rates of MyoPS were increased equivalently over 0.5–4.5 h postexercise recovery (P < 0.05) but remained elevated at 24–28 h postexercise only following the HIGH trial. In conclusion, an acute bout of high- but not low-intensity aerobic exercise in the fasted state resulted in a sustained elevation of both MitoPS and MyoPS at 24–28 h postexercise recovery. PMID:24595306

Relations between muscle endurance and subjectively reported fatigue, walking capacity, and participation in mildly affected adolescents with cerebral palsy.

PubMed

Eken, Maaike M; Houdijk, Han; Doorenbosch, Caroline A M; Kiezebrink, Francisca E M; van Bennekom, Coen A M; Harlaar, Jaap; Dallmeijer, Annet J

2016-08-01

To investigate the relation between muscle endurance and subjectively reported fatigue, walking capacity, and participation in mildly affected adolescents with cerebral palsy (CP) and peers with typical development. In this case-control study, knee extensor muscle endurance was estimated from individual load-endurance curves as the load corresponding to a 15-repetition maximum in 17 adolescents with spastic CP (six males, 11 females; age 12-19y) and 18 adolescents with typical development (eight males, 10 females; age 13-19y). Questionnaires were used to assess subjectively reported fatigue (Pediatric Quality of Life Inventory Multidimensional Fatigue Scale) and participation (Life-Habits questionnaire). Walking capacity was assessed using the 6-minute walk test. Relations were determined using multiple regression analyses. Muscle endurance related significantly to subjectively reported fatigue and walking capacity in adolescents with CP, while no relations were found for adolescents with typical development (subjectively reported fatigue: regression coefficient β [95% confidence intervals] for CP=23.72 [6.26 to 41.18], for controls=2.72 [-10.26 to 15.69]; walking capacity β for CP=125m [-87 to 337], for controls=2m [-86 to 89]). The 15-repetition maximum did not relate to participation in adolescents with CP. Subjectively reported fatigue and reduced walking capacity in adolescents with CP are partly caused by lower muscle endurance of knee extensors. Training of muscle endurance might contribute to reducing the experience of fatigue and improving walking capacity. Reduced muscle endurance seems to have no effect on participation. © 2016 Mac Keith Press.

Aerobic training in adults after atrial switch procedure for transposition of the great arteries improves exercise capacity without impairing systemic right ventricular function.

PubMed

Westhoff-Bleck, Mechthild; Schieffer, Bernhard; Tegtbur, Uwe; Meyer, Gerd Peter; Hoy, Ludwig; Schaefer, Arnd; Tallone, Ezequiel Marcello; Tutarel, Oktay; Mertins, Ramona; Wilmink, Lena Mara; Anker, Stefan D; Bauersachs, Johann; Roentgen, Philipp

2013-12-05

Exercise training safely and efficiently improves symptoms in patients with heart failure due to left ventricular dysfunction. However, studies in congenital heart disease with systemic right ventricle are scarce and results are controversial. In a randomised controlled study we investigated the effect of aerobic exercise training on exercise capacity and systemic right ventricular function in adults with d-transposition of the great arteries after atrial redirection surgery (28.2 ± 3.0 years after Mustard procedure). 48 patients (31 male, age 29.3 ± 3.4 years) were randomly allocated to 24 weeks of structured exercise training or usual care. Primary endpoint was the change in maximum oxygen uptake (peak VO2). Secondary endpoints were systemic right ventricular diameters determined by cardiac magnetic resonance imaging (CMR). Data were analysed per intention to treat analysis. At baseline peak VO2 was 25.5 ± 4.7 ml/kg/min in control and 24.0 ± 5 ml/kg/min in the training group (p=0.3). Training significantly improved exercise capacity (treatment effect for peak VO2 3.8 ml/kg/min, 95% CI: 1.8 to 5.7; p=0.001), work load (p=0.002), maximum exercise time (p=0.002), and NYHA class (p=0.046). Systemic ventricular function and volumes determined by CMR remained unchanged. None of the patients developed signs of cardiac decompensation or arrhythmias while on exercise training. Aerobic exercise training did not detrimentally affect systemic right ventricular function, but significantly improved exercise capacity and heart failure symptoms. Aerobic exercise training can be recommended for patients following atrial redirection surgery to improve exercise capacity and to lessen or prevent heart failure symptoms. ( ClinicalTrials.gov #NCT00837603). © 2013.

Robot-assisted gait training improves brachial–ankle pulse wave velocity and peak aerobic capacity in subacute stroke patients with totally dependent ambulation

PubMed Central

Han, Eun Young; Im, Sang Hee; Kim, Bo Ryun; Seo, Min Ji; Kim, Myeong Ok

2016-01-01

Abstract Objective: Brachial–ankle pulse wave velocity (baPWV) evaluates arterial stiffness and also predicts early outcome in stroke patients. The objectives of this study were to investigate arterial stiffness of subacute nonfunctional ambulatory stroke patients and to compare the effects of robot-assisted gait therapy (RAGT) combined with rehabilitation therapy (RT) on arterial stiffness and functional recovery with those of RT alone. Method: The RAGT group (N = 30) received 30 minutes of robot-assisted gait therapy and 30 minutes of conventional RT, and the control group (N = 26) received 60 minutes of RT, 5 times a week for 4 weeks. baPWV was measured and calculated using an automated device. The patients also performed a symptom-limited graded exercise stress test using a bicycle ergometer, and parameters of cardiopulmonary fitness were recorded. Clinical outcome measures were categorized into 4 categories: activities of daily living, balance, ambulatory function, and paretic leg motor function and were evaluated before and after the 4-week intervention. Results: Both groups exhibited significant functional recovery in all clinical outcome measures after the 4-week intervention. However, peak aerobic capacity, peak heart rate, exercise tolerance test duration, and baPWV improved only in the RAGT group, and the improvements in baPWV and peak aerobic capacity were more noticeable in the RAGT group than in the control group. Conclusion: Robot-assisted gait therapy combined with conventional rehabilitation therapy represents an effective method for reversing arterial stiffness and improving peak aerobic capacity in subacute stroke patients with totally dependent ambulation. However, further large-scale studies with longer term follow-up periods are warranted to measure the effects of RAGT on secondary prevention after stroke. PMID:27741123

Limits to sustainable muscle performance: interaction between glycolysis and oxidative phosphorylation.

PubMed

Conley, K E; Kemper, W F; Crowther, G J

2001-09-01

This paper proposes a mechanism responsible for setting the sustainable level of muscle performance. Our contentions are that the sustainable work rate is determined (i) at the muscle level, (ii) by the ability to maintain ATP supply and (iii) by the products of glycolysis that may inhibit the signal for oxidative phosphorylation. We argue below that no single factor 'limits' sustainable performance, but rather that the flux through and the interaction between glycolysis and oxidative phosphorylation set the level of sustainable ATP supply. This argument is based on magnetic resonance spectroscopy measurements of the sources and sinks for energy in vivo in human muscle and rattlesnake tailshaker muscle during sustained contractions. These measurements show that glycolysis provides between 20% (human muscle) and 40% (tailshaker muscle) of the ATP supply during sustained contractions in these muscles. We cite evidence showing that this high glycolytic flux does not reflect an O(2) limitation or mitochondria operating at their capacity. Instead, this flux reflects a pathway independent of oxidative phosphorylation for ATP supply during aerobic exercise. The consequence of this high glycolytic flux is accumulation of H(+), which we argue inhibits the rise in the signal activating oxidative phosphorylation, thereby restricting oxidative ATP supply to below the oxidative capacity. Thus, both glycolysis and oxidative phosphorylation play important roles in setting the highest steady-state ATP synthesis flux and thereby determine the sustainable level of work by exercising muscle.

Aerobic fitness in women and responses to lower body negative pressure

NASA Technical Reports Server (NTRS)

Frey, Mary Anne Bassett; Mathes, Karen L.; Hoffler, G. Wyckliffe

1987-01-01

The role of tolerance to orthostatic stress in the maintenance of high aerobic fitness in women was investigated by examining the responses of heart rate, stroke volume, cardiac output, Heather index of contractility, arterial pressure, peripheral resistance, change in calf circumference, and thoracic impedance of healthy female subjects to lower body negative pressure (LBNP) applied for 5 min at -50 mm Hg or until a subject became presyncopal. The testing protocol involved a stepwise reduction in pressure and consisted of two parts: an LBNP test in supine position followed by a treadmill test to peak aerobic capacity. Women were found to exhibit the same response pattern to LBNP as was previously reported by Convertino et al. (1984) for men. The results do not support the hypothesis that orthostatic tolerance in women is inversely related to aerobic fitness, as demonstrated by a finding that the peak aerobic capacity of subjects who became presyncopal did not differ from the peak of the tolerant subjects, and that hemodynamic responses to LBNPL were not a function of aerobic capacity.

Limited Association Between Aerobic Fitness and Pain in Healthy Individuals: A Cross-Sectional Study.

PubMed

Jones, Matthew D; Booth, John; Taylor, Janet L; Barry, Benjamin K

2016-10-01

In healthy individuals and people with chronic pain, an inverse association between physical activity level and pain has been reported. Associations between objectively measured fitness and pain have also been found in people with chronic pain, but it is not clear whether the same relations are apparent in healthy individuals. The purpose of the present study was to examine the relation between aerobic capacity and pain in healthy individuals. Pressure pain threshold, ischemic pain tolerance, and pain ratings during ischemia were assessed and analyzed in relation to aerobic capacity in 35 healthy individuals. Correlation and multiple linear regression were used to analyze the data. Data from previous similar studies in healthy individuals and people with fibromyalgia were extracted and collated by literature review to support interpretation of the experimental data. No relation was found between aerobic capacity and any measure of pain, with the exception of a moderate inverse association between aerobic capacity and lower body pressure pain threshold in males (r = -0.58, P = 0.03) when data from male and female participants were analyzed separately. The limited association between aerobic capacity and quantitative sensory testing of pain was consistent with the data synthesis from previous studies of healthy individuals but differed from studies of people with fibromyalgia. Aerobic capacity is unrelated to pain in healthy young adults. For people with chronic pain, the negative relation between aerobic capacity and pain presumably arises from the underlying pathophysiology and/or associated behaviors of the disease process. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

[Effects of aerobic exercise combined with resistance training on the cardiorespiratory fitness and exercise capacity of patients with stable coronary artery disease].

PubMed

Liu, S X; Chen, Y Y; Xie, K L; Zhang, W L

2017-12-24

Objective: To observe the effects of aerobic exercise combined with resistance training on the cardiorespiratory fitness and exercise capacity of patients with stable coronary artery disease (CAD) . Methods: From June 2014 to December 2015, 73 patients with stable CAD in our department were recruited and randomly assigned to two groups: the control group ( n= 38) and the exercise group ( n= 35) . Patients in both groups received conventional medical treatment for CAD and related cardiac health education. While for patients in exercise group, a twelve-week aerobic exercise combined with resistance training program were applied on top of conventional treatment and health education. Cardiorespiratory fitness and exercise capacity were evaluated by cardiopulmonary exercise testing. Results: (1) The exercise capacity was significantly increased in the exercise group after 12 weeks training as compared to baseline level: peak oxygen uptake per kilogram ( (26.25±5.14) ml·kg(-1)·min(-1) vs. (20.88±4.59) ml·kg(-1)·min(-1)) , anaerobic threshold ( (15.24±2.75) ml·kg(-1)·min(-1) vs. (13.52±2.92) ml·kg(-1)·min(-1)], peak oxygen pulse ( (11.91±2.89) ml/beat vs. (9.77±2.49) ml/beat) , peak Watts ( (113.2±34.0) W vs. (103.7±27.9) W) , peak metabolic equivalent ( (7.57±1.46) METs vs. (6.00±1.32) METs) (all P< 0.05 vs. baseline) . (2) The degree of improvement of peak oxygen uptake per kilogram ( (26.25±5.14) ml·kg(-1)·min(-1) vs. (22.32±4.00) ml·kg(-1)·min(-1)) , anaerobic threshold ( (15.24±2.75) ml·kg(-1)·min(-1) vs. (13.76±2.51) ml·kg(-1)·min(-1)) , peak oxygen pulse ( (11.91±2.89) ml/beat vs. (9.99±2.15) ml/beat) and peak metabolic equivalent ( (7.57±1.46) METs vs. (6.47±1.17) METs) were significantly higher in exercise group than in control group (all P< 0.05) . Conclusion: Aerobic training at an aerobic threshold level combined with Thera-band resistance training is safe for patients with stable coronary artery disease. This combined

Body composition, muscle capacity, and physical function in older adults: an integrated conceptual model.

PubMed

Brady, Anne O; Straight, Chad R; Evans, Ellen M

2014-07-01

The aging process leads to adverse changes in body composition (increases in fat mass and decreases in skeletal muscle mass), declines in physical function (PF), and ultimately increased risk for disability and loss of independence. Specific components of body composition or muscle capacity (strength and power) may be useful in predicting PF; however, findings have been mixed regarding the most salient predictor of PF. The development of a conceptual model potentially aids in understanding the interrelated factors contributing to PF with the factors of interest being physical activity, body composition, and muscle capacity. This article also highlights sex differences in these domains. Finally, factors known to affect PF, such as sleep, depression, fatigue, and self-efficacy, are discussed. Development of a comprehensive conceptual model is needed to better characterize the most salient factors contributing to PF and to subsequently inform the development of interventions to reduce physical disability in older adults.

Effects of High-Intensity Interval Training on Aerobic Capacity in Cardiac Patients: A Systematic Review with Meta-Analysis

PubMed Central

Xie, Bin; Yan, Xianfeng

2017-01-01

Purpose. The aim of this study was to compare the effects of high-intensity interval training (INTERVAL) and moderate-intensity continuous training (CONTINUOUS) on aerobic capacity in cardiac patients. Methods. A meta-analysis identified by searching the PubMed, Cochrane Library, EMBASE, and Web of Science databases from inception through December 2016 compared the effects of INTERVAL and CONTINUOUS among cardiac patients. Results. Twenty-one studies involving 736 participants with cardiac diseases were included. Compared with CONTINUOUS, INTERVAL was associated with greater improvement in peak VO2 (mean difference 1.76 mL/kg/min, 95% confidence interval 1.06 to 2.46 mL/kg/min, p < 0.001) and VO2 at AT (mean difference 0.90 mL/kg/min, 95% confidence interval 0.0 to 1.72 mL/kg/min, p = 0.03). No significant difference between the INTERVAL and CONTINUOUS groups was observed in terms of peak heart rate, peak minute ventilation, VE/VCO2 slope and respiratory exchange ratio, body mass, systolic or diastolic blood pressure, triglyceride or low- or high-density lipoprotein cholesterol level, flow-mediated dilation, or left ventricular ejection fraction. Conclusions. This study showed that INTERVAL improves aerobic capacity more effectively than does CONTINUOUS in cardiac patients. Further studies with larger samples are needed to confirm our observations. PMID:28386556

Is high-intensity interval training more effective on improving cardiometabolic risk and aerobic capacity than other forms of exercise in overweight and obese youth? A meta-analysis.

PubMed

García-Hermoso, A; Cerrillo-Urbina, A J; Herrera-Valenzuela, T; Cristi-Montero, C; Saavedra, J M; Martínez-Vizcaíno, V

2016-06-01

The scientific interest in high-intensity interval training (HIIT) has greatly increased during recent years. The objective of this meta-analysis was to determine the effectiveness of HIIT interventions on cardio-metabolic risk factors and aerobic capacity in overweight and obese youth, in comparison with other forms of exercise. A computerized search was made using seven databases. The analysis was restricted to studies that examined the effect of HIIT interventions on cardio-metabolic and/or aerobic capacity in pediatric obesity (6-17 years old). Nine studies using HIIT interventions were selected (n = 274). Standarized mean difference (SMD) and 95% confidence intervals were calculated. The DerSimonian-Laird approach was used. HIIT interventions (4-12 week duration) produced larger decreases in systolic blood pressure (SMD = 0.39; -3.63 mmHg) and greater increases in maximum oxygen uptake (SMD = 0.59; 1.92 ml/kg/min) than other forms of exercise. Also, type of comparison exercise group and duration of study were moderators. HIIT could be considered a more effective and time-efficient intervention for improving blood pressure and aerobic capacity levels in obese youth in comparison to other types of exercise. © 2016 World Obesity. © 2016 World Obesity.

Exercise and nutritional interventions for improving aging muscle health.

PubMed

Forbes, Scott C; Little, Jonathan P; Candow, Darren G

2012-08-01

Skeletal muscle mass declines with age (i.e., sarcopenia) resulting in muscle weakness and functional limitations. Sarcopenia has been associated with physiological changes in muscle morphology, protein and hormonal kinetics, insulin resistance, inflammation, and oxidative stress. The purpose of this review is to highlight how exercise and nutritional intervention strategies may benefit aging muscle. It is well known that resistance exercise training increases muscle strength and size and evidence also suggests that resistance training can increase mitochondrial content and decrease oxidative stress in older adults. Recent findings suggest that fast-velocity resistance exercise may be an effective intervention for older adults to enhance muscle power and functional capacity. Aerobic exercise training may also benefit aging skeletal muscle by enhancing mitochondrial bioenergetics, improving insulin sensitivity, and/or decreasing oxidative stress. In addition to exercise, creatine monohydrate, milk-based proteins, and essential fatty acids all have biological effects which could enhance some of the physiological adaptations from exercise training in older adults. Additional research is needed to determine whether skeletal muscle adaptations to increased activity in older adults are further enhanced with effective nutritional interventions and whether this is due to enhanced muscle protein synthesis, improved mitochondrial function, and/or a reduced inflammatory response.

Effect of aerobic fitness on the physiological stress responses at work.

PubMed

Ritvanen, Tiina; Louhevaara, Veikko; Helin, Pertti; Halonen, Toivo; Hänninen, Osmo

2007-01-01

The aim of the present study was to examine the effects of aerobic fitness on physiological stress responses experienced by teachers during working hours. Twenty-six healthy female and male teachers aged 33-62 years participated in the study. The ratings of perceived stress visual analogue scale (VAS), and the measurement of physiological responses (norepinephrine, epinephrine, cortisol, diastolic and systolic blood pressure, heart rate (HR), and trapezius muscle activity by electromyography (EMG), were determined. Predicted maximal oxygen uptake (VO(2)max) was measured using the submaximal bicycle ergometer test. The predicted VO(2)max was standardized for age using residuals of linear regression analyses. Static EMG activity, HR and VAS were associated with aerobic fitness in teachers. The results suggest that a higher level of aerobic fitness may reduce muscle tension, HR and perceived work stress in teachers.

Measurement Agreement between Estimates of Aerobic Fitness in Youth: The Impact of Body Mass Index

ERIC Educational Resources Information Center

Saint-Maurice, Pedro F.; Welk, Gregory J.; Laurson, Kelly R.; Brown, Dale D.

2014-01-01

Purpose: The purpose of this study was to examine the impact of body mass index (BMI) on the agreement between aerobic capacity estimates from different Progressive Aerobic Cardiorespiratory Endurance Run (PACER) equations and the Mile Run Test. Method: The agreement between 2 different tests of aerobic capacity was examined on a large data set…

Cycle training induces muscle hypertrophy and strength gain: strategies and mechanisms.

PubMed

Ozaki, Hayao; Loenneke, J P; Thiebaud, R S; Abe, T

2015-03-01

Cycle training is widely performed as a major part of any exercise program seeking to improve aerobic capacity and cardiovascular health. However, the effect of cycle training on muscle size and strength gain still requires further insight, even though it is known that professional cyclists display larger muscle size compared to controls. Therefore, the purpose of this review is to discuss the effects of cycle training on muscle size and strength of the lower extremity and the possible mechanisms for increasing muscle size with cycle training. It is plausible that cycle training requires a longer period to significantly increase muscle size compared to typical resistance training due to a much slower hypertrophy rate. Cycle training induces muscle hypertrophy similarly between young and older age groups, while strength gain seems to favor older adults, which suggests that the probability for improving in muscle quality appears to be higher in older adults compared to young adults. For young adults, higher-intensity intermittent cycling may be required to achieve strength gains. It also appears that muscle hypertrophy induced by cycle training results from the positive changes in muscle protein net balance.

Gender Difference in Aerobic Capacity and the Contribution by Body Composition and Haemoglobin Concentration: A Study in Young Indian National Hockey Players

PubMed Central

Kailashiya, Jyotsna

2016-01-01

Introduction Although gender difference in aerobic capacity is known, the contributing factors have been researched seldom. Aim To investigate the gender gap and the contribution by percentage Body Fat (BF), Body Mass Index (BMI) and haemoglobin concentration Hb. Materials and Methods The study was conducted on 30 (17 males, 13 females) training status matched young hockey players. Healthy players who were playing upto national level competition were included. BW (Body Weight), BF, BMI, LBM (Lean Body Mass), rHR (restring Heart Rate), HRR (Heart Rate Recovery), Hb, a/rVO2max (absolute/relative), a/rPWC (Physical Work Capacity) and RMR (Resting Metabolic Rate) were measured and analysed. Results There was significant gender difference in the measured parameters. Difference in a/rVO2max remained significant even after controlling for BF, BMI and Hb. Multiple regression and correlation analysis revealed gender difference in VO2max/LBM was due to: BMI(31.91%)>BF(27.60%)>Hb(9.91%). BMI also significantly contributed 3.66% of VO2max/LBM variance, independent of that by gender. Difference in RMR was mainly related to LBM, BF and BMI. Conclusion The study provided an understanding for gender gap in aerobic capacity. Differences in BMI & BF were one of the main reasons. PMID:28050360

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

Effects of inspiratory muscle training on pulmonary function, respiratory muscle strength and functional capacity in patients with atrial fibrillation: a randomized controlled trial.

PubMed

Zeren, Melih; Demir, Rengin; Yigit, Zerrin; Gurses, Hulya N

2016-12-01

To investigate the effects of inspiratory muscle training on pulmonary function, respiratory muscle strength and functional capacity in patients with atrial fibrillation. Prospective randomized controlled single-blind study. Cardiology department of a university hospital. A total of 38 patients with permanent atrial fibrillation were randomly allocated to either a treatment group (n = 19; age 66.2 years (8.8)) or a control group (n = 19; age 67.1 years (6.4)). The training group received inspiratory muscle training at 30% of maximal inspiratory pressure for 15 minutes twice a day, 7 days a week, for 12 weeks alongside the standard medical treatment. The control group received standard medical treatment only. Spirometry, maximal inspiratory and expiratory pressures and 6-minute walking distance was measured at the beginning and end of the study. There was a significant increase in maximal inspiratory pressure (27.94 cmH 2 O (8.90)), maximal expiratory pressure (24.53 cmH 2 O (10.34)), forced vital capacity (10.29% (8.18) predicted), forced expiratory volume in one second (13.88% (13.42) predicted), forced expiratory flow 25%-75% (14.82% (12.44) predicted), peak expiratory flow (19.82% (15.62) predicted) and 6-minute walking distance (55.53 m (14.13)) in the training group (p < 0.01). No significant changes occurred in the control group (p > 0.05). Inspiratory muscle training can improve pulmonary function, respiratory muscle strength and functional capacity in patients with atrial fibrillation. © The Author(s) 2016.

Construct validity of functional capacity tests in healthy workers

PubMed Central

2013-01-01

Background Functional Capacity (FC) is a multidimensional construct within the activity domain of the International Classification of Functioning, Disability and Health framework (ICF). Functional capacity evaluations (FCEs) are assessments of work-related FC. The extent to which these work-related FC tests are associated to bio-, psycho-, or social factors is unknown. The aims of this study were to test relationships between FC tests and other ICF factors in a sample of healthy workers, and to determine the amount of statistical variance in FC tests that can be explained by these factors. Methods A cross sectional study. The sample was comprised of 403 healthy workers who completed material handling FC tests (lifting low, overhead lifting, and carrying) and static work FC tests (overhead working and standing forward bend). The explainable variables were; six muscle strength tests; aerobic capacity test; and questionnaires regarding personal factors (age, gender, body height, body weight, and education), psychological factors (mental health, vitality, and general health perceptions), and social factors (perception of work, physical workloads, sport-, leisure time-, and work-index). A priori construct validity hypotheses were formulated and analyzed by means of correlation coefficients and regression analyses. Results Moderate correlations were detected between material handling FC tests and muscle strength, gender, body weight, and body height. As for static work FC tests; overhead working correlated fair with aerobic capacity and handgrip strength, and low with the sport-index and perception of work. For standing forward bend FC test, all hypotheses were rejected. The regression model revealed that 61% to 62% of material handling FC tests were explained by physical factors. Five to 15% of static work FC tests were explained by physical and social factors. Conclusions The current study revealed that, in a sample of healthy workers, material handling FC tests were

Predicting Functional Capacity From Measures of Muscle Mass in Postmenopausal Women.

PubMed

Orsatti, Fábio Lera; Nunes, Paulo Ricardo Prado; Souza, Aletéia de Paula; Martins, Fernanda Maria; de Oliveira, Anselmo Alves; Nomelini, Rosekeila Simões; Michelin, Márcia Antoniazi; Murta, Eddie Fernando Cândido

2017-06-01

Menopause increases body fat and decreases muscle mass and strength, which contribute to sarcopenia. The amount of appendicular muscle mass has been frequently used to diagnose sarcopenia. Different measures of appendicular muscle mass have been proposed. However, no studies have compared the most salient measure (appendicular muscle mass corrected by body fat) of the appendicular muscle mass to physical function in postmenopausal women. To examine the association of 3 different measurements of appendicular muscle mass (absolute, corrected by stature, and corrected by body fat) with physical function in postmenopausal women. Cross-sectional descriptive study. Outpatient geriatric and gynecological clinic. Forty-eight postmenopausal women with a mean age (standard deviation [SD]) of 62.1 ± 8.2 years, with mean (SD) length of menopause of 15.7 ± 9.8 years and mean (SD) body fat of 43.6% ± 9.8%. Not applicable. Appendicular muscle mass measure was measured with dual-energy x-ray absorptiometry. Physical function was measured by a functional capacity questionnaire, a short physical performance battery, and a 6 minute-walk test. Muscle quality (leg extensor strength to lower-body mineral-free lean mass ratio) and sum of z scores (sum of each physical function tests z score) were performed to provide a global index of physical function. The regression analysis showed that appendicular muscle mass corrected by body fat was the strongest predictor of physical function. Each increase in the standard deviation of appendicular muscle mass corrected by body fat was associated with a mean sum of z score increase of 59% (standard deviation), whereas each increase in absolute appendicular muscle mass and appendicular muscle mass corrected by stature were associated with a mean sum of z scores decrease of 23% and 36%, respectively. Muscle quality was associated with appendicular muscle mass corrected by body fat. These findings indicate that appendicular muscle mass corrected

The effects of aerobic exercise and strengthening exercise on pain pressure thresholds.

PubMed

Lee, Han Suk

2014-07-01

[Purpose] We assessed the effects of aerobic exercise and strengthening exercise on pain pressure thresholds (PPTs) over time. [Subjects and Methods] Fifteen healthy participants were recruited and randomly divided into 3 groups: aerobic exercise, strengthening exercise, and control. The subjects in the aerobic group walked on a treadmill for 40 min at 6.5 km/h. The subjects in the strength group performed circuit training that included bench press, lat pull down, biceps curl, triceps extension, and shoulder press based on the perceived exertion for 40 min. The subjects in the control group rested without any exercise in a quiet room for 40 min. The PPTs of 5 potential muscle trigger points before exercise, and immediately after 10 and 40 min of exercise or rest were measured using an electronic algometer (JTECH Medical, USA). The Friedman's, Kruskal-Wallis, and Mann-Whitney tests were performed using SPSS 18.0 (IBM, Korea). [Results] The PPTs of all subjects decreased after 10 min of exercise, but the difference was not statistically significant. The PPTs of the control group decreased after 40 min. Furthermore, the PPTs of 3 muscles increased after 40 min of aerobic exercise and of 6 muscles after 40 min of strengthening exercise. No significant difference in PPTs was noted among the groups. [Conclusion] The results show that 40 min is a more appropriate exercise time, although the efficacy of controlling pain did not differ between strengthening exercise and aerobic exercise.

Functional properties of myoglobins from five whale species with different diving capacities.

PubMed

Helbo, Signe; Fago, Angela

2012-10-01

Whales show an exceptionally wide range of diving capabilities and many express high amounts of the O(2) carrier protein myoglobin (Mb) in their muscle tissues, which increases their aerobic diving capacity. Although previous studies have mainly focused on the muscle Mb concentration and O(2) carrying capacity as markers of diving behavior in whales, it still remains unexplored whether whale Mbs differ in their O(2) affinities and nitrite reductase and peroxidase enzymatic activities, all functions that could contribute to differences in diving capacities. In this study, we have measured the functional properties of purified Mbs from five toothed whales and two baleen whales and have examined their correlation with average dive duration. Results showed that some variation in functional properties exists among whale Mbs, with toothed whale Mbs having higher O(2) affinities and nitrite reductase activities (similar to those of horse Mb) compared with baleen whale Mbs. However, these differences did not correlate with average dive duration. Instead, a significant correlation was found between whale Mb concentration and average duration and depth of dives, and between O(2) affinity and nitrite reductase activity when including horse Mb. Despite the fact that the functional properties showed little species-specific differences in vitro, they may still contribute to enhancing diving capacity as a result of the increased muscle Mb concentration found in extreme divers. In conclusion, Mb concentration rather than specific functional reactivities may support whale diving performance.

Mitochondrial uncoupling reduces exercise capacity despite several skeletal muscle metabolic adaptations.

PubMed

Schlagowski, A I; Singh, F; Charles, A L; Gali Ramamoorthy, T; Favret, F; Piquard, F; Geny, B; Zoll, J

2014-02-15

The effects of mitochondrial uncoupling on skeletal muscle mitochondrial adaptation and maximal exercise capacity are unknown. In this study, rats were divided into a control group (CTL, n = 8) and a group treated with 2,4-dinitrophenol, a mitochondrial uncoupler, for 28 days (DNP, 30 mg·kg(-1)·day(-1) in drinking water, n = 8). The DNP group had a significantly lower body mass (P < 0.05) and a higher resting oxygen uptake (Vo2, P < 0.005). The incremental treadmill test showed that maximal running speed and running economy (P < 0.01) were impaired but that maximal Vo2 (Vo2max) was higher in the DNP-treated rats (P < 0.05). In skinned gastrocnemius fibers, basal respiration (V0) was higher (P < 0.01) in the DNP-treated animals, whereas the acceptor control ratio (ACR, Vmax/V0) was significantly lower (P < 0.05), indicating a reduction in OXPHOS efficiency. In skeletal muscle, DNP activated the mitochondrial biogenesis pathway, as indicated by changes in the mRNA expression of PGC1-α and -β, NRF-1 and -2, and TFAM, and increased the mRNA expression of cytochrome oxidase 1 (P < 0.01). The expression of two mitochondrial proteins (prohibitin and Ndufs 3) was higher after DNP treatment. Mitochondrial fission 1 protein (Fis-1) was increased in the DNP group (P < 0.01), but mitofusin-1 and -2 were unchanged. Histochemical staining for NADH dehydrogenase and succinate dehydrogenase activity in the gastrocnemius muscle revealed an increase in the proportion of oxidative fibers after DNP treatment. Our study shows that mitochondrial uncoupling induces several skeletal muscle adaptations, highlighting the role of mitochondrial coupling as a critical factor for maximal exercise capacities. These results emphasize the importance of investigating the qualitative aspects of mitochondrial function in addition to the amount of mitochondria.

Maximal oxygen uptake is proportional to muscle fiber oxidative capacity, from chronic heart failure patients to professional cyclists.

PubMed

van der Zwaard, Stephan; de Ruiter, C Jo; Noordhof, Dionne A; Sterrenburg, Renske; Bloemers, Frank W; de Koning, Jos J; Jaspers, Richard T; van der Laarse, Willem J

2016-09-01

V̇o2 max during whole body exercise is presumably constrained by oxygen delivery to mitochondria rather than by mitochondria's ability to consume oxygen. Humans and animals have been reported to exploit only 60-80% of their mitochondrial oxidative capacity at maximal oxygen uptake (V̇o2 max). However, ex vivo quantification of mitochondrial overcapacity is complicated by isolation or permeabilization procedures. An alternative method for estimating mitochondrial oxidative capacity is via enzyme histochemical quantification of succinate dehydrogenase (SDH) activity. We determined to what extent V̇o2 max attained during cycling exercise differs from mitochondrial oxidative capacity predicted from SDH activity of vastus lateralis muscle in chronic heart failure patients, healthy controls, and cyclists. V̇o2 max was assessed in 20 healthy subjects and 28 cyclists, and SDH activity was determined from biopsy cryosections of vastus lateralis using quantitative histochemistry. Similar data from our laboratory of 14 chronic heart failure patients and 6 controls were included. Mitochondrial oxidative capacity was predicted from SDH activity using estimated skeletal muscle mass and the relationship between ex vivo fiber V̇o2 max and SDH activity of isolated single muscle fibers and myocardial trabecula under hyperoxic conditions. Mitochondrial oxidative capacity predicted from SDH activity was related (r(2) = 0.89, P < 0.001) to V̇o2 max measured during cycling in subjects with V̇o2 max ranging from 9.8 to 79.0 ml·kg(-1)·min(-1) V̇o2 max measured during cycling was on average 90 ± 14% of mitochondrial oxidative capacity. We conclude that human V̇o2 max is related to mitochondrial oxidative capacity predicted from skeletal muscle SDH activity. Mitochondrial oxidative capacity is likely marginally limited by oxygen supply to mitochondria. Copyright © 2016 the American Physiological Society.

Effects of 16-week high-intensity interval training using upper and lower body ergometers on aerobic fitness and morphological changes in healthy men: a preliminary study

PubMed Central

Osawa, Yusuke; Azuma, Koichiro; Tabata, Shogo; Katsukawa, Fuminori; Ishida, Hiroyuki; Oguma, Yuko; Kawai, Toshihide; Itoh, Hiroshi; Okuda, Shigeo; Matsumoto, Hideo

2014-01-01

It is unclear whether combined leg and arm high-intensity interval training (HIIT) improves fitness and morphological characteristics equal to those of leg-based HIIT programs. The aim of this study was to compare the effects of HIIT using leg-cycling (LC) and arm-cranking (AC) ergometers with an HIIT program using only LC. Effects on aerobic capacity and skeletal muscle were analyzed. Twelve healthy male subjects were assigned into two groups. One performed LC-HIIT (n=7) and the other LC- and AC-HIIT (n=5) twice weekly for 16 weeks. The training programs consisted of eight to 12 sets of >90% VO2 (the oxygen uptake that can be utilized in one minute) peak for 60 seconds with a 60-second active rest period. VO2 peak, watt peak, and heart rate were measured during an LC incremental exercise test. The cross-sectional area (CSA) of trunk and thigh muscles as well as bone-free lean body mass were measured using magnetic resonance imaging and dual-energy X-ray absorptiometry. The watt peak increased from baseline in both the LC (23%±38%; P<0.05) and the LC–AC groups (11%±9%; P<0.05). The CSA of the quadriceps femoris muscles also increased from baseline in both the LC (11%±4%; P<0.05) and the LC–AC groups (5%±5%; P<0.05). In contrast, increases were observed in the CSA of musculus psoas major (9%±11%) and musculus anterolateral abdominal (7%±4%) only in the LC–AC group. These results suggest that a combined LC- and AC-HIIT program improves aerobic capacity and muscle hypertrophy in both leg and trunk muscles. PMID:25395872

Effects of 16-week high-intensity interval training using upper and lower body ergometers on aerobic fitness and morphological changes in healthy men: a preliminary study.

PubMed

Osawa, Yusuke; Azuma, Koichiro; Tabata, Shogo; Katsukawa, Fuminori; Ishida, Hiroyuki; Oguma, Yuko; Kawai, Toshihide; Itoh, Hiroshi; Okuda, Shigeo; Matsumoto, Hideo

2014-01-01

It is unclear whether combined leg and arm high-intensity interval training (HIIT) improves fitness and morphological characteristics equal to those of leg-based HIIT programs. The aim of this study was to compare the effects of HIIT using leg-cycling (LC) and arm-cranking (AC) ergometers with an HIIT program using only LC. Effects on aerobic capacity and skeletal muscle were analyzed. Twelve healthy male subjects were assigned into two groups. One performed LC-HIIT (n=7) and the other LC- and AC-HIIT (n=5) twice weekly for 16 weeks. The training programs consisted of eight to 12 sets of >90% VO2 (the oxygen uptake that can be utilized in one minute) peak for 60 seconds with a 60-second active rest period. VO2 peak, watt peak, and heart rate were measured during an LC incremental exercise test. The cross-sectional area (CSA) of trunk and thigh muscles as well as bone-free lean body mass were measured using magnetic resonance imaging and dual-energy X-ray absorptiometry. The watt peak increased from baseline in both the LC (23%±38%; P<0.05) and the LC-AC groups (11%±9%; P<0.05). The CSA of the quadriceps femoris muscles also increased from baseline in both the LC (11%±4%; P<0.05) and the LC-AC groups (5%±5%; P<0.05). In contrast, increases were observed in the CSA of musculus psoas major (9%±11%) and musculus anterolateral abdominal (7%±4%) only in the LC-AC group. These results suggest that a combined LC- and AC-HIIT program improves aerobic capacity and muscle hypertrophy in both leg and trunk muscles.

31P Magnetic Resonance Spectroscopy Assessment of Muscle Bioenergetics as a Predictor of Gait Speed in the Baltimore Longitudinal Study of Aging.

PubMed

Choi, Seongjin; Reiter, David A; Shardell, Michelle; Simonsick, Eleanor M; Studenski, Stephanie; Spencer, Richard G; Fishbein, Kenneth W; Ferrucci, Luigi

2016-12-01

Aerobic fitness and muscle bioenergetic capacity decline with age; whether such declines explain age-related slowing of walking speed is unclear. We hypothesized that muscle energetics and aerobic capacity are independent correlates of walking speed in simple and challenging performance tests and that they account for the observed age-related decline in walking speed in these same tests. Muscle bioenergetics was assessed as postexercise recovery rate of phosphocreatine (PCr), k PCr , using phosphorus magnetic resonance spectroscopy ( 31 P-MRS) in 126 participants (53 men) of the Baltimore Longitudinal Study of Aging aged 26-91 years (mean = 72 years). Four walking tasks were administered-usual pace over 6 m and 150 seconds and fast pace over 6 m and 400 m. Separately, aerobic fitness was assessed as peak oxygen consumption (peak VO 2 ) using a graded treadmill test. All gait speeds, k PCr , and peak VO 2 were lower with older age. Independent of age, sex, height, and weight, both k PCr and peak VO 2 were positively and significantly associated with fast pace and long distance walking but only peak VO 2 and not k PCr was significantly associated with usual gait speed over 6 m. Both k PCr and peak VO 2 substantially attenuated the association between age and gait speed for all but the least stressful walking task of 6 m at usual pace. Muscle bioenergetics assessed using 31 P-MRS is highly correlated with walking speed and partially explains age-related poorer performance in fast and long walking tasks. Published by Oxford University Press on behalf of The Gerontological Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy.

PubMed

Rosenberry, Ryan; Chung, Susie; Nelson, Michael D

2018-02-20

Exercise represents a major hemodynamic stress that demands a highly coordinated neurovascular response in order to match oxygen delivery to metabolic demand. Reactive hyperemia (in response to a brief period of tissue ischemia) is an independent predictor of cardiovascular events and provides important insight into vascular health and vasodilatory capacity. Skeletal muscle oxidative capacity is equally important in health and disease, as it determines the energy supply for myocellular processes. Here, we describe a simple, non-invasive approach using near-infrared spectroscopy to assess each of these major clinical endpoints (reactive hyperemia, neurovascular coupling, and muscle oxidative capacity) during a single clinic or laboratory visit. Unlike Doppler ultrasound, magnetic resonance images/spectroscopy, or invasive catheter-based flow measurements or muscle biopsies, our approach is less operator-dependent, low-cost, and completely non-invasive. Representative data from our lab taken together with summary data from previously published literature illustrate the utility of each of these end-points. Once this technique is mastered, application to clinical populations will provide important mechanistic insight into exercise intolerance and cardiovascular dysfunction.

Gait characteristics of individuals with multiple sclerosis before and after a 6-month aerobic training program.

PubMed

Rodgers, M M; Mulcare, J A; King, D L; Mathews, T; Gupta, S C; Glaser, R M

1999-07-01

Individuals who have multiple sclerosis (MS) typically experience problems with physical activities such as walking, resulting from the combined effects of skeletal muscle weakness, sensory disturbances, spasticity, gait ataxia, and reduction in aerobic capacity. The aim of this study was to determine whether a 6-mo exercise program designed for aerobic conditioning might also affect gait abnormalities in individuals with MS. Subjects included 18 individuals with MS who presented a range of disability. Passive range of motion (PROM) in the lower limbs was measured and gait analyzed before and after exercise conditioning. Three-dimensional kinematics, ground reaction forces (GRF), and electromyographic information were acquired as subjects walked at self-selected velocities. Hip PROM increased following conditioning. Mean walking velocity, cadence, and posterior shear GRF (push-off force) decreased. During walking, maximum ankle dorsiflexion decreased and ankle plantarflexion increased. Total knee flexion/extension range during the walking cycle decreased slightly as did maximum hip extension. Results suggest this 6-mo training program had minimal effect on gait abnormalities.

Screening identification of aerobic denitrification bacteria with high soil desalinization capacity

NASA Astrophysics Data System (ADS)

Jin, H.; Chen, H.; Jin, H.; Qian, Y.; Zhang, K.

2017-08-01

In order to study the mechanism of bacteria used in the saline soil remediation process, the aerobic denitrification bacteria were isolated from an agricultural greenhouse soil in a farm in East China’s Zhejiang Province. The identification, nitrogen reducing characteristics and the denitrification effect of bacteria from different soils at various locations were investigated. The results showed that the NO3- removal rate was 91% with bacteria from the greenhouse soil under aerobic conditions in 52 h, and the bacteria were identified as Gram-positive Castellaniella denitrification bacteria.

Combination of exercise training and diet restriction normalizes limited exercise capacity and impaired skeletal muscle function in diet-induced diabetic mice.

PubMed

Suga, Tadashi; Kinugawa, Shintaro; Takada, Shingo; Kadoguchi, Tomoyasu; Fukushima, Arata; Homma, Tsuneaki; Masaki, Yoshihiro; Furihata, Takaaki; Takahashi, Masashige; Sobirin, Mochamad A; Ono, Taisuke; Hirabayashi, Kagami; Yokota, Takashi; Tanaka, Shinya; Okita, Koichi; Tsutsui, Hiroyuki

2014-01-01

Exercise training (EX) and diet restriction (DR) are essential for effective management of obesity and insulin resistance in diabetes mellitus. However, whether these interventions ameliorate the limited exercise capacity and impaired skeletal muscle function in diabetes patients remains unexplored. Therefore, we investigated the effects of EX and/or DR on exercise capacity and skeletal muscle function in diet-induced diabetic mice. Male C57BL/6J mice that were fed a high-fat diet (HFD) for 8 weeks were randomly assigned for an additional 4 weeks to 4 groups: control, EX, DR, and EX+DR. A lean group fed with a normal diet was also studied. Obesity and insulin resistance induced by a HFD were significantly but partially improved by EX or DR and completely reversed by EX+DR. Although exercise capacity decreased significantly with HFD compared with normal diet, it partially improved with EX and DR and completely reversed with EX+DR. In parallel, the impaired mitochondrial function and enhanced oxidative stress in the skeletal muscle caused by the HFD were normalized only by EX+DR. Although obesity and insulin resistance were completely reversed by DR with an insulin-sensitizing drug or a long-term intervention, the exercise capacity and skeletal muscle function could not be normalized. Therefore, improvement in impaired skeletal muscle function, rather than obesity and insulin resistance, may be an important therapeutic target for normalization of the limited exercise capacity in diabetes. In conclusion, a comprehensive lifestyle therapy of exercise and diet normalizes the limited exercise capacity and impaired muscle function in diabetes mellitus.

Effects of a high-intensity intermittent training program on aerobic capacity and lipid profile in trained subjects

PubMed Central

Ouerghi, Nejmeddine; Khammassi, Marwa; Boukorraa, Sami; Feki, Moncef; Kaabachi, Naziha; Bouassida, Anissa

2014-01-01

Background Data regarding the effect of training on plasma lipids are controversial. Most studies have addressed continuous or long intermittent training programs. The present study evaluated the effect of short-short high-intensity intermittent training (HIIT) on aerobic capacity and plasma lipids in soccer players. Methods The study included 24 male subjects aged 21–26 years, divided into three groups: experimental group 1 (EG1, n=8) comprising soccer players who exercised in addition to regular short-short HIIT twice a week for 12 weeks; experimental group 2 (EG2, n=8) comprising soccer players who exercised in a regular football training program; and a control group (CG, n=8) comprising untrained subjects who did not practice regular physical activity. Maximal aerobic velocity and maximal oxygen uptake along with plasma lipids were measured before and after 6 weeks and 12 weeks of the respective training program. Results Compared with basal values, maximal oxygen uptake had significantly increased in EG1 (from 53.3±4.0 mL/min/kg to 54.8±3.0 mL/min/kg at 6 weeks [P<0.05] and to 57.0±3.2 mL/min/kg at 12 weeks [P<0.001]). Maximal oxygen uptake was increased only after 12 weeks in EG2 (from 52.8±2.7 mL/min/kg to 54.2±2.6 mL/min/kg, [P<0.05]), but remain unchanged in CG. After 12 weeks of training, maximal oxygen uptake was significantly higher in EG1 than in EG2 (P<0.05). During training, no significant changes in plasma lipids occurred. However, after 12 weeks, total and low-density lipoprotein cholesterol levels had decreased (by about 2%) in EG1 but increased in CG. High-density lipoprotein cholesterol levels increased in EG1 and EG2, but decreased in CG. Plasma triglycerides decreased by 8% in EG1 and increased by about 4% in CG. Conclusion Twelve weeks of short-short HIIT improves aerobic capacity. Although changes in the lipid profile were not significant after this training program, they may have a beneficial impact on health. PMID:25378960

Effects of thermal increase on aerobic capacity and swim performance in a tropical inland fish.

PubMed

McDonnell, Laura H; Chapman, Lauren J

2016-09-01

Rising water temperature associated with climate change is increasingly recognized as a potential stressor for aquatic organisms, particularly for tropical ectotherms that are predicted to have narrow thermal windows relative to temperate ectotherms. We used intermittent flow resting and swimming respirometry to test for effects of temperature increase on aerobic capacity and swim performance in the widespread African cichlid Pseudocrenilabrus multicolor victoriae, acclimated for a week to a range of temperatures (2°C increments) between 24 and 34°C. Standard metabolic rate (SMR) increased between 24 and 32°C, but fell sharply at 34°C, suggesting either an acclimatory reorganization of metabolism or metabolic rate depression. Maximum metabolic rate (MMR) was elevated at 28 and 30°C relative to 24°C. Aerobic scope (AS) increased between 24 and 28°C, then declined to a level comparable to 24°C, but increased dramatically 34°C, the latter driven by the drop in SMR in the warmest treatment. Critical swim speed (Ucrit) was highest at intermediate temperature treatments, and was positively related to AS between 24 and 32°C; however, at 34°C, the increase in AS did not correspond to an increase in Ucrit, suggesting a performance cost at the highest temperature. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Sarcopenia Is Associated With Lower Skeletal Muscle Capillarization and Exercise Capacity in Older Adults.

PubMed

Prior, Steven J; Ryan, Alice S; Blumenthal, Jacob B; Watson, Jonathan M; Katzel, Leslie I; Goldberg, Andrew P

2016-08-01

Skeletal muscle capillary rarefaction limits the transcapillary transport of nutrients and oxygen to muscle and may contribute to sarcopenia and functional impairment in older adults. We tested the hypothesis that skeletal muscle capillarization and exercise capacity (VO2max) are lower in sarcopenic than in nonsarcopenic older adults and that the degree of sarcopenia is related to lower skeletal muscle capillarization. Body composition, VO2max, and vastus lateralis capillarization were determined in 76 middle-aged and older men and women (age = 61±1 years, body mass index [BMI] = 30.7±0.5kg/m(2) [mean ± SEM]). Participants were classified as sarcopenic if appendicular lean mass divided by BMI (ALMBMI) was less than 0.789 for men or less than 0.512 for women. Sarcopenic subjects (ALMBMI = 0.65±0.04, n = 16) had 20% lower capillary-to-fiber ratio, as well as 13% and 15% lower VO2max expressed as mL/kg/min or L/min, respectively, compared with sex-, race-, and age-matched participants without sarcopenia (ALMBMI = 0.81±0.05, n = 16; p < .05). In all 76 subjects, ALMBMI, thigh muscle cross-sectional area, and VO2max correlated directly with capillarization (r = .30-.37, p ≤ .05), after accounting for age, sex, and race. These findings suggest that low skeletal muscle capillarization is one factor that may contribute to sarcopenia and reduced exercise capacity in older adults by limiting diffusion of substrates, oxygen, hormones, and nutrients. Strategies to prevent the aging-related decline in skeletal muscle capillarization may help to prevent or slow the progression of sarcopenia and its associated functional declines in generally healthy older adults. Published by Oxford University Press on behalf of the Gerontological Society of America 2016.

Is Maximum Food Intake in Endotherms Constrained by Net or Factorial Aerobic Scope? Lessons from the Leaf-Eared Mouse.

PubMed

Maldonado, Karin; Sabat, Pablo; Piriz, Gabriela; Bogdanovich, José M; Nespolo, Roberto F; Bozinovic, Francisco

2016-01-01

Food availability varies substantially throughout animals' lifespans, thus the ability to profit from high food levels may directly influence animal fitness. Studies exploring the link between basal metabolic rate (BMR), growth, reproduction, and other fitness traits have shown varying relationships in terms of both magnitude and direction. The diversity of results has led to the hypothesis that these relationships are modulated by environmental conditions (e.g., food availability), suggesting that the fitness consequences of a given BMR may be context-dependent. In turn, there is indirect evidence that individuals with an increased capacity for aerobic work also have a high capacity for acquiring energy from food. Surprisingly, very few studies have explored the correlation between maximum rates of energy acquisition and BMR in endotherms, and to the best of our knowledge, none have attempted to elucidate relationships between the former and aerobic capacity [e.g., maximum metabolic rate (MMR), aerobic scope (Factorial aerobic scope, FAS; Net aerobic scope, NAS)]. In this study, we measured BMR, MMR, maximum food intake (recorded under low ambient temperature and ad libitum food conditions; MFI), and estimated aerobic scope in the leaf-eared mouse ( Phyllotis darwini ). We, then, examined correlations among these variables to determine whether metabolic rates and aerobic scope are functionally correlated, and whether an increased aerobic capacity is related to a higher MFI. We found that aerobic capacity measured as NAS is positively correlated with MFI in endotherms, but with neither FAS nor BMR. Therefore, it appears plausible that the capacity for assimilating energy under conditions of abundant resources is determined adaptively by NAS, as animals with higher NAS would be promoted by selection. In theory, FAS is an invariant measurement of the extreme capacity for energy turnover in relation to resting expenditure, whereas NAS represents the maximum capacity

Logistic Risk Model for the Unique Effects of Inherent Aerobic Capacity on (+)G(sub z) Tolerance Before and After Simulated Weightlessness

NASA Technical Reports Server (NTRS)

Ludwig, David A.; Convertino, Victor A.; Goldwater, Danielle J.; Sandler, Harold

1987-01-01

Small sample size (n less than 1O) and inappropriate analysis of multivariate data have hindered previous attempts to describe which physiologic and demographic variables are most important in determining how long humans can tolerate acceleration. Data from previous centrifuge studies conducted at NASA/Ames Research Center, utilizing a 7-14 d bed rest protocol to simulate weightlessness, were included in the current investigation. After review, data on 25 women and 22 men were available for analysis. Study variables included gender, age, weight, height, percent body fat, resting heart rate, mean arterial pressure, Vo(sub 2)max and plasma volume. Since the dependent variable was time to greyout (failure), two contemporary biostatistical modeling procedures (proportional hazard and logistic discriminant function) were used to estimate risk, given a particular subject's profile. After adjusting for pro-bed-rest tolerance time, none of the profile variables remained in the risk equation for post-bed-rest tolerance greyout. However, prior to bed rest, risk of greyout could be predicted with 91% accuracy. All of the profile variables except weight, MAP, and those related to inherent aerobic capacity (Vo(sub 2)max, percent body fat, resting heart rate) entered the risk equation for pro-bed-rest greyout. A cross-validation using 24 new subjects indicated a very stable model for risk prediction, accurate within 5% of the original equation. The result for the inherent fitness variables is significant in that a consensus as to whether an increased aerobic capacity is beneficial or detrimental has not been satisfactorily established. We conclude that tolerance to +Gz acceleration before and after simulated weightlessness is independent of inherent aerobic fitness.

Rapid maturation of the muscle biochemistry that supports diving in Pacific walruses (Odobenus rosmarus divergens)

USGS Publications Warehouse

Norem, Shawn R.; Jay, Chadwick V.; Burns, Jennifer M.; Fischbach, Anthony S.

2015-01-01

Physiological constraints dictate animals’ ability to exploit habitats. For marine mammals, it is important to quantify physiological limits that influence diving and their ability to alter foraging behaviors. We characterized age-specific dive limits of walruses by measuring anaerobic (acid-buffering capacity) and aerobic (myoglobin content) capacities of the muscles that power hind (longissimus dorsi) and fore (supraspinatus) flipper propulsion. Mean buffering capacities were similar across muscles and age classes (a fetus, five neonatal calves, a 3 month old and 20 adults), ranging from 41.31 to 54.14 slykes and 42.00 to 46.93 slykes in the longissimus and supraspinatus, respectively. Mean myoglobin in the fetus and neonatal calves fell within a narrow range (longissimus: 0.92–1.68 g 100 g−1 wet muscle mass; supraspinatus: 0.88–1.64 g 100 g−1 wet muscle mass). By 3 months post-partum, myoglobin in the longissimus increased by 79%, but levels in the supraspinatus remained unaltered. From 3 months post-partum to adulthood, myoglobin increased by an additional 26% in the longissimus and increased by 126% in the supraspinatus; myoglobin remained greater in the longissimus compared with the supraspinatus. Walruses are unique among marine mammals because they are born with a mature muscle acid-buffering capacity and attain mature myoglobin content early in life. Despite rapid physiological development, small body size limits the diving capacity of immature walruses and extreme sexual dimorphism reduces the diving capacity of adult females compared with adult males. Thus, free-ranging immature walruses likely exhibit the shortest foraging dives while adult males are capable of the longest foraging dives.

Effects of passive muscle stiffness measured by Shear Wave Elastography, muscle thickness, and body mass index on athletic performance in adolescent female basketball players.

PubMed

Akkoc, Orkun; Caliskan, Emine; Bayramoglu, Zuhal

2018-05-02

Athletic performance in basketball comprises the contributions of anaerobic and aerobic performance. The aim was to investigate the effects of passive muscle stiffness, using shear wave elastography (SWE), as well as muscle thickness, and body mass index (BMI), on both aerobic and anaerobic performances in adolescent female basketball players.Material and methods: Anaerobic and aerobic (VO2max) performance was assessed using the vertical jump and shuttle run tests, respectively, in 24 volunteer adolescent female basketball players. Passive muscle stiffness of the rectus femoris (RF), gastrocnemius medialis (GM), gastrocnemius lateralis (GL) and soleus muscles were measured by SWE, and the thickness of each muscle was assessed by gray scale ultrasound. The BMI of each participant was also calculated. The relationship between vertical jump and VO2max values, and those of muscle stiffness, thickness, and BMI were investigated via Pearson's correlation and multivariate linear regression analysis. No significant correlation was observed between muscle stiffness and VO2max or vertical jump (p>0.05). There was significant negative correlation between GL thickness and VO2max (p=0.026), and soleus thickness and VO2max (p=0.046). There was also a significant negative correlation between BMI and VO2max (p=0.001). Conclusions: This preliminary work can be a reference for future research. Although our article indicates that passive muscle stiffness measured by SWE is not directly related to athletic performance, future comprehensive studies should be performed in order to illuminate the complex nature of muscles. The  maintenance of lower muscle thickness and optimal BMI may be associated with better aerobic performance.

Skeletal Muscle CAP Expression Increases after Dietary Restriction and Aerobic Training in Women with a History of Gestational Diabetes.

PubMed

Ryan, Alice S; Serra, Monica C

2016-01-01

The purpose is to determine the effects of 6 months caloric restriction and aerobic training (3x/wk) (CR+AEX) on c-CBL associated protein (CAP) gene expression in women with a history of GDM. CAP is involved in cell signaling and protein ubiquitination, and is linked to the development of insulin resistance. Obese (BMI=32 ± 1 kg/m 2 , % fat=46 ± 2, X ± SEM), sedentary (VO2 max=21.2 ± 1.2 ml/kg/min), women aged 52 ± 2 years participated in 6 months D+WL (n=10) with body composition, fitness (VO2 max), and glucose tolerance testing. Insulin sensitivity was assessed during the last 30 min of 2-hour hyperinsulinemic-euglycemic clamps (40 mU.m -2 .min -1 ) pre and post interventions. Vastus lateralis skeletal muscle biopsies (n=7) were conducted and CAP, GLUT4 and glycogen synthase (GS) gene expression measured by RT-PCR. No change in FFM by DXA was observed, but body weight decreased 8% with losses of total body fat mass (P<0.05) and a 10% increase in VO2 max (P<0.01). Glucose and insulin areas under the curve by OGTT decreased (P<0.05). Glucose utilization during the clamp increased 27% (23.1 ± 3.8 vs. 29.4 ± 3.6 umol.kg.min -1 , P<0.05). Vastus lateralis skeletal muscle CAP expression increased 21% (P<0.05) but GLUT4 did not. Results suggest that changes in CAP could be involved in the improvement in glucose metabolism with caloric restriction and aerobic training in women with a history of gestational diabetes.

Red grape leaf extract improves endurance capacity by facilitating fatty acid utilization in skeletal muscle in mice.

PubMed

Minegishi, Yoshihiko; Haramizu, Satoshi; Hase, Tadashi; Murase, Takatoshi

2011-09-01

Improving endurance capacity leads to increased athletic performance and active lifestyles. The aim of this study was to investigate the effect of the intake of red grape leaf extract (RGLE), used as a traditional herbal medicine in the Mediterranean area, on endurance capacity in mice. Male BALB/c mice were divided into three experimental groups with similar swimming times and body weights; control group, 0.2% (w/w) and 0.5% RGLE group. Swimming times were measured for evaluation of endurance capacity once a week during the 10-week experimental period. Blood and tissues were collected from anesthetized mice immediately after 30 min of swimming exercise, and analyzed blood component and fatty acid oxidation enzyme activity, and gene expression in soleus muscle and mesenteric adipose tissue. Endurance capacity was improved by RGLE in a dose-related manner, and was significantly longer in the 0.5% RGLE group than in the control group at week 10. Plasma lactate levels after exercise in the 0.5% RGLE group were significantly lower than that in the control group. RGLE induced the upregulation of hormone-sensitive lipase mRNA in mesenteric adipose tissue, increased the plasma free fatty acid concentration after exercise, and enhanced fatty acid oxidation enzyme activity in the soleus muscle. Furthermore, peroxisome proliferator-activated receptor-gamma coactivator 1α (Pgc1α) and its downstream target genes were also significantly upregulated in the soleus muscle in the 0.5% RGLE group. Intake of RGLE upregulated Pgc1α expression and facilitated fatty acid oxidation in skeletal muscle, and these effects contributed, in part, to improve endurance capacity.

Effects of Physical Activity and Inactivity on Muscle Fatigue

PubMed Central

Bogdanis, Gregory C.

2012-01-01

The aim of this review was to examine the mechanisms by which physical activity and inactivity modify muscle fatigue. It is well known that acute or chronic increases in physical activity result in structural, metabolic, hormonal, neural, and molecular adaptations that increase the level of force or power that can be sustained by a muscle. These adaptations depend on the type, intensity, and volume of the exercise stimulus, but recent studies have highlighted the role of high intensity, short-duration exercise as a time-efficient method to achieve both anaerobic and aerobic/endurance type adaptations. The factors that determine the fatigue profile of a muscle during intense exercise include muscle fiber composition, neuromuscular characteristics, high energy metabolite stores, buffering capacity, ionic regulation, capillarization, and mitochondrial density. Muscle fiber-type transformation during exercise training is usually toward the intermediate type IIA at the expense of both type I and IIx myosin heavy-chain isoforms. High-intensity training results in increases of both glycolytic and oxidative enzymes, muscle capillarization, improved phosphocreatine resynthesis and regulation of K+, H+, and lactate ions. Decreases of the habitual activity level due to injury or sedentary lifestyle result in partial or even compete reversal of the adaptations due to previous training, manifested by reductions in fiber cross-sectional area, decreased oxidative capacity, and capillarization. Complete immobilization due to injury results in markedly decreased force output and fatigue resistance. Muscle unloading reduces electromyographic activity and causes muscle atrophy and significant decreases in capillarization and oxidative enzymes activity. The last part of the review discusses the beneficial effects of intermittent high-intensity exercise training in patients with different health conditions to demonstrate the powerful effect of exercise on health and well being. PMID

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.

Effects of aging on mitochondrial function in skeletal muscle of American Quarter Horses

PubMed Central

Li, Chengcheng; White, Sarah H.; Warren, Lori K.

2016-01-01

Skeletal muscle function, aerobic capacity, and mitochondrial (Mt) function have been found to decline with age in humans and rodents. However, not much is known about age-related changes in Mt function in equine skeletal muscle. Here, we compared fiber-type composition and Mt function in gluteus medius and triceps brachii muscle between young (age 1.8 ± 0.1 yr, n = 24) and aged (age 17-25 yr, n = 10) American Quarter Horses. The percentage of myosin heavy chain (MHC) IIX was lower in aged compared with young muscles (gluteus, P = 0.092; triceps, P = 0.012), while the percentages of MHC I (gluteus; P < 0.001) and MHC IIA (triceps; P = 0.023) were increased. Mass-specific Mt density, indicated by citrate synthase activity, was unaffected by age in gluteus, but decreased in aged triceps (P = 0.023). Cytochrome-c oxidase (COX) activity per milligram tissue and per Mt unit decreased with age in gluteus (P < 0.001 for both) and triceps (P < 0.001 and P = 0.003, respectively). Activity of 3-hydroxyacyl-CoA dehydrogenase per milligram tissue was unaffected by age, but increased per Mt unit in aged gluteus and triceps (P = 0.023 and P < 0.001, respectively). Mt respiration of permeabilized muscle fibers per milligram tissue was unaffected by age in both muscles. Main effects of age appeared when respiration was normalized to Mt content, with increases in LEAK, oxidative phosphorylation capacity, and electron transport system capacity (P = 0.038, P = 0.045, and P = 0.007, respectively), independent of muscle. In conclusion, equine skeletal muscle aging was accompanied by a shift in fiber-type composition, decrease in Mt density and COX activity, but preserved Mt respiratory function. PMID:27283918

Optimizing functional exercise capacity in the elderly surgical population.

PubMed

Carli, Franco; Zavorsky, Gerald S

2005-01-01

There are several studies on the effect of exercise post surgery (rehabilitation), but few studies have looked at augmenting functional capacity prior to surgical admission (prehabilitation). A programme of prehabilitation is proposed in order to enhance functional exercise capacity in elderly patients with the intent to minimize the postoperative morbidity and accelerate postsurgical recovery. Few studies have looked at exercise prehabilitation to improve functional capacity prior to surgical admission. Prehabilitation prior to orthopaedic surgery does not seem to improve quality of life or recovery. However, prehabilitation prior to abdominal or cardiac surgery, based on 275 elderly patients, results in fewer postoperative complications, shorter postoperative length of stay, improved quality of life, and reduced declines in functional disability compared to sedentary controls. A concentrated 3-month progressive exercise prehabilitation programme consisting of aerobic training at 45-65% of maximal heart rate reserve (%HRR) along with periodic high-intensity interval training ( approximately 90% HRR) four times per week, 30-50 minutes per session, is recommended for improving cardiovascular functioning. A strength training programme of about 10 different exercises focused on large, multi-jointed muscle groups should also be implemented twice per week at a mean training intensity of 80% of one-repetition maximum. Finally, a minimum of 140 g ( approximately 560 kcal) of carbohydrate (CHO) should be taken 3 h before training to increase liver and muscle glycogen stores and a minimum of about 200 kcal of mixed protein-CHO should be ingested within 30 min following training to enhance muscle hypertrophy.

Divergent skeletal muscle respiratory capacities in rats artificially selected for high and low running ability: a role for Nor1?

PubMed Central

Stephenson, Erin J.; Stepto, Nigel K.; Koch, Lauren G.; Britton, Steven L.

2012-01-01

Inactivity-related diseases are becoming a huge burden on Western society. While there is a major environmental contribution to metabolic health, the intrinsic properties that predispose or protect against particular health traits are harder to define. We used rat models of inborn high running capacity (HCR) and low running capacity (LCR) to determine inherent differences in mitochondrial volume and function, hypothesizing that HCR rats would have greater skeletal muscle respiratory capacity due to an increase in mitochondrial number. Additionally, we sought to determine if there was a link between the expression of the orphan nuclear receptor neuron-derived orphan receptor (Nor)1, a regulator of oxidative metabolism, and inherent skeletal muscle respiratory capacity. LCR rats were 28% heavier (P < 0.0001), and fasting serum insulin concentrations were 62% greater than in HCR rats (P = 0.02). In contrast, HCR rats had better glucose tolerance and reduced adiposity. In the primarily oxidative soleus muscle, maximal respiratory capacity was 21% greater in HCR rats (P = 0.001), for which the relative contribution of fat oxidation was 20% higher than in LCR rats (P = 0.02). This was associated with increased citrate synthase (CS; 33%, P = 0.009) and β-hydroxyacyl-CoA (β-HAD; 33%, P = 0.0003) activities. In the primarily glycolytic extensor digitum longus muscle, CS activity was 29% greater (P = 0.01) and β-HAD activity was 41% (P = 0.0004) greater in HCR rats compared with LCR rats. Mitochondrial DNA copy numbers were also elevated in the extensor digitum longus muscles of HCR rats (35%, P = 0.049) and in soleus muscles (44%, P = 0.16). Additionally, HCR rats had increased protein expression of individual mitochondrial respiratory complexes, CS, and uncoupling protein 3 in both muscle types (all P < 0.05). In both muscles, Nor1 protein was greater in HCR rats compared with LCR rats (P < 0.05). We propose that the differential expression of Nor1 may contribute to the

Hindlimb unloading increases oxidative stress and disrupts antioxidant capacity in skeletal muscle

NASA Technical Reports Server (NTRS)

Lawler, John M.; Song, Wook; Demaree, Scott R.; Bloomfield, S. A. (Principal Investigator)

2003-01-01

Skeletal muscle disuse with space-flight and ground-based models (e.g., hindlimb unloading) results in dramatic skeletal muscle atrophy and weakness. Pathological conditions that cause muscle wasting (i.e., heart failure, muscular dystrophy, sepsis, COPD, cancer) are characterized by elevated "oxidative stress," where antioxidant defenses are overwhelmed by oxidant production. However, the existence, cellular mechanisms, and ramifications of oxidative stress in skeletal muscle subjected to hindlimb unloading are poorly understood. Thus we examined the effects of hindlimb unloading on hindlimb muscle antioxidant enzymes (e.g., superoxide dismutase, catalase, glutathione peroxidase), nonenzymatic antioxidant scavenging capacity (ASC), total hydroperoxides, and dichlorohydrofluorescein diacetate (DCFH-DA) oxidation, a direct indicator of oxidative stress. Twelve 6 month old Sprague Dawley rats were divided into two groups: 28 d of hindlimb unloading (n = 6) and controls (n = 6). Hindlimb unloading resulted in a small decrease in Mn-superoxide dismutase activity (10.1%) in the soleus muscle, while Cu,Zn-superoxide dismutase increased 71.2%. In contrast, catalase and glutathione peroxidase, antioxidant enzymes that remove hydroperoxides, were significantly reduced in the soleus with hindlimb unloading by 54.5 and 16.1%, respectively. Hindlimb unloading also significantly reduced ASC. Hindlimb unloading increased soleus lipid hydroperoxide levels by 21.6% and hindlimb muscle DCFH-DA oxidation by 162.1%. These results indicate that hindlimb unloading results in a disruption of antioxidant status, elevation of hydroperoxides, and an increase in oxidative stress.

Capillarity, oxidative capacity and fibre composition of the soleus and gastrocnemius muscles of rats in hypothyroidism.

PubMed Central

Sillau, A H

1985-01-01

Muscle capillarity, mean and maximal diffusion distances and muscle fibre composition were evaluated in frozen sections stained for myosin ATPase of the soleus and the white area of the gastrocnemius medial head (gastrocnemius) of rats made hypothyroid by the injection of propylthiouracil (PTU) (50 mg kg-1) every day for 21 or 42 days. Oxygen consumption in the presence of excess ADP and Pi with pyruvate plus malate as substrates and the activity of cytochrome c oxidase were measured in muscle homogenates. Treatment with PTU decreased body oxygen consumption and the concentration of triiodothyronine in plasma. The capacity of the soleus and gastrocnemius muscles' homogenates to oxidize pyruvate plus malate and their cytochrome c oxidase activity were reduced after 21 or 42 days of treatment with PTU. Fibre composition in the soleus muscle was changed by treatment with PTU. There was a decrease in the proportion of type IIa or fast glycolytic oxidative fibres and an increase in type I or slow oxidative fibres. After 21 days of PTU administration there was also an increase in the proportion of fibres classified as IIc. The changes in fibre composition are believed to be the result of changes in the types of myosin synthesized by the fibres. Therefore, the fibres classified as IIc are, most probably, IIa fibres in the process of changing their myosin to that of the type I fibres. No changes in fibre composition were evident in the white area of the gastrocnemius medial head, an area made up of IIb or fast glycolytic fibres. The indices of capillarity: capillary density and capillary to fibre ratio, as well as mean and maximal diffusion distances from the capillaries, were not changed by the treatment with PTU in the muscles studied. The lack of changes in capillarity in spite of significant changes in oxidative capacity indicates that in skeletal muscle capillarity is not necessarily related to the oxidative capacity of the fibres. PMID:3989729

Decreased maximal aerobic capacity with use of a triphasic oral contraceptive in highly active women: a randomised controlled trial

PubMed Central

Lebrun, C; Petit, M; McKenzie, D; Taunton, J; Prior, J

2003-01-01

Background: Oral contraceptives are commonly used by women athletes. However, their effect on athletic performance is unclear. Objectives: To examine the effects of a moderate dose, triphasic oral contraceptive on measures of athletic performance in highly trained women athletes. Methods: This is a double blind, placebo controlled trial in 14 women with ovulatory menstrual cycles and maximal aerobic capacity (VO2MAX) ≥50 ml/kg/min. Four measures of athletic performance were tested: VO2MAX, anaerobic capacity (anaerobic speed test), aerobic endurance (time to fatigue at 90% of VO2MAX), and isokinetic strength (Cybex II dynamometer). Height, weight, and six skinfold measurements were also recorded. All these observational tests were completed during both the follicular and mid-luteal phases of an ovulatory menstrual cycle. Cycle phases were confirmed by assaying plasma oestradiol and progesterone. Participants were subsequently randomly assigned to either a tricyclic oral contraceptive or placebo and retested in identical fashion (oral contraceptive phase). Results: Absolute and relative changes in VO2MAX from follicular to oral contraceptive phase decreased in the oral contraceptive group by 4.7%, whereas the placebo group showed a slight increase (+1.5%) over the same time period. Two of the women taking oral contraceptive had decreases of 4 and 9 ml/kg/min. In contrast, most women in the placebo group improved or maintained VO2MAX. There was also a significant increase in the sum of skinfolds in women taking oral contraceptive compared with those taking placebo (p<0.01). There were no significant changes in other physiological variables (maximum ventilation, heart rate, respiratory exchange ratio, packed cell volume) or measures of performance (anaerobic speed test, aerobic endurance, isokinetic strength) as a function of oral contraceptive treatment. Conclusions: The decrease in VO2MAX that occurs when oral contraceptive is taken may influence elite sporting

[Lipid and metabolic profiles in adolescents are affected more by physical fitness than physical activity (AVENA study)].

PubMed

García-Artero, Enrique; Ortega, Francisco B; Ruiz, Jonatan R; Mesa, José L; Delgado, Manuel; González-Gross, Marcela; García-Fuentes, Miguel; Vicente-Rodríguez, Germán; Gutiérrez, Angel; Castillo, Manuel J

2007-06-01

To determine whether the level of physical activity or physical fitness (i.e., aerobic capacity and muscle strength) in Spanish adolescents influences lipid and metabolic profiles. From a total of 2859 Spanish adolescents (age 13.0-18.5 years) taking part in the AVENA (Alimentación y Valoración del Estado Nutricional en Adolescentes) study, 460 (248 male, 212 female) were randomly selected for blood analysis. Their level of physical activity was determined by questionnaire. Aerobic capacity was assessed using the Course-Navette test. Muscle strength was evaluated using manual dynamometry, the long jump test, and the flexed arm hang test. A lipid-metabolic cardiovascular risk index was derived from the levels of triglycerides, low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), and glucose. No relationship was found between the level of physical activity and lipid-metabolic index in either sex. In contrast, there was an inverse relationship between the lipid-metabolic index and aerobic capacity in males (P=.003) after adjustment for physical activity level and muscle strength. In females, a favorable lipid-metabolic index was associated with greater muscle strength (P=.048) after adjustment for aerobic capacity. These results indicate that, in adolescents, physical fitness, and not physical activity, is related to lipid and metabolic cardiovascular risk. Higher aerobic capacity in males and greater muscle strength in females were associated with lower lipid and metabolic risk factors for cardiovascular disease.

Effects of muscular and aqua aerobic combined exercise on metabolic indices in elderly women with metabolic syndrome

PubMed Central

Yoo, Yong-Kwon; Kim, Soo-Keun; Song, Min-Sun

2013-01-01

The purpose of this study was to investigate the effects of muscle strengthening exercise using elastic thera-band and aquatic aerobic combined exercise on metabolic syndrome index in elderly with metabolic syndrome. Fifty-four were assigned to muscle strengthening exercise group (n = 19), aquatic aerobic exercise group (n = 19), and combined exercise group (n = 16). The muscle strength exercise, aquatic aerobic exercise and combined exercise were provided three times a week for 12 weeks. Metabolic syndrome indices[Fasting blood glucose, triglyceride, high density lipoprotein cholesterol (HDL-C), systolic blood pressure, diastolic blood pressure and waist circumference] were measured before and after the program. One-way ANOVA, paired t-test and two-way repeated ANOVA were used with the SPSS program for data analysis. There was a significant difference in triglyceride (p < .001), HDL-C (p = .010) and waist circumference (p = .016). Triglyceride and waist circumference was significantly decreased in combined group than muscle strength exercise group and aquatic exercise group. HDL-C was significantly increased in combined group than muscle strength exercise group. The results indicate that combined exercise was more effective in the improvement of dyslipidemia and abdominal obesity. PMID:25566424

Effects of muscular and aqua aerobic combined exercise on metabolic indices in elderly women with metabolic syndrome.

PubMed

Yoo, Yong-Kwon; Kim, Soo-Keun; Song, Min-Sun

2013-12-01

The purpose of this study was to investigate the effects of muscle strengthening exercise using elastic thera-band and aquatic aerobic combined exercise on metabolic syndrome index in elderly with metabolic syndrome. Fifty-four were assigned to muscle strengthening exercise group (n = 19), aquatic aerobic exercise group (n = 19), and combined exercise group (n = 16). The muscle strength exercise, aquatic aerobic exercise and combined exercise were provided three times a week for 12 weeks. Metabolic syndrome indices[Fasting blood glucose, triglyceride, high density lipoprotein cholesterol (HDL-C), systolic blood pressure, diastolic blood pressure and waist circumference] were measured before and after the program. One-way ANOVA, paired t-test and two-way repeated ANOVA were used with the SPSS program for data analysis. There was a significant difference in triglyceride (p < .001), HDL-C (p = .010) and waist circumference (p = .016). Triglyceride and waist circumference was significantly decreased in combined group than muscle strength exercise group and aquatic exercise group. HDL-C was significantly increased in combined group than muscle strength exercise group. The results indicate that combined exercise was more effective in the improvement of dyslipidemia and abdominal obesity.

High aerobic fitness is associated with lower total and regional adiposity in 12-year-old overweight boys.

PubMed

Ostojic, S M; Stojanovic, M D

2010-12-01

The objective of the present study was to determine relationship between aerobic (cardiovascular) fitness and body composition in both non-overweight and overweight 12-year-old school boys. A cross-sectional study was conducted in a random sample of 10 elementary schools. The study participants were a 170 healthy fifth-grade elementary school boys aged 11.9±0.4 years. Anthropometric data (height, body mass, waist circumference, abdominal skinfold thickness) were collected according to standard procedure. Total body fat and muscle mass percentage were assessed by bioimpedance analysis. Body Mass Index (BMI) age-specific cutoff points were used for overweight definition and boys were placed in two groups overweight and non-overweight. Aerobic fitness (VO2max) was assessed with the multistage shuttle-run fitness test. Boys were grouped into high (upper two quintiles) and low (lower two quintiles) aerobic fitness based on age distribution. Waist circumference, abdominal skinfold thickness and total body fat were lower while muscle mass percentage was higher in overweight boys with high aerobic fitness in comparison with boys at the same BMI category with low fitness level (P<0.05). Aerobic fitness was inversely correlated with body fat in the whole group of subjects (r=-0,57, P<0.05), with particularly high correlation between VO2max and muscle mass in overweight boys (r=0.68, P<0.05). Indicators of local and total adiposity were lower in boys with high aerobic fitness. It seems that high aerobic fitness has is positively associated with body composition in overweight boys.

Anthropometry, somatotypes, and aerobic power in ballet, contemporary dance, and dancesport.

PubMed

Liiv, Helena; Wyon, Matthew A; Jürimäe, Toivo; Saar, Meeli; Mäestu, Jarek; Jürimäe, Jaak

2013-12-01

This study compared anthropometric variables, somatotypes, and aerobic capacity between three groups of dancers: classical ballet dancers (M 33, F 56), contemporary dancers (M 28, F 109), and dancesport dancers (M 30, F 30). The assumption was that different functional requirements should produce differences in the anthropometric and aerobic capacity variables among the three groups. Anthropometric data for body mass index (BMI) and somatotypes were measured. Body fat percentage was measured by dual-energy x-ray absorptiometry. Maximal oxygen consumption and aerobic power were measured during an incremental treadmill test until exhaustion. Dancesport athletes were taller compared with same gender contemporary dancers (p<0.05). Female ballet dancers had a lower body mass and BMI compared with their contemporary dance and dancesport equivalents (p<0.001). There was significant difference between dance styles in endomorphy (F2,221 = 8.773, p<0.001) and mesomorphy (F2,221 = 21.458, p<0.001) scores. Dancesport dancers had significantly greater VO2max values (p<0.01). It was concluded that female contemporary dancers are generally more muscular than their ballet counterparts, while dancesport dancers are taller and heavier, less muscular, with slightly greater adioposity compared to the classical ballet dancers. Ballet dancers had the lowest body fat percentage, weight, and BMI values. Dancesport dancers had greater aerobic capacity than the ballet dancers. Based on this study, we conclude that dancers in these three styles differ in some aspects of anthropometric variables, somatotypes, and aerobic capacity, but we cannot say is it because of the training or selection or both.

SCD1 activity in muscle increases triglyceride PUFA content, exercise capacity, and PPARδ expression in mice[S

PubMed Central

Rogowski, Michael P.; Flowers, Matthew T.; Stamatikos, Alexis D.; Ntambi, James M.; Paton, Chad M.

2013-01-01

Stearoyl-CoA desaturase (SCD)1 converts saturated fatty acids into monounsaturated fatty acids. Using muscle overexpression, we sought to determine the role of SCD1 expression in glucose and lipid metabolism and its effects on exercise capacity in mice. Wild-type C57Bl/6 (WT) and SCD1 muscle transgenic (SCD1-Tg) mice were generated, and expression of the SCD1 transgene was restricted to skeletal muscle. SCD1 overexpression was associated with increased triglyceride (TG) content. The fatty acid composition of the muscle revealed a significant increase in polyunsaturated fatty acid (PUFA) content of TG, including linoleate (18:2n6). Untrained SCD1-Tg mice also displayed significantly increased treadmill exercise capacity (WT = 6.6 ± 3 min, Tg = 71.9 ± 9.5 min; P = 0.0009). SCD1-Tg mice had decreased fasting plasma glucose, glucose transporter (GLUT)1 mRNA, fatty acid oxidation, mitochondrial content, and increased peroxisome proliferator-activated receptor (PPAR)δ and Pgc-1 protein expression in skeletal muscle. In vitro studies in C2C12 myocytes revealed that linoleate (18:2n6) and not oleate (18:1n9) caused a 3-fold increase in PPARδ and a 9-fold increase in CPT-1b with a subsequent increase in fat oxidation. The present model suggests that increasing delta-9 desaturase activity of muscle increases metabolic function, exercise capacity, and lipid oxidation likely through increased PUFA content, which increases PPARδ expression and activity. However, the mechanism of action that results in increased PUFA content of SCD1-Tg mice remains to be elucidated. PMID:23918045

Measurement of Human Skeletal Muscle Oxidative Capacity by 31P-MRS: A Cross-Validation with in vitro measurements

PubMed Central

Lanza, Ian R.; Bhagra, Sumit; Nair, K. Sreekumaran; Port, John D.

2011-01-01

Purpose To cross-validate skeletal muscle oxidative capacity measured by 31P-MRS with in vitro measurements of oxidative capacityin mitochondria isolated from muscle biopsies of the same muscle group in 18 healthy adults. Materials and Methods Oxidative capacity in vivo was determined from PCr recovery kinetics following a 30s maximal isometric knee extension. State 3 respiration was measured in isolated mitochondria using high-resolution respirometry. A second cohort of 10 individuals underwent two 31P-MRS testing sessions to assess the test-retest reproducibility of the method. Results Overall, the in vivo and in vitro methods were well-correlated (r = 0.66 –0.72) and showed good agreement by Bland Altman plots. Excellent reproducibility was observed for the PCr recovery rate constant (CV = 4.6%, ICC = 0.85) and calculated oxidative capacity (CV = 3.4%, ICC = 0.83). Conclusion These results indicate that 31P-MRS corresponds well with gold-standard in vitro measurements and is highly reproducible. PMID:22006551

Flight Capacity of Bactrocera dorsalis (Diptera: Tephritidae) Adult Females Based on Flight Mill Studies and Flight Muscle Ultrastructure

PubMed Central

Chen, Peng; Yuan, Ruiling; Wang, Xiaowei; Xu, Jin

2015-01-01

The oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is considered a major economic threat in many regions worldwide. To better comprehend flight capacity of B. dorsalis and its physiological basis, a computer-monitored flight mill was used to study flight capacity of B. dorsalis adult females of various ages, and the changes of its flight muscle ultrastructures were studied by transmission electron microscopy. The flight capacity (both speed and distance) changed significantly with age of B. dorsalis female adults, peaking at about 15 d; the myofibril diameter of the flight muscle of test insects at 15-d old was the longest, up to 1.56 µm, the sarcomere length at 15-d old was the shortest, averaging at 1.37 µm, volume content of mitochondria of flight muscle at 15-d old reached the peak, it was 32.64%. This study provides the important scientific data for better revealing long-distance movement mechanism of B. dorsalis. PMID:26450591

Relationships between Lower Limb Muscle Strength and Locomotor Capacity in Children and Adolescents with Cerebral Palsy Who Walk Independently

ERIC Educational Resources Information Center

Ferland, Chantale; Lepage, Celine; Moffet, Helene; Maltais, Desiree B.

2012-01-01

This study aimed to quantify relationships between lower limb muscle strength and locomotor capacity for children and adolescents with cerebral palsy (CP) to identify key muscle groups for strength training. Fifty 6- to 16-year-olds with CP (Gross Motor Function Classification System level I or II) participated. Isometric muscle strength of hip…

Sweat Rates During Continuous and Interval Aerobic Exercise: Implications for NASA Multipurpose Crew Vehicle (MPCV) Missions

NASA Technical Reports Server (NTRS)

Ryder, Jeffrey W.; Scott, Jessica; Ploutz-Snyder, Robert; Ploutz-Snyder, Lori L.

2016-01-01

Aerobic deconditioning is one of the effects spaceflight. Impaired crewmember performance due to loss of aerobic conditioning is one of the risks identified for mitigation by the NASA Human Research Program. Missions longer than 8 days will involve exercise countermeasures including those aimed at preventing the loss of aerobic capacity. The NASA Multipurpose Crew Vehicle (MPCV) will be NASA's centerpiece architecture for human space exploration beyond low Earth orbit. Aerobic exercise within the small habitable volume of the MPCV is expected to challenge the ability of the environmental control systems, especially in terms of moisture control. Exercising humans contribute moisture to the environment by increased respiratory rate (exhaling air at 100% humidity) and sweat. Current acceptable values are based on theoretical models that rely on an "average" crew member working continuously at 75% of their aerobic capacity (Human Systems Integration Requirements Document). Evidence suggests that high intensity interval exercise for much shorter durations are equally effective or better in building and maintaining aerobic capacity. This investigation will examine sweat and respiratory rates for operationally relevant continuous and interval aerobic exercise protocols using a variety of different individuals. The results will directly inform what types of aerobic exercise countermeasures will be feasible to prescribe for crewmembers aboard the MPCV.

Aerobic capacity of Peruvian Quechua: a test of the developmental adaptation hypothesis.

PubMed

Kiyamu, Melisa; Rivera-Chira, María; Brutsaert, Tom D

2015-03-01

High altitude natives are reported to have outstanding work capacity in spite of the challenge of oxygen transport and delivery in hypoxia. To evaluate the developmental effect of lifelong exposure to hypoxia on aerobic capacity, VO2peak was measured on two groups of Peruvian Quechua subjects (18-35 years), who differed in their developmental exposure to altitude. Male and female volunteers were recruited in Lima, Peru (150 m), and were divided in two groups, based on their developmental exposure to hypoxia, those: a) Born at sea-level individuals (BSL), with no developmental exposure to hypoxia (n = 34) and b) Born at high-altitude individuals (BHA) with full developmental exposure to hypoxia (n = 32), but who migrated to sea-level as adults (>16-years-old). Tests were conducted both in normoxia (BP = 750 mm Hg) and normobaric hypoxia at sea-level (BP = 750 mm Hg, FiO2  = 0.12, equivalent to 4,449 m), after a 2-month training period (in order to control for initial differences in physical fitness) at sea-level. BHA had a significantly higher VO2peak at hypoxia (40.31 ± 1.0 ml/min/kg) as compared to BSL (35.78 ± 0.96 ml/min/kg, P = 0.001), adjusting for sex. The decrease of VO2peak at HA relative to SL (ΔVO2peak ) was not different between groups, controlling for baseline levels (VO2peak at sea-level) and sex (BHA = 0.35 ± 0.04 l/min, BSL = 0.44 ± 0.04 l/min; P = 0.12). Forced vital capacity (controlling for height) and the residuals of VO2peak (controlling for weight) had a significant association in the BHA group only (r = 0.155; P = 0.031). In sum, results indicate that developmental exposure to altitude constitutes an important factor to determine superior exercise performance. © 2014 Wiley Periodicals, Inc.

Strength Training for Skeletal Muscle Endurance after Stroke

PubMed Central

Ivey, Frederick M.; Prior, Steven J.; Hafer-Macko, Charlene E.; Katzel, Leslie I.; Macko, Richard F.; Ryan, Alice S.

2018-01-01

Background and Purpose Initial studies support the use of strength training (ST) as a safe and effective intervention after stroke. Our previous work shows that relatively aggressive, higher intensity ST translates into large effect sizes for paretic and non-paretic leg muscle volume, myostatin expression, and maximum strength post-stroke. An unanswered question pertains to how our unique ST model for stroke impacts skeletal muscle endurance (SME). Thus, we now report on ST-induced adaptation in the ability to sustain isotonic muscle contraction. Methods Following screening and baseline testing, hemiparetic stroke participants were randomized to either ST or an attention-matched stretch control group (SC). Those in the ST group trained each leg individually to muscle failure (20 repetition sets, 3× per week for 3 months) on each of three pneumatic resistance machines (leg press, leg extension, and leg curl). Our primary outcome measure was SME, quantified as the number of submaximal weight leg press repetitions possible at a specified cadence. The secondary measures included one-repetition maximum strength, 6-minute walk distance (6MWD), 10-meter walk speeds, and peak aerobic capacity (VO2 peak). Results ST participants (N = 14) had significantly greater SME gains compared with SC participants (N = 16) in both the paretic (178% versus 12%, P < .01) and non-paretic legs (161% versus 12%, P < .01). These gains were accompanied by group differences for 6MWD (P < .05) and VO2 peak (P < .05). Conclusion Our ST regimen had a large impact on the capacity to sustain submaximal muscle contraction, a metric that may carry more practical significance for stroke than the often reported measures of maximum strength. PMID:27865696

Outpatient rehabilitation as an intervention to improve employees' physical capacity.

PubMed

Ojala, Birgitta; Nygård, Clas-Håkan; Nikkari, Seppo T

2016-01-01

The aging of the workforce poses new challenges for maintaining work ability. Because of limited information on the effectiveness of vocational rehabilitation performed in traditional inpatient programs, extended interest in outpatient rehabilitation has risen in the past few years. We examined the effects of a new outpatient rehabilitation program where every participant defined their own goals to improve work ability by the aid of a goal-oriented multi-professional team. This report will focus on the employees' physical capacity during a nine-month program. A total of 605 municipal employees from different production areas of the City of Tampere took part in the outpatient rehabilitation program, implemented by the occupational health unit. Groups of 12 employees participated in eight one-day sessions at intervals of two to three weeks; the final follow-up was 9 months from the beginning. Submaximal aerobic capacity was tested by a calibrated cycle ergometer with a commercial program (Aino Fitware pro, Helsinki, Finland). Musculoskeletal tests assessed muscle strength, balance and mobility. During the 9-month follow-up of the rehabilitation program, the employees' physical capacity was improved. The follow-up test scores from a total of 329 employees were significantly higher in the submaximal aerobic capacity test (p < 0.001). Other tests were also improved, such as standing on one foot (p = 0.001), back side bending flexibility test (p < 0.001), dynamic sit up (p = 0.001), upper extremity right (p < 0.001), and knee bending (p = 0.029). About 40% of the participants did not have an adequate health situation to take part in physical capacity tests; however they took part in the intervention. The new outpatient rehabilitation program organized by the occupational health unit had a positive influence on employees' physical capacity during a nine-month follow up.

(–)-Epicatechin enhances fatigue resistance and oxidative capacity in mouse muscle

PubMed Central

Nogueira, Leonardo; Ramirez-Sanchez, Israel; Perkins, Guy A; Murphy, Anne; Taub, Pam R; Ceballos, Guillermo; Villarreal, Francisco J; Hogan, Michael C; Malek, Moh H

2011-01-01

Abstract The flavanol (–)-epicatechin, a component of cacao (cocoa), has been shown to have multiple health benefits in humans. Using 1-year-old male mice, we examined the effects of 15 days of (–)-epicatechin treatment and regular exercise on: (1) exercise performance, (2) muscle fatigue, (3) capillarity, and (4) mitochondrial biogenesis in mouse hindlimb and heart muscles. Twenty-five male mice (C57BL/6N) were randomized into four groups: (1) water, (2) water–exercise (W-Ex), (3) (–)-epicatechin ((–)-Epi), and (4) (–)-epicatechin–exercise ((–)-Epi-Ex). Animals received 1 mg kg−1 of (–)-epicatechin or water (vehicle) via oral gavage (twice daily). Exercise groups underwent 15 days of treadmill exercise. Significant increases in treadmill performance (∼50%) and enhanced in situ muscle fatigue resistance (∼30%) were observed with (–)-epicatechin. Components of oxidative phosphorylation complexes, mitofilin, porin, nNOS, p-nNOS, and Tfam as well as mitochondrial volume and cristae abundance were significantly higher with (–)-epicatechin treatment for hindlimb and cardiac muscles than exercise alone. In addition, there were significant increases in skeletal muscle capillarity. The combination of (–)-epicatechin and exercise resulted in further increases in oxidative phosphorylation-complex proteins, mitofilin, porin and capillarity than (–)-epicatechin alone. These findings indicate that (–)-epicatechin alone or in combination with exercise induces an integrated response that includes structural and metabolic changes in skeletal and cardiac muscles resulting in greater endurance capacity. These results, therefore, warrant the further evaluation of the underlying mechanism of action of (–)-epicatechin and its potential clinical application as an exercise mimetic. PMID:21788351

Physical capacity and risk for long-term sickness absence: a prospective cohort study among 8664 female health care workers.

PubMed

Rasmussen, Charlotte Diana Nørregaard; Andersen, Lars Louis; Clausen, Thomas; Strøyer, Jesper; Jørgensen, Marie Birk; Holtermann, Andreas

2015-05-01

To assess the prospective associations between self-reported physical capacity and risk of long-term sickness absence among female health care workers. Female health care workers answered a questionnaire about physical capacity and were followed in a national register of sickness absence lasting for two or more consecutive weeks during 1-year follow-up. Using Cox regression hazard ratio analyses adjusted for age, smoking, body mass index, physical workload, job seniority, psychosocial work conditions, and previous sickness absence, we modeled risk estimates for sickness absence from low and medium physical capacity. Low and medium aerobic fitness, low muscle strength, low flexibility, and low overall physical capacity significantly increased the risk for sickness absence with 20% to 34% compared with health care workers with high capacity. Low physical capacity increases the risk of long-term sickness absence among female health care workers.

Exercise Responses to Gravity-Independent Flywheel Aerobic and Resistance Training.

PubMed

Owerkowicz, Tomasz; Cotter, Joshua A; Haddad, Fadia; Yu, Alvin M; Camilon, Marinelle L; Hoang, Theresa N; Jimenez, Daniel J; Kreitenberg, Arthur; Tesch, Per A; Caiozzo, Vincent J; Adams, Gregory R

2016-02-01

Although several exercise systems have been developed to mitigate the physiological deconditioning that occurs in microgravity, few have the capacity to positively impact multiple physiological systems and still meet the volume/mass requirements needed for missions beyond low Earth orbit. The purpose of this study was to test the gravity-independent Multi-Mode Exercise Device (M-MED) for both resistance (RE) and aerobic (AE) training stimuli. Eight men and nine women (mean age 22.0 ± 0.4 yr) completed 5 wk of training on the M-MED: RE 4 × 7 squats 2 d/wk, and AE 4 × 4-min rowing bouts at ∼90% Vo2max 3 d/wk. Pre- and post-training data collection included an aerobic capacity test, MR imaging, strength testing, and vastus lateralis muscle biopsy. Vo2max increased 8%, 3RM strength 18%, and quadriceps femoris cross-sectional area (CSA) 10%. Knee extensor strength increased at all isokinetic speeds tested. Subjects also demonstrated improved fatigue resistance in knee extension. At the cellular and molecular level, the biopsy revealed increases in mixed myofiber CSA (13%), citrate synthase activity (26%), total RNA concentration (24%), IGF-I mRNA (77%), and Type IIa myosin heavy chain (MHC) mRNA (8%), and a concomitant decrease in Type IIx MHC mRNA (-23%). None of the changes were gender-specific. Both the functional outcomes and biomarker changes indicate that a very low volume of M-MED exercise results in robust adaptation in the cardiovascular and musculoskeletal systems. The M-MED has the potential to provide a wide range of countermeasure exercises and should be considered for testing in ground-based spaceflight simulation.

Aerobic exercise + weight loss decreases skeletal muscle myostatin expression and improves insulin sensitivity in older adults.

PubMed

Ryan, A S; Li, G; Blumenthal, J B; Ortmeyer, H K

2013-07-01

To determine whether aerobic exercise training + weight loss (AEX + WL) would affect the expression of myostatin and its relationship with insulin sensitivity in a longitudinal, clinical intervention study. Thirty-three obese sedentary postmenopausal women and men (n = 17 and 16, age: 61 ± 1 years, body mass index: 31 ± 1 kg/m(2) , VO2 max: 21.9 ± 1.0 mL/kg/min, X ± Standard error of the mean (SEM)) completed 6 months of 3 days/week AEX + WL. During an 80 mU m(-2) min(-1) hyperinsulinemic-euglycemic clamp, we measured glucose utilization (M), myostatin, myogenin, and MyoD gene expression by real-time RT-PCR in vastus lateralis muscle at baseline and 2 h. Body weight (-8%) and fat mass (-17%) decreased after AEX + WL (P < 0.001). Fat-free mass (FFM) and mid-thigh muscle area by computed tomography did not change but muscle attenuation increased (P < 0.05). VO2 max increased 14% (P < 0.001). AEX + WL increased M by 18% (P < 0.01). Myostatin gene expression decreased 19% after AEX + WL (P < 0.05). Basal mRNA myostatin levels were negatively associated with M before the intervention (r = -0.43, P < 0.05). Insulin infusion increased myoD and myogenin expression before and after AEX + WL (both P < 0.001) but basal levels did not change. The insulin effect on myostatin expression was associated with the change in M after AEX + WL (r = 0.56, P < 0.005). Exercise and weight loss results in a downregulation of myostatin mRNA and an improvement in insulin sensitivity in obese older men and women. Copyright © 2012 The Obesity Society.

Change in the antioxidative capacity of extraocular muscles in patients with exotropia.

PubMed

Jung, Su Kyung; Choi, Jun Sob; Shin, Sun Young

2015-04-01

We compared the oxidative stress and antioxidant capacities of the medial rectus muscles (MRMs) between the patients with constant exotropia and control subjects. A total of 40 MRMs from patients with constant exotropia and 40 MRMs from normal donor eyes (controls) were assessed. Neuronal nitric oxide synthase (nNOS), superoxide dismutase (SOD), and catalase levels were compared between the two groups using western blot analysis. In addition, the lipofuscin accumulation level was compared between the exotropic and control groups. According to western blot analysis, the nNOS level was significantly higher in the exotropic group than in the control group (P < 0.05). On the other hand, a catalase expression level was higher in the control group than in the exotropic group (P < 0.05). The SOD1 level did not show a significant difference between the two groups. The relative lipofuscin fluorescence intensity was higher in the exotropic group than in the control group (P < 0.001). Based on these findings, the MRMs of patients with exotropia had a redox imbalance status. Further study is needed to investigate whether this imbalance in antioxidant capacity is present in the extraocular muscles of patients with other strabismus.

Supine Treadmill Exercise in Lower Body Negative Pressure Combined with Resistive Exercise Counteracts Bone Loss, Reduced Aerobic Upright Exercise Capacity and Reduced Muscle Strength

NASA Technical Reports Server (NTRS)

Meuche, Sabine; Schneider, S. M.; Lee, S. M. C.; Macias, B. R.; Smith, S. M.; Watenpaugh, D. E.; Hargens, A. R.

2006-01-01

Long-term exposure to weightlessness leads to cardiovascular and musculoskeletal deconditioning. In this report, the effectiveness of combined supine treadmill exercise in a lower body negative pressure chamber (LBNPex) and flywheel resistive exercise (Rex) countermeasures was determined to prevent bone loss, reduced aerobic upright exercise capacity and reduced muscle strength. We hypothesized that exercise subjects would show less decrease in bone mineral density (BMD), peak oxygen consumption (VO2pk) and knee extensor strength (KES) than control subjects. Sixteen healthy female subjects participated in a 60-d 6(sup 0) head-down tilt bed rest (BR) study after providing written informed consent. Subjects were assigned to one of two groups: a non-exercising control group CON or an exercise group EX performing LBNPex 2-4 d/wk and Rex every 3rd-d. VO2pk was measured with a maximal, graded, upright treadmill test performed pre-BR and on 3-d after BR. BMD was assessed before and 3-d after BR. Isokinetic KES was measured before and 5-d after BR. Two-way repeated measures ANOVA were performed. Statistical significance was set at p less than 0.05. CON experienced a significant decrease in BMD in the trochanter (PRE: 0.670 plus or minus 0.045; POST: 0.646 plus or minus 0.352 g (raised dot) per square centimeter) and in the whole hip (PRE=0.894 plus or minus 0.059; POST: 0.858 plus or minus 0.057 g (raised dot) per square centimeter). BMD also decreased significantly in EX in the trochanter (PRE: 0.753 plus or minus 0.0617; POST: 0.741 plus or minus 0.061 g (raised dot) per square centimeter) and whole hip (PRE: 0.954 plus or minus 0.067; POST: 0.935 plus or minus 0.069 g (raised dot) per square centimeter). BMD losses were significantly less in EX than in CON subjects. VO2pk was significantly decreased in the CON after BR (PRE: 38.0 plus or minus 4.8; POST: 29.9 plus or minus 4.2 ml (raised dot) per kilogram per minute), but not in the EX (PRE: 39.0 plus or minus 2.0; POST

Exercise in myasthenia gravis: A feasibility study of aerobic and resistance training.

PubMed

Rahbek, Martin Amadeus; Mikkelsen, Erik Elgaard; Overgaard, Kristian; Vinge, Lotte; Andersen, Henning; Dalgas, Ulrik

2017-10-01

It has not been established whether progressive resistance training (PRT) and aerobic training (AT) are feasible and efficient in myasthenia gravis (MG). Fifteen subjects with generalized MG (Myasthenia Gravis Foundation of America (MGFA) clinical classification II-IV) were randomly assigned to 20 training sessions during 8 weeks of either PRT or AT. Feasibility was evaluated based on adherence, drop-out rate, adverse events, and Quantitative Myasthenia Gravis (QMG) score. Twelve subjects (MGFA II, n = 11; MGFA III, n=1) completed the intervention with a mean adherence of 95 % ± 8. One dropout (PRT) could potentially be related to PRT. Both groups reported adverse events, including bulbar symptoms (n = 2) and increased fatigue (n = 3), but no change in QMG score was observed in either group. The PRT group showed increases in maximal strength and functional capacity. Eight weeks of moderate to high intensity AT and PRT were feasible for most patients with mild MG. Maximal strength and functional capacity increased in the PRT group. Muscle Nerve 56: 700-709, 2017. © 2017 Wiley Periodicals, Inc.

Migratory preparation associated alterations in pectoralis muscle biochemistry and proteome in Palearctic-Indian emberizid migratory finch, red-headed bunting, Emberiza bruniceps.

PubMed

Banerjee, Somanshu; Chaturvedi, Chandra Mohini

2016-03-01

Avian migration is an exceptionally high-energy-demanding process, which is met by the accumulation and utilization of fuel stores as well as the alterations in muscle physiology prior to their flight. Pre-migratory fattening coupled with changes in flight muscle metabolic enzymes and proteome is required to provide the necessary fuel and muscle performance required for migration. We studied how the serum metabolites (urea, uric acid, and creatinine), pectoralis muscle metabolites (glycogen, glucose, and cholesterol), muscle metabolic enzymes (CPT, HOAD, CS, MDH, CCO, CK, LDH, PFK, MLPL, and PK), liver lipogenic enzyme (FAS), and pectoralis muscle proteins get altered in pre-migratory and non-migratory buntings. Significantly increased pectoralis muscle fatty acid oxidation (CPT and HOAD activity), aerobic/anaerobic capacity (CS, CCO, and MDH activity), glycolytic capacity (PFK and PK activity), lipolysis (muscle LPL), and burst power (CK activity) were observed prior to the spring migration in pre-migratory buntings, whereas significantly increased pectoralis muscle anaerobic capacity (LDH activity) was observed in non-migratory buntings. Significant increase in the liver FAS showed profound lipogenesis prior to the spring migration. In this study, we have also investigated whether muscle has differential protein content during the pre-migratory and non-migratory phases of the annual migratory cycle. Twenty-nine proteins are identified and well characterized varying in expression significantly during the pre-migratory and non-migratory phases. These findings indicate that significant pre-migratory fattening and alterations in flight (pectoralis) muscle biochemistry and proteome in between the non- and pre-migratory phases may play a significant role in pre-migratory flight muscle preparation in these long-route migrants. Copyright © 2015 Elsevier Inc. All rights reserved.

Interval training based on ventilatory anaerobic threshold improves aerobic functional capacity and metabolic profile: a randomized controlled trial in coronary artery disease patients.

PubMed

Tamburús, Nayara Y; Kunz, Vandeni C; Salviati, Mariana R; Castello Simões, Viviane; Catai, Aparecida M; Da Silva, Ester

2016-02-01

Exercise training has been an essential component of cardiac rehabilitation. However, it is not known if interval training (IT) based on the ventilatory anaerobic threshold (VAT) could be effective in improving aerobic functional capacity and metabolic profile in patients without or with coronary artery disease (CAD). To investigate the effects of an IT program, based-intensity between 70-110% of workload reached at the VAT, on the aerobic functional capacity and metabolic profile of patients with and without CAD. Randomized controlled trial. Outpatients from a cardiac rehabilitation. A sample was composed of 32 patients with CAD (CAD group) and 32 patients without CAD (noCAD group) that were randomized into a trained or control groups. Submaximal cardiopulmonary exercise test on the cycle ergometer and blood samples were realized at baseline and post 16 weeks of IT program. The cardiorespiratory variables were obtained at the VAT level. Trained groups (CAD-T, N.=15; noCAD-T, N.=15) underwent a supervised three-week session IT program (30-40 minutes each exercise session, at the intensity workloads equivalent to %VAT [70-110%]) for 16 weeks. After 16 weeks of IT program, there were a significant increase of VO(2VAT) and workload in the trained groups (P<0.05), while in the control groups VO(2VAT) and heart rate decreased (P<0.05). Body mass and body index mass decreased in trained groups (P<0.05), and low-density lipoprotein increased only in noCAD group after 16 weeks (P<0.05). The magnitude of the improvement in VO(2VAT) was related to VO(2VAT) (r=-0.57, P<0.05) and workload (r=-0.52, P<0.05) at baseline. The IT program prescribed with intensities based on VAT improved the aerobic functional capacity and decreased body mass and body index mass loss in patients with and without CAD. IT program based on VAT provides new possibilities for cardiac rehabilitation in relation to individualized exercise prescription of the interval training.

Effect of aerobic vs combined aerobic-strength training on 1-year, post-cardiac rehabilitation outcomes in women after a cardiac event.

PubMed

Arthur, Heather M; Gunn, Elizabeth; Thorpe, Kevin E; Ginis, Kathleen Martin; Mataseje, Lin; McCartney, Neil; McKelvie, Robert S

2007-11-01

To compare the effect and sustainability of 6 months combined aerobic/strength training vs aerobic training alone on quality of life in women after coronary artery by-pass graft surgery or myocardial infarction. Prospective, 2-group, randomized controlled trial. Ninety-two women who were 8-10 weeks post-coronary artery by-pass graft surgery or myocardial infarction, able to attend supervised exercise, and fluent in English. The aerobic training alone group had supervised exercise twice a week for 6 months. The aerobic/strength training group received aerobic training plus upper and lower body resistance exercises. The amount of active exercise time was matched between groups. The primary outcome, quality of life, was measured by the MOS SF-36; secondary outcomes were self-efficacy, strength and exercise capacity. After 6 months of supervised exercise training both groups showed statistically significant improvements in physical quality of life (p = 0.0002), peak VO2 (19% in aerobic/strength training vs 22% in aerobic training alone), strength (p < 0.0001) and self-efficacy for stair climbing (p = 0.0024), lifting (p < 0.0001) and walking (p = 0.0012). However, by 1-year follow-up there was a statistically significant difference in physical quality of life in favor of the aerobic/strength training group (p = 0.05). Women with coronary artery disease stand to benefit from both aerobic training alone and aerobic/strength training. However, continued improvement in physical quality of life may be achieved through combined strength and aerobic training.

Marination effects on water states and water-holding capacity of broiler pectoralis major muscle with different color lightness

USDA-ARS?s Scientific Manuscript database

A total of four experiments were carried out to investigate the effect of marination on water states and water-holding capacity (WHC) of broiler pectoralis (p.) major muscle selected based on raw muscle color lightness. Boneless, skinless p. major were collected at 6-8 h postmortem from deboning li...

Membrane thickening aerobic digestion processes.

PubMed

Woo, Bryen

2014-01-01

Sludge management accounts for approximately 60% of the total wastewater treatment plant expenditure and laws for sludge disposal are becoming increasingly stringent, therefore much consideration is required when designing a solids handling process. A membrane thickening aerobic digestion process integrates a controlled aerobic digestion process with pre-thickening waste activated sludge using membrane technology. This process typically features an anoxic tank, an aerated membrane thickener operating in loop with a first-stage digester followed by second-stage digestion. Membrane thickening aerobic digestion processes can handle sludge from any liquid treatment process and is best for facilities obligated to meet low total phosphorus and nitrogen discharge limits. Membrane thickening aerobic digestion processes offer many advantages including: producing a reusable quality permeate with minimal levels of total phosphorus and nitrogen that can be recycled to the head works of a plant, protecting the performance of a biological nutrient removal liquid treatment process without requiring chemical addition, providing reliable thickening up to 4% solids concentration without the use of polymers or attention to decanting, increasing sludge storage capacities in existing tanks, minimizing the footprint of new tanks, reducing disposal costs, and providing Class B stabilization.

Catabolic efficiency of aerobic glycolysis: the Warburg effect revisited.

PubMed

Vazquez, Alexei; Liu, Jiangxia; Zhou, Yi; Oltvai, Zoltán N

2010-05-06

Cancer cells simultaneously exhibit glycolysis with lactate secretion and mitochondrial respiration even in the presence of oxygen, a phenomenon known as the Warburg effect. The maintenance of this mixed metabolic phenotype is seemingly counterintuitive given that aerobic glycolysis is far less efficient in terms of ATP yield per moles of glucose than mitochondrial respiration. Here, we resolve this apparent contradiction by expanding the notion of metabolic efficiency. We study a reduced flux balance model of ATP production that is constrained by the glucose uptake capacity and by the solvent capacity of the cell's cytoplasm, the latter quantifying the maximum amount of macromolecules that can occupy the intracellular space. At low glucose uptake rates we find that mitochondrial respiration is indeed the most efficient pathway for ATP generation. Above a threshold glucose uptake rate, however, a gradual activation of aerobic glycolysis and slight decrease of mitochondrial respiration results in the highest rate of ATP production. Our analyses indicate that the Warburg effect is a favorable catabolic state for all rapidly proliferating mammalian cells with high glucose uptake capacity. It arises because while aerobic glycolysis is less efficient than mitochondrial respiration in terms of ATP yield per glucose uptake, it is more efficient in terms of the required solvent capacity. These results may have direct relevance to chemotherapeutic strategies attempting to target cancer metabolism.

Effect of aerobic training and resistance training on circulating irisin level and their association with change of body composition in overweight/obese adults: a pilot study.

PubMed

Kim, H-J; Lee, H-J; So, B; Son, J S; Yoon, D; Song, W

2016-06-20

The novel myokine irisin has been reported as a therapeutic target for metabolic disease. The objective of this study is to reveal the effects of aerobic training (AT) and resistance training (RT) on circulating irisin levels and their associations with change of body composition in overweight/obese adults. Twenty eight overweight/obese adults (BMI>23 kg/m(2)) were included in this study and compared before and after 8 weeks of exercise program (60 min/day, 5 times in a week). The subjects, in both aerobic and resistance training, showed significant improvement in anthropometric parameters and exercise capacities including maximal oxygen uptake and muscle strength. Interestingly, the circulating irisin was significantly increased in resistance training group (p=0.002) but not in aerobic training (p=0.426) compared to control group. In addition, we found the positive correlation between change of the circulating irisin and muscle mass (r=0.432, p=0.022) and the negative correlation between change of the circulating irisin and fat mass (r=-0.407, p=0.031). In the present pilot study, we found that circulating irisin level was increased by 8 weeks of resistance training in overweight/obese adults, suggesting that resistance training could be the efficient exercise type in overweight/obese considering positive change of body composition concomitant with increase of irisin levels.

Adaptive remodeling of skeletal muscle energy metabolism in high-altitude hypoxia: Lessons from AltitudeOmics.

PubMed

Chicco, Adam J; Le, Catherine H; Gnaiger, Erich; Dreyer, Hans C; Muyskens, Jonathan B; D'Alessandro, Angelo; Nemkov, Travis; Hocker, Austin D; Prenni, Jessica E; Wolfe, Lisa M; Sindt, Nathan M; Lovering, Andrew T; Subudhi, Andrew W; Roach, Robert C

2018-05-04

Metabolic responses to hypoxia play important roles in cell survival strategies and disease pathogenesis in humans. However, the homeostatic adjustments that balance changes in energy supply and demand to maintain organismal function under chronic low oxygen conditions remain incompletely understood, making it difficult to distinguish adaptive from maladaptive responses in hypoxia-related pathologies. We integrated metabolomic and proteomic profiling with mitochondrial respirometry and blood gas analyses to comprehensively define the physiological responses of skeletal muscle energy metabolism to 16 days of high-altitude hypoxia (5260 m) in healthy volunteers from the AltitudeOmics project. In contrast to the view that hypoxia down-regulates aerobic metabolism, results show that mitochondria play a central role in muscle hypoxia adaptation by supporting higher resting phosphorylation potential and enhancing the efficiency of long-chain acylcarnitine oxidation. This directs increases in muscle glucose toward pentose phosphate and one-carbon metabolism pathways that support cytosolic redox balance and help mitigate the effects of increased protein and purine nucleotide catabolism in hypoxia. Muscle accumulation of free amino acids favor these adjustments by coordinating cytosolic and mitochondrial pathways to rid the cell of excess nitrogen, but might ultimately limit muscle oxidative capacity in vivo Collectively, these studies illustrate how an integration of aerobic and anaerobic metabolism is required for physiological hypoxia adaptation in skeletal muscle, and highlight protein catabolism and allosteric regulation as unexpected orchestrators of metabolic remodeling in this context. These findings have important implications for the management of hypoxia-related diseases and other conditions associated with chronic catabolic stress. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Positional Role Differences in the Aerobic and Anaerobic Power of Elite Basketball Players.

PubMed

Pojskić, Haris; Šeparović, Vlatko; Užičanin, Edin; Muratović, Melika; Mačković, Samir

2015-12-22

The aim of the present study was to compare the aerobic and anaerobic power and capacity of elite male basketball players who played multiple positions. Fifty-five healthy players were divided into the following three different subsamples according to their positional role: guards (n = 22), forwards (n = 19) and centers (n = 14). The following three tests were applied to estimate their aerobic and anaerobic power and capacities: the countermovement jump (CMJ), a multistage shuttle run test and the Running-based Anaerobic Sprint Test (RAST). The obtained data were used to calculate the players' aerobic and anaerobic power and capacities. To determine the possible differences between the subjects considering their different positions on the court, one-way analysis of variance (ANOVA) with the Bonferroni post-hoc test for multiple comparisons was used. The results showed that there was a significant difference between the different groups of players in eleven out of sixteen measured variables. Guards and forwards exhibited greater aerobic and relative values of anaerobic power, allowing shorter recovery times and the ability to repeat high intensity, basketball-specific activities. Centers presented greater values of absolute anaerobic power and capacities, permitting greater force production during discrete tasks. Coaches can use these data to create more individualized strength and conditioning programs for different positional roles.

Combined aerobic and resistance exercise program improves task performance in patients with heart failure.

PubMed

Gary, Rebecca A; Cress, M Elaine; Higgins, Melinda K; Smith, Andrew L; Dunbar, Sandra B

2011-09-01

To assess the effects of a home-based aerobic and resistance training program on the physical function of adults with New York Heart Association (NYHA) class II and III patients and systolic heart failure (HF). Randomized controlled trial. Home based. Stable patients (N=24; mean age, 60 ± 10 y; left ventricular ejection fraction, 25% ± 9%; 50% white; 50% women) with New York Heart Association (NYHA) classes II and III (NYHA class III, 58%) systolic heart failure (HF). A 12-week progressive home-based program of moderate-intensity aerobic and resistance exercise. Attention control wait list participants performed light stretching and flexibility exercises. A 10-item performance-based physical function measure, the Continuous Scale Physical Functional Performance test (CS-PFP10), was the major outcome variable and included specific physical activities measured in time to complete a task, weight carried during a task, and distance walked. Other measures included muscle strength, HRQOL (Minnesota Living With Heart Failure Questionnaire, Epworth Sleepiness Scale), functional capacity (Duke Activity Status Index), and disease severity (brain natriuretic peptide) levels. After the exercise intervention, 9 of 10 specific task activities were performed more rapidly, with increased weight carried by exercise participants compared with the attention control wait list group. Exercise participants also showed significant improvements in CS-PFP10 total score (P<.025), upper and lower muscle strength, and HRQOL (P<.001) compared with the attention control wait list group. Adherence rates were 83% and 99% for the aerobic and resistance training, respectively. Patients with stable HF who participate in a moderate-intensity combined aerobic and resistance exercise program may improve performance of routine physical activities of daily living by using a home-based exercise approach. Performance-based measures such as the CS-PFP10 may provide additional insights into physical

Associations Between Attitudes Toward Physical Education and Aerobic Capacity in Hungarian High School Students.

PubMed

Kaj, Mónika; Saint-Maurice, Pedro F; Karsai, István; Vass, Zoltán; Csányi, Tamás; Boronyai, Zoltán; Révész, László

2015-06-26

The purpose of this study was to create a physical education (PE) attitude scale and examine how it is associated with aerobic capacity (AC). Participants (n = 961, aged 15-20 years) were randomly selected from 26 Hungarian high schools. AC was estimated from performance on the Progressive Aerobic Cardiovascular and Endurance Run test, and the attitude scale had 31 items measured on a Likert scale that ranged from 1 to 5. Principal component analysis was used to examine the structure of the questionnaire while several 2-way analyses of variance and multiple linear regression (MLR) were computed to examine trends in AC and test the association between component scores obtained from the attitude scale and AC, respectively. Five components were identified: health orientation in PE (C1), avoid failure in PE (C2), success orientation in PE (C3), attitude toward physical activity (C4), and cooperation and social experience in PE (C5). There was a statistically significant main effect for sex on C3 (p < .05), C4 (p < .001), and C5 (p < .05) indicating that boys' scores were higher than girls. The Sex × Age interaction was also statistically significant (p < .05) and follow-up comparisons revealed sex differences in C5 for 15-year-old participants. Girls showed statistically significant higher values than boys in C5 at the age of 16 years. MLR results revealed that component scores were significantly associated with AC (p < .05). Statistically significant predictors included C1, C2, C3, and C4 for boys and C2 and C4 for girls. The 5-component scale seems to be suitable for measuring students' attitudes toward PE. The design of the study does not allow for direct associations between attitudes and AC but suggests that these 2 might be related.

Skeletal muscle homeostasis and plasticity in youth and ageing: impact of nutrition and exercise.

PubMed

Brook, M S; Wilkinson, D J; Phillips, B E; Perez-Schindler, J; Philp, A; Smith, K; Atherton, P J

2016-01-01

Skeletal muscles comprise a substantial portion of whole body mass and are integral for locomotion and metabolic health. Increasing age is associated with declines in both muscle mass and function (e.g. strength-related performance, power) with declines in muscle function quantitatively outweighing those in muscle volume. The mechanisms behind these declines are multi-faceted involving both intrinsic age-related metabolic dysregulation and environmental influences such as nutritional and physical activity. Ageing is associated with a degree of 'anabolic resistance' to these key environmental inputs, which likely accelerates the intrinsic processes driving ageing. On this basis, strategies to sensitize and/or promote anabolic responses to nutrition and physical activity are likely to be imperative in alleviating the progression and trajectory of sarcopenia. Both resistance- and aerobic-type exercises are likely to confer functional and health benefits in older age, and a clutch of research suggests that enhancement of anabolic responsiveness to exercise and/or nutrition may be achieved by optimizing modifications of muscle-loading paradigms (workload, volume, blood flow restriction) or nutritional support (e.g. essential amino acid/leucine) patterns. Nonetheless, more work is needed in which a more holistic view in ageing studies is taken into account. This should include improved characterization of older study recruits, that is physical activity/nutritional behaviours, to limit confounding variables influencing whether findings are attributable to age, or other environmental influences. Nonetheless, on balance, ageing is associated with declines in muscle mass and function and a partially related decline in aerobic capacity. There is also good evidence that metabolic flexibility is impaired in older age. © 2015 The Authors. Acta Physiologica published by John Wiley & Sons Ltd on behalf of Scandinavian Physiological Society.

Systemic SMAD7 Gene Therapy Increases Striated Muscle Mass and Enhances Exercise Capacity in a Dose-Dependent Manner.

PubMed

Maricelli, Joseph W; Bishaw, Yemeserach M; Wang, Bo; Du, Min; Rodgers, Buel D

2018-03-01

Striated muscle wasting occurs with a variety of disease indications, contributing to mortality and compromising life quality. Recent studies indicate that the recombinant adeno-associated virus (serotype 6) Smad7 gene therapeutic, AVGN7, enhances skeletal and cardiac muscle mass and prevents cancer-induced wasting of both tissues. This is accomplished by attenuating ActRIIb intracellular signaling and, as a result, the physiological actions of myostatin and other ActRIIb ligands. AVGN7 also enhances isolated skeletal muscle twitch force, but is unknown to improve systemic muscle function similarly, especially exercise capacity. A 2-month-long dose-escalation study was therefore conducted using 5 × 10 11 , 1 × 10 12 , and 5 × 10 12 vg/mouse and different tests of systemic muscle function. Body mass, skeletal muscle mass, heart mass, and forelimb grip strength were all increased in a dose-dependent manner, as was the fiber cross-sectional area of tibialis anterior muscles. Maximal oxygen consumption (VO 2 max), a measure of metabolic rate, was similarly enhanced during forced treadmill running, and although the total distance traveled was only elevated by the highest dose, all doses reduced the energy expenditure rate compared to control mice injected with an empty vector. Such improvements in VO 2 max are consistent with physiological cardiac hypertrophy, which is highly beneficial and a normal adaptive response to exercise. This was particularly evident at the lowest dose tested, which had minimal significant effects on skeletal muscle mass and/or function, but increased heart weight and exercise capacity. These results together suggest that AVGN7 enhances striated muscle mass and systemic muscle function. They also define minimally effective and optimal doses for future preclinical trials and toxicology studies and in turn will aid in establishing dose ranges for clinical trials.

Metabolic fuel kinetics in fish: swimming, hypoxia and muscle membranes.

PubMed

Weber, Jean-Michel; Choi, Kevin; Gonzalez, Alex; Omlin, Teye

2016-01-01

Muscle performance depends on the supply of metabolic fuels and disposal of end-products. Using circulating metabolite concentrations to infer changes in fluxes is highly unreliable because the relationship between these parameters varies greatly with physiological state. Quantifying fuel kinetics directly is therefore crucial to the understanding of muscle metabolism. This review focuses on how carbohydrates, lipids and amino acids are provided to fish muscles during hypoxia and swimming. Both stresses force white muscle to produce lactate at higher rates than it can be processed by aerobic tissues. However, lactate accumulation is minimized because disposal is also strongly stimulated. Exogenous supply shows that trout have a much higher capacity to metabolize lactate than observed during hypoxia or intense swimming. The low density of monocarboxylate transporters and their lack of upregulation with exercise explain the phenomenon of white muscle lactate retention. This tissue operates as a quasi-closed system, where glycogen stores act as an 'energy spring' that alternates between explosive power release during swimming and slow recoil from lactate in situ during recovery. To cope with exogenous glucose, trout can completely suppress hepatic production and boost glucose disposal. Without these responses, glycemia would increase four times faster and reach dangerous levels. The capacity of salmonids for glucoregulation is therefore much better than presently described in the literature. Instead of albumin-bound fatty acids, fish use lipoproteins to shuttle energy from adipose tissue to working muscles during prolonged exercise. Proteins may play an important role in fueling muscle work in fish, but their exact contribution is yet to be established. The membrane pacemaker theory of metabolism accurately predicts general properties of muscle membranes such as unsaturation, but it does not explain allometric patterns of specific fatty acids. Investigations of

The association among skeletal muscle phosphocreatine recovery, adiposity, and insulin resistance in children.

PubMed

Wells, Greg D; Banks, Laura; Caterini, Jessica E; Thompson, Sara; Noseworthy, Michael D; Rayner, Tammy; Syme, Catriona; McCrindle, Brian W; Hamilton, Jill

2017-04-01

Obesity is associated with cardiometabolic disturbances, which may have significant implications for musculoskeletal health and exercise tolerance. We sought to determine the association between muscle structure, function, and metabolism in adolescents across the weight spectrum. This cross-sectional case-control study included overweight and obese participants (n = 24) 8-18 years of age with a body mass index (BMI) ≥ 85th percentile for age and gender, and non-obese participants (n = 24) with a BMI < 85 th percentile. Body composition, physical activity, peak aerobic capacity, cardiometabolic blood markers and insulin resistance (measured by the homeostatic model assessment of insulin resistance, HOMA-IR), skeletal muscle mitochondrial oxidative capacity (via 31 Phosphorous-Magnetic Resonance Spectroscopy, 31 P-MRS, to assess phosphocreatine (PCr) recovery after exercise), and extramyocellular and intramyocellular lipid (IMCL) levels (via 1 Hydrogen-MRS) were assessed. Stepwise regression was performed to examine the factors associated with oxidative capacity. bese and overweight patients had similar age, height, and physical activity to non-obese controls, but obese and overweight participants exhibited higher insulin resistance. Obese and overweight participants had longer PCr recovery than non-obese controls following 5x30s of moderate-intensity exercise (51.2 ± 20.1 s vs. 23.9 ± 7.5 s, p = 0.004). In univariate correlation analysis, impaired PCr recovery was associated with a higher BMI z-score (r s  = 0.51, p < 0.001), circulating triglycerides (r s  = 0.41, p = 0.005), and HOMA-IR (r s  = 0.46, p = 0.001). In stepwise multivariate regression analysis, impaired PCr recovery was associated with a higher BMI z-score (β = 0.47, p = 0.002), but not insulin resistance (β = 0.07, p = 0.07) or circulating triglycerides (β = 0.16 p = 0.33). A slower phosphocreatine recovery

An aerobic walking programme versus muscle strengthening programme for chronic low back pain: a randomized controlled trial.

PubMed

Shnayderman, Ilana; Katz-Leurer, Michal

2013-03-01

To assess the effect of aerobic walking training as compared to active training, which includes muscle strengthening, on functional abilities among patients with chronic low back pain. Randomized controlled clinical trial with blind assessors. Outpatient clinic. Fifty-two sedentary patients, aged 18-65 years with chronic low back pain. Patients who were post surgery, post trauma, with cardiovascular problems, and with oncological disease were excluded. Experimental 'walking' group: moderate intense treadmill walking; control 'exercise' group: specific low back exercise; both, twice a week for six weeks. Six-minute walking test, Fear-Avoidance Belief Questionnaire, back and abdomen muscle endurance tests, Oswestry Disability Questionnaire, Low Back Pain Functional Scale (LBPFS). Significant improvements were noted in all outcome measures in both groups with non-significant difference between groups. The mean distance in metres covered during 6 minutes increased by 70.7 (95% confidence interval (CI) 12.3-127.7) in the 'walking' group and by 43.8 (95% CI 19.6-68.0) in the 'exercise' group. The trunk flexor endurance test showed significant improvement in both groups, increasing by 0.6 (95% CI 0.0-1.1) in the 'walking' group and by 1.1 (95% CI 0.3-1.8) in the 'exercise' group. A six-week walk training programme was as effective as six weeks of specific strengthening exercises programme for the low back.

A Geometric Capacity-Demand Analysis of Maternal Levator Muscle Stretch Required for Vaginal Delivery.

PubMed

Tracy, Paige V; DeLancey, John O; Ashton-Miller, James A

2016-02-01

Because levator ani (LA) muscle injuries occur in approximately 13% of all vaginal births, insights are needed to better prevent them. In Part I of this paper, we conducted an analysis of the bony and soft tissue factors contributing to the geometric "capacity" of the maternal pelvis and pelvic floor to deliver a fetal head without incurring stretch injury of the maternal soft tissue. In Part II, we quantified the range in demand, represented by the variation in fetal head size and shape, placed on the maternal pelvic floor. In Part III, we analyzed the capacity-to-demand geometric ratio, g, in order to determine whether a mother can deliver a head of given size without stretch injury. The results of a Part I sensitivity analysis showed that initial soft tissue loop length (SL) had the greatest effect on maternal capacity, followed by the length of the soft tissue loop above the inferior pubic rami at ultimate crowning, then subpubic arch angle (SPAA) and head size, and finally the levator origin separation distance. We found the more caudal origin of the puborectal portion of the levator muscle helps to protect it from the stretch injuries commonly observed in the pubovisceral portion. Part II fetal head molding index (MI) and fetal head size revealed fetal head circumference values ranging from 253 to 351 mm, which would increase up to 11 mm upon face presentation. The Part III capacity-demand analysis of g revealed that, based on geometry alone, the 10th percentile maternal capacity predicted injury for all head sizes, the 25th percentile maternal capacity could deliver half of all head sizes, while the 50th percentile maternal capacity could deliver a head of any size without injury. If ultrasound imaging could be operationalized to make measurements of ratio g, it might be used to usefully inform women on their level of risk for levator injury during vaginal birth.

Impact of NFL PLAY 60 Programming on Elementary School Children's Body Mass Index and Aerobic Capacity: The NFL PLAY 60 FitnessGram Partnership Project

ERIC Educational Resources Information Center

Saint-Maurice, Pedro F.; Bai, Yang; Welk, Gregory J.; Bandelli, Lorraine N.; Allums-Featherston, Kelly; Candelaria, Norma

2017-01-01

Background: We examined the impact of the Fuel Up to Play 60 (FUTP60) program on children's body mass index (BMI) and aerobic capacity (AC). Methods: Participation in the FUTP60 and both BMI and AC profiles were collected through the NFL PLAY 60 FitnessGram Partnership Project involving over 100 schools from 22 US states. We specifically examined…

The effect of exhausting aerobic exercise on the timing of anticipatory postural adjustments.

PubMed

Strang, A J; Choi, H J; Berg, W P

2008-03-01

The aim of the study was to investigate the influence of exhausting aerobic exercise on the timing of anticipatory postural adjustments (APAs). The APAs of 12 participants were recorded at baseline, after a .VO2max running test, and again following a 45-min rest period. APAs were induced using a rapid bilateral arm-raising maneuver, and were analyzed in the rectus abdominis, hamstring group, gluteal group, and lumbar and thoracic paraspinal muscles using electromyography. Postural stability was assessed by monitoring anterior/posterior displacement of the center of pressure using a force plate. We hypothesized that APA onset would be ear lier following exhausting aerobic exercise as compared to the baseline measures, but that this effect would be transient (i.e., APA onset following the rest period would not differ from that at baseline). Exhausting aerobic exercise resulted in a significantly earlier APA in one of the 5 muscles evaluated, the thoracic paraspinal group, and this effect persisted 45-min postexercise. Exhausting aerobic exercise did not affect postural stability during the rapid arm-raising maneuver. The findings lend tentative support for the notion that earlier APAs constitute a functional adaptation by the motor system to maintain postural stability in the presence of fatigue.

The influence of muscle fiber type composition on the patterns of responses for electromyographic and mechanomyographic amplitude and mean power frequency during a fatiguing submaximal isometric muscle action.

PubMed

Beck, T W; Housh, T J; Fry, A C; Cramer, J T; Weir, J P; Schilling, B K; Falvo, M J; Moore, C A

2007-07-01

The purpose of this investigation was to examine the influence of muscle fiber type composition on the patterns of responses for electromyographic (EMG) and mechanomyographic (MMG) amplitude and mean power frequency (MPF) during a fatiguing submaximal isometric muscle action. Five resistance-trained (mean +/- SD age = 23.2 +/- 3.7 yrs) and five aerobically-trained (mean +/- SD age = 32.6 +/- 5.2 yrs) men volunteered to perform a fatiguing, 30-sec submaximal isometric muscle action of the leg extensors at 50% of the maximum voluntary contraction (MVC). Muscle biopsies from the vastus lateralis revealed that the myosin heavy chain (MHC) composition for the resistance-trained subjects was 59.0 +/- 4.2% Type IIa, 0.1 +/- 0.1% Type IIx, and 40.9 +/- 4.3% Type I. The aerobically-trained subjects had 27.4 +/- 7.8% Type IIa, 0.0 +/- 0.0% Type IIx, and 72.6 +/- 7.8% Type I MHC. The patterns of responses and mean values for absolute and normalized EMG amplitude and MPF during the fatiguing muscle action were similar for the resistance-trained and aerobically-trained subjects. The resistance-trained subjects demonstrated relatively stable levels for absolute and normalized MMG amplitude and MPF across time, but the aerobically-trained subjects showed increases in MMG amplitude and decreases in MMG MPE The absolute MMG amplitude and MPF values for the resistance-trained subjects were also greater than those for the aerobi-cally-trained subjects. These findings suggested that unlike surface EMG, MMG may be a useful noninvasive technique for examining fatigue-related differences in muscle fiber type composition.

Effects of a 12-week, short-interval, intermittent, low-intensity, slow-jogging program on skeletal muscle, fat infiltration, and fitness in older adults: randomized controlled trial.

PubMed

Ikenaga, Masahiro; Yamada, Yosuke; Kose, Yujiro; Morimura, Kazuhiro; Higaki, Yasuki; Kiyonaga, Akira; Tanaka, Hiroaki

2017-01-01

We developed a short-interval, low-intensity, slow-jogging (SJ) program consisting of sets of 1 min of SJ at walking speed and 1 min of walking. We aimed to examine the effects of an easily performed SJ program on skeletal muscle, fat infiltration, and fitness in older adults. A total of 81 community-dwelling, independent, older adults (70.8 ± 4.0 years) were randomly assigned to the SJ or control group. The SJ group participants were encouraged to perform 90 min of SJ at their anaerobic threshold (AT) intensity and 90 min of walking intermittently per week. Aerobic capacity at the AT and sit-to-stand (STS) scores were measured. Intracellular water (ICW) in the legs was assessed by segmental multi-frequency bioelectrical impedance analysis. Subcutaneous (SAT) and intermuscular (IMAT) adipose tissue and muscle cross-sectional area (CSA) were measured at the mid-thigh using computed tomography. A total of 75 participants (37 SJ group, 38 controls) completed the 12-week intervention. The AT and STS improved in the SJ group compared with the controls (AT 15.7 vs. 4.9 %, p < 0.01; STS 12.9 vs. 4.5 %, p < 0.05). ICW in the upper leg increased only in the SJ group (9.7 %, p < 0.05). SAT and IMAT were significantly decreased only in the SJ group (p < 0.01). The 12-week SJ program was easily performed by older adults with low skeletal muscle mass, improved aerobic capacity, muscle function, and muscle composition in older adults.

Comparative analysis of the 1-mile run test evaluation formulae: assessment of aerobic capacity in male law enforcement officers aged 20-23 years.

PubMed

Kayihan, Gürhan; Özkan, Ali; Köklü, Yusuf; Eyuboğlu, Ender; Akça, Firat; Koz, Mitat; Ersöz, Gülfem

2014-04-01

The purpose of this study was to compare values of aerobic performance in the 1-mile run test (1-MRT) using different formulae. Aerobic capacities of 351 male volunteers working for the Turkish National Police within the age range of 20-23 years were evaluated by the 1-MRT and the 20-metre shuttle run (20-MST). VO2max values were estimated by the prediction equations developed by George et al. (1993), Cureton et al. (1995) and Kline et al. (1987) for the 1-MRT and by Leger and Lambert (1982) for the 20-MST. The difference between the results of the different formulae was significant (p = 0.000). The correlation coefficient between the estimated VO2max using Cureton's equation, George's equation, Kline's equation and the 20-MST were 0.691 (p < 0.001), 0.486 (p < 0.001) and 0.608 (p < 0.001), respectively. The highest correlation coefficient was between the VO2max estimated by the 20-MST and Cureton's equation. Similarly, the highest correlation coefficient (r = -0.779) was between the 1-mile run time and the VO2max estimated by Cureton's equation. When analysing more vigorous exercise than sub-maximal exercise, we suggest that Cureton's equation be used to predict the VO2max from 1-mile run/walk performance in large numbers of healthy individuals with high VO2max. This research compares the use of 3 different formulae to estimate VO2max from 1-mile run/walk performance in male law enforcement officers aged 20-23 years for the first time and reports the most accurate formula to use when evaluating aerobic capacities of large numbers of healthy individuals.

Exercise training prevents skeletal muscle damage in an experimental sepsis model

PubMed Central

Coelho, Carla Werlang; Jannig, Paulo R; de Souza, Arlete B; Fronza, Hercilio; Westphal, Glauco A; Petronilho, Fabricia; Constantino, Larissa; Dal-Pizzol, Felipe; Ferreira, Gabriela K; Streck, Emilio E; Silva, Eliezer

2013-01-01

OBJECTIVE: Oxidative stress plays an important role in skeletal muscle damage in sepsis. Aerobic exercise can decrease oxidative stress and enhance antioxidant defenses. Therefore, it was hypothesized that aerobic exercise training before a sepsis stimulus could attenuate skeletal muscle damage by modulating oxidative stress. Thus, the aim of this study was to evaluate the effects of aerobic physical preconditioning on the different mechanisms that are involved in sepsis-induced myopathy. METHODS: Male Wistar rats were randomly assigned to either the untrained or trained group. The exercise training protocol consisted of an eight-week treadmill program. After the training protocol, the animals from both groups were randomly assigned to either a sham group or a cecal ligation and perforation surgery group. Thus, the groups were as follows: sham, cecal ligation and perforation, sham trained, and cecal ligation and perforation trained. Five days after surgery, the animals were euthanized and their soleus and plantaris muscles were harvested. Fiber cross-sectional area, creatine kinase, thiobarbituric acid reactive species, carbonyl, catalase and superoxide dismutase activities were measured. RESULTS: The fiber cross-sectional area was smaller, and the creatine kinase, thiobarbituric acid reactive species and carbonyl levels were higher in both muscles in the cecal ligation and perforation group than in the sham and cecal ligation and perforation trained groups. The muscle superoxide dismutase activity was higher in the cecal ligation and perforation trained group than in the sham and cecal ligation and perforation groups. The muscle catalase activity was lower in the cecal ligation and perforation group than in the sham group. CONCLUSION: In summary, aerobic physical preconditioning prevents atrophy, lipid peroxidation and protein oxidation and improves superoxide dismutase activity in the skeletal muscles of septic rats. PMID:23420166

Effects of Marathon Running on Aerobic Fitness and Performance in Recreational Runners One Week after a Race.

PubMed

Takayama, Fuminori; Aoyagi, Atsushi; Shimazu, Wataru; Nabekura, Yoshiharu

2017-01-01

It is not clear whether or not recreational runners can recover aerobic fitness and performance within one week after marathon running. This study aimed to investigate the effects of running a marathon race on aerobic fitness and performance one week later. Eleven recreational runners (six men, five women) completed the race in 3 h 36 min 20 s ± 41 min 34 s (mean ± standard deviation). Before and 7 days after the race, they performed a treadmill running test. Perceived muscle soreness was assessed before the race and for the following 7 days. The magnitude of changes in the treadmill running test was considered possibly trivial for maximal oxygen uptake ([Formula: see text]O 2 max) (mean difference -1.2 ml/kg/min; ±90% confidence limits 2 ml/kg/min), unclear for %[Formula: see text]O 2 max at anaerobic threshold (AT) (-0.5; ±4.1%) and RE (0.2; ±3.5 ml/kg/km), and likely trivial for both velocity at AT and peak (-0.2; ±0.49 km/h and -0.3; ±0.28 km/h). Perceived muscle soreness increased until 3 days after the race, but there were no clear differences between the values before the race and 4-7 days after it. These results show that physiological capacity associated with marathon running performance is recovered within 7 days after a marathon run.

Effects of Marathon Running on Aerobic Fitness and Performance in Recreational Runners One Week after a Race

PubMed Central

Aoyagi, Atsushi; Shimazu, Wataru

2017-01-01

It is not clear whether or not recreational runners can recover aerobic fitness and performance within one week after marathon running. This study aimed to investigate the effects of running a marathon race on aerobic fitness and performance one week later. Eleven recreational runners (six men, five women) completed the race in 3 h 36 min 20 s ± 41 min 34 s (mean ± standard deviation). Before and 7 days after the race, they performed a treadmill running test. Perceived muscle soreness was assessed before the race and for the following 7 days. The magnitude of changes in the treadmill running test was considered possibly trivial for maximal oxygen uptake (V˙O2max) (mean difference −1.2 ml/kg/min; ±90% confidence limits 2 ml/kg/min), unclear for %V˙O2max at anaerobic threshold (AT) (−0.5; ±4.1%) and RE (0.2; ±3.5 ml/kg/km), and likely trivial for both velocity at AT and peak (−0.2; ±0.49 km/h and −0.3; ±0.28 km/h). Perceived muscle soreness increased until 3 days after the race, but there were no clear differences between the values before the race and 4–7 days after it. These results show that physiological capacity associated with marathon running performance is recovered within 7 days after a marathon run. PMID:29138757

Human Skeletal Muscle Health with Spaceflight

NASA Astrophysics Data System (ADS)

Trappe, Scott

2012-07-01

This lecture will overview the most recent aerobic and resistance exercise programs used by crewmembers while aboard the International Space Station (ISS) for six months and examine its effectiveness for protecting skeletal muscle health. Detailed information on the exercise prescription program, whole muscle size, whole muscle performance, and cellular data obtained from muscle biopsy samples will be presented. Historically, detailed information on the exercise program while in space has not been available. These most recent exercise and muscle physiology findings provide a critical foundation to guide the exercise countermeasure program forward for future long-duration space missions.

Effect of intermittent normobaric hypoxia on aerobic capacity and cognitive function in older people.

PubMed

Schega, Lutz; Peter, Beate; Brigadski, Tanja; Leßmann, Volkmar; Isermann, Berend; Hamacher, Dennis; Törpel, Alexander

2016-11-01

Physical exercise, especially aerobic training, improves physical performance and cognitive function of older people. Furthermore, it has been speculated that age-associated deteriorations in physical performance and cognitive function could be counteracted through exposures to passive intermittent normobaric hypoxia (IH). Thus, the present investigation aimed at investigating the effect of passive IH combined with subsequent aerobic training on hematological parameters and aerobic physical performance (V˙O 2max ) as well as peripheral levels of the neurotrophin brain-derived neurotrophic factor (BDNF) and cognitive function. Randomized controlled trial in a repeated measure design. 34 older participants were randomly assigned to an intervention group (IG) or control group (CG). While IG was supplied with passive IH for 90min, CG breathed ambient air. Subsequently, both groups underwent 30min of aerobic training three times per week for four consecutive weeks. Aerobic physical performance and cognitive function was tested with spiroergometry and the Stroop test. Blood samples were taken to measure hematological parameters and the peripheral serum BDNF-level. We found increases in the values of hematological parameters, the time to exhaustion in the load test and an augmented and sustainable improvement in cognitive function within the IG of the older people only. However, in both groups, the V˙O 2max and serum BDNF-level did not increase. Based on these results, hypoxic training seems to be beneficial to enhance hematological parameters, physical performance and cognitive function in older people. The current hypoxic-dose was not able to enhance the serum BDNF-level or V˙O 2max . Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Aerobic Capacity is Related to Repeated Sprint Ability with Sprint Distances Less Than 40 Meters

PubMed Central

SANDERS, GABRIEL J.; TURNER, ZACHARY; BOOS, BRIAN; PEACOCK, COREY A.; PEVELER, WILLARD; LIPPING, ALAR

2017-01-01

Research is inconclusive regarding the association between aerobic fitness (objectively measured VO2max) and repeated sprint performance when the sprints are less than 40 meters. Soccer athletes must be able to repeat sprints without significant decreases in speed and strength and conditioning coaches need to better understand if aerobic fitness is related to repeated sprint ability (RSA). Twenty (10 male, 10 female) Division I soccer athletes first completed a graded maximal treadmill test to measure VO2max. Then on a separate day, athletes completed the RSA test. The RSA test consisted of 10, 30-meter sprints which athletes repeated every 30 seconds. There were significant negative correlations (r ≤ −0.69, P < 0.001) between VO2max and all 10-sprint times and average sprint time. More aerobically fit Division I soccer athletes were faster at all time points during the RSA test. Aerobic fitness is associated with faster sprint times during a more anaerobic RSA test when sprint distances are less than 40 meters. PMID:28344734

Low-Level Laser Therapy (LLLT) in Dystrophin-Deficient Muscle Cells: Effects on Regeneration Capacity, Inflammation Response and Oxidative Stress.

PubMed

Macedo, Aline Barbosa; Moraes, Luis Henrique Rapucci; Mizobuti, Daniela Sayuri; Fogaça, Aline Reis; Moraes, Fernanda Dos Santos Rapucci; Hermes, Tulio de Almeida; Pertille, Adriana; Minatel, Elaine

2015-01-01

The present study evaluated low-level laser therapy (LLLT) effects on some physiological pathways that may lead to muscle damage or regeneration capacity in dystrophin-deficient muscle cells of mdx mice, the experimental model of Duchenne muscular dystrophy (DMD). Primary cultures of mdx skeletal muscle cells were irradiated only one time with laser and analyzed after 24 and 48 hours. The LLLT parameter used was 830 nm wavelengths at 5 J/cm² fluence. The following groups were set up: Ctrl (untreated C57BL/10 primary muscle cells), mdx (untreated mdx primary muscle cells), mdx LA 24 (mdx primary muscle cells - LLLT irradiated and analyzed after 24 h), and mdx LA 48 (mdx primary muscle cells - LLLT irradiated and analyzed after 48 h). The mdx LA 24 and mdx LA 48 groups showed significant increase in cell proliferation, higher diameter in muscle cells and decreased MyoD levels compared to the mdx group. The mdx LA 48 group showed significant increase in Myosin Heavy Chain levels compared to the untreated mdx and mdx LA 24 groups. The mdx LA 24 and mdx LA 48 groups showed significant increase in [Ca2+]i. The mdx group showed significant increase in H2O2 production and 4-HNE levels compared to the Ctrl group and LLLT treatment reduced this increase. GSH levels and GPx, GR and SOD activities increased in the mdx group. Laser treatment reduced the GSH levels and GR and SOD activities in dystrophic muscle cells. The mdx group showed significant increase in the TNF-α and NF-κB levels, which in turn was reduced by the LLLT treatment. Together, these results suggest that the laser treatment improved regenerative capacity and decreased inflammatory response and oxidative stress in dystrophic muscle cells, indicating that LLLT could be a helpful alternative therapy to be associated with other treatment for dystrophinopathies.

Enhancing of women functional status with metabolic syndrome by cardioprotective and anti-inflammatory effects of combined aerobic and resistance training.

PubMed

Tibana, Ramires Alsamir; Nascimento, Dahan da Cunha; de Sousa, Nuno Manuel Frade; de Souza, Vinicius Carolino; Durigan, João; Vieira, Amilton; Bottaro, Martim; Nóbrega, Otávio de Toledo; de Almeida, Jeeser Alves; Navalta, James Wilfred; Franco, Octavio Luiz; Prestes, Jonato

2014-01-01

These data describe the effects of combined aerobic plus resistance training (CT) with regards to risk factors of metabolic syndrome (MetS), quality of life, functional capacity, and pro- and anti-inflammatory cytokines in women with MetS. In this context, thirteen women (35.4 ± 6.2 yr) completed 10 weeks of CT consisting of three weekly sessions of ~60 min aerobic training (treadmill at 65-70% of reserve heart rate, 30 min) and resistance training (3 sets of 8-12 repetitions maximum for main muscle groups). Dependent variables were maximum chest press strength; isometric hand-grip strength; 30 s chair stand test; six minute walk test; body mass; body mass index; body adiposity index; waist circumference; systolic (SBP), diastolic and mean blood pressure (MBP); blood glucose; HDL-C; triglycerides; interleukins (IL) 6, 10 and 12, osteoprotegerin (OPG) and serum nitric oxide metabolite (NOx); quality of life (SF-36) and Z-Score of MetS. There was an improvement in muscle strength on chest press (p = 0.009), isometric hand-grip strength (p = 0.03) and 30 s chair stand (p = 0.007). There was a decrease in SBP (p = 0.049), MBP (p = 0.041), Z-Score of MetS (p = 0.046), OPG (0.42 ± 0.26 to 0.38 ± 0.19 ng/mL, p<0.05) and NOx (13.3 ± 2.3 µmol/L to 9.1 ± 2.3 µmol/L; p<0.0005). IL-10 displayed an increase (13.6 ± 7.5 to 17.2 ± 12.3 pg/mL, p < 0.05) after 10 weeks of training. Combined training also increased the perception of physical capacity (p = 0.011). This study endorses CT as an efficient tool to improve blood pressure, functional capacity, quality of life and reduce blood markers of inflammation, which has a clinical relevance in the prevention and treatment of MetS.

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

Resistance training and mitochondrial metabolism

USDA-ARS?s Scientific Manuscript database

Objective: To determine if resistance exercise training improves skeletal muscle substrate oxidative capacity in older adults. Background: A decline in skeletal muscle oxidative capacity occurs with aging. Aerobic exercise increases skeletal muscle’s ability to oxidize multiple substrates. Th...

Sites of superoxide and hydrogen peroxide production by muscle mitochondria assessed ex vivo under conditions mimicking rest and exercise.

PubMed

Goncalves, Renata L S; Quinlan, Casey L; Perevoshchikova, Irina V; Hey-Mogensen, Martin; Brand, Martin D

2015-01-02

The sites and rates of mitochondrial production of superoxide and H2O2 in vivo are not yet defined. At least 10 different mitochondrial sites can generate these species. Each site has a different maximum capacity (e.g. the outer quinol site in complex III (site IIIQo) has a very high capacity in rat skeletal muscle mitochondria, whereas the flavin site in complex I (site IF) has a very low capacity). The maximum capacities can greatly exceed the actual rates observed in the absence of electron transport chain inhibitors, so maximum capacities are a poor guide to actual rates. Here, we use new approaches to measure the rates at which different mitochondrial sites produce superoxide/H2O2 using isolated muscle mitochondria incubated in media mimicking the cytoplasmic substrate and effector mix of skeletal muscle during rest and exercise. We find that four or five sites dominate during rest in this ex vivo system. Remarkably, the quinol site in complex I (site IQ) and the flavin site in complex II (site IIF) each account for about a quarter of the total measured rate of H2O2 production. Site IF, site IIIQo, and perhaps site EF in the β-oxidation pathway account for most of the remainder. Under conditions mimicking mild and intense aerobic exercise, total production is much less, and the low capacity site IF dominates. These results give novel insights into which mitochondrial sites may produce superoxide/H2O2 in vivo. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Sites of Superoxide and Hydrogen Peroxide Production by Muscle Mitochondria Assessed ex Vivo under Conditions Mimicking Rest and Exercise*

PubMed Central

Goncalves, Renata L. S.; Quinlan, Casey L.; Perevoshchikova, Irina V.; Hey-Mogensen, Martin; Brand, Martin D.

2015-01-01