Purpose The aim of this study was to evaluate the effects of Vernonia cinerea Less. (VC) supplementation and exercise on oxidative stress biomarkers, beta-endorphin release, and the rate of cigarette smoking. Methods Volunteer smokers were randomly divided into four groups: group 1: VC supplement; group 2: exercise with VC supplement; group 3: exercise; and group 4: control. VC was prepared by wash and dry techniques and taken orally before smoking, matching the frequency of strenuous exercise (three times weekly). Before and after a two month period, exhaled carbon monoxide (CO), blood oxidative stress (malondialdehyde [MDA], nitric oxide [NOx], protein hydroperoxide [PrOOH] and total antioxidant capacity [TAC]), beta-endorphin and smoking rate were measured, and statistically analyzed. Results In Group 1, MDA, PrOOH, and NOx significantly decreased, whereas TAC increased (p < 0.05). In Group 2, MDA and PrOOH decreased (p < 0.05), with no other changes noted (p > 0.05). In Group 3, MDA, PrOOH, NOx, TAC, and beta-endorphin levels increased significantly (p < 0.05). Group 4 showed no change in oxidative stress variables or beta-endorphine levels (p > 0.05). All groups had lower levels of CO after the intervention. The smoking rate for light cigarette decreased in group 2(62.7%), 1(59.52%), 3 (53.57%) and 4(14.04%), whereas in self-rolled cigarettes it decreased in group 1 (54.47%), 3 (42.30%), 2 (40%) and 4 (9.2%). Conclusion Supplementation with Vernonia cinerea Less and exercise provided benefit related to reduced smoking rate, which may be related to oxidaive stress and beta-endorphine levels.
This report discusses the changes in lipid and enzyme parameters of individuals under the influence of ingestion of high saturated fat-high caloric diets while engaged in a training regimen of strenuous exercise. Results show a consistent increase in neut...
G. L. Calvy L. H. Coffin M. M. Gertler L. D. Cady
Music is known to be capable of reducing perceived exertion during strenuous physical activity. The current interpretation of this modulating effect of music is that music may be perceived as a diversion from unpleasant proprioceptive sensations that go along with exhaustion. Here we investigated the effects of music on perceived exertion during a physically strenuous task, varying musical agency, a task that relies on the experience of body proprioception, rather than simply diverting from it. For this we measured psychologically indicated exertion during physical workout with and without musical agency while simultaneously acquiring metabolic values with spirometry. Results showed that musical agency significantly decreased perceived exertion during workout, indicating that musical agency may actually facilitate physically strenuous activities. This indicates that the positive effect of music on perceived exertion cannot always be explained by an effect of diversion from proprioceptive feedback. Furthermore, this finding suggests that the down-modulating effect of musical agency on perceived exertion may be a previously unacknowledged driving force for the development of music in humans: making music makes strenuous physical activities less exhausting. PMID:24127588
Fritz, Thomas Hans; Hardikar, Samyogita; Demoucron, Matthias; Niessen, Margot; Demey, Michiel; Giot, Olivier; Li, Yongming; Haynes, John-Dylan; Villringer, Arno; Leman, Marc
Music is known to be capable of reducing perceived exertion during strenuous physical activity. The current interpretation of this modulating effect of music is that music may be perceived as a diversion from unpleasant proprioceptive sensations that go along with exhaustion. Here we investigated the effects of music on perceived exertion during a physically strenuous task, varying musical agency, a task that relies on the experience of body proprioception, rather than simply diverting from it. For this we measured psychologically indicated exertion during physical workout with and without musical agency while simultaneously acquiring metabolic values with spirometry. Results showed that musical agency significantly decreased perceived exertion during workout, indicating that musical agency may actually facilitate physically strenuous activities. This indicates that the positive effect of music on perceived exertion cannot always be explained by an effect of diversion from proprioceptive feedback. Furthermore, this finding suggests that the down-modulating effect of musical agency on perceived exertion may be a previously unacknowledged driving force for the development of music in humans: making music makes strenuous physical activities less exhausting.
Fritz, Thomas Hans; Hardikar, Samyogita; Demoucron, Matthias; Niessen, Margot; Demey, Michiel; Giot, Olivier; Li, Yongming; Haynes, John-Dylan; Villringer, Arno; Leman, Marc
A 51-year-old highly fit man presented for dyspnea with strenuous aerobic exercise. The patient was asymptomatic and all tests were normal at rest. With increasing exercise intensity, he suddenly complained of dyspnea and showed a severe exercise-induced hypoxemia with an excessive alveolar-arterial oxygen tension difference. In agitated saline contrast echocardiography at peak exercise, a large amount of left to right shunt was identified after > 5 cardiac cycles, which suggests the presence of exercise-induced intrapulmonary arteriovenous shunt in this patient.
Kim, Tae-Jun; Hong, Seong-Eun; Jung, Dong-Min; Choi, Nan-Young; Kim, Yong-Kyun; Park, Seung-Ah; Kim, Soon-Young; Park, Woo-Jung
Physical exercise is considered to exert a positive effect on health, whereas strenuous or excessive exercise (Exe) causes fatigue and damage to muscle and immune functions. The underlying molecular mechanisms are still unclear. We designed a protocol to mimic Exe and explore the ensuing cellular damage and involvement of mitochondrial dynamics. We found that Exe was prone to decrease endurance
Zhihui Feng; Liyuan Bai; Jiong Yan; Yuan Li; Weili Shen; Ying Wang; Karin Wertz; Peter Weber; Yong Zhang; Yan Chen; Jiankang Liu
This study examined the extent to which 10 minutes of prior exercise (PE) at a workload adjusted to maintain a heart rate (HR) of 140 beats per minute could facilitate the mobilization of the oxygen transport system in a strenuous criterion task (CT). The control treatment involved completion of the CT following 10 minutes of rest on the…
Gutin, Bernard; And Others
In this study, we aimed to compare the effects of a single bout of acute moderate and strenuous running exercise on the production of interleukin-17 (IL-17), interleukin-6 (IL-6), interleukin-1 receptor antagonist (IL-1ra) and inflammatory response of skeletal muscles in regularly trained rats. Eight week old rats were trained by treadmill running 5 days per week for 13 weeks at the durations of 30 min (moderate) and 60 min (strenuous). Two days after the last training session, the animals were subjected to a single bout of moderate or strenuous exercise and serum samples were analyzed for IL-17, IL-6, IL-1ra levels and myeloperoxidase (MPO) activity of gastrocnemius muscle were determined. IL-17 level significantly increased in strenuous exercise group when compared to that of sedentary controls (p < 0.01), On the other hand, only in the moderate exercise group, there was a negative correlation between IL-6 and IL-17 levels (r = - 0.857 and p = 0.014). In conclusion, acute single bout of strenuous exercise increased IL-17 production in trained rats and, this cytokine may be involved in inflammatory process of skeletal muscles. Key points A single bout of acute strenuous running exercise markedly elevated IL-17 production. This preliminary result should be supported by forthcoming studies that investigate the role of IL-17 in acute inflammatory process of skeletal muscle.
Duzova, Halil; Karakoc, Yunus; Emre, Memet Hanifi; Dogan, Zumrut Yilmaz; Kilinc, Evren
We aimed to investigate the effects of a single session of prolonged strenuous exercise (PSE) on arterial stiffness by measuring pulse wave velocity (PWV) before and after competition in an ultramarathon. A total of 20 routine ultramarathon competitors (UM) completed baseline and postrace evaluation of central PWV (cPWV), upper-limb PWV (uPWV), and lower-limb PWV (lPWV) using carotid artery - femoral artery, carotid artery - finger, and femoral artery - toe segments, respectively. Fourteen additional age- and gender-matched normally active participants (NA) took part in the identical baseline evaluation but did not participate in the race. Average ultramarathon completion time was 30 h 47 min. Mean arterial blood pressure was reduced after exercise (before exercise (pre), 92 ± 7 mm Hg; after exercise (post), 84 ± 7 mm Hg; P < 0.001), whereas heart rate was increased (pre, 57 ± 10 beats·min(-1); post, 73 ± 12 beats·min(-1); P < 0.001). Also, lPWV (pre, 11.8 ± 3.6 m·s(-1); post, 9.6 ± 2.6 m·s(-1); P < 0.05) and uPWV (pre, 5.0 ± 0.53 m·s(-1); post, 4.4 ± 0.8 m·s(-1); P < 0.01) were reduced after exercise. No change in cPWV occurred (pre, 4.1 ± 0.8 m·s(-1); post, 3.9 ± 1.3 m·s(-1); P = 0.55). At baseline, the NA group had significantly increased cPWV in comparison with the UM group (UM, 4.1 ± 0.8 m·s(-1); NA, 7.4 ± 1.3 m·s(-1); P < 0.001). Acute participation in PSE influenced peripheral but not central arterial stiffness. Those who routinely participate in PSE have reduced central arterial stiffness as compared with normally active, age- and gender-matched controls. PMID:22606960
Phillips, Aaron A; Cote, Anita T; Foulds, Heather J; Charlesworth, Sarah; Bredin, Shannon S D; Burr, Jamie F; Ngai, Shirley; Ivey, Adam; Drury, C Taylor; Fougere, Renee J; Warburton, Darren E R
Changes were explored in the behavior of circulating monocytes and their potential association with the activation of the coagulation system as assessed following strenuous exercise. Twelve men and nine women from the Norwegian national cross country skiing team and 19 men and six women from a level just below that of the national team were studied before and after ski race competition. Mononuclear cells were isolated after incubation of heparinized blood with lipopolysaccharides (LPS; 3 ng.ml-1) for 2 h. After a 50 km race for men, the specific thromboplastin activity of the stimulated monocytes rose from 3.5 x 10(-3)/10(6) cells to 21.4 x 10(-3)/10(6) cells. This probably reflects the mobilization of a new population of monocytes that are more sensitive to such stimuli. Resting top-athlete skiers had monocytes which were significantly less responsive to the LPS stimulus compared to nontrained people. There was an inverse correlation of plasma factor VII and the monocyte responsiveness to in vitro stimulation (r = 0.814; P less than 0.002) from blood drawn after a race. Furthermore, factor VII was significantly reduced after a 50 km race, and a modest decline in the fibrinogen level was also observed (P less than 0.05). It is concluded that endurance ski racing causes white cell mobilization and more active white cells that may induce activation of the coagulation system and account for the involvement of factor VII and fibrinogen. PMID:2674588
Osterud, B; Olsen, J O; Wilsgård, L
Summary Twelve subjects (aged 21–38 years) participated in a 90-km cross-country ski race lasting 4.45–6.50 h. In order to investigate\\u000a a metabolic role for secretin and vasoactive intestinal polypeptide (VIP) during long-term strenuous exercise, seven of the\\u000a subjects were given an oral hypertonic glucose solution while the others had no nutrient intake immediately after the race.\\u000a The plasma concentrations of secretin
O. Øktedalen; P. K. Opstad; O. B. Schaffalitzky de Muckadell
In the context of a model of health-related social control, we compared the associations among social control strategies, affective and behavioral reactions, and exercise for parental and peer influence agents. Late adolescent college students (n = 227) completed questionnaires that focused on social control from a parent or a peer who attempted to increase their exercising. Results from this cross-sectional study revealed that most relationships in the model were similar for parent and peer influence agents, however, (a) negative social control was a stronger predictor of reactance among parents than peers; (b) positive affect was a stronger predictor of attempts to change among peers than parents; and (c) positive affect predicted frequency of strenuous exercise only among parents. Decreasing parents' use of negative social control strategies and increasing adolescents' positive affective reactions to parental social control agents may be keys to promoting positive lifestyle changes in late adolescence. PMID:24931557
Pugliese, John A; Okun, Morris A
A high-performance liquid chromatographic (HPLC) analysis of human serum albumin (HSA) using an ion-exchange (DEAE-form) column shows three components: The principal component corresponds to human mercaptalbumin (HMA); the secondary to nonmercaptalbumin (HNA), having mixed disulfide with cystine (HNA[Cys]), or oxidized glutathione (HNA[Glut]); and the tertiary to HNA, oxidized more highly than mixed disulfide. The purpose of the present study is to clarify the effects of strenuous exercise load on HMA--><--HNA conversion (i.e., dynamic change in redox state) of HSA from elite kendo athletes (n=30; 20.0+/-1.1 years old). They participated in an intensive kendo training camp for 5 d. The mean value for the HMA fraction (f[HMA]) of kendo athletes after camp (62.8+/-2.4%) was significantly lower than before camp (71.9+/-3.7%) (p<0.0005). In contrast, the mean value for f(HNA-1) (i.e., f[HNA(Cys) and HNA(Glut)]) after camp (34.2+/-2.1%) was significantly higher than before camp (25.7+/-3.7%) (p<0.0005). These results suggested that strenuous physical exercise markedly increased the oxidized albumin level in extracellular fluids during the intensive training camp. PMID:12139771
Imai, Hajime; Hayashi, Tomoya; Negawa, Tsuneo; Nakamura, Koji; Tomida, Mihoko; Koda, Kunihide; Tajima, Tomio; Koda, Yasuko; Suda, Kazuhiro; Era, Seiichi
Strenuous exercise induces muscle damage due to a highly increased generation of free radicals and inflammatory response and therefore, in this type of exercise, it is important to reduce both oxidative stress and inflammation, at least their negative aspects. The purpose of this study was investigate, for the first time, whether a purified, standard water-soluble fraction obtained from Phlebodium decamanum could reduce the over-expression of inflammation and oxidative stress induced by strenuous exercise. The physical test consisted of a constant run that combined several degrees of high effort (mountain run and ultra-endurance), in permanent climbing. Biochemical parameters, oxidative stress and inflammatory mediators were assessed. The results showed that oral supplementation of P. decumanum during high-intensity exercise effectively reduces the degree of oxidative stress (decreased 8-hydroxy-2'-deoxyguanosine and isoprostanes generation, increased antioxidant enzyme activities in erythrocyte and total antioxidant status in plasma). The data obtained also indicate that this supplementation is efficient in reducing the inflammatory response through the decrease of TNF-? and increase of sTNF-RII, but kept the levels of IL-6 and IL-1ra. In conclusion, oral supplementation of P. decamanum extract during high-intensity exercise effectively reduces the degree of oxidative stress and has anti-inflammatory protective effects, preventing the over-expression of TNF-? but keeping the levels and effects of IL-6. These findings provide a basis for similar Phlebodium supplementation for both professional and amateur athletes performing strenuous exercise in order to reduce the undesirable effects of the oxidative stress and inflammation signalling elicited during high-intensity exercise. PMID:22212862
Díaz-Castro, Javier; Guisado, Rafael; Kajarabille, Naroa; García, Carmen; Guisado, Isabel M; De Teresa, Carlos; Ochoa, Julio J
Digoxin-like immunoreactive factors (DLIFs) in serum may represent endogenous cardiotropic agents. We determined if blood levels of these endogenous factors changed during prolonged strenuous exercise. Total and loosely protein-bound (LPB) DLIF were measured by radioimmunoassay in the serum of nine healthy subjects during prolonged exercise to exhaustion. Mean total and LPB serum levels of DLIF increased by 72% (580 to 945 pg/mL) and 63% (53 to 91 pg/mL) over baseline values in digoxin equivalents (p less than 0.01), respectively, after three hours of exercise at 70% of VO2max. The prevalent serum nonesterified fatty acids (arachidonic, linoleic, oleic, palmitic, and stearic acids) as well as hydrocortisone did not account for the observed elevations in DLIF. Percent left ventricular fractional shortening (%FS) and mean velocity of left ventricular circumferential fiber shortening (mVCF) measured echocardiographically were lower (-18.0% and -16.4%, respectively, p less than 0.05) after exercise as compared to prior to exercise. Cardiac left ventricular dysfunction as measured by %FS did correlate with blood levels of DLIF (r = -0.680, p less than 0.02). These observations may suggest a relationship between serum levels of DLIF and cardiac fatigue. PMID:3336270
Valdes, R; Hagberg, J M; Vaughan, T E; Lau, B W; Seals, D R; Ehsani, A A
It is well known that a temporary anemia occurs frequently in the early period of training to the strenuous physical exercise. This anemia is named 'sports anemia'. Yamada clarified its cause as due to an increased fragility of the red blood cells. In oth...
K. Hirakawa H. Yoshimura
. We administered a potassium bicarbonate supplement to rats on strenuous treadmill training in order to determine the effect\\u000a on bone mass and the metabolic acidosis seen with this type of training. A sample of 45 93-day-old female Wistar rats with\\u000a a mean initial weight of 267 ± 17 g were studied. The control group (15 rats) was not exercised
H. Rico; L. Aznar; E. R. Hernández; C. Seco; A. Sanchez-Atrio; L. F. Villa; J. J. Gervas
Clinical, haematological and pathological studies were undertaken in Jordan in a stud of 103 racing horses clinically suffering from babesiosis and apparently healthy animals. Out of 47 horses which participated in strenuous exercise, three mares showed sudden onset of immobility and reluctance to move and two mares died. Clinical examination revealed that these five horses (group 1) had fever, anorexia, weakness and severe icterus and, in two mares, haemoglobinuria. Haematological examination revealed that all five horses were heavily parasitized with Babesia equi. This was also found in four horses (group 2) with no evidence of clinical babesiosis. In group 3 (94 horses), neither clinical signs nor B. equi were observed in the blood. The horses in group 1 and 2 recovered after treatment with imidocarb. When the mean values of white blood cell count, red blood cell count, haemoglobin and packed cell volume in group 1 were compared with those for groups 2 and 3, a significant difference was found (P < 0.05). A significant difference was also found when the mean values were compared before and after treatment. Examination of serum total protein, bilirubin and serum enzymes revealed a significant decrease in the mean value of total serum protein (P < 0.05), and a significant increase in the mean values of bilirubin (P < 0.05) in group 1 compared to groups 2 and 3. A significant elevation in the mean value of aspartate aminotransaminase, gamma-glutamyltransferase and creatine phosphokinase and a substantial elevation in the mean value of alkaline phosphatase was also observed in group 1 compared to groups 2 and 3. Postmortem examination of the dead horses showed that the animals had icterus, hepatomegaly and full urinary bladder with deep-red urine. Histopathological examination of the liver showed massive centrilobular degeneration and necrosis. The bile canaliculi and bile ducts were prominent and plugged with dark-brown to canary-coloured bile pigments. The lungs had congestion, oedema, and thrombosis of pulmonary veins. Our results suggest that the horses suffered from B. equal with clinical manifestation following exercise. The clinical, haematological and pathological findings indicate that the animals suffered from haemolytic anaemia which responded to imidocarb therapy. PMID:9187024
Hailat, N Q; Lafi, S Q; al-Darraji, A M; al-Ani, F K
Physical stressors, such as strenuous exercise, can have numerous effects on the human body including the immune system. The aim of this study was to evaluate the gene expression profile of Th1/Th2 cytokines and related transcription factor genes in order to investigate possible immune imbalances before and after a marathon. Blood samples were collected from 16 normal volunteers 24-48h before and one week after completing a marathon race. Gene expression of Th1 and Th2 related cytokines from human peripheral blood mononuclear cells (PBMC) was analyzed using Human Th1-Th2-Th3 RT(2) Profiler PCR Array and qRT-PCR that measured the transcript levels of 84 genes related to T cell activation. We found that PBMC express a characteristic Th2-like gene profile one week post-marathon compared to pre-marathon. The majority of genes up-regulated one week post-marathon such as IL-4, GATA3, and CCR4 were Th2 associated. For Th1-related genes, CXCR3 and IRF1 were up-regulated one week post-marathon. There was a trend of down-regulation of two Th1 related genes, T-bet and STAT1. Th3-related gene expression patterns did not change in the study. The ratios of both IFN-?/IL-4 and T-bet/GATA3 gene expressions were significantly lower one week after marathon. These findings suggest that a Th1/Th2 immune imbalance persisted at least 1 week after completion of a marathon which offers a mechanistic rationale for the increased risk of upper respiratory tract infections often reported after strenuous exercise. PMID:24853398
Xiang, Lianbin; Rehm, Kristina E; Marshall, Gailen D
This study aimed to investigate the possible changes in serum leptin concentration caused by acute exercise and the effects\\u000a of zinc deficiency on these changes. Forty male rats were divided into control-control, control-elercise, zinc-deficient-control,\\u000a and zinc-deficient-exercise groups (10 rats in each). Control-exercise and zinc-deficient-exercise groups performed exercisse\\u000a at 6 m\\/min speed on a rodent treadmill for 60 min or until
Hakki Gökbel; Abdülkerim Kasim Baltaci; Ka?an Üçok; Nilsel Okudan; Rasim Mo?ulkoç
The effects of strenuous exercise and ex vivo stimulation of TLR3 and TLR4 pathways on the expression of six inflammatory genes in equine pulmonary leukocytes were investigated. The genes tested were interferon-beta (IFN-?), interleukin-1-beta (IL-1?), interleukin-6 (IL-6), interferon gamma-induced protein 10 (IP-10), chemokine (c-c motif) ligand 5 (RANTES) and tumor necrosis factor-alpha (TNF-?). We hypothesized that strenuous exercise would modulate basal gene expression on one hand and modulate the response to bacterial lipopolysaccharide (LPS) and to polyinosinic:polycytidylic acid (Poly IC) on the other hand. Eight young Thoroughbred mares were selected for the experiment. Bronchoalveolar lavages were performed on horses 48 h before and 24h after the completion of treadmill exercise until fatigue. Differential counts were performed on the bronchoalveolar lavage cells. Real-time PCR was used to quantify cytokine expression in pulmonary leukocytes. Target gene expression was normalized to the expression of three housekeeping genes (HKG). There were no significant differences in the mRNA expression of the six cytokines between pre-exercise and post-exercise cells. LPS and Poly IC induced respectively significant increases of TNF-?, IFN-?, IL-6, IL-1?, and TNF-?, IFN-?, IP-10 and RANTES, both before and after exercise. However, exercise induced a significant decrease of the genes response to LPS and Poly IC. These findings may suggest that strenuous treadmill exercise exerts a deleterious effect on part of the pulmonary immune response in horses 24h following an intense physical activity. PMID:22578853
Mignot, Clémence C; Pirottin, Dimitri; Farnir, Frédéric; de Moffarts, Brieuc; Molitor, Céline; Lekeux, Pierre; Art, Tatiana
Summary The aim of this study was to elucidate the mechanism by which the disappearance of blood lactate following severe exercise is enhanced during active recovery in comparison with recovery at rest. Rates of decline of arterialised venous blood lactate concentrations in man after maximal one-leg exercise were compared during four different modes of recovery: passive (PR), exercise of the muscles
P. McLoughlin; N. McCaffrey; J. B. Moynihan
We observed the effects of sodium bicarbonate supplement on bone mass in rats on strenuous treadmill training. Sixty female\\u000a Wistar rats (93-days-old; mean initial weight 261 ± 16 g) were studied. One group of 15 rats was killed at the beginning of\\u000a the experiments (basal control group), while another group of 15 rats was not manipulated (Exer?NaB?). Another group of
Horaeio Rico; Enriqlieta Paez; Luis Aznar; Emma R. Hernández; Cristina Seco; Luis F. Villa; Juan J. Gervas
Many authors attribute the antioxidant activity of brewed coffee to its caffeine content. In addition, caffeine intake has been associated with increased performance during physical exercise. This study analyzed the in vivo effects of drinking caffeinated and decaffeinated instant coffee (8%, w/v) on oxidative stress and antioxidant enzyme activity in the anterior tibialis muscles of rats subjected to intense exercise. It was observed that exercise induced lipid peroxidation (estimated using malondialdehyde) and protein oxidation (evaluated by determining the formation of carbonyl groups) in the muscle (P?0.05). Decaffeinated instant coffee and caffeine solution did not exhibit antioxidant activity in vivo. Caffeinated instant coffee beverage intake did not induce changes in superoxide dismutase and glutathione peroxidase activities but was able to diminish lipid and protein oxidation in the anterior tibialis muscles of rats after exercise (P?0.05), contributing to a reduction in the oxidative stress triggered by exercise. PMID:22173821
Viana, André Luiz Machado; Fonseca, Miriam das Dores Mendes; Meireles, Elisson Lamin Jerônimo; Duarte, Stella Maris da Silveira; Rodrigues, Maria Rita; Paula, Fernanda Borges de Araujo
Nineteen competitive cyclists participated in a week-long study to determine if prolonged, intense aerobic exercise produced a significant change in plasma, erythrocyte, and/or urine values for zinc(Zn) and copper(Cu). Subjects pedaled a cycle ergometer f...
K. K. Edgren
. The ability of alprazolam to diminish cortisol response and favor ovarian function could make it useful in the prevention\\u000a of osteopenia in athletes in selected cases. A sample of 45 female Wistar rats, all 93 days old and with a mean initial weight\\u000a of 267 ± 17 g, were studied. Rats were exposed to a high-performance level of exercise
H Rico; J. J. Gervas; E. R. Hernández; C. Seco; L. F. Villa; M. Revilla; A. Sanchez-Atrio
Aim To establish whether exercise?induced vertical breast displacement and discomfort in women with large breasts were reduced during deep water running compared to treadmill running. Methods Sixteen women (mean age ?=?32 years, range 19–43 years; mean mass ?=?74.1?kg, range 61–114?kg; mean height ?=?1.7?m, range 1.61–1.74?m), who were professionally sized to wear a C+ bra cup, were recruited as representative of women with large breasts. After extensive familiarisation, vertical breast motion of the participants was quantified as they ran at a self?selected stride rate on a treadmill and in 2.4?m deep water. Immediately after running, the subjects rated their breast discomfort and breast pain (visual analogue scale) and their perceived exertion (Borg scale). Breast discomfort, breast pain, perceived exertion, vertical breast displacement and vertical breast velocity were compared between the two experimental conditions. Results Exercise?induced breast discomfort was significantly less and perceived exertion was significantly greater during deep water running relative to treadmill running. Although there was no significant between?condition difference in vertical breast displacement, mean peak vertical breast velocity was significantly (p<0.05) less during deep water (upward mean (SD): 29.7 (14.0)?cm.s?1; downward: 31.1 (17.0)?cm.s?1) compared to treadmill running (upward mean (SD): 81.4 (21.7)?cm.s?1; downward: 100.0 (25.0)?cm.s?1). Conclusion Deep water running was perceived as a more strenuous but comfortable exercise mode for women with large breasts. Increased comfort was attributed to reduced vertical breast velocity rather than reduced vertical breast displacement.
McGhee, Deirdre E; Steele, Julie R; Power, Bruce M
BACKGROUND: Delayed onset muscle soreness (DOMS) is a frequent problem after unaccustomed exercise. No universally accepted treatment exists. Massage therapy is often recommended for this condition but uncertainty exists about its effectiveness. AIM: To determine whether post-exercise massage alleviates the symptoms of DOMS after a bout of strenuous exercise. METHOD: Various computerised literature searches were carried out and located seven
Obesity contributes to stress induced impairments in endothelium-dependent vasodilation (EDV), a precursor to atherosclerosis. Since obesity is associated with inflammation and oxidative stress, we sought to determine if a single bout of strenuous weight lifting (SWL) reduces EDV among sedentary obese adults. Participants included 9 obese (OB) (BMI 30.0–40.0 kg/m2) and 8 lean (LN) (BMI 18.5–24.9 kg/m2) sedentary young women. All participants underwent a single bout of SWL using a progressive leg-press protocol. Brachial artery flow-mediated dilation (FMD) (an index of EDV) was determined using ultrasonography before and after SWL. Sublingual nitroglycerin (NTG) was used to determine brachial artery endothelium-independent vasodilation following SWL. Brachial artery FMD was significantly reduced in OB and LN women (LN: 6.4 ± 1.6%, p = 0.22) after SWL. There was no difference in the magnitude of change pre- and post-SWL between groups (OB: ?2.4 ± 0.6% and LN: ?2.2 ± 1.6%, p = 0.84). Dilation to NTG was lower in OB (21.6 ± 1.3%) compared to LN women (27.6 ± 2.1%, p = 0.02) and associated with body weight (r = ?0.70, p = 0.01). These data suggest that EDV is reduced in woman after acute resistance exercise. Dilations to NTG were lower in obese compared to lean woman and associated with body weight suggesting that changes in sensitivity of blood vessels to NO occurs during obesity. These findings may be important for understanding vascular risk following acute exercise in obesity.
Franklin, Nina C.; Ali, Mohamed; Goslawski, Melissa; Wang, Edward; Phillips, Shane A.
We have previously shown in a rat model that a single bout of high-intensity aerobic exercise 20 h before a simulated dive reduces bubble formation and after the dive protects from lethal decompression sickness. The present study investigated the importance of these findings in man. Twelve healthy male divers were compressed in a hyperbaric chamber to 280 kPa at a rate of 100 kPa min(-1) breathing air and remaining at pressure for 80 min. The ascent rate was 9 m min(-1) with a 7 min stop at 130 kPa. Each diver underwent two randomly assigned simulated dives, with or without preceding exercise. A single interval exercise performed 24h before the dive consisted of treadmill running at 90% of maximum heart rate for 3 min, followed by exercise at 50% of maximum heart rate for 2 min; this was repeated eight times for a total exercise period of 40 min. Venous gas bubbles were monitored with an ultrasonic scanner every 20 min for 80 min after reaching surface pressure. The study demonstrated that a single bout of strenuous exercise 24h before a dive to 18 m of seawater significantly reduced the average number of bubbles in the pulmonary artery from 0.98 to 0.22 bubbles cm(-2)(P= 0.006) compared to dives without preceding exercise. The maximum bubble grade was decreased from 3 to 1.5 (P= 0.002) by pre-dive exercise, thereby increasing safety. This is the first report to indicate that pre-dive exercise may form the basis for a new way of preventing serious decompression sickness. PMID:14755001
Dujic, Zeljko; Duplancic, Darko; Marinovic-Terzic, Ivana; Bakovic, Darija; Ivancev, Vladimir; Valic, Zoran; Eterovic, Davor; Petri, Nadan M; Wisløff, Ulrik; Brubakk, Alf O
Rationale: The relationship between interstitial lung abnormalities (ILA) and exercise capacity has not been comprehensively evaluated. Objectives: To assess the validity of the 6-minute walk test in subjects with ILA, and to examine the association between ILA and 6-minute walk distance (6MWD). Methods: Spearman correlation coefficients were used to assess the strength of the relationships between 6MWD and relevant measures of dyspnea, health-related quality of life, and pulmonary function in a cohort of 2,416 people who smoke from the COPDGene study. Unadjusted and adjusted linear and logistic regression models were used to assess the strength of the association between ILA and 6MWD. Measurements and Main Results: In all subjects, and in those with ILA, 6MWD in COPDGene was associated with relevant clinical and physiologic measures. The mean 6MWD in COPDGene subjects with ILA was 386 m (SD, 128 m), and 82% and 19% of subjects with ILA had 6MWDs less than or equal to 500 and 250 m, respectively. ILA was associated with a reduced 6MWD in univariate (?30 m; 95% confidence interval, ?50 to ?10; P = 0.004) and multivariate models (?19 m; 95% confidence interval, ?33 to ?5; P = 0.008). Compared with subjects without ILA, subjects with ILA had an 80% and 77% increase in their odds to have a walk distance limited to less than or equal to 500 and 250 m, respectively. Although these findings were dependent on ILA subtype, they were not limited to those with COPD. Conclusions: Our study demonstrates that ILA is associated with measurable decrements in the 6MWD of people who smoke. Clinical trial registered with www.clinicaltrials.gov (NCT 00608764).
Doyle, Tracy J.; Washko, George R.; Fernandez, Isis E.; Nishino, Mizuki; Okajima, Yuka; Yamashiro, Tsuneo; Divo, Miguel J.; Celli, Bartolome R.; Sciurba, Frank C.; Silverman, Edwin K.; Hatabu, Hiroto; Rosas, Ivan O.
Resistance exercise training, also known as weight training or strength training, involves the use of muscular strength to\\u000a work against a resistance or force. A large cohort study showed that resistance exercise was associated with reduced risk\\u000a of cardiovascular disease. Resistance exercise increases lean body mass, improves muscular strength, and produces small reductions\\u000a in body fat and blood pressure in
Angela S. Alberga; Ronald J. Sigal; Glen P. Kenny
Research designed to discover strategies to delay onset and progression of Alzheimer's disease (AD) and dementia in general is ongoing world wide. Regular physical exercise is an important element in overall health promotion and might also be an effective strategy to delay onset of dementia. A growing body of evidence suggests that regular exercise is associated with a reduced risk
E. B. LARSON; L. WANG
KIME, R., J. IM, D. MOSER, Y. LIN, S. NIOKA, T. KATSUMURA, and B. CHANCE. Reduced Heterogeneity of Muscle Deoxygenation during Heavy Bicycle Exercise. Med. Sci. Sports Exerc., Vol. 37, No. 3, pp. 412- 417, 2005. Purpose: This study evaluated heterogeneity of muscle O2 dynamics in a single muscle during bicycle exercise using an eight-channel near-infrared continuous wave spectroscopy (NIRcws)
RYOTARO KIME; JOOHEE IM; DANIEL MOSER; YUANQING LIN; SHOKO NIOKA; TOSHIHITO KATSUMURA; BRITTON CHANCE
This study sought to evaluate the effects of a single session of exercise on the expression of Hsp70, of c-jun N-terminal kinase (JNK), and insulin receptor substrate 1 serine 612 (IRS(ser612)) phosphorylation in the skeletal muscle of obese and obese insulin-resistant patients. Twenty-seven volunteers were divided into three experimental groups (eutrophic insulin-sensitive, obese insulin-sensitive, and obese insulin-resistant) according to their body mass index and the presence of insulin resistance. The volunteers performed 60 min of aerobic exercise on a cycle ergometer at 60 % of peak oxygen consumption. M. vastus lateralis samples were obtained before and after exercise. The protein expressions were evaluated by Western blot. Our findings show that compared with paired eutrophic controls, obese subjects have higher basal levels of p-JNK (100?±?23 % vs. 227?±?67 %, p?=?0.03) and p-IRS-1(ser612) (100?±?23 % vs. 340?±?67 %, p?0.001) and reduced HSP70 (100?±?16 % vs. 63?±?12 %, p?0.001). The presence of insulin resistance results in a further increase in p-JNK (460?±?107 %, p?0.001) and a decrease in Hsp70 (46?±?5 %, p?=?0.006), but p-IRS-1(ser612) levels did not differ from obese subjects (312?±?73 %, p?>?0.05). Exercise reduced p-JNK in obese insulin-resistant subjects (328?±?33 %, p?=?0.001), but not in controls or obese subjects. Furthermore, exercise reduced p-IRS-1(ser612) for both obese (122?±?44 %) and obese insulin-resistant (185?±?36 %) subjects. A main effect of exercise was observed in HSP70 (p?=?0.007). We demonstrated that a single session of exercise promotes changes that characterize a reduction in cellular stress that may contribute to exercise-induced increase in insulin sensitivity. PMID:23975543
de Matos, Mariana Aguiar; Ottone, Vinícius de Oliveira; Duarte, Tamiris Campos; Sampaio, Pâmela Fiche da Matta; Costa, Karine Beatriz; Fonseca, Cheyenne Alves; Neves, Miguel Pontes Correa; Schneider, Suzanne Maria; Moseley, Pope; Coimbra, Cândido Celso; Magalhães, Flávio de Castro; Rocha-Vieira, Etel; Amorim, Fabiano Trigueiro
Regular physical exercise is broadly recommended by current European and American hypertension guidelines. It remains elusive, however, whether exercise leads to a reduction of blood pressure in resistant hypertension as well. The present randomized controlled trial examines the cardiovascular effects of aerobic exercise on resistant hypertension. Resistant hypertension was defined as a blood pressure ?140/90 mm Hg in spite of 3 antihypertensive agents or a blood pressure controlled by ?4 antihypertensive agents. Fifty subjects with resistant hypertension were randomly assigned to participate or not to participate in an 8- to 12-week treadmill exercise program (target lactate, 2.0±0.5 mmol/L). Blood pressure was assessed by 24-hour monitoring. Arterial compliance and cardiac index were measured by pulse wave analysis. The training program was well tolerated by all of the patients. Exercise significantly decreased systolic and diastolic daytime ambulatory blood pressure by 6±12 and 3±7 mm Hg, respectively (P=0.03 each). Regular exercise reduced blood pressure on exertion and increased physical performance as assessed by maximal oxygen uptake and lactate curves. Arterial compliance and cardiac index remained unchanged. Physical exercise is able to decrease blood pressure even in subjects with low responsiveness to medical treatment. It should be included in the therapeutic approach to resistant hypertension. PMID:22802220
Dimeo, Fernando; Pagonas, Nikolaos; Seibert, Felix; Arndt, Robert; Zidek, Walter; Westhoff, Timm H
The purpose of this study was to determine if Pilates exercise could improve dynamic balance, flexibility, reaction time and muscle strength in order to reduce the number of falls among older women. 60 female volunteers over the age of 65 from a residential home in Ankara participated in this study. Participants joined a 12-week series of 1-hour Pilates sessions three times per week. Dynamic balance, flexibility, reaction time and muscle strength were measured before and after the program. The number of falls before and during the 12-week period was also recorded. Dynamic balance, flexibility, reaction time and muscle strength improved (p < 0. 05) in the exercise group when compared to the non-exercise group. In conclusion, Pilates exercises are effective in improving dynamic balance, flexibility, reaction time, and muscle strength as well as decreasing the propensity to fall in older women. Key points Pilates-based exercises improve dynamic balance, reaction time and muscle strength in the elderly. Pilates exercise may reduce the number of falls in elderly women by increasing these fitness parameters.
Irez, Gonul Babayigit; Ozdemir, Recep Ali; Evin, Ruya; Irez, Salih Gokhan; Korkusuz, Feza
This study tested the effects of 10 min of aerobic exercise, a chocolate snack, or guided imagery as a means of reducing the learned helplessness effects due to the experience of an unsolvable task. It was hypothesized that exposure to unsolvable tasks would lead to a higher level of anxiety, engagement in more task-irrelevant cognitions, and a poorer performance on
Matisyohu Weisenberg; Yael Gerby; Mario Mikulincer
BACKGROUND: Long distance running causes acute muscle damage resulting in inflammation and decreased force production. Endurance athletes use NSAIDs during competition to prevent or reduce pain, which carries the risk of adverse effects. Tart cherries, rich in antioxidant and anti-inflammatory properties, may have a protective effect to reduce muscle damage and pain during strenuous exercise. This study aimed to assess
Kerry S Kuehl; Erica T Perrier; Diane L Elliot; James C Chesnutt
A reduction in exercise efficiency accompanies ageing in humans. Here we evaluated the impact of changes in the contractile-coupling and mitochondrial-coupling efficiencies on the reduction in exercise efficiency in the elderly. Nine adult (mean, 38.8 years old) and 40 elderly subjects (mean, 68.8 years old) performed a cycle ergometer test to measure O2 uptake and leg power output up to the aerobic limit ( ). Reduced leg power output per unit O2 uptake was reflected in a drop in delta efficiency (?D) from 0.27 ± 0.01 (mean ± SEM) in adults to 0.22 ± 0.01 in the elderly group. Similar declines with age were apparent for both the leg power output at and the ATP generation capacity (ATPmax) determined in vivo using (31)P magnetic resonance spectroscopy. These similar declines resulted in unchanged contractile-coupling efficiency values (?C) in the adult (0.50 ± 0.05) versus the elderly group (0.58 ± 0.04) and agreed with independent measures of muscle contractile-coupling efficiency in human quadriceps (0.5). The mitochondrial-coupling efficiency calculated from the ratio of delta to contractile-coupling efficiencies in the adults (?D/?C = 0.58 ± 0.08) corresponded to values for well-coupled mitochondria (0.6); however, ?D/?C was significantly lower in the elderly subjects (0.44 ± 0.03). Conversion of ATPmax per mitochondrial volume (ATPmax/Vv[mt,f]) reported in these groups into thermodynamic units confirmed this drop in mitochondrial-coupling efficiency from 0.57 ± 0.08 in adults to 0.41 ± 0.03 in elderly subjects. Thus, two independent methods revealed that reduced mitochondrial-coupling efficiency was a key part of the drop in exercise efficiency in these elderly subjects and may be an important part of the loss of exercise performance with age. PMID:23085769
Conley, Kevin E; Jubrias, Sharon A; Cress, M Elaine; Esselman, Peter
OBJECTIVE: To determine the effects of community group exercise on falls prevention in older people living in their own residences. DESIGN: Systematic review with meta-analysis. Twenty randomized controlled trials that compared fall rates in older people, who participated in group exercise programs, with fall rates in those who did not exercise. SETTING: Community exercise centers. PARTICIPANTS: Subjects 60 years of
John K. Miller
The metabolic syndrome (MetS) is associated with a threefold increase risk of cardiovascular disease (CVD) mortality partly due to increased arterial stiffening. We compared the effects of aerobic exercise training on arterial stiffening/mechanics in MetS subjects without overt CVD or type 2 diabetes. MetS and healthy control (Con) subjects underwent 8 wk of exercise training (ExT; 11 MetS and 11 Con) or remained inactive (11 MetS and 10 Con). The following measures were performed pre- and postintervention: radial pulse wave analysis (applanation tonometry) was used to measure augmentation pressure and index, central pressures, and an estimate of myocardial efficiency; arterial stiffness was assessed from carotid-femoral pulse-wave velocity (cfPWV, applanation tonometry); carotid thickness was assessed from B-mode ultrasound; and peak aerobic capacity (gas exchange) was performed in the seated position. Plasma matrix metalloproteinases (MMP) and CVD risk (Framingham risk score) were also assessed. cfPWV was reduced (P < 0.05) in MetS-ExT subjects (7.9 ± 0.6 to 7.2 ± 0.4 m/s) and Con-ExT (6.6 ± 1.8 to 5.6 ± 1.6 m/s). Exercise training reduced (P < 0.05) central systolic pressure (116 ± 5 to 110 ± 4 mmHg), augmentation pressure (9 ± 1 to 7 ± 1 mmHg), augmentation index (19 ± 3 to 15 ± 4%), and improved myocardial efficiency (155 ± 8 to 168 ± 9), but only in the MetS group. Aerobic capacity increased (P < 0.05) in MetS-ExT (16.6 ± 1.0 to 19.9 ± 1.0) and Con-ExT subjects (23.8 ± 1.6 to 26.3 ± 1.6). MMP-1 and -7 were correlated with cfPWV, and both MMP-1 and -7 were reduced post-ExT in MetS subjects. These findings suggest that some of the pathophysiological changes associated with MetS can be improved after aerobic exercise training, thereby lowering their cardiovascular risk. PMID:24744384
Donley, David A; Fournier, Sara B; Reger, Brian L; DeVallance, Evan; Bonner, Daniel E; Olfert, I Mark; Frisbee, Jefferson C; Chantler, Paul D
Strenuous and/or prolonged exercise causes transient perturbations in immune function. It is well accepted that this is one mechanism contributing to the higher occurrence of infection (e.g. upper respiratory tract infection (URTI)) in athletes, especially endurance athletes. URTI or upper respiratory tract (URT) symptoms can negatively affect training and competition performance but athletes must train intensively to be successful. Therefore, interventions that can legitimately enhance immune function and reduce URTI risk can be of benefit to athletes. Bovine colostrum supplementation has been investigated as a possible nutritional countermeasure to enhance (or maintain) immune function, and reduce URTI risk, following strenuous or prolonged exercise and during intensive training periods. There is convincing evidence that daily supplementation with bovine colostrum, for a number of weeks (and preliminary evidence for acute effects after a single dose), can maintain intestinal barrier integrity, immune function and reduce the chances of suffering URTI or URT symptoms in athletes or those undertaking heavy training. The mechanisms are not fully understood at present but there is preliminary evidence suggesting that the effects on immune function are attributable, at least in part, to small bioactive components that survive digestion and are biologically available after consumption, but further work is required. In summary, the balance of existing evidence does support the notion that bovine colostrum is beneficial for certain groups of athletes, such as those involved in strenuous training (e.g. endurance athletes), in terms of immunity and resistance to infection. PMID:23075556
Strenuous exercise leads to an increase in metabolic rate, increased production of reactive oxygen species, and compromised antioxidant defense systems. To study the effects of oxidative stress during strenuous exercise, a homogeneous group of 31 male subjects participated in a 6-month, 5 days\\/week training schedule involving two extreme marches of 50 km and 80 km at sea level, separated by
Shlomit Chevion; Danny S. Moran; Yuval Heled; Yoav Shani; Gilad Regev; Benny Abbou; Eduard Berenshtein; Earl R. Stadtman; Yoram Epstein
This two-group pretest and posttest quasi-experimental study aimed to evaluate the effects of a Tai Chi exercise programme on exercise behaviour and blood pressure (BP) in outpatients with hypertension. The experimental group (n = 27) received the Yang-style Tai Chi exercise programme three times a week for 8 weeks. The control group (n = 31) received routine care with no Tai Chi exercise. Exercise behaviour and exercise time using Routine Health Care Behaviour scale and BP were assessed at baseline and 8 weeks. The experimental group had a significant improvement on exercise behaviour (t = 2.11, P < 0.001) and exercise time (t = 1.44, P = 0.003), and a significant reduction in systolic BP (t = 2.57, P 0.001) and diastolic BPs (t = 2.86, P < 0.001) compared with those of the control group. Tai Chi is an inexpensive and viable exercise and can improve exercise behaviour and BP control in outpatients with hypertension. Tai Chi exercise might offer outpatients with hypertension additional options, such as an adjunct to formal cardiac rehabilitation or as an exercise alternative in their management of hypertension. Nursing staff can easily learn and incorporate this exercise in patient education or care planning in the care of patients with hypertension in outpatient settings. PMID:23181955
Lo, Hui-Ming; Yeh, Ching-Yi; Chang, Shu-Chuan; Sung, Huei-Chuan; Smith, Graeme D
This study investigated the impact of ice vests and hand/forearm immersion on accelerating the physiological recovery between two bouts of strenuous exercise in the heat [mean (SD), 49.1(1.3)°C, RH 12 (1)]. On four occasions, eight firefighters completed two 20-min bouts of treadmill walking (5 km h, 7.5% gradient) while wearing standard firefighter protective clothing. Each bout was separated by a 15-min recovery period, during which one of four conditions were administered: ice vest (VEST), hand/forearm immersion (W), ice vest combined with hand/forearm immersion (VEST + W) and control (CON). Core temperature was significantly lower at the end of the recovery period in the VEST + W (37.97 ± 0.23°C) and W (37.96 ± 0.19°C) compared with the VEST (38.21 ± 0.12°C) and CON (38.29 ± 0.25°C) conditions and remained consistently lower throughout the second bout of exercise. Heart rate responses during the recovery period and bout 2 were similar between the VEST + W and W conditions which were significantly lower compared with the VEST and CON which did not differ from each other. Mean skin temperature was significantly lower at the start of bout 2 in the cooling conditions compared with CON; these differences reduced as exercise progressed. These findings demonstrate that hand/forearm immersion (~19°C) is more effective than ice vests in reducing the physiological strain when firefighters re-enter structural fires after short rest periods. Combining ice vests with hand/forearm immersion provides no additional benefit. PMID:21079990
Barr, David; Reilly, Thomas; Gregson, Warren
The recent surge in childhood obesity has renewed interest in studying exercise as a therapeutic means of metabolizing fat.\\u000a However, carbohydrate (CHO) intake attenuates whole body fat oxidation during exercise in healthy children and may suppress\\u000a fat metabolism in obese youth. To determine the impact of CHO intake on substrate utilization during submaximal exercise in\\u000a obese boys, seven obese boys
Lisa Chu; Michael C. Riddell; Tim Takken; Brian W. Timmons
Exercise stress is associated with increased risk for upper respiratory tract infection. We have shown that exercise stress can increase susceptibility to infection. Quercetin, a flavonoid present in a wide variety of fruits and vegetables, has been reported to inhibit infectivity and replication of a broad spectrum of viruses and may offset the increase in susceptibility to infection associated with stressful exercise. This study examined the effects of quercetin feedings on susceptibility to the influenza virus A/Puerto Rico/8/34 (H1N1) following stressful exercise. Mice were randomly assigned to one of four treatment groups: exercise-placebo, exercise-quercetin, control-placebo, or control-quercetin. Exercise consisted of a run to fatigue (140 min) on a treadmill for 3 consecutive days. Quercetin (12.5 mg/kg) was administered via gavage for 7 days before viral challenge. At 30 min after the last bout of exercise or rest, mice (n = 23ÃÂ30) were intranasally inoculated with a standardized dose of influenza virus (0.04 hemagglutinating units). Mice were monitored daily for morbidity (time to sickness), symptom severity, and mortality (time to death) for 21 days. Exercise stress was associated with an increased susceptibility to infection [morbidity, mortality, and symptom severity on days 5ÃÂ7 (P < 0.05)]; quercetin offset the increase in susceptibility to infection [morbidity, mortality, and symptom severity on days 5ÃÂ7 (P < 0.05)] that was associated with stressful exercise. These data suggest that short-term quercetin feedings may prove to be an effective strategy to lessen the impact of stressful exercise on susceptibility to respiratory infection.
PhD J Mark Davis (University of South Carolina Exercise Science); E A Murphy (University of South Carolina Exercise Science); J L McClellan (University of South Carolina Exercise Science); M D Carmichael (University of South Carolina Exercise Science); J D Gangemi (Clemson University Microbiology and Molecular Medicine)
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: 37.8 plus or minus 1.9 ml (raised dot) per kilogram per minute). KES was significantly reduced by 30% in Con (PRE: 113 plus or minus 12; POST: 78 plus or minus 8 N-m), but was not different in EX (PRE: 126 plus or minus 25; POST: 115 plus or minus 25 N-m). The combination LBNPex and Rex during 60-d BR protects against cardiovascular and musculoskeletal deconditioning and may be efficacious countermeasure for prolonged space flight.
Meuche, Sabine; Schneider, S. M.; Lee, S. M. C.; Macias, B. R.; Smith, S. M.; Watenpaugh, D. E.; Hargens, A. R.
The calf and forearm blood flows (Q\\u000acalf and Q\\u000aforearm respectively), blood pressure, heart rate and oxygen uptake of six men and women were studied during combined leg and handgrip exercise to determine whether a reduction of exercise-induced hyperaemia would occur in the active leg when exhausting rhythmic handgrip exercise at 50% maximal voluntary contraction (MVC) was superimposed upon
Atsuko Kagaya; Mitsuru Saito; Futoshi Ogita; Minoru Shinohara
Regular exercise is a healthy behavior associated with desirable benefits. Regular exercise also makes manifest 2 fundamental behaviors-a choice and the discipline to continuously act on that choice. This cross-sectional analysis of more than 10 000 adults examines the association of regular exercise with unhealthy behaviors. Compared with people who are more regularly exercising, nonexercisers are less likely to choose to change an unhealthy habit. Nonexercisers are also much less likely to be confident of their success when they do choose a habit to change. Regular exercise seems to be a gateway behavior for reducing other unhealthy habits. PMID:24887529
Wasson, John H
The authors review the role of physical exercise in reducing childhood and adolescent posttraumatic stress disorder, anxiety, and depression. A good deal of the existing research on the influence of exercise in reducing negative emotional states and enhancing perceptions of self-efficacy has been conducted with adult samples. Comparatively few empirical studies that target children and adolescents have been done; however,
Robert W. Motta; Meredith E. McWilliams; Jennifer T. Schwartz; Robert S. Cavera
The authors review the role of physical exercise in reducing childhood and adolescent posttraumatic stress disorder, anxiety, and depression. A good deal of the existing research on the influence of exercise in reducing negative emotional states and enhancing perceptions of self-efficacy has been conducted with adult samples. Comparatively few…
Motta, Robert W.; McWilliams, Meredith E.; Schwartz, Jennifer T.; Cavera, Robert S.
PurposeThere is a lack of awareness among physicians, dieticians, and public health planners as to the prevalence of iron deficiency and anemia among adolescents undergoing strenuous physical training. The aim of this study was to estimate the prevalence of iron deficiency and anemia among male adolescents undergoing such activity.
Drorit Merkel; Michael Huerta; Itamar Grotto; Dalit Blum; Orna Tal; Eliezer Rachmilewitz; Eitan Fibach; Yoram Epstein; Ofer Shpilberg
The purpose of the present study was to investigate the effects of Lycium barbarum polysaccharides (LBP) on exercise-induced oxidative stress in rats. Rats were divided into four groups, i.e., one control group and three LBP treated groups. The animals received an oral administration of physiological saline or LBP (100, 200 and 400 mg/kg body weight) for 28 days. On the day of the exercise test, rats were required to run to exhaustion on the treadmill. Body weight, endurance time, malondialdehyde (MDA), super oxide dismutase (SOD) and glutathione peroxidase (GPX) level of rats were measured. The results showed that the body weight of rats in LBP treated groups were not significantly different from that in the normal control group before and after the experiment (P > 0.05). After exhaustive exercise, the mean endurance time of treadmill running to exhaustion of rats in LBP treated groups were significantly prolonged compared with that in the normal control group. MDA levels of rats in LBP treated groups were significantly decreased compared with that in the normal control group (P < 0.05). SOD and GPX levels of rats in LBP treated groups were significantly increased compared with that in the normal control group (P < 0.05). Together, these results indicate that LBP was effective in preventing oxidative stress after exhaustive exercise.
Shan, Xiaozhong; Zhou, Junlai; Ma, Tao; Chai, Qiongxia
The purpose of this study was to evaluate the effectiveness of a cool vest (CV) to reduce heat strain during exercise, facilitate recovery, and minimize heat strain during subsequent return to exercise and heat exposure. Male volunteers (n=12) were monito...
L. R. Ramirez R. D. Hagan M. P. Shannon B. L. Bennett J. A. Hodgdon
Abstract We tested the hypotheses that (1) the compensatory vasodilatation in skeletal muscle during hypoxic exercise is attenuated in ageing humans and (2) local inhibition of nitric oxide (NO) synthesis in the forearm of ageing humans will have less impact on the compensatory dilatation during rhythmic exercise with hypoxia, due to a smaller compensatory dilator response. Eleven healthy older subjects (61 ± 2 years) performed forearm exercise (10% and 20% of maximum) during saline infusion (control) and NO synthase inhibition (NG-monomethyl-l-arginine; l-NMMA) under normoxic and normocapnic hypoxic (80% arterial O2 saturation) conditions. Forearm vascular conductance (FVC; ml min?1 (100 mmHg)?1) was calculated from forearm blood flow (ml min?1) and blood pressure (mmHg). To further examine the effects of ageing on the compensatory vasodilator response to hypoxic exercise we compared the difference in ?FVC (% change compared to respective normoxic exercise trial) between the older subjects (present study) and previously published data from an identical protocol in young subjects. During the control condition, the compensatory vasodilator response to hypoxia was similar between the old and young groups at 10% exercise (28 ± 6%vs. 40 ± 8%, P = 0.11) but attenuated at 20% exercise (14 ± 4%vs. 31 ± 6%, P < 0.05). l-NMMA during hypoxic exercise only blunted the compensatory vasodilator response in the young group (P < 0.05). Our data suggest that ageing reduces the compensatory vasodilator response to hypoxic exercise via blunted NO signalling.
Casey, Darren P; Walker, Branton G; Curry, Timothy B; Joyner, Michael J
Nucleotides released within the heart under pathological conditions can be involved in cardioprotection or cardiac fibrosis through the activation purinergic P2Y(2) and P2Y(6) receptors, respectively. We previously demonstrated that adult P2Y(4)-null mice display a microcardia phenotype related to a cardiac angiogenic defect. To evaluate the functional consequences of this defect, we performed here a combination of cardiac monitoring and exercise tests. We investigated the exercise capacity of P2Y(4) wild-type and P2Y(4)-null mice in forced swimming and running tests. Analysis of their stress, locomotion, and resignation was realized in open field, black and white box, and tail suspension experiments. Exercise-induced cardiac hypertrophy was evaluated after repeated and prolonged exercise in P2Y(4) wild-type and P2Y(4)-null hearts. We showed that P2Y(4)-null mice have a lower exercise capacity in both swimming and treadmill tests. This was not related to decreased motivation or increased stress, since open field, white and black box, and mouse tail suspension tests gave comparable results in P2Y(4) wild-type and P2Y(4)-null mice. Heart rate and blood pressure rose normally in P2Y(4)-null swimming mice equipped with a telemetric implant. On the contrary, we observed a delayed recovery of postexercise blood pressure after exercise in P2Y(4)-null mice. The heart rate increment in response to catecholamines was also similar in P2Y(4) wild-type and P2Y(4)-null implanted mice, which is consistent with a similar level of cardiac ?-receptor expression. Interestingly, the heart of P2Y(4)-null mice displayed a reduced sympathetic innervation associated with a decreased norepinephrine level. We also demonstrated that exercise-induced cardiac hypertrophy was lower in P2Y(4)-null mice after repeated and prolonged exercise. This was associated with a lower increase in cardiomyocyte size and microvessel density. In conclusion, besides its role in cardiac development, P2Y(4) receptor could constitute an important regulator of acute and chronic response to exercise. PMID:22865387
Horckmans, Michael; Léon-Gómez, Elvira; Robaye, Bernard; Balligand, Jean-Luc; Boeynaems, Jean-Marie; Dessy, Chantal; Communi, Didier
The present study aims to explore how selenium supplementation affects the element distribution in the liver tissue of rats subjected to strenuous swimming exercise. Thirty-two Spraque-Dawley male rats were equally divided into the four groups: Group 1, normal control group. Group 2, selenium-supplemented, non-swimming (0.6 mg/kg/day sodium selenite) group. Group 3, swimming, no supplementation group. Group 4, swimming, selenium-supplemented (0.6 mg/kg/day sodium selenite) group. After one month, the animals were decapitated and liver tissue samples were collected to determine the levels of lead, cobalt, boron, molybdenum, chromium, sulfur, magnesium, sodium, potassium, phosphorus, copper, iron, zinc and selenium. The chromium, molybdenum, iron, sodium and potassium values were higher in the swimming groups, relative to controls. Group 3 had significantly lower lead levels (p<0.001). The highest cobalt levels were obtained in the Group 1 and that of the Group 2 was higher than in the Groups 3 and 4. The boron values in the Group 3 were higher than those in all other groups. The copper and magnesium levels were higher in the Groups 3 and 4, compared to the Groups 1 and 2. The highest phosphorus levels were found in the Group 1. The highest selenium and zinc values were obtained in the Group 2 and those of the Group 4 were higher than in the Groups 1 and 3. Group 1 had higher selenium and zinc levels than the Group 3. The results of the present study demonstrated that selenium-supplemented rats subjected to strenuous swimming exercise had distinct elements distribution in liver tissue. Also, selenium supplementation offsets the decrease in zinc levels in rats subjected to vigorous swimming (Tab. 3, Ref. 20). PMID:23253021
Sivrikaya, A; Akil, M; Bicer, M; Kilic, M; Baltaci, A K; Mogulkoc, R
The purpose of this study was to evaluate the effects of human head hair on thermoregulation during exercise carried out under solar radiation. 10 healthy male subjects (mean±SD: 25.1±2.5 yr; height: 176.2±4.0?cm; weight: 73.7±6.7?kg; VO(2max) 56.2±5.3?mLO(2)·kg (-1)·min (-1)) took part in 2 1 h-long trials of continuous exercise on a treadmill at 50% VO2(max) under solar radiation that were separated by at least 2 days. Whereas for the first trial they retained their natural head hair (HAIR), in the second trial their hair was totally shaved (NOHAIR). Several properties were measured, including environmental heat stress (Wet Bulb Globe Temperature index - WBGT, °C), heart rate, rectal temperature, skin temperature, head temperature, and global sweat rate. The main findings were that whereas there was a lower sweat rate in the HAIR condition (HAIR: 7.08±0.79 vs. NOHAIR: 7.67±0.79?g·m (-2)·min (-1); p=0.03), there were no significant differences in any of the other variables between the HAIR and NOHAIR trials. In conclusion, the presence of head hair resulted in a lower sweat rate. PMID:20683812
Coelho, L G M; Ferreira-Junior, J B; Martini, A R P; Borba, D A; Coelho, D B; Passos, R L F; Fonseca, M A da; Moura-Lima, F A S; Prado, L S; Rodrigues, L O C
This study investigated the impact of ice vests and hand\\/forearm immersion on accelerating the physiological recovery between\\u000a two bouts of strenuous exercise in the heat [mean (SD), 49.1(1.3)°C, RH 12 (1)]. On four occasions, eight firefighters completed\\u000a two 20-min bouts of treadmill walking (5 km h, 7.5% gradient) while wearing standard firefighter protective clothing. Each\\u000a bout was separated by a 15-min recovery
David Barr; Thomas Reilly; Warren Gregson
Physical exercise preconditioning is known to ameliorate stroke-induced injury. In addition to several other mechanisms, the beneficial effect of preischemic exercise following stroke is due to an upregulated capacity to maintain energy supplies. Adult male Sprague-Dawley rats were used in exercise and control groups. After 1-3 weeks of exercise, several enzymes were analyzed as a gauge of the direct effect of physical exercise on cerebral metabolism. As a measure of metabolic capacity, an ADP/ATP ratio was obtained. Glucose transporters (GLUT1 and GLUT3) were monitored to assess glucose influx, and phosphofructokinase (PFK) was measured to determine the rate of glycolysis. Hypoxia-induced factor-1? (HIF-1?) and 5'AMP-activated protein kinase (AMPK) levels were also determined. These same analyses were performed on preconditioned and control rats following an ischemic/reperfusion (I/R) insult. Our results show that GLUT1, GLUT3, PFK, AMPK, and HIF-1? were all increased following 3 weeks of exercise training. In addition, the ADP/ATP ratio was chronically elevated during these 3 weeks. After I/R injury, HIF-1? and AMPK were significantly higher in exercised rats. The ADP/ATP ratio was reduced in preconditioned rats in the acute phase after stroke, suggesting a lower level of metabolic disorder. GLUT1 and GLUT3 were also increased in the acute phase in exercise rats, indicating that these rats were better able to increase rates of metabolism immediately after ischemic injury. In addition, PFK expression was increased in exercise rats showing an enhanced glycolysis resulting from exercise preconditioning. Altogether, exercise preconditioning increased the rates of glucose metabolism, allowing a more rapid and more substantial increase in ATP production following stroke. PMID:23553672
Dornbos, David; Zwagerman, Nathan; Guo, Miao; Ding, Jamie Y; Peng, Changya; Esmail, Fatema; Sikharam, Chaitanya; Geng, Xiaokun; Guthikonda, Murali; Ding, Yuchuan
In the present study we examined the effect of hyperthermia on the middle cerebral artery mean blood velocity (MCA Vmean) during prolonged exercise. We predicted that the cerebral circulation would be impaired when hyperthermia is present during exercise and assumed that this could be observed as a reduced MCA Vmean. Eight endurance trained men (maximum oxygen uptake (V?O2,max) 70 ± 1 ml min?1 kg?1 (mean ±s.e.m.)) performed two exercise trials at 57 % of V?O2,max on a cycle ergometer in a hot (40 °C; hyperthermic trial) and in a thermoneutral environment (18 °C; control trial). In the hyperthermic trial, the oesophageal temperature increased throughout the exercise period reaching a peak value of 40.0 ± 0.1 °C at exhaustion after 53 ± 4 min of exercise. In the control trial, exercise was maintained for 1 h without any signs of fatigue and with core temperature stabilised at 37.8 ± 0.1 °C after ?15 min of exercise. Concomitant with the development of hyperthermia, MCA Vmean declined by 26 ± 3 % from 73 ± 4 cm s?1 at the beginning of exercise to 54 ± 4 cm s?1 at exhaustion (P < 0.001). In contrast, MCA Vmean remained unchanged at 70-72 cm s?1 throughout the 1 h control trial. When individually determined regression lines for MCA Vmean and arterial carbon dioxide pressure (Pa,CO2) obtained during preliminary exercise tests were used to account for the differences in Pa,CO2 between the hyperthermic and control trial, it appeared that more than half of the reduction in MCA Vmean (56 ± 8 %) was related to a hyperventilation-induced drop in Pa,CO2. Declining cardiac output and arterial blood pressure accounted for the remaining part of the hyperthermia-induced reduction in MCA Vmean. The present results demonstrate that the development of hyperthermia during prolonged exercise is associated with a marked reduction in MCA Vmean.
Nybo, Lars; Nielsen, Bodil
Hypercholesterolemia impairs endothelial function [e.g., the nitric oxide (NO)-cyclic GMP-phosphodiesterase 5 (PDE5) pathway], limits shear stress-induced vasodilation, and is therefore expected to reduce exercise-induced vasodilation. To assess the actual effects of hypercholesterolemia on endothelial function and exercise-induced vasodilation, we compared the effects of endothelial NO synthase (eNOS) and PDE5 inhibition in chronically instrumented Yucatan (Control) and Rapacz familial hypercholesterolemic (FH) swine, at rest and during treadmill exercise. The increases in systemic vascular conductance produced by ATP (relative to nitroprusside) and exercise were blunted in FH compared with Control swine. The vasoconstrictor response to eNOS inhibition, with nitro-l-arginine (NLA), was attenuated in FH compared with Control swine, both at rest and during exercise. Furthermore, whereas the vasodilator response to nitroprusside was enhanced slightly, the vasodilator response to PDE5 inhibition, with EMD360527, was reduced in FH compared with Control swine. Finally, in the pulmonary circulation, FH resulted in attenuated vasodilator responses to ATP, while maintaining the responses to both NLA and EMD360527. In conclusion, hypercholesterolemia reduces exercise-induced vasodilation in the systemic but not the pulmonary circulation. This reduction appears to be the principal result of a decrease in NO bioavailability, which is mitigated by a lower PDE5 activity.
de Beer, Vincent J.; Merkus, Daphne; Bender, Shawn B.; Tharp, Darla L.; Bowles, Douglas K.; Duncker, Dirk J.
Aim: Increased sodium/calcium exchanger activity (NCX1, an important regulator of cardiomyocyte cystolic calcium) may provoke arrhythmias. Exercise training can decrease NCX1 expression in animals with heart failure improving cytosolic calcium regulation, and could thereby reduce the risk for ventricular fibrillation (VF). Methods: To test this hypothesis, a 2-min coronary occlusion was made during the last minute of exercise in dogs with healed myocardial infarctions; 23 had VF (S, susceptible) and 13 did not (R, resistant). The animals were randomly assigned to either 10-week exercise training (progressively increasing treadmill running; S n?=?9; R n?=?8) or 10-week sedentary (S n?=?14; R n?=?5) groups. At the end of the 10-week period, the exercise?+?ischemia test provoked VF in sedentary but not trained susceptible dogs. On a subsequent day, cardiac tissue was harvested and NCX1 protein expression was determined by Western blot. Results: In the sedentary group, NCX1 expression was significantly (ANOVA, P?0.05) higher in susceptible compared to resistant dogs. In contrast, NCX1 levels were similar in the exercise trained resistant and susceptible animals. Conclusion: These data suggest that exercise training can restore a more normal NCX1 level in dogs susceptible to VF, improving cystolic calcium regulation and could thereby reduce the risk for sudden death following myocardial infarction.
Kukielka, Monica; Holycross, Bethany J.; Billman, George E.
Delayed secondary biochemical and cellular changes after traumatic brain injury continue for months to years, and are associated with chronic neuroinflammation and progressive neurodegeneration. Physical activity can reduce inflammation and facilitate recovery after brain injury. Here, we investigated the time-dependent effects, and underlying mechanisms of post-traumatic exercise initiation on outcome after moderate traumatic brain injury using a well-characterized mouse controlled cortical impact model. Late exercise initiation beginning at 5 weeks after trauma, but not early initiation of exercise at 1 week, significantly reduced working and retention memory impairment at 3 months, and decreased lesion volume compared to non-exercise injury controls. Cognitive recovery was associated with attenuation of classical inflammatory pathways, activation of alternative inflammatory responses and enhancement of neurogenesis. In contrast, early initiation of exercise failed to alter behavioral recovery or lesion size, while increasing the neurotoxic pro-inflammatory responses. These data underscore the critical importance of timing of exercise initiation after trauma and its relation to neuroinflammation, and challenge the widely held view that effective neuroprotection requires early intervention.
Piao, Chun-Shu; Stoica, Bogdan A.; Wu, Junfang; Sabirzhanov, Boris; Zhao, Zaorui; Cabatbat, Rainier; Loane, David J.; Faden, Alan I.
Objective: The study aimed at uncovering the correlates of reduced exercise in depressive patients. On the basis of the Health Action Process Approach (Schwarzer, 2011 ), we hypothesised that reduced exercise in depressive patients can be explained by motivational deficits and volitional deficits. Design: A longitudinal sample of 56 clinically depressive outpatients was compared to a sample of 56 parallelised non-depressive controls. Main outcome measures: Self-reported intention, exercise, and motivational and volitional HAPA variables were measured with self-report questionnaires at baseline and four-week follow-up. Results: Depressive patients showed a motivational deficit: they had significantly reduced intentions to exercise compared to non-depressive participants, and they suffered from reduced self-efficacy and increased negative outcome expectations. No differences were found with regard to positive outcome expectations. Depressive patients also showed a volitional deficit: depressive high-intenders were less capable of transforming their intention into action than non-depressive high-intenders. They produced less action plans, had less maintenance self-efficacy and were more easily distracted by barriers. Conclusion: The lower level of exercise among depressive patients is partly due to motivational, partly to volitional deficits. Interventions should be stage-matched and should focus on pessimistic beliefs (negative outcome expectations, self-efficacy) and planning deficits in depression. PMID:24785393
Krämer, Lena V; Helmes, Almut W; Seelig, Harald; Fuchs, Reinhard; Bengel, Jürgen
Diaphragmatic breathing is relaxing and therapeutic, reduces stress, and is a fundamental procedure of Pranayama Yoga, Zen, transcendental meditation and other meditation practices. Analysis of oxidative stress levels in people who meditate indicated that meditation correlates with lower oxidative stress levels, lower cortisol levels and higher melatonin levels. It is known that cortisol inhibits enzymes responsible for the antioxidant activity
Daniele Martarelli; Mario Cocchioni; Stefania Scuri; Pierluigi Pompei
BACKGROUND: Older heart failure (HF) patients exhibit exercise intolerance during activities of daily living. We hypothesized that reduced lower extremity blood flow (LBF) due to reduced forward cardiac output would contribute to submaximal exercise intolerance in older HF patients. METHODS AND RESULTS: Twelve HF patients both with preserved and reduced left ventricular ejection fraction (LVEF) (aged 68 ± 10 years)
Chirapa Puntawangkoon; Dalane W Kitzman; Stephen B Kritchevsky; Craig A Hamilton; Barbara Nicklas; Xiaoyan Leng; Peter H Brubaker; W Gregory Hundley
Exercise-induced asthma (EIA) refers to the transient narrowing of the airways following strenuous exercise in asthmatic and otherwise healthy individuals. Despite the heterogeneous treatment options for patients with EIA, there remains a substantial burden of unaddressed disease, even with optimal treatment. Epidemiological studies indicate that patients frequently resort to complementary and alternative therapies while being treated for asthma and other chronic health conditions. There is now convincing evidence that many dietary factors such as increased omega-3 polyunsaturated fatty acids, antioxidant intake and caffeine, and a sodium-restricted diet can reduce the severity of EIA. It is important that these dietary therapies be safe, effective, and likely to be used by individuals with EIA. This review will critically examine whether dietary modification represents a beneficial intervention for asthmatic individuals with EIA. PMID:23531894
Mickleborough, Timothy D; Head, Sally K; Lindley, Martin R
The aim of this investigation was to examine the effect of aerobic exercise (AE) on uric acid (UA), total antioxidant activity (TAA), oxidative stress (OS) and nitrite a stable nitric oxide (NO) metabolite in saliva from persons with Down syndrome (DS). Stimulated saliva was sampled from 12 participants 1 hour before and immediately after a 1,600-meter walking test. Uric acid (UA) was assayed by enzymatic method, TAA by ABTS method, lipid hydroperoxides (OS marker) by the ferrous iron/xylenol orange (FOX) method and nitrite concentration by the Griess reaction. Aerobic exercise (AE) caused a decrease in salivary lipid hydroperoxides in persons with DS (p = 0.001). Aerobic exercise (AE), however, did not affect salivary UA, TAA, and nitrite. This result suggested that AE can be considered as a way to reduce the OS in persons with DS, particularly in the mouth cavity. PMID:19731179
Zambrano, Jean C; Marquina, Ramón; Sulbarán, Nancy; Rodríguez-Malaver, Antonio J; Reyes, Rafael A
Purpose Preeclampsia is a leading cause of perinatal mortality and morbidity, and it increases maternal risk for future cardiovascular disease. The purpose of the study was to explore the relationships among stretching exercise, autonomic cardiac response, and the development of preeclampsia. Design Secondary data analysis. Methods Heart rate and pulse pressure were longitudinally examined in this secondary data analysis among women who engaged in stretching exercise daily from 18 weeks of gestation to the end of pregnancy compared with women who did walking exercise daily during the same time period. A total of 124 women were randomized to either stretching (n=60) or walking (n=64) in the parent study. Findings Heart rates in the stretching group were consistently lower than those in the walking group. Conclusions Based on the results of this secondary data analyses, a physiologic framework for possible beneficial effects of stretching exercise by enhancing autonomic responses on reducing risks for preeclampsia is proposed and discussed. Clinical Relevance If the protective effect is established, stretching exercise can be translated into nursing intervention for prenatal care.
Acetazolamide (Acz) is used at altitude to prevent acute mountain sickness, but its effect on exercise capacity under hypoxic conditions is uncertain. Nine healthy men completed this double-blind, randomized, crossover study. All subjects underwent incremental exercise to exhaustion with an inspired O(2) fraction of 0.13, hypoxic ventilatory responses, and hypercapnic ventilatory responses after Acz (500 mg twice daily for 5 doses) and placebo. Maximum power of 203 +/- 38 (SD) W on Acz was less than the placebo value of 225 +/- 40 W (P < 0.01). At peak exercise, arterialized capillary pH was lower and Po(2) higher on Acz (P < 0.01). Ventilation was 118.6 +/- 20.0 l/min at the maximal power on Acz and 102.4 +/- 20.7 l/min at the same power on placebo (P < 0.02), and Borg score for leg fatigue was increased on Acz (P < 0.02), with no difference in Borg score for dyspnea. Hypercapnic ventilatory response on Acz was greater (P < 0.02), whereas hypoxic ventilatory response was unchanged. During hypoxic exercise, Acz reduced exercise capacity associated with increased perception of leg fatigue. Despite increased ventilation, dyspnea was not increased. PMID:12391068
Garske, Luke A; Brown, Michael G; Morrison, Stephen C
Patients suffering from depression frequently display hyperactivity of the hypothalamic-pituitary-adrenal axis (HPA) resulting in elevated cortisol levels. One main symptom of this condition is anhedonia. There is evidence that exercise training can be used as a rehabilitative intervention in the treatment of depressive disorders. In this scenario, the aim of the present study was to assess the effect of an aerobic exercise training protocol on the depressive-like behavior, anhedonia, induced by repeated dexamethasone administration. The study was carried out on adult male Wistar rats randomly divided into four groups: the "control group" (C), "exercise group" (E), "dexamethasone group" (D) and the "dexamethasone plus exercise group" (DE). The exercise training consisted of swimming (1 h/d, 5 d/wk) for 3 weeks, with an overload of 5% of the rat body weight. Every day rats were injected with either dexamethasone (D/DE) or saline solution (C/E). Proper positive controls, using fluoxetine, were run in parallel. Decreased blood corticosterone levels, reduced adrenal cholesterol synthesis and adrenal weight (HPA disruption), reduced preference for sucrose consumption and increased immobility time (depressive-like behavior), marked hippocampal DNA oxidation, increased IL-10 and total brain-derived neurotrophic factor (BDNF; pro-plus mature-forms) and a severe loss of body mass characterized the dexamethasone-treated animals. Besides increasing testosterone blood concentrations, the swim training protected depressive rats from the anhedonic state, following the same profile as fluoxetine, and also from the dexamethasone-induced impaired neurochemistry. The data indicate that physical exercise could be a useful tool in preventing and treating depressive disorders. PMID:21712072
Sigwalt, A R; Budde, H; Helmich, I; Glaser, V; Ghisoni, K; Lanza, S; Cadore, E L; Lhullier, F L R; de Bem, A F; Hohl, A; de Matos, F J; de Oliveira, P A; Prediger, R D; Guglielmo, L G A; Latini, A
Exercise - National Multiple Sclerosis Society Skip to navigation Skip to content Menu Navigation National Multiple Sclerosis Society Search v Make a Donation ... now Download now Publication Stretching for People with MS Illustrated manual showing range of motion, stretching, and ...
Abstract Exercise in hypoxia is associated with reduced muscle oxidative function and impaired exercise tolerance. We hypothesised that dietary nitrate supplementation (which increases plasma [nitrite] and thus NO bioavailability) would ameliorate the adverse effects of hypoxia on muscle metabolism and oxidative function. In a double-blind, randomised crossover study, nine healthy subjects completed knee-extension exercise to the limit of tolerance (Tlim), once in normoxia (20.9% O2; CON) and twice in hypoxia (14.5% O2). During 24 h prior to the hypoxia trials, subjects consumed 0.75 L of nitrate-rich beetroot juice (9.3 mmol nitrate; H-BR) or 0.75 L of nitrate-depleted beetroot juice as a placebo (0.006 mmol nitrate; H-PL). Muscle metabolism was assessed using calibrated 31P-MRS. Plasma [nitrite] was elevated (P < 0.01) following BR (194 ± 51 nm) compared to PL (129 ± 23 nm) and CON (142 ± 37 nM). Tlim was reduced in H-PL compared to CON (393 ± 169 vs. 471 ± 200 s; P < 0.05) but was not different between CON and H-BR (477 ± 200 s). The muscle [PCr], [Pi] and pH changed at a faster rate in H-PL compared to CON and H-BR. The [PCr] recovery time constant was greater (P < 0.01) in H-PL (29 ± 5 s) compared to CON (23 ± 5 s) and H-BR (24 ± 5 s). Nitrate supplementation reduced muscle metabolic perturbation during exercise in hypoxia and restored exercise tolerance and oxidative function to values observed in normoxia. The results suggest that augmenting the nitrate–nitrite–NO pathway may have important therapeutic applications for improving muscle energetics and functional capacity in hypoxia.
Vanhatalo, Anni; Fulford, Jonathan; Bailey, Stephen J; Blackwell, James R; Winyard, Paul G; Jones, Andrew M
Strenuous bouts of prolonged exercise and heavy training are associated with depressed immune cell function. Furthermore, inadequate or inappropriate nutrition can compound the negative influence of heavy exertion on immunocompetence. Dietary deficiencies of protein and specific micronutrients have long been associated with immune dysfunction. An adequate intake of iron, zinc and vitamins A, E, B6 and B12 is particularly important
Michael Gleeson; David C Nieman; Bente K Pedersen
Uric acid (UA) possesses free-radical-scavenging properties, and systemic administration is known to increase serum antioxidant capacity. However, it is not known whether this protects against oxidative stress. The effects of raising UA concentration were studied during acute aerobic physical exercise in healthy subjects, as a model of oxidative stress characterized by increased circulating 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) concentrations. Twenty healthy subjects were recruited to a randomized double-blind placebo-controlled crossover study, and underwent systemic administration of 0.5 g of UA in 250 ml of 0.1% lithium carbonate/4% dextrose vehicle or vehicle alone as control. Subjects performed high-intensity aerobic exercise for 20 min to induce oxidative stress. Plasma 8-iso-PGF2alpha concentrations were determined at baseline, after exercise and after recovery for 20 min. A single bout of high-intensity exercise caused a significant increase in plasma 8-iso-PGF2alpha concentrations from 35.0 +/- 4.7 pg/ml to 45.6 +/- 6.7 pg/ml (P<0.01). UA administration raised serum urate concentration from 293 +/- 16 to 487 +/- 16 micromol/l (P<0.001), accompanied by increased serum antioxidant capacity from 1786+/-39 to 1899 +/- 45 micromol/l (P<0.01). UA administration abolished the exercise-induced elevation of plasma 8-iso-PGF2alpha concentrations. High UA concentrations are associated with increased serum antioxidant capacity and reduced oxidative stress during acute physical exercise in healthy subjects. These findings indicate that the antioxidant properties of UA are of biological importance in vivo. PMID:12801243
Waring, W S; Convery, A; Mishra, V; Shenkin, A; Webb, D J; Maxwell, S R J
Extrapolation from post-exercise measurements has been used to estimate respiratory and blood gas parameters during exercise. This may not be accurate in exercise with reduced breathing frequency (RBF), since spontaneous breathing usually follows exercise. This study was performed to ascertain whether measurement of oxygen saturation and blood gases immediately after exercise accurately reflected their values during exercise with RBF. Eight healthy male subjects performed an incremental cycling test with RBF at 10 breaths per minute. A constant load test with RBF (B10) was then performed to exhaustion at the peak power output obtained during the incremental test. Finally, the subjects repeated the constant load test with spontaneous breathing (SB) using the same protocol as B10. Pulmonary ventilation (VE), end-tidal oxygen (PETO2), and carbon dioxide pressures (PETCO2) and oxygen saturation (SaO2) were measured during both constant load tests. The partial pressures of oxygen (PO2) and carbon dioxide (PCO2) in capillary blood were measured during the last minute of exercise, immediately following exercise and during the third minute of recovery. At the end of exercise RBF resulted in lower PETO2, SaO2 and PO2, and higher PETCO2 and PCO2 when compared to spontaneous breathing during exercise. Lower SaO2 and PETO2 were detected only for the first 16s and 20s of recovery after B10 compared to the corresponding period in SB. There were no significant differences in PO2 between SB and B10 measured immediately after the exercise. During recovery from exercise, PETCO2 remained elevated for the first 120s in the B10 trial. There were also significant differences between SB and B10 in PCO2 immediately after exercise. We conclude that RBF during high intensity exercise results in hypoxia; however, due to post-exercise hyperpnoea, measurements of blood gas parameters taken 15s after cessation of exercise did not reflect the changes in PO2 and SaO2 seen during exercise. Key points In some sports, the environment is inappropriate for direct measurement of respiratory and blood gas parameters during exercise. To overcome this problem, extrapolation from post-exercise measurements has often been used to estimate changes in respiratory and blood gas parameters during exercise. The possibility of hypoxia and hypercapnia during exercise with reduced breathing frequency has been tested by measuring capillary blood sampled after the exercise. Reduced breathing frequency during high intensity exercise results in hypoxia; however, due to marked post-exercise hyperventilation, measurements of blood gas parameters taken 15 s after the cessation of exercise did not yield any changes in these parameters. Despite hyperventilation during recovery, hypercapnia could be detected by measuring blood gas parameters within 15 s after the exercise with reduced breathing frequency.
Kapus, Jernej; Usaj, Anton; Kapus, Venceslav; Strumbelj, Boro
Extrapolation from post-exercise measurements has been used to estimate respiratory and blood gas parameters during exercise. This may not be accurate in exercise with reduced breathing frequency (RBF), since spontaneous breathing usually follows exercise. This study was performed to ascertain whether measurement of oxygen saturation and blood gases immediately after exercise accurately reflected their values during exercise with RBF. Eight healthy male subjects performed an incremental cycling test with RBF at 10 breaths per minute. A constant load test with RBF (B10) was then performed to exhaustion at the peak power output obtained during the incremental test. Finally, the subjects repeated the constant load test with spontaneous breathing (SB) using the same protocol as B10. Pulmonary ventilation (VE), end-tidal oxygen (PETO2), and carbon dioxide pressures (PETCO2) and oxygen saturation (SaO2) were measured during both constant load tests. The partial pressures of oxygen (PO2) and carbon dioxide (PCO2) in capillary blood were measured during the last minute of exercise, immediately following exercise and during the third minute of recovery. At the end of exercise RBF resulted in lower PETO2, SaO2 and PO2, and higher PETCO2 and PCO2 when compared to spontaneous breathing during exercise. Lower SaO2 and PETO2 were detected only for the first 16s and 20s of recovery after B10 compared to the corresponding period in SB. There were no significant differences in PO2 between SB and B10 measured immediately after the exercise. During recovery from exercise, PETCO2 remained elevated for the first 120s in the B10 trial. There were also significant differences between SB and B10 in PCO2 immediately after exercise. We conclude that RBF during high intensity exercise results in hypoxia; however, due to post-exercise hyperpnoea, measurements of blood gas parameters taken 15s after cessation of exercise did not reflect the changes in PO2 and SaO2 seen during exercise. Key pointsIn some sports, the environment is inappropriate for direct measurement of respiratory and blood gas parameters during exercise. To overcome this problem, extrapolation from post-exercise measurements has often been used to estimate changes in respiratory and blood gas parameters during exercise.The possibility of hypoxia and hypercapnia during exercise with reduced breathing frequency has been tested by measuring capillary blood sampled after the exercise.Reduced breathing frequency during high intensity exercise results in hypoxia; however, due to marked post-exercise hyperventilation, measurements of blood gas parameters taken 15 s after the cessation of exercise did not yield any changes in these parameters.Despite hyperventilation during recovery, hypercapnia could be detected by measuring blood gas parameters within 15 s after the exercise with reduced breathing frequency. PMID:24150010
Kapus, Jernej; Ušaj, Anton; Kapus, Venceslav; Strumbelj, Boro
To evaluate the parasitemia, nitrergic neurons, and cytokines in Trypanosoma cruzi-infected mice subjected to moderate physical exercise, forty male Swiss mice, 30days of age, were divided: Trained Control (TC), Trained Infected (TI), Sedentary Control (SC), and Sedentary Infected (SI). The moderate physical exercise program on a treadmill lasted 8weeks. Three days after completing the moderate physical exercise program, the TI and SI groups were inoculated with 1300 blood trypomastigotes of the Y strain of T. cruzi, and parasitemia was evaluated from day 4 to day 22 after inoculation. After 75days of infection, cytokines were measured and colonic neurons were quantified using immunofluorescence to identify neuronal nitric oxide synthase (nNOS). The results were analyzed using analysis of variance - Tukey and Kruskal-Wallis tests, to 5% significance. Moderate physical exercise reduced the parasite peak on day 8 of infection and total parasitemia (p<0.05), contributed to survival of number of nNOS-immunoreactive neurons (p<0.01) and promoted neuronal hypertrophy of the neurons (p<0.05), increased the synthesis of tumor necrosis factor-? (p<0.01) and transforming growth factor-? (p>0.05), providing beneficial effects to the host by acting on the immune system to preserve nitrergic neurons. PMID:24667137
Moreira, Neide Martins; Zanoni, Jacqueline Nelisis; de Oliveira Dalálio, Márcia Machado; de Almeida Araújo, Eduardo José; Braga, Caroline Felício; de Araújo, Silvana Marques
Purpose This pilot study examined if the combination of exercise training and reducing sedentary time (ST) results in greater changes to health markers than either intervention alone. Methods Fifty-seven overweight/obese participants (19M/39F) (mean ± SD; age 43.6 ± 9.9 y, BMI 35.1 ± 4.6 kg/m2) completed the 12-week study and were randomly assigned to 1) EX: exercise 5-days/week for 40-minutes/session at moderate intensity; 2) rST: reduce ST and increase non-exercise physical activity; 3) EX-rST: combination of EX and rST and 4) CON: maintain behavior. Fasting lipids, blood pressure (BP), VO2 peak, BMI and 2-hr oral glucose tolerance tests were completed pre- and post-intervention. Results EX and EX-rST increased VO2 peak by ~10% and decreased systolic BP (both p<0.001). BMI decreased by ?3.3% (95% CI: ?4.6 to ?1.9%) for EX-rST and ?2.2% (?3.5 to 0.0%) for EX. EX-rST significantly increased C-ISI by 17.8% (2.8 to 32.8%) and decreased insulin area-under-the-curve by 19.4% (?31.4 to ?7.3%). No other groups improved in insulin action variables. rST group decreased ST by 7% (~50 min/day), however BP was the only health-related outcome that improved. Conclusions EX and EX-rST improved VO2 peak and BMI providing further evidence that moderate intensity exercise is beneficial. The within-group analysis provides preliminary evidence that exercising and reducing ST may result in improvements in metabolic biomarkers that are not seen with exercise alone, though between group differences did not reach statistical significance. Future studies, with larger samples, should examine health-related outcomes resulting from greater reductions in ST over longer intervention periods.
Keadle, Sarah Kozey; Lyden, Kate; Staudenmayer, John; Hickey, Amanda; Viskochil, Richard; Braun, Barry; Freedson, Patty S.
Investigation of whether males' gender roles mediated their perception of strenuous physical exercise indicated that, in comparison to "feminine" males, "masculine" males reported lower physical strain, while "androgynous" males had more positive effect and greater endurance. (Author/CB)
Rejeski, W. Jack; And Others
The effect of strenuous exercise and training was studied on plasma triglyceride, nonesterified fatty acid (NEFA), cholesterol, and phospholipid levels, as well as plasma lipoprotein fractions separated by a new agarose gel electrophoretic method. Exercis...
N. M. Papadopoulos C. M. Bloor J. C. Standefer
This pilot study examined if the combination of exercise training and reducing sedentary time (ST) results in greater changes to health markers than either intervention alone. Fifty-seven overweight/obese participants (19 males/39 females) (mean ± SD; age, 43.6 ± 9.9 years; body mass index (BMI), 35.1 ± 4.6 kg·m(-2)) completed the 12-week study and were randomly assigned to (i) EX: exercise 5 days·week(-1) for 40 min·session(-1) at moderate intensity; (ii) rST: reduce ST and increase nonexercise physical activity; (iii) EX-rST: combination of EX and rST; and (iv) CON: maintain behavior. Fasting lipids, blood pressure (BP), peak oxygen uptake, BMI, and 2-h oral glucose tolerance tests were completed pre- and post-intervention. EX and EX-rST increased peak oxygen uptake by ?10% and decreased systolic BP (both p < 0.001). BMI decreased by -3.3% (95% confidence interval: -4.6% to -1.9%) for EX-rST and -2.2% (-3.5% to 0.0%) for EX. EX-rST significantly increased composite insulin-sensitivity index by 17.8% (2.8% to 32.8%) and decreased insulin area under the curve by 19.4% (-31.4% to -7.3%). No other groups improved in insulin action variables. rST group decreased ST by 7% (?50 min·day(-1)); however, BP was the only health-related outcome that improved. EX and EX-rST improved peak oxygen uptake and BMI, providing further evidence that moderate-intensity exercise is beneficial. The within-group analysis provides preliminary evidence that exercising and reducing ST may result in improvements in metabolic biomarkers that are not seen with exercise alone, though between-group differences did not reach statistical significance. Future studies, with larger samples, should examine health-related outcomes resulting from greater reductions in ST over longer intervention periods. PMID:24971677
Kozey Keadle, Sarah; Lyden, Kate; Staudenmayer, John; Hickey, Amanda; Viskochil, Richard; Braun, Barry; Freedson, Patty S
Due to the potential anti-inflammatory properties of fish-derived long chain n-3 fatty acids, it has been suggested that athletes should regularly consume fish oils-although evidence in support of this recommendation is not clear. While fish oils can positively modulate immune function, it remains possible that, due to their high number of double bonds, there may be concurrent increases in lipid peroxidation. The current study aims to investigate the effect of fish oil supplementation on exercise-induced markers of oxidative stress and muscle damage. Twenty males underwent a 6-week double-blind randomized placebo-controlled supplementation trial involving two groups (fish oil or placebo). After supplementation, participants undertook 200 repetitions of eccentric knee contractions. Blood samples were taken presupplementation, postsupplementation, immediately, 24, 48, and 72 hr postexercise and muscle soreness/maximal voluntary contraction (MVC) assessed. There were no differences in creatine kinase, protein carbonyls, endogenous DNA damage, muscle soreness or MVC between groups. Plasma thiobarbituric acid reactive substances (TBARS) were lower (p < .05) at 48 and 72 hr post exercise and H2O2 stimulated DNA damage was lower (p < .05) immediately postexercise in the fish oil, compared with the control group. The current study demonstrates that fish oil supplementation reduces selected markers of oxidative stress after a single bout of eccentric exercise. PMID:24225668
Gray, Patrick; Chappell, Andrew; Jenkinson, Alison McE; Thies, Frank; Gray, Stuart R
Prolonged intermittent-sprint exercise (i.e., team sports) induce disturbances in skeletal muscle structure and function that are associated with reduced contractile function, a cascade of inflammatory responses, perceptual soreness, and a delayed return to optimal physical performance. In this context, recovery from exercise-induced fatigue is traditionally treated from a peripheral viewpoint, with the regeneration of muscle physiology and other peripheral factors the target of recovery strategies. The direction of this research narrative on post-exercise recovery differs to the increasing emphasis on the complex interaction between both central and peripheral factors regulating exercise intensity during exercise performance. Given the role of the central nervous system (CNS) in motor-unit recruitment during exercise, it too may have an integral role in post-exercise recovery. Indeed, this hypothesis is indirectly supported by an apparent disconnect in time-course changes in physiological and biochemical markers resultant from exercise and the ensuing recovery of exercise performance. Equally, improvements in perceptual recovery, even withstanding the physiological state of recovery, may interact with both feed-forward/feed-back mechanisms to influence subsequent efforts. Considering the research interest afforded to recovery methodologies designed to hasten the return of homeostasis within the muscle, the limited focus on contributors to post-exercise recovery from CNS origins is somewhat surprising. Based on this context, the current review aims to outline the potential contributions of the brain to performance recovery after strenuous exercise.
Minett, Geoffrey M.; Duffield, Rob
The aim of the present study was to investigate the effect of long-term continuation of low-intensity exercise training on weight maintenance, substrate metabolism, and [beta ][ndash ]adrenergic-mediated fat oxidation in weight-reduced obese men. Preceding this part of the study, subjects lost 15 [plusmn] 6 kg of body weight by energy restriction with or without low-intensity exercise training. Twenty-nine subjects (diet
Dorien P. van Aggel-Leijssen; Wim H. Saris; Gabby B. Hul; Marleen A. van Baak
In this study a fall in serum uric acid (SUA) concentration was associated with the intensive physical exercise over a period of 12 weeks. It was concluded that the chronic effects of a physical training program do not necessarily mimic the temporary effe...
L. H. Cronau P. J. Rasch J. W. Hamby H. J. Burns
The purpose of this study was to examine the effects of a systematic exercise program on sedentary males. The 12 male volunteers were all in occupations which did not require strenuous physical exercise, and they were not carrying out any regular program of exercise. (The mean age for the group was 46 years.) A battery of anthropometric tests and…
Bolonchuk, W. W.; Clayton, R. D.
Provides background relating cardiorespiratory disease to physical activity. Three laboratory activities are described: pulse response to posture change and quiet activity, pulse response to exercise (mild increasing to strenuous), and ability to extract oxygen. The last includes information on construction of an ergometer. (CS)
Jenkins, Robert R.
Certain neurotransmitters (i.e., acetylcholine, catecholamines, and serotonin) are formed from dietary constituents (i.e., choline, tyrosine and tryptophan). Changing the consumption of these precursors alters release of their respective neurotransmitter products. The neurotransmitter acetylcholine is released from the neuromuscular junction and from brain. It is formed from choline, a common constituent in fish, liver, and eggs. Choline is also incorporated into cell membranes; membranes may likewise serve as an alternative choline source for acetylcholine synthesis. In trained athletes, running a 26 km marathon reduced plasma choline by approximately 40%, from 14.1 to 8.4 uM. Changes of similar magnitude have been shown to reduce acetylcholine release from the neuromuscular junction in vivo. Thus, the reductions in plasma choline associated with strenuous exercise may reduce acetylcholine release, and could thereby affect endurance or performance.
Conlay, L. A.; Sabounjian, L. A.; Wurtman, R. J.
BACKGROUND: While there are compelling observational data confirming that individuals who exercise are healthier, the efficacy of aerobic exercise interventions to reduce metabolic risk and improve insulin sensitivity in older people has not been fully elucidated. Furthermore, while low birth weight has been shown to predict adverse health outcomes later in life, its influence on the response to aerobic exercise
Francis M Finucane; Jessica Horton; Lisa R Purslow; David B Savage; Soren Brage; Hervé Besson; Kenneth Horton; Ema Lucia De Rolfe; Alison Sleigh; Stephen J Sharp; Helen J Martin; Avan Aihie Sayer; Cyrus Cooper; Ulf Ekelund; Simon J Griffin; Nicholas J Wareham
Hypertension, or the chronic elevation in resting arterial blood pressure (BP), is a significant risk factor for cardiovascular disease and estimated to affect ~1 billion adults worldwide. The goals of treatment are to lower BP through lifestyle modifications (smoking cessation, weight loss, exercise training, healthy eating and reduced sodium intake), and if not solely effective, the addition of antihypertensive medications. In particular, increased physical exercise and decreased sedentarism are important strategies in the prevention and management of hypertension. Current guidelines recommend both aerobic and dynamic resistance exercise training modalities to reduce BP. Mounting prospective evidence suggests that isometric exercise training in normotensive and hypertensive (medicated and non-medicated) cohorts of young and old participants may produce similar, if not greater, reductions in BP, with meta-analyses reporting mean reductions of between 10 and 13 mmHg systolic, and 6 and 8 mmHg diastolic. Isometric exercise training protocols typically consist of four sets of 2-min handgrip or leg contractions sustained at 20-50 % of maximal voluntary contraction, with each set separated by a rest period of 1-4 min. Training is usually completed three to five times per week for 4-10 weeks. Although the mechanisms responsible for these adaptations remain to be fully clarified, improvements in conduit and resistance vessel endothelium-dependent dilation, oxidative stress, and autonomic regulation of heart rate and BP have been reported. The clinical significance of isometric exercise training, as a time-efficient and effective training modality to reduce BP, warrants further study. This evidence-based review aims to summarize the current state of knowledge regarding the effects of isometric exercise training on resting BP. PMID:24174307
Millar, Philip J; McGowan, Cheri L; Cornelissen, Véronique A; Araujo, Claudio G; Swaine, Ian L
I have helped scientists at NASA-JSC in analyzing data from many projects. Some of the major ones are: (1) cardiovascular responses to lower body negative pressure (LBNP) following bed rest, (2) the effects of dietary sodium, (3) in-flight cycle exercise mitigates reduced oxygen consumption at submaximal heart rates following space flight, (4) exercise thermoregulation after 13 days of head down bed rest, and (5) bed rest induced orthostatic intolerance. Many of the projects have now been completed and some of them are in the process of being published and others have been presented at national meetings. These projects have helped me be a true statistician and given me a real-life perspective of how interesting and complicated data can be. As a by-product of of these involvements I have been able to write and publish some methodological research that have applications in NASA and elsewhere. For instance, while I was at JSC, I happened to meet Dr. Al Feiveson and got into a discussion of the Space Shuttle Reliability. This led us to rethink about the way the data on the accelerated life testing of space shuttle pressure vessels had been analyzed. This has resulted in a major statistical paper and the paper has appeared in one of the top journals in the field of Statistics. A review of the paper by the editor of the journal was published in AmStatNews, a copy is attached with this report. I have presented these findings at the national/international statistics conference and at other places. I have also written another paper on reliability and a paper on calibration techniques that have applications in the engineering and the biomedical branches of NASA. Further, I am currently in the process of writing at least two more papers that have direct applications in NASA related studies.
Kulkarni, Pandurang M.
Aims/Hypothesis Older adults are at a high risk for syncope due to orthostatic intolerance (OI), and this risk increases with comorbid type 2 diabetes and vasoactive medications. Despite many benefits, previous investigations have shown worsening OI with aerobic training. We examined whether aerobic exercise reduced OI in older adults with type 2 diabetes who were given a short-acting vasoactive agent (nitroglycerin). Methods Forty older adults (25 males and 15 females, mean age 71.4 ± 0.7 years, ranging in age from 65 to 83 years) with type 2 diabetes were recruited. Subjects were randomized to each of 2 groups: an aerobic group (3 months of vigorous aerobic exercise) and a nonaerobic (no aerobic exercise) group. Exercise sessions were supervised by a certified exercise trainer 3 times per week. After being given 400 ?g of sublingual nitroglycerin, each subject was placed in a 70° head-up tilt for 30 minutes. Results When the 2 groups were compared using a Cox proportional hazards model, tilt table tolerance was significantly better in the aerobic group as compared to in the nonaerobic group (?2MC = 7.271, P = 0.007). Conclusions Our findings indicate that a relatively short aerobic exercise intervention can improve postnitroglycerin orthostatic tolerance in older adults with type 2 diabetes.
Madden, Kenneth M.; Lockhart, Chris K.; Potter, Tiffany F.; Cuff, Darcye J.; Meneilly, Graydon S.
The oral ingestion of beta-alanine, the rate-limiting precursor in carnosine synthesis, has been shown to elevate the muscle carnosine content. Carnosine is thought to act as a physiologically relevant pH buffer during exercise but direct evidence is lacking. Acidosis has been hypothesised to influence oxygen uptake kinetics during high-intensity exercise. The present study aimed to investigate whether oral beta-alanine supplementation could reduce acidosis during high-intensity cycling and thereby affect oxygen uptake kinetics. 14 male physical education students participated in this placebo-controlled, double-blind study. Subjects were supplemented orally for 4 weeks with 4.8 g/day placebo or beta-alanine. Before and after supplementation, subjects performed a 6-min cycling exercise bout at an intensity of 50% of the difference between ventilatory threshold (VT) and VO(2peak). Capillary blood samples were taken for determination of pH, lactate, bicarbonate and base excess, and pulmonary oxygen uptake kinetics were determined with a bi-exponential model fitted to the averaged breath-by-breath data of three repetitions. Exercise-induced acidosis was significantly reduced following beta-alanine supplementation compared to placebo, without affecting blood lactate and bicarbonate concentrations. The time delay of the fast component (Td(1)) of the oxygen uptake kinetics was significantly reduced following beta-alanine supplementation compared to placebo, although this did not reduce oxygen deficit. The parameters of the slow component did not differ between groups. These results indicate that chronic beta-alanine supplementation, which presumably increased muscle carnosine content, can attenuate the fall in blood pH during high-intensity exercise. This may contribute to the ergogenic effect of the supplement found in some exercise modes. PMID:19841932
Baguet, Audrey; Koppo, Katrien; Pottier, Andries; Derave, Wim
Erythropoietin (Epo) is a glycoprotein hormone that promotes the production of red blood cells. Recombinant human Epo (rhEpo) is illicitly used to improve performance in endurance sports. Doping in sports is discouraged by the screening of athletes for rhEPO in urine. The adopted test is based on a combination of isoelectric focusing and double immunoblotting, and distinguishes between endogenous and recombinant human Epo. We show here that this widely used test can occasionally lead to the false-positive detection of rhEpo (epoetin-beta) in postexercise, protein-rich urine, probably because the adopted monoclonal anti-Epo antibodies are not monospecific. PMID:16493001
Beullens, Monique; Delanghe, Joris R; Bollen, Mathieu
Erythropoietin (Epo) is a glycoprotein hor- mone that promotes the production of red blood cells. Recombinant human Epo (rhEpo) is illicitly used to improve perfor- mance in endurance sports. Doping in sports is discouraged by the screening of athletes for rhEPO in urine. The adopted test is based on a combination of isoelec- tric focusing and double immunoblotting, and distinguishes
Monique Beullens; Joris R. Delanghe; Mathieu Bollen
Omega-3 fatty acids (omega-3) have anti-inflammatory properties. However, it is not known if omega-3 supplementation attenuates exercise-induced inflammation. We tested the hypothesis that omega-3 supplementation reduces inflammation that is induced by eccentric arm curl exercise. Healthy adult men and women (n=11; 35 ± 10 y) performed eccentric biceps curls on two occasions, once after 14d of dietary omega-3 restriction (control trial) and again after 7d of 3,000 mg/d omega-3 supplementation (omega-3 trial). Before and 48 h after eccentric exercise, signs of inflammation was assessed by measuring soreness ratings, swelling (arm circumference and arm volume), and temperature (infrared skin sensor). Arm soreness increased (p < 0.0001) in response to eccentric exercise; the magnitude of increase in soreness was 15% less in the omega-3 trial (p = 0.004). Arm circumference increased after eccentric exercise in the control trial (p = 0.01) but not in the omega-3 trial (p = 0.15). However, there was no difference between trials (p = 0.45). Arm volume and skin temperature did not change in response to eccentric exercise in either trial. These findings suggest that omega-3 supplementation decreases soreness, as a marker of inflammation, after eccentric exercise. Based on these findings, omega-3 supplementation could provide benefits by minimizing post-exercise soreness and thereby facilitate exercise training in individuals ranging from athletes undergoing heavy conditioning to sedentary subjects or patients who are starting exercise programs or medical treatments such as physical therapy or cardiac rehabilitation. Key points Dietary supplementation with omega-3 fatty acids has been shown to reduce inflammation in numerous inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease, and Chrohn’s disease. Although strenuous exercise is known to cause acute increases in inflammation, it is not clear if omega-3 fatty acid supplementation attenuates this adverse response to exercise. Our research demonstrates that 3000 mg·d-1 omega-3 fatty acid supplementation minimizes the severe, delayed-onset muscle soreness that results from strenuous eccentric strength exercise. This information, along with a plethora of information showing that omega-3 fatty acid supplementation has other health benefits, demonstrates that a readily available over the counter nutritional supplement (i.e. omega-3 fatty acids) reduces delayed-onset soreness caused by strenuous strength exercise. This information has obvious relevance to athletic populations but also to other groups such as physical therapy patients and newly admitted cardiac rehabilitation patients, as muscle soreness, if left unchecked, can slow the progress in adapting to a new exercise program. Furthermore, as inflammation is known to be involved in the pathogenesis if numerous diseases, including heart disease, cancer, and diabetes, it is likely prudent for individuals to use inflammation-attenuating interventions, such as omega-3 supplementation, to keep inflammatory responses to physical activity at a minimum.
Jouris, Kelly B.; McDaniel, Jennifer L.; Weiss, Edward P.
This study describes the effects of strenuous live-fire fire fighting drills and 90min of recovery on hematological and psychological variables. Eleven fire fighters performed three trials of fire fighting tasks in a training structure that contained live fires. Plasma volume decreased immediately following the drill, but returned to baseline following recovery and aggressive rehydration. Blood glucose and sodium concentrations were
Denise L. Smith; Steven J. Petruzzello; Mike A. Chludzinski; John J. Reed; Jeffrey A. Woods
Continuous high glycemic load and inactivity challenge glucose homeostasis and fat oxidation. Hyperglycemia and high intramuscular glucose levels mediate insulin resistance, a precursor state of type 2 diabetes. The aim was to investigate whether a carbohydrate (CHO)-reduced diet combined with high-intensity interval training (HIIT) enhances the beneficial effects of the diet alone on insulin sensitivity and fat oxidation in obese individuals. Nineteen obese subjects underwent 14 days of CHO-reduced and energy-restricted diet. Ten of them combined the diet with HIIT (4 min bouts at 90% VO(2peak) up to 10 times, 3 times a week). Oral glucose insulin sensitivity (OGIS) increased significantly in both groups; [diet-exercise (DE) group: pre 377 ± 70, post 396 ± 68 mL min(-1) m(-2); diet (D) group: pre 365 ± 91, post 404 ± 87 mL min(-1) m(-2); P < 0.001]. Fasting respiratory exchange ratio (RER) decreased significantly in both groups (DE group: pre 0.91 ± 0.06, post 0.88 ± 0.06; D group: pre 0.92 ± 0.07, post 0.86 ± 0.07; P = 0.002). VO(2peak) increased significantly in the DE group (pre 27 ± 5, post 32 ± 6 mL kg(-1) min(-1); P < 0.001), but not in the D group (pre 26 ± 9, post 26 ± 8 mL kg(-1) min(-1)). Lean mass and resistin were preserved only in the DE group (P < 0.05). Fourteen days of CHO-reduced diet improved OGIS and fat oxidation (RER) in obese subjects. The energy-balanced HIIT did not further enhance these parameters, but increased aerobic capacity (VO(2peak)) and preserved lean mass and resistin. PMID:20628884
Sartor, Francesco; de Morree, Helma M; Matschke, Verena; Marcora, Samuele M; Milousis, Athanasios; Thom, Jeanette M; Kubis, Hans-Peter
Previously we have shown that chronic as well as a single bout of exercise 20 h prior to a simulated dive protects rats from severe decompression illness (DCI) and death. However, the mechanism behind this protection is still not known. The present study determines the effect of inhibiting nitric oxide synthase (NOS) on bubble formation in acutely exercised and sedentary
U. Wisloff; Russell S. Richardson; Alf O. Brubakk
Exercise is recommended both as a prophylactic and also as a therapeutic approach for patients with established coronary artery disease. In this study, we investigated the effect of a normal chow diet, with or without exercise in LDL r?\\/? mice with preexisting atherosclerotic lesions. A total of 28 LDL r?\\/? mice (LDL receptor knock out mice, 4–6 weeks old) were
Sumathi Ramachandran; Meera Penumetcha; Nadya Khan Merchant; Nalini Santanam; Rong Rong; Sampath Parthasarathy
Study objectives We proposed that mice supplemented with quercetin, a class of flavonoids known to have antioxidant and anti-inflammatory properties, will have profound effects on the pathophysiology of atherosclerosis when combined with exercise. Study design Forty C57BL6 LDLr ?/? mice were divided into four groups (n?=?10): control untreated (NN); control group supplemented with 100 ?g/day of quercetin (NQ); exercise group (EN); and exercise group supplemented with 100 ?g/day of quercetin (EQ). All animals were fed atherogenic diet. The exercise groups were run on a treadmill for 30 minutes, 15 m/min for 5 days/week for 30 days. After 30 day animals were sacrificed and tissues were harvested. Results and conclusion Mice supplemented with quercetin during exercise sessions had 78% atherosclerotic plaque reduction compared to control mice and 40% less atherosclerotic plaque formation compared to control group supplemented with quercetin. The manifestation of the combination of quercetin supplementation with exercise was more evident in the pro-reverse cholesterol transport genes, indicating a plausible mechanism for their combined beneficial effect. The pathogenesis of atherosclerosis, the major cause of cardiovascular diseases (CVD), is multifactorial and therefore its treatment approaches and the ability to regress the plaque are complicated. Data from research on animal models and clinical studies have indicated that moderate daily exercise can alleviate the risk for the development of atherosclerotic plaques, while the same has not been true for the supplementation of antioxidants.
Resistance exercises that load the axial skeleton, such as the parallel squat, are incorporated as a critical component of a space exercise program designed to maximize the stimuli for bone remodeling and muscle loading. Astronauts on the International Space Station perform regular resistance exercise using the Advanced Resistive Exercise Device (ARED). Squat exercises on Earth entail moving a portion of the body weight plus the added bar load, whereas in microgravity the body weight is 0, so all load must be applied via the bar. Crewmembers exercising in microgravity currently add approx.70% of their body weight to the bar load as compensation for the absence of the body weight. This level of body weight replacement (BWR) was determined by crewmember feedback and personal experience without any quantitative data. The purpose of this evaluation was to utilize computational simulation to determine the appropriate level of BWR in microgravity necessary to replicate lower extremity joint work during squat exercise in normal gravity based on joint work. We hypothesized that joint work would be positively related to BWR load.
DeWitt, John K.; Fincke, Renita S.; Logan, Rachel L.; Guilliams, Mark E.; Ploutz-Snyder, Lori L.
RANTES and its CCR5 receptor trigger inflammation and its progression to insulin resistance in obese. In the present study, we investigated for the first time the effect of physical exercise on the expression of RANTES and CCR5 in obese humans. Fifty-seven adult nondiabetic subjects (17 lean and 40 obese) were enrolled in a 3-month supervised physical exercise. RANTES and CCR5 expressions were measured in PBMCs and subcutaneous adipose tissue before and after exercise. Circulating plasma levels of RANTES were also investigated. There was a significant increase in RANTES and CCR5 expression in the subcutaneous adipose tissue of obese compared to lean. In PBMCs, however, while the levels of RANTES mRNA and protein were comparable between both groups, CCR5 mRNA was downregulated in obese subjects (P < 0.05). Physical exercise significantly reduced the expression of both RANTES and CCR5 (P < 0.05) in the adipose tissue of obese individuals with a concomitant decrease in the levels of the inflammatory markers TNF-?, IL-6, and P-JNK. Circulating RANTES correlated negatively with anti-inflammatory IL-1ra (P = 0.001) and positively with proinflammatory IP-10 and TBARS levels (P < 0.05). Therefore, physical exercise may provide an effective approach for combating the deleterious effects associated with obesity through RANTES signaling in the adipose tissue.
Baturcam, Engin; Tiss, Ali; Khadir, Abdelkrim; Al-Ghimlas, Fahad; Al-Khairi, Irina; Cherian, Preethi; Elkum, Naser; John, Jeena; Kavalakatt, Sina; Lehe, Cynthia; Warsame, Samia; Behbehani, Kazem; Dermime, Said
RANTES and its CCR5 receptor trigger inflammation and its progression to insulin resistance in obese. In the present study, we investigated for the first time the effect of physical exercise on the expression of RANTES and CCR5 in obese humans. Fifty-seven adult nondiabetic subjects (17 lean and 40 obese) were enrolled in a 3-month supervised physical exercise. RANTES and CCR5 expressions were measured in PBMCs and subcutaneous adipose tissue before and after exercise. Circulating plasma levels of RANTES were also investigated. There was a significant increase in RANTES and CCR5 expression in the subcutaneous adipose tissue of obese compared to lean. In PBMCs, however, while the levels of RANTES mRNA and protein were comparable between both groups, CCR5 mRNA was downregulated in obese subjects (P < 0.05). Physical exercise significantly reduced the expression of both RANTES and CCR5 (P < 0.05) in the adipose tissue of obese individuals with a concomitant decrease in the levels of the inflammatory markers TNF- ? , IL-6, and P-JNK. Circulating RANTES correlated negatively with anti-inflammatory IL-1 ra (P = 0.001) and positively with proinflammatory IP-10 and TBARS levels (P < 0.05). Therefore, physical exercise may provide an effective approach for combating the deleterious effects associated with obesity through RANTES signaling in the adipose tissue. PMID:24895488
Baturcam, Engin; Abubaker, Jehad; Tiss, Ali; Abu-Farha, Mohamed; Khadir, Abdelkrim; Al-Ghimlas, Fahad; Al-Khairi, Irina; Cherian, Preethi; Elkum, Naser; Hammad, Maha; John, Jeena; Kavalakatt, Sina; Lehe, Cynthia; Warsame, Samia; Behbehani, Kazem; Dermime, Said; Dehbi, Mohammed
Mean pulmonary arterial pressure (Ppa) during exercise is significantly higher in individuals aged ?50 yr compared with their younger counterparts, but the reasons for this are unknown. Blood flow through intrapulmonary arteriovenous anastomoses (IPAVA) can be detected during exercise or while breathing hypoxic gas mixtures using saline contrast echocardiography in almost all healthy young individuals. It has been previously hypothesized that a lower degree of exercise-induced blood flow through IPAVA is associated with high Ppa during exercise. This association may suggest that individuals who are known to have high Ppa during exercise, such as those ?50 yr of age, may have lower blood flow through IPAVA, but the presence and degree of exercise-induced blood flow through IPAVA has not been specifically studied in older populations. Using transthoracic saline contrast echocardiography, we investigated the potential effects of age on exercise-induced blood flow through IPAVA in a cross-section of subjects aged 19-72 yr. To verify our findings, we assessed the effects of age on hypoxia-induced blood flow through IPAVA. Age groups were ?41 yr (younger, n = 16) and ?50 yr (older, n = 14). Qualitatively measured exercise- and hypoxia-induced blood flow through IPAVA was significantly lower in older individuals compared with younger controls. Older individuals also had significantly higher pulmonary arterial systolic pressure and total pulmonary resistance (TPR) during exercise. Low blood flow through IPAVA was independently associated with high TPR. The reasons for the age-related decrease in blood flow through IPAVA are unknown. PMID:24627355
Cameron Norris, H; Mangum, Tyler S; Duke, Joseph W; Straley, Taylor B; Hawn, Jerold A; Goodman, Randy D; Lovering, Andrew T
Acute tyrosine administration is associated with increased exercise capacity in the heat. To explore whether reduced plasma tyrosine and phenylalanine (tyrosine precursor) is associated with impaired exercise capacity in the heat, eight healthy, moderately trained male volunteers, unacclimated to exercise in the heat, performed two tests in a crossover design separated by at least 7 days. In a randomised, double-blind fashion, subjects ingested 500 mL flavoured, sugar-free water containing amino acids [(TYR-free; isoleucine 15 g, leucine 22.5 g, valine 17.5 g, lysine 17.5 g, methionine 5 g, threonine 10 g, tryptophan 2.5 g)] to lower the ratio of plasma tyrosine plus phenylalanine:amino acids competing for blood-brain barrier uptake (CAA), a key determinant of brain uptake, or a balanced mixture (BAL; TYR-free plus 12.5 g tyrosine and 12.5 g phenylalanine). One hour later, subjects cycled to exhaustion at 63 ± 5 % [Formula: see text]O2peak in 30 °C and 60 % relative humidity. Pre-exercise ratio of plasma tyrosine plus phenylalanine:?CAA declined 75 ± 5 % from rest in TYR-free (P < 0.001), but was unchanged in BAL (P = 0.061). Exercise time was shorter in TYR-free (59.8 ± 19.0 min vs. 66.2 ± 16.9 min in TYR-free and BAL respectively; P = 0.036). Heart rate (P = 0.298), core (P = 0.134) and skin (P = 0.384) temperature, RPE (P > 0.05) and thermal sensation (P > 0.05) were similar at exhaustion in both trials. These data indicate that acutely depleting plasma catecholamine precursors:?CAA is associated with reduced submaximal exercise capacity in the heat. PMID:23288035
Tumilty, Les; Davison, Glen; Beckmann, Manfred; Thatcher, Rhys
Women with breast cancer who were suffering from treatment-related menopausal symptoms experienced symptom relief with cognitive behavioral therapy, physical exercise, or both, according to a Dutch study published October 8, 2012, in the Journal of Clinical Oncology.
rate of 100 kPa min?1 breathing air and remaining at pressure for 80 min. The ascent rate was 9 m min?1 with a 7 min stop at 130 kPa. Each diver underwent two randomly assigned simulated dives, with or without preceding exercise. A single interval exercise performed 24 h before the dive consisted of treadmill running at 90% of maximum
Zeljko Dujic; Ivana Marinovic-Terzic; Darija Bakovi ´ c; Ulrik Wisløff; Alf O. Brubakk; S. Olavs
It is unclear whether regular exercise alone (no caloric restriction) is a useful strategy to reduce adiposity and obesity-related metabolic risk factors in obese girls. We examined the effects of aerobic (AE) vs. resistance exercise (RE) alone on visceral adipose tissue (VAT), intrahepatic lipid, and insulin sensitivity in obese girls. Forty-four obese adolescent girls (BMI ?95th percentile, 12-18 yr) with abdominal obesity (waist circumference 106.5 ± 11.1 cm) were randomized to 3 mo of 180 min/wk AE (n = 16) or RE (n = 16) or a nonexercising control group (n = 12). Total fat and VAT were assessed by MRI and intrahepatic lipid by proton magnetic resonance spectroscopy. Intermuscular AT (IMAT) was measured by CT. Insulin sensitivity was evaluated by a 3-h hyperinsulinemic (80 mU·m(2)·min(-1)) euglycemic clamp. Compared with controls (0.13 ± 1.10 kg), body weight did not change (P > 0.1) in the AE (-1.31 ± 1.43 kg) and RE (-0.31 ± 1.38 kg) groups. Despite the absence of weight loss, total body fat (%) and IMAT decreased (P < 0.05) in both exercise groups compared with control. Compared with control, significant (P < 0.05) reductions in VAT (?-15.68 ± 7.64 cm(2)) and intrahepatic lipid (?-1.70 ± 0.74%) and improvement in insulin sensitivity (?0.92 ± 0.27 mg·kg(-1)·min(-1) per ?U/ml) were observed in the AE group but not the RE group. Improvements in insulin sensitivity in the AE group were associated with the reductions in total AT mass (r = -0.65, P = 0.02). In obese adolescent girls, AE but not RE is effective in reducing liver fat and visceral adiposity and improving insulin sensitivity independent of weight loss or calorie restriction. PMID:24045865
Lee, SoJung; Deldin, Anthony R; White, David; Kim, YoonMyung; Libman, Ingrid; Rivera-Vega, Michelle; Kuk, Jennifer L; Sandoval, Sandra; Boesch, Chris; Arslanian, Silva
The purpose of the present study was to investigate moderate intensity progressive resistance exercise (PRE) in growing adolescent rats and its effect on muscle hypertrophy (defined as an increase in fiber cross-sectional area). We hypothesized that in adolescent animals moderate intensity PRE would increase: 1) fiber cross-sectional area (CSA); 2) myosin heavy chain (MyHC) content; and 3) expression and phosphorylation of cell signaling molecules involved in translational regulation, compared to age-matched sedentary controls (SED). In the PRE group, three-week old male rats were trained to climb a vertical ladder as a mode of PRE training such that by 10 weeks, all animals in the PRE group had progressed to carry an additional 80% of body weight per climb. In agreement with our hypotheses, we observed that 10 weeks of moderate PRE in adolescent animals was sufficient to increase CSA of muscle fibers and increase MyHC content. Average muscle fiber CSA increased by greater than 10% and total MyHC content increased by 35% (p<0.05) in the PRE group compared to SED animals. Concurrently, we investigated sustained changes in the expression and phosphorylation of key signaling molecules that are previously identified regulators of hypertrophy in adult animal models. Contrary to our hypotheses, expression and phosphorylation of the translational regulators mTOR and Akt were not increased in the PRE group. In addition, we observed that the ratio of phosphorylated-to-unphosphorylated ribosomal protein S6 (rpS6) was reduced over six-fold in PRE animals (p<0.05) and total rpS6 protein levels were unchanged between PRE and sedentary animals (p>0.05). We conclude that moderate intensity PRE is sufficient to induce muscle hypertrophy in adolescent animals while the signaling mechanisms associated with muscle hypertrophy may differ between growing adolescents and adults.
Hellyer, Nathan J.; Nokleby, Jessica J.; Thicke, Bethany M.; Zhan, Wen-Zhi; Sieck, Gary C.; Mantilla, Carlos B.
The purpose of this study was to investigate moderate intensity progressive resistance exercise (PRE) in growing adolescent rats and its effect on muscle hypertrophy (defined as an increase in fiber cross-sectional area [CSA]). We hypothesized that in adolescent animals moderate intensity PRE would increase (a) fiber CSA; (b) myosin heavy chain (MyHC) content; and (c) expression and phosphorylation of cell signaling molecules involved in translational regulation, compared with that in age-matched sedentary (SED) controls. In the PRE group, 3-week-old male rats were trained to climb a vertical ladder as a mode of PRE training such that by 10 weeks all animals in the PRE group had progressed to carry an additional 80% of their body weight per climb. In agreement with our hypotheses, we observed that 10 weeks of moderate PRE in adolescent animals was sufficient to increase the CSA of muscle fibers and increase MyHC content. The average muscle fiber CSA increased by >10%, and the total MyHC content increased by 35% (p < 0.05) in the PRE group compared with that in the SED animals. Concurrently, we investigated sustained changes in the expression and phosphorylation of key signaling molecules that are previously identified regulators of hypertrophy in adult animal models. Contrary to our hypotheses, expression and phosphorylation of the translational regulators mammalian target of rapamycin and Akt were not increased in the PRE group. In addition, we observed that the ratio of phosphorylated-to-unphosphorylated ribosomal protein S6 (rpS6) was reduced over sixfold in PRE animals (p < 0.05) and that total rpS6 protein levels were unchanged between PRE and SED animals (p > 0.05). We conclude that moderate intensity PRE is sufficient to induce muscle hypertrophy in adolescent animals, whereas the signaling mechanisms associated with muscle hypertrophy may differ between growing adolescents and adults. PMID:22614147
Hellyer, Nathan J; Nokleby, Jessica J; Thicke, Bethany M; Zhan, Wen-Zhi; Sieck, Gary C; Mantilla, Carlos B
Apoptosis occurring secondary to spinal cord injury (SCI) causes further neural damage and functional loss. In this study, a rat model was used to investigate the effect of treadmill exercise on SCI-induced apoptosis and expression of neurotrophic factors. To produce SCI, a contusion injury (10 g × 25 mm) was applied subsequent to laminectomy at the T9–T10 level. Following SCI, treadmill exercise was performed for six weeks. Hindlimb motor function was evaluated with a grid-walking test. The expression of neurotrophic factors and the level of apoptosis at the site of SCI were determined by western blotting. SCI reduced hindlimb motor function and suppressed expression of neurotrophin (NT)-3 and insulin-like growth factor (IGF)-1. Expression of phosphatidylinositol 3-kinase (PI3K), the ratio of phosphorylated Akt to Akt (pAkt/Akt) and the ratio of B-cell lymphoma 2 (Bcl-2) to Bax (Bcl-2/Bax) were decreased, and cleaved caspase-3 expression was increased by SCI. Treadmill exercise enhanced hindlimb motor function and increased expression of nerve growth factor (NGF), NT-3 and IGF-1 in the SCI rats. Treadmill exercise increased PI3K expression, the pAkt/Akt and the Bcl-2/Bax ratios, and suppressed cleaved caspase-3 expression in the injured spinal cord. This study demonstrated that treadmill exercise promotes the recovery of motor function by suppressing apoptosis in the injured spinal cord. The beneficial effect of exercise may be attributed to the increase in expression of neurotrophic factors via activation of the PI3K/Akt pathway.
JUNG, SUN-YOUNG; KIM, DAE-YOUNG; YUNE, TAE YOUNG; SHIN, DONG-HOON; BAEK, SANG-BIN; KIM, CHANG-JU
This report presents nonexperimental retrospective data on the weights, menstrual cycle intervals, pregnancy symptoms, and running programs of two women who exercised intensely during their first two trimesters. Although these two cases suggest that strenuous anaerobic exercise during pregnancy is not harmful, more studies are needed. (IAH)
Cohen, Gloria C.; And Others
Our objective was to determine the prevalence and distribution of fasciculations in healthy adults and to assess the effect of age, caffeine and exercise. Fasciculations were studied with ultrasonography in 58 healthy adults in various age categories. Questionnaires were used to determine effect of caffeine and regular exercise on the presence of fasciculations. Finally, we tested the effect of strenuous
Jiske Fermont; Ilse M. P. Arts; Sebastiaan Overeem; Bert U. Kleine; H. Jurgen Schelhaas; Machiel J. Zwarts
This review describes the current state of knowledge on the hazards of exercise and the potential benefits of physical activity on the gastrointestinal tract. In particular, acute strenuous exercise may provoke gastrointestinal symptoms such as heartburn or diarrhoea. A substantial part (20–50%) of endurance athletes are hampered by these symptoms which may deter them from participation in training and competitive
H P F PETERS; W R DE VRIES; G P VANBERGE-HENEGOUWEN; L M A AKKERMANS
It has previously been shown that females incur less muscle damage than males after strenuous exercise, but limited data are available for humans. To determine possible differences between the sexes in humans, the response to high-force eccentric exercise was examined in a large sample of women (n = 83) and men (n = 82). The participants performed a bout of
John Rinard; Priscilla M. Clarkson; Lucille L. Smith; Marlene Grossman
Reduced olfactory efficiency in sniffer dogs results mainly from overheating, and causes physiological and behavioural resources to be diverted from concentration on the assigned task and applied instead to methods of body cooling. Dogs do not possess sweat glands, and panting is the main means of cooling the body. Since a dog can either sniff or pant, but can never
Irit Gazit; Joseph Terkel
Cryotherapy is an effective treatment for acute sports injury to soft tissue, although the effect of cryotherapy on exercise-induced muscle damage is unclear. The aim of this study was to assess the effects of cold water immersion on the symptoms of exercise-induced muscle damage following strenuous eccentric exercise. After performing a bout of damage-inducing eccentric exercise (eight sets of five
ROGER ESTON; DANIEL PETERS
INTRODUCTION: Since strenuous exercise for 10 min during preoxygenation was shown to provide better protection from decompression sickness (DCS) incidence than resting preoxygenation, a logical question was: would a longer period of strenuous exercise improve protection even further? HYPOTHESIS: Increased strenuous exercise duration during preoxygenation increases DCS protection. METHODS: There were 60 subjects, 30 men and 30 women, who were exposed to 9,144 m (4.3 psia) for 4 h while performing mild, upper body exercise. Before the exposures, each subject performed three preoxygenation profiles on different days in balanced order: a 90-min resting preoxygenation control; a 240-min resting preoxygenation control; and a 90-min preoxygenation including exercise during the first 15 min. The subjects were monitored at altitude for venous gas emboli (VGE) with an echo-imaging system and observed for signs and symptoms of DCS. RESULTS: There were no significant differences in occurrence of DCS following any of the three preoxygenation procedures. Results were also comparable to an earlier report of 42% DCS with a 60-min preoxygenation including a 10-min exercise. There was no difference between VGE incidence in the comparison of protection offered by a 90-min preoxygenation with or without 13 min of strenuous exercise. The DCS incidence following a 240-min resting preoxygenation, 40%, was higher than observed during NASA studies and nearly identical with the earlier 42% DCS after a 60-min preoxygenation including exercise during the first 10 min. CONCLUSION: The protection offered by a 10 min exercise in a 60-min preoxygenation was not increased with extension of the preoxygenation exercise period to 15 min in a 90-min preoxygenation, indicating an upper time limit to the beneficial effects of strenuous exercise.
Webb, James T.; Pilmanis, Andrew A.; Fischer, Michele D.; Kannan, Nandini
Athletic performance may be initially enabled but then become limited by changes in body fluids. This subject is reviewed in three parts: physiological responses, replacement strategies, and the influences of nutrition and feeding management. Emphasis on losses in sweat during strenuous exercise have focused attention on replacement of water and electrolytes, but the economies of water and energy are intertwined,
David S. Kronfeld
Summary. Recent studies have questioned the safety of calcium antagonists in general, and short-acting dihydropyridine derivatives in particular. Reasons include excessive catecholamine stimulation after stress. We therefore wanted to assess whether amlodipine, a second generation dihydropyridine with a prolonged plasma half-life, would show a more favourable haemodynamic and biochemical profile after strenuous exercise. For this purpose, we studied 9 healthy
Sinisa Stankovic; Vanessa Panz; Eric Klug; Guiseppe Di Nicola; Barry Isaac Joffe
Both obesity and aging increase intrahepatic fat (IHF) content, which leads to nonalcoholic fatty liver disease (NAFLD) and metabolic abnormalities such as insulin resistance. We evaluated the effects of diet and diet in conjunction with exercise on IHF content and associated metabolic abnormalities in obese older adults. Eighteen obese (BMI ?30 kg\\/m2) older (?65 years old) adults completed a 6-month
Krupa Shah; Abby Stufflebaum; Tiffany N. Hilton; David R. Sinacore; Samuel Klein; Dennis T. Villareal
Examines how the impromptu speech exercise affects trait and situational communication apprehension (CA). Uses McCroskey's Personal Report of Communication Apprehension to study trait CA and Clevenger's Speaker Anxiety Scale to measure situational CA. Indicates that subjects who completed the impromptu speech significantly lowered their…
Rumbough, Timothy B.
Context: The number of obese children with insulin resistance and type 2 diabetes is increasing, but the best management strategy is not clear. Objective: The objective of this study was to assess the effect of a structured 8-wk exercise training program on insulin resistance and changes in body composition in obese children. Design: The study was 8 wk of structured
Lana M Bell; Katie Watts; Aris Siafarikas; Alisha Thompson; Nirubasini Ratnam; Max K Bulsara; Judith Finn; Gerry ODriscoll; Daniel J Green; Timothy W Jones; Elizabeth A Davis
The purpose of this investigation was to compare the effects of brief treadmill exercise and meditation with a placebo-control treatment for reduction in several physiological and psychological measures of stress, anxiety, and tension before and after a written final examination in 48 high-test anxiety subjects. The subjects, 24 men and 24 women,…
Sime, Wesley E.
"Study finds physiological changes in one muscle help ease pain." This press release describes the experimental design and findings from the published study "Effect of contrasting physical exercise on rapid force capacity of chronically painful muscles" by Lars L. Andersen, Jesper L. Andersen, Charlotte Suetta, Michael Kjaer, Karen Sogaard, and Gisela Sjogaard in Journal of Applied Physiology, September 2009.
APS Communications Office (American Physiological Society Communications Office)
Purpose To examine whether apparent advantages following training in meditation over exercise can be attributed to specific symptoms, functional impairments, or quality of life indicators assessed by the Wisconsin Upper Respiratory Symptom Survey (WURSS-24). Methods Results from the randomized controlled trial “Meditation or Exercise for Preventing Acute Respiratory Illness” (MEPARI) showed mean global severity and total days of illness were worse in Control (358, 8.9) compared to Exercise (248, 5.1) or Meditation (144, 5.0). Global severity of illness was estimated using area-under-the-curve from daily self-reported severity scores on the WURSS-24. For the current project, we estimated within-group WURSS item-level severity and between-group effect sizes (Cohen's “d” statistic) relative to control. The item-level effect sizes were grouped into 1) symptoms and 2) function and quality of life domains. Results Among the 3 groups, mediators showed the lowest severity estimates for 21 of 22 WURSS items. Item-level Cohen's “d” indicated most benefit was evident in WURSS items representing function and quality of life. Compared to exercise, meditation fostered larger reductions in illness severity, although due mostly to improved function and the quality of life domain (d = ? 0.33, p<0.001) compared to symptom domain (d = ? 0.22, p<0.001). Conclusions The apparent advantage of training in meditation over exercise for reducing cold and flu illness is explained more by improved function and quality of life than by a reduction in symptom severity.
Obasi, Chidi N.; Brown, Roger; Ewers, Tola; Barlow, Shari; Gassman, Michele; Zgierska, Aleksandra; Coe, Christopher L.; Barrett, Bruce
Both chronic mild stress and an injection of corticosterone induce depression-like states in rodents. To further link mitochondrial dysfunction to the pathophysiology of major depression, here we describe two rat models of a depressive-like state induced by chronic unpredictable mild stress (CUMS) or corticosterone treatment (CORT). It is also a model that allows the simultaneous study of effects of exercise preconditioning on behavioral, electrophysiological, biochemical and molecular markers in the same animal. Exercise preconditioning ahead of CUMS and CORT treatment prevents many behavioral abnormalities resulted from CUMS. The changes in mitochondrial activity in brain and reduced expressions of superoxide dismutase (SOD1, SOD2), mitofusin (Mfn1, Mfn2) as well as brain-derived neurotrophic factor (BDNF) suggest that both CORT and CUMS may impair mitochondrial function and/or expressions of mitofusion and antioxidant enzymes that, in turn, may increase oxidative stress and reduce energy production in brain with depression-like behaviors. These findings suggest an underlying mechanism by which CORT, as well as CUMS, induces brain mitochondrial dysfunction that is associated with depressive-like states. Remarkably, physical exercise is identified as a helpful and preventive measure to promote mitochondrial function and expressions of mitofusin, BDNF and antioxidant enzymes in brain, so as to protect brain energy metabolism against CUMS, rather than the compound of corticosterone. PMID:22244747
Liu, Weina; Zhou, Chenglin
The aim of this study was to investigate the effect of a cyclooxygenase (COX)-2 inhibitor on the recovery of muscle function, inflammation, regeneration after, and adaptation to, unaccustomed eccentric exercise. Thirty-three young males and females participated in a double-blind, placebo-controlled experiment. Seventy unilateral, voluntary, maximal eccentric actions with the elbow flexors were performed twice (bouts 1 and 2) with the same arm, separated by 3 weeks. The test group participants were administered 400 mg/day of celecoxib for 9 days after bout 1. After both bouts 1 and 2, concentric and isometric force-generating capacity was immediately reduced (approximately 40-50%), followed by the later appearance of muscle soreness and increased serum creatine kinase levels. Radiolabelled autologous leukocytes (detected by scintigraphy) and monocytes/macrophages (histology) accumulated in the exercised muscles, simultaneously with increased satellite cell activity. These responses were reduced and recovery was faster after bout 2 than 1, demonstrating a repeated-bout effect. No differences between the celecoxib and placebo groups were detected, except for muscle soreness, which was attenuated by celecoxib. In summary, celecoxib, a COX-2 inhibitor, did not detectably affect recovery of muscle function or markers of inflammation and regeneration after unaccustomed eccentric exercise, nor did the drug influence the repeated-bout effect. However, it alleviated muscle soreness. PMID:19522751
Paulsen, G; Egner, I M; Drange, M; Langberg, H; Benestad, H B; Fjeld, J G; Hallén, J; Raastad, T
Inflammation may accompany obesity and a variety of diseases, or result from excessive exercise. The aim of this study was to investigate the anti-inflammatory effect of whole-body cryostimulation on the inflammatory response induced by eccentric exercise under laboratory conditions. The study also sought to establish if cold treatment changes the lipid profile and modifies energy expenditure in young people. Eighteen healthy and physically active, college-aged men volunteered to participate in the experiment. They were divided into two subgroups: CRY- submitted to whole-body cryostimulation, and CONT- a control group. Both groups performed eccentric work to induce muscle damage. Blood samples were collected before and 24 h after the exercise. Over the five days that followed, the CRY group was exposed to a series of 10 sessions in a cryogenic chamber (twice a day, for 3 min, at a temperature of -110?C). After this period of rest, both groups repeated a similar eccentric work session, following the same schedule of blood collection. The perceived pain was noted 24h after each session of eccentric workout. A 30-minute step up/down work-out induced delayed-onset muscle soreness in both groups. The five-day recovery period accompanied by exposure to cold significantly enhanced the concentration of the anti-inflammatory cytokine IL-10. It also led to a pronounced reduction in levels of the pro-inflammatory cytokine IL-1?, and reduced muscle damage. The values for IL-10 before the second bout of eccentric exercise in the CRY group were 2.0-fold higher in comparison to baseline, whereas in the CONT group, the concentration remained unchanged. Furthermore, blood concentrations of the pro-inflammatory cytokine IL-1? fell significantly in the CRY group. The main finding of this study was that a series of 10 sessions of whole body cryostimulation significantly reduced the inflammatory response induced by eccentric exercise. The lipid profile was also improved, but there was no effect on energy expenditure during the exercise. PMID:24998353
Ziemann, Ewa; Olek, Robert A; Grzywacz, Tomasz; Kaczor, Jan J; Antosiewicz, J?drzej; Skrobot, Wojciech; Kujach, Sylwester; Laskowski, Rados?aw
Exercise raises brain serotonin release and is postulated to cause fatigue in athletes; ingestion of branched-chain amino acids (BCAA), by competitively inhibiting tryptophan transport into brain, lowers brain tryptophan uptake and serotonin synthesis and release in rats, and reputedly in humans prevents exercise-induced increases in serotonin and fatigue. This latter effect in humans is disputed. But BCAA also competitively inhibit tyrosine uptake into brain, and thus catecholamine synthesis and release. Since increasing brain catecholamines enhances physical performance, BCAA ingestion could lower catecholamines, reduce performance and thus negate any serotonin-linked benefit. We therefore examined in rats whether BCAA would reduce both brain tryptophan and tyrosine concentrations and serotonin and catecholamine synthesis. Sedentary and exercising rats received BCAA or vehicle orally; tryptophan and tyrosine concentrations and serotonin and catecholamine synthesis rates were measured 1 h later in brain. BCAA reduced brain tryptophan and tyrosine concentrations, and serotonin and catecholamine synthesis. These reductions in tyrosine concentrations and catecholamine synthesis, but not tryptophan or serotonin synthesis, could be prevented by co-administering tyrosine with BCAA. Complete essential amino acid mixtures, used to maintain or build muscle mass, were also studied, and produced different effects on brain tryptophan and tyrosine concentrations and serotonin and catecholamine synthesis. Since pharmacologically increasing brain catecholamine function improves physical performance, the finding that BCAA reduce catecholamine synthesis may explain why this treatment does not enhance physical performance in humans, despite reducing serotonin synthesis. If so, adding tyrosine to BCAA supplements might allow a positive action on performance to emerge. PMID:23904096
Choi, Sujean; Disilvio, Briana; Fernstrom, Madelyn H; Fernstrom, John D
Both obesity and aging increase intrahepatic fat (IHF) content, which leads to non-alcoholic fatty liver disease and metabolic abnormalities such as insulin resistance. We evaluated the effects of diet and diet in conjunction with exercise on IHF content and associated metabolic abnormalities in obese older adults. Eighteen obese (BMI ?30 kg/m2) older (?65 years old) adults completed a 6-month clinical trial. Participants were randomized to diet (D group; n=9) or diet+exercise (D+E group; n=9). Primary outcome was IHF quantified by magnetic resonance spectroscopy. Secondary outcomes included insulin sensitivity (assessed by oral glucose tolerance), body composition (assessed by DXA), physical function (VO2peak and strength), glucose, lipids, and blood pressure. Body weight (D: ?9±1%, D+E: ?10±2%, both p<0.05) and fat mass (D: ?13±3%, D+E ?16±3%, both p<0.05) decreased in both groups but there was no difference between groups. IHF decreased to a similar extent in both groups (D: ?46±11%, D+E: ?45 ± 8%, both p<0.05), which was accompanied by comparable improvements in insulin sensitivity (D: 66±25%, D+E: 68±28%, both p<0.05). The relative decreases in IHF correlated directly with relative increases in insulin sensitivity index (r=?0.52; p<0.05). Improvements in VO2peak, strength, plasma triglyceride and HDL-cholesterol concentration, and diastolic blood pressure occurred in the D+E group (all p<0.05) but not in the D group. Diet with or without exercise results in significant decreases in IHF content accompanied by considerable improvements in insulin sensitivity in obese older adults. The addition of exercise to diet therapy improves physical function and other obesity- and aging-related metabolic abnormalities.
Shah, Krupa; Stufflebam, Abby; Hilton, Tiffany N.; Sinacore, David R.; Klein, Samuel; Villareal, Dennis T.
. In this study we investigated the extent to which an initial eccentric exercise consisting of two (2ECC) or six maximal eccentric\\u000a actions (6ECC) of the elbow flexors would produce a similar effect to 24 maximal eccentric actions (24ECC), on a second bout\\u000a of 24ECC performed 2 weeks later. Male students (n=34) were assigned to one of three groups, and with
Kazunori Nosaka; K. Sakamoto; M. Newton; P. Sacco
AIM: We sought to evaluate musculoskeletal discomfort and mental and physical fatigue in the call-center workers of an airline company before and after a supervised exercise program compared with rest breaks during the work shift. INTRODUCTION: This was a longitudinal pilot study conducted in a flight-booking call-center for an airline in São Paulo, Brazil. Occupational health activities are recommended to decrease the negative effects of the call-center working conditions. In practice, exercise programs are commonly recommended for computer workers, but their effects have not been studied in call-center operators. METHODS: Sixty-four call-center operators participated in this study. Thirty-two subjects were placed into the experimental group and attended a 10-min daily exercise session for 2 months. Conversely, 32 participants were placed into the control group and took a 10-min daily rest break during the same period. Each subject was evaluated once a week by means of the Corlett-Bishop body map with a visual analog discomfort scale and the Chalder fatigue questionnaire. RESULTS: Musculoskeletal discomfort decreased in both groups, but the reduction was only statistically significant for the spine and buttocks (p=0.04) and the sum of the segments (p=0.01) in the experimental group. In addition, the experimental group showed significant differences in the level of mental fatigue, especially in questions related to memory Rienzo, #181ff and tiredness (p=0.001). CONCLUSIONS: Our preliminary results demonstrate that appropriately designed and supervised exercise programs may be more efficient than rest breaks in decreasing discomfort and fatigue levels in call-center operators.
de Castro Lacaze, Denise Helena; Sacco, Isabel de C. N.; Rocha, Lys Esther; de Braganca Pereira, Carlos Alberto; Casarotto, Raquel Aparecida
AMP-activated protein kinase (AMPK) is a key energy-sensitive enzyme that controls numerous metabolic and cellular processes. Mammalian target of rapamycin (mTOR) is another energy/nutrient-sensitive kinase that controls protein synthesis and cell growth. In this study we determined whether older versus younger men have alterations in the AMPK and mTOR pathways in skeletal muscle, and examined the effect of a long term resistance type exercise training program on these signaling intermediaries. Older men had decreased AMPK?2 activity and lower phosphorylation of AMPK and its downstream signaling substrate acetyl-CoA carboxylase (ACC). mTOR phosphylation also was reduced in muscle from older men. Exercise training increased AMPK?1 activity in older men, however, AMPK?2 activity, and the phosphorylation of AMPK, ACC and mTOR, were not affected. In conclusion, older men have alterations in the AMPK-ACC and mTOR pathways in muscle. In addition, prolonged resistance type exercise training induces an isoform-selective up regulation of AMPK activity.
Li, Mengyao; Verdijk, Lex B.; Sakamoto, Kei; Ely, Brian; van Loon, Luc J.C.; Musi, Nicolas
The myofibrillar protein synthesis (MPS) response to resistance exercise (REX) and protein ingestion during energy deficit (ED) is unknown. In young men (n = 8) and women (n = 7), we determined protein signaling and resting postabsorptive MPS during energy balance [EB; 45 kcal·kg fat-free mass (FFM)(-1)·day(-1)] and after 5 days of ED (30 kcal·kg FFM(-1)·day(-1)) as well as MPS while in ED after acute REX in the fasted state and with the ingestion of whey protein (15 and 30 g). Postabsorptive rates of MPS were 27% lower in ED than EB (P < 0.001), but REX stimulated MPS to rates equal to EB. Ingestion of 15 and 30 g of protein after REX in ED increased MPS ~16 and ~34% above resting EB (P < 0.02). p70 S6K Thr(389) phosphorylation increased above EB only with combined exercise and protein intake (~2-7 fold, P < 0.05). In conclusion, short-term ED reduces postabsorptive MPS; however, a bout of REX in ED restores MPS to values observed at rest in EB. The ingestion of protein after REX further increases MPS above resting EB in a dose-dependent manner. We conclude that combining REX with increased protein availability after exercise enhances rates of skeletal muscle protein synthesis during short-term ED and could in the long term preserve muscle mass. PMID:24595305
Areta, José L; Burke, Louise M; Camera, Donny M; West, Daniel W D; Crawshay, Siobhan; Moore, Daniel R; Stellingwerff, Trent; Phillips, Stuart M; Hawley, John A; Coffey, Vernon G
Serum iron levels have been shown to decline both with fever and with strenuous exercise, leading to the supposition that\\u000a the decrease might be the result of a rise in core body temperature. To evaluate this hypothesis, the serum iron response\\u000a to an exercise-induced 1.5?C rise in core body temperature was measured. To increase core temperature, five females and two
Michael J. Buono; Michelle T. Barrack; Fabienne Bouton-Sander; Patricia Bradley; Kristina A. Majer Cottonaro
Background No previous studies have examined the effect of intensive exercise in systemic sclerosis patients with pulmonary impairment. The objective of this study was to examine the effect of an eight-week intensive aerobic exercise and muscle endurance training program for patients with systemic sclerosis with 50–100% of forced vital capacity. Methods A single-subject experimental design with repeated systematic measures during a six week A-phase (non-interventional baseline period) and an eight week B-phase (exercise intervention period) was used. Three women and one man with median age 66 years and median disease duration of 3.5?years completed aerobic exercise corresponding to 15 on the Borg RPE scale (strenuous) and muscular endurance training three times/week. Physical capacity (six-minute walk test), aerobic capacity (submaximal treadmill test) and muscle endurance in shoulder and hip flexion (Functional Index 2) were assessed every other week throughout the 14-week study. Activity limitation (Health Assessment Questionnaire), quality of life (Short Form 36), Raynaud, Fatigue and Global Health during the recent week (Visual Analogue Scales) were assessed at weeks 0, 6, 14. Results Three participants improved significantly in muscular endurance, and two participants improved significantly or clinically relevant in aerobic capacity. All other variables remained unchanged, except for a trend towards reduced fatigue. Conclusions This eight week exercise program was largely successful with positive effects on aerobic capacity and muscle endurance. Trial registration Clinicaltrials.gov Identifier: NCT01813578
Biological motion stimuli, such as orthographically projected stick figure walkers, are ambiguous about their orientation in depth. The projection of a stick figure walker oriented towards the viewer, therefore, is the same as its projection when oriented away. Even though such figures are depth-ambiguous, however, observers tend to interpret them as facing towards them more often than facing away. Some have speculated that this facing-the-viewer bias may exist for sociobiological reasons: Mistaking another human as retreating when they are actually approaching could have more severe consequences than the opposite error. Implied in this hypothesis is that the facing-towards percept of biological motion stimuli is potentially more threatening. Measures of anxiety and the facing-the-viewer bias should therefore be related, as researchers have consistently found that anxious individuals display an attentional bias towards more threatening stimuli. The goal of this study was to assess whether physical exercise (Experiment 1) or an anxiety induction/reduction task (Experiment 2) would significantly affect facing-the-viewer biases. We hypothesized that both physical exercise and progressive muscle relaxation would decrease facing-the-viewer biases for full stick figure walkers, but not for bottom- or top-half-only human stimuli, as these carry less sociobiological relevance. On the other hand, we expected that the anxiety induction task (Experiment 2) would increase facing-the-viewer biases for full stick figure walkers only. In both experiments, participants completed anxiety questionnaires, exercised on a treadmill (Experiment 1) or performed an anxiety induction/reduction task (Experiment 2), and then immediately completed a perceptual task that allowed us to assess their facing-the-viewer bias. As hypothesized, we found that physical exercise and progressive muscle relaxation reduced facing-the-viewer biases for full stick figure walkers only. Our results provide further support that the facing-the-viewer bias for biological motion stimuli is related to the sociobiological relevance of such stimuli.
Heenan, Adam; Troje, Nikolaus F.
Every other day feeding (EOD) and exercise induce changes in cell metabolism. The aim of the present work was to know if both EOD and exercise produce similar effects on physical capacity, studying their physiological, biochemical and metabolic effects on muscle. Male OF-1 mice were fed either ad libitum (AL) or under EOD. After 18 weeks under EOD, animals were also trained by using a treadmill for another 6 weeks and then analyzed for physical activity. Both, EOD and endurance exercise increased the resistance of animals to extenuating activity and improved motor coordination. Among the groups that showed the highest performance, AL and EOD trained animals, ALT and EODT respectively, only the EODT group was able to increase glucose and triglycerides levels in plasma after extenuating exercise. No high effects on mitochondrial respiratory chain activities or protein levels neither on coenzyme Q levels were found in gastrocnemius muscle. However, exercise and EOD did increase ?-oxidation activity in this muscle accompanied by increased CD36 levels in animals fed under EOD and by changes in shape and localization of mitochondria in muscle fibers. Furthermore, EOD and training decreased muscle damage after strenuous exercise. EOD also reduced the levels of lipid peroxidation in muscle. Our results indicate that EOD improves muscle performance and resistance by increasing lipid catabolism in muscle mitochondria at the same time that prevents lipid peroxidation and muscle damage.
Rodriguez-Bies, Elizabeth; Santa-Cruz Calvo, Sara; Fontan-Lozano, Angela; Pena Amaro, Jose; Berral de la Rosa, Francisco J.; Carrion, Angel M.; Navas, Placido; Lopez-Lluch, Guillermo
Sensitivity of the Athlete Blood Passport for blood doping could be improved by including total haemoglobin mass (Hb(mass)), but this measure may be unreliable immediately following strenuous exercise. We examined the stability of Hb(mass) following ultra-endurance triathlon (3.8 km swim, 180 km bike, 42.2 km run). 26 male sub-elite triathletes, 18 Racers and 8 Controls, were tested for Hb(mass) using CO re-breathing, twice 1-5 days apart. Racers were measured before and 1-3 h after the triathlon. Controls did no vigorous exercise on either test day. Serum haptoglobin concentration and urine haemoglobin concentration were measured to assess intravascular haemolysis. There was a 3.2% (p<0.01) increase in Racers' Hb(mass) from pre-race (976 g ± 14.6%, mean ±% coefficient of variation) to post-race (1 007 g ± 13.8%), as opposed to a - 0.5% decrease in Controls (pre-race 900 g ± 13.9%, post-race 896 g ± 12.4%). Haptoglobin was - 67% (p<0.01) reduced in Racers (pre-race 0.48 g / L ± 150%, post-race 0.16 g / L ± 432%), compared to - 6% reduced in Controls (pre-race 1.08 g / L ± 37%, post-race 1.02 g / L ± 37%). Decreased serum haptoglobin concentration in Racers, which is suggestive of mild intravascular blood loss, was contrary to the apparent Hb(mass) increase post-race. Ultra-endurance triathlon racing may confound the accuracy of post-exercise Hb(mass) measures, possibly due to splenic contraction or an increased rate of CO diffusion to intramuscular myoglobin. PMID:22706938
Gough, C E; Eastwood, A; Saunders, P U; Anson, J M; Gore, C J
The use of exercise interventions to manage cancer-related fatigue (CRF) is a rapidly developing field of study. However, results are inconsistent and difficult to interpret across the literature, making it difficult to draw accurate conclusions regarding the true effectiveness of exercise interventions for CRF management. The aims of this study were to apply a meta-analysis to quantitatively assess the effects of exercise intervention strategies on CRF, and to elucidate appropriate exercise prescription guidelines. A systematic search of electronic databases and relevant journals and articles was conducted. Studies were eligible if subjects were over the age of 18 years, if they had been given a diagnosis of or had been treated for cancer, if exercise was used to treat CRF as a primary or secondary endpoint, and if the effects of the intervention were evaluated quantitatively and presented adequate statistical data for analysis. A total of 16 studies, representing 1426 participants (exercise, 759; control, 667) were included in a meta-analysis using a fixed-effects model. The standardized mean difference effect size (SMD) was used to test the effect of exercise on CRF between experimental and control groups. The results indicate a small but significant effect size in favour of the use of exercise interventions for reducing CRF (SMD 0.26, p < 0.001). Furthermore, aerobic exercise programs caused a significant reduction in CRF (SMD 0.21, p < 0.001) and overall, exercise was able to significantly improve aerobic and musculoskeletal fitness compared with control groups (p < 0.01). Further investigation is still required to determine the effects of exercise on potential underlying mechanisms related to the pathophysiology of CRF. PMID:22067010
McMillan, Elliott M; Newhouse, Ian J
We examined the pacing strategy and the magnitude of the end spurt during a 200-kJ cycling time trial performed 12-14 h after an exercise protocol designed to reduce muscle glycogen content. 9 physically-active men performed 5 familiarization sessions and 2 experimental 200-kJ time trials in either a control condition (CON) or after an exercise protocol performed the previous evening that was designed to induce muscle glycogen depletion (EP). Mean total time was faster and power output was higher in the CON than in the EP (P<0.01). A fast-start was maintained until the 50-kJ section in CON, but only the 25-kJ section for EP (P<0.05). The power outputs during the 50-, 150- and 200-kJ sections, and the magnitude of the end-spurt, were significantly higher for the CON than for the EP condition (P<0.05). There was no significant difference in the rating of perceived exertion (overall feeling and feeling in legs) between conditions. In conclusion, a protocol designed to decrease muscle glycogen stores reduced the duration of the fast-start and the magnitude of the end spurt during a 200-kJ cycling time trial, impairing the overall performance. PMID:23325716
Lima-Silva, A E; Correia-Oliveira, C R; Tenorio, L; Melo, A A; Bertuzzi, R; Bishop, D
This study investigated the involvement of the adenosinergic system in antiallodynia induced by exercise in an animal model of complex regional pain syndrome type I (CRPS-I). Furthermore, we analyzed the role of the opioid receptors on exercise-induced analgesia. Ischemia/reperfusion (IR) mice, nonexercised and exercised, received intraperitoneal injections of caffeine (10mg/kg, a non selective adenosine receptor antagonist), 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) (0.1mg/kg, a selective adenosine A receptor antagonist), ZM241385 (3mg/kg, a selective adenosine A receptor antagonist), adenosine deaminase inhibitor erythro-9-(2-hydroxy-3nonyl) adenine [(EHNA), 5mg/kg, an adenosine deaminase inhibitor] or naloxone (1mg/kg, a nonselective opioid receptor antagonist). The results showed that high-intensity swimming exercise reduced mechanical allodynia in an animal model of CRPS-I in mice. The antiallodynic effect caused by exercise was reversed by pretreatment with caffeine, naloxone, DPCPX but it was not modified by ZM241385 treatment. In addition, treatment with EHNA, which suppresses the breakdown of adenosine to inosine, enhanced the pain-relieving effects of the high-intensity swimming exercise. This is the first report demonstrating that repeated sessions of high-intensity swimming exercise attenuate mechanical allodynia in an animal model of CRPS-I and that the mechanism involves endogenous adenosine and adenosine A receptors. This study supports the use of high-intensity exercise as an adjunct therapy for CRPS-I treatment. PMID:23291454
Martins, D F; Mazzardo-Martins, L; Soldi, F; Stramosk, J; Piovezan, A P; Santos, A R S
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-? and -?, 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. PMID:24336883
Schlagowski, A I; Singh, F; Charles, A L; Gali Ramamoorthy, T; Favret, F; Piquard, F; Geny, B; Zoll, J
Proper muscle activation is a key feature of survival in different tasks in daily life as well as sports performance, but can be impaired in elderly and in diseases. Therefore it is also clinically important to better understand the phenomenon that can be elucidated in humans non-invasively by positron emission tomography (PET) with measurements of spatial heterogeneity of glucose uptake within and among muscles during exercise. We studied six healthy young men during 35 minutes of cycling at relative intensities of 30% (low), 55% (moderate), and 75% (high) of maximal oxygen consumption on three separate days. Glucose uptake in the quadriceps femoris muscle group (QF), the main force producing muscle group in recreational cycling, and its four individual muscles, was directly measured using PET and 18F-fluoro-deoxy-glucose. Within-muscle heterogeneity was determined by calculating the coefficient of variance (CV) of glucose uptake in PET image voxels within the muscle of interest, and among-muscles heterogeneity of glucose uptake in QF was expressed as CV of the mean glucose uptake values of its separate muscles. With increasing intensity, within-muscle heterogeneity decreased in the entire QF as well as within its all four individual parts. Among-muscles glucose uptake heterogeneity also decreased with increasing intensity. However, mean glucose uptake was consistently lower and heterogeneity higher in rectus femoris muscle that is known to consist of the highest percentage of fast twitch type II fibers, compared to the other three QF muscles. In conclusion, these results show that in addition to increased contribution of distinct muscle parts, with increases in exercise intensity there is also an enhanced recruitment of muscle fibers within all of the four heads of QF, despite established differences in muscle-part specific fiber type distributions. Glucose uptake heterogeneity may serve as a useful non-invasive tool to elucidate muscle activation in aging and diseased populations.
Kemppainen, Jukka; Fujimoto, Toshihiko; Knuuti, Juhani; Kalliokoski, Kari K.
Context: Two-dimensional (or medial knee displacement [MKD]) and 3-dimensional (3D) knee valgus are theorized to contribute to anterior cruciate ligament injuries. However, whether these displacements can be improved in the double-legged squat (DLS) after an exercise intervention is unclear. Objective: To determine if MKD and 3D knee valgus are improved in a DLS after an exercise intervention. Design: ?Randomized controlled clinical trial. Setting: Research laboratory. Patients or Other Participants: A total of 32 participants were enrolled in this study and were randomly assigned to the control (n = 16) or intervention (n = 16) group. During a DLS, all participants demonstrated knee valgus that was corrected with a heel lift. Intervention(s): ?The intervention group completed 10 sessions of directed exercise that focused on hip and ankle strength and flexibility over a 2- to 3-week period. Main Outcome Measure(s): We assessed MKD and 3D knee valgus during the DLS using an electromagnetic tracking system. Hip strength and ankle-dorsiflexion range of motion were measured. Change scores were calculated for MKD and 3D valgus at 0%, 10%, 20%, 30%, 40%, and 50% phases, and group (2 levels)-by phase (6 levels) repeated-measures analyses of variance were conducted. Independent t tests were used to compare change scores in other variables (? < .05). Results: The MKD decreased from 20% to 50% of the DLS (P = .02) and 3D knee valgus improved from 30% to 50% of the squat phase (P = .001). Ankle-dorsiflexion range of motion (knee extended) increased in the intervention group (P = .009). No other significant findings were observed (P > .05). Conclusions: ?The intervention reduced MKD and 3D knee valgus during a DLS. The intervention also increased ankle range of motion. Our inclusion criteria might have limited our ability to observe changes in hip strength.
Bell, David R.; Oates, D. Craig; Clark, Micheal A.; Padua, Darin A.
The mechanisms that regulate the enhanced skeletal muscle oxidative capacity observed when training with reduced carbohydrate (CHO) availability are currently unknown. The aim of the present study was to test the hypothesis that reduced CHO availability enhances p53 signaling and expression of genes associated with regulation of mitochondrial biogenesis and substrate utilization in human skeletal muscle. In a repeated-measures design, muscle biopsies (vastus lateralis) were obtained from eight active males before and after performing an acute bout of high-intensity interval running with either high (HIGH) or low CHO availability (LOW). Resting muscle glycogen (HIGH, 467 ± 19; LOW, 103 ± 9 mmol/kg dry wt) was greater in HIGH compared with LOW (P < 0.05). Phosphorylation (P-) of ACC(Ser79) (HIGH, 1.4 ± 0.4; LOW, 2.9 ± 0.9) and p53(Ser15) (HIGH, 0.9 ± 0.4; LOW, 2.6 ± 0.8) was higher in LOW immediately postexercise and 3 h postexercise, respectively (P < 0.05). Before and 3 h postexercise, mRNA content of pyruvate dehydrogenase kinase 4, mitochondrial transcription factor A, cytochrome-c oxidase IV, and PGC-1? were greater in LOW compared with HIGH (P < 0.05), whereas carnitine palmitoyltransferase-1 showed a trend toward significance (P = 0.09). However, only PGC-1? expression was increased by exercise (P < 0.05), where three-fold increases occurred independently of CHO availability. We conclude that the exercise-induced increase in p53 phosphorylation is enhanced in conditions of reduced CHO availability, which may be related to upstream signaling through AMPK. Given the emergence of p53 as a molecular regulator of mitochondrial biogenesis, such nutritional modulation of contraction-induced p53 activation has implications for both athletic and clinical populations. PMID:23364526
Bartlett, Jonathan D; Louhelainen, Jari; Iqbal, Zafar; Cochran, Andrew J; Gibala, Martin J; Gregson, Warren; Close, Graeme L; Drust, Barry; Morton, James P
Endurance athletes exhibit sinus bradycardia, that is a slow resting heart rate, associated with a higher incidence of sinus node (pacemaker) disease and electronic pacemaker implantation. Here we show that training-induced bradycardia is not a consequence of changes in the activity of the autonomic nervous system but is caused by intrinsic electrophysiological changes in the sinus node. We demonstrate that training-induced bradycardia persists after blockade of the autonomous nervous system in vivo in mice and in vitro in the denervated sinus node. We also show that a widespread remodelling of pacemaker ion channels, notably a downregulation of HCN4 and the corresponding ionic current, If. Block of If abolishes the difference in heart rate between trained and sedentary animals in vivo and in vitro. We further observe training-induced downregulation of Tbx3 and upregulation of NRSF and miR-1 (transcriptional regulators) that explains the downregulation of HCN4. Our findings provide a molecular explanation for the potentially pathological heart rate adaptation to exercise training.
D'Souza, Alicia; Bucchi, Annalisa; Johnsen, Anne Berit; Logantha, Sunil Jit R.J.; Monfredi, Oliver; Yanni, Joseph; Prehar, Sukhpal; Hart, George; Cartwright, Elizabeth; Wisloff, Ulrik; Dobryznski, Halina; DiFrancesco, Dario; Morris, Gwilym M.; Boyett, Mark R.
Endurance athletes exhibit sinus bradycardia, that is a slow resting heart rate, associated with a higher incidence of sinus node (pacemaker) disease and electronic pacemaker implantation. Here we show that training-induced bradycardia is not a consequence of changes in the activity of the autonomic nervous system but is caused by intrinsic electrophysiological changes in the sinus node. We demonstrate that training-induced bradycardia persists after blockade of the autonomous nervous system in vivo in mice and in vitro in the denervated sinus node. We also show that a widespread remodelling of pacemaker ion channels, notably a downregulation of HCN4 and the corresponding ionic current, If. Block of If abolishes the difference in heart rate between trained and sedentary animals in vivo and in vitro. We further observe training-induced downregulation of Tbx3 and upregulation of NRSF and miR-1 (transcriptional regulators) that explains the downregulation of HCN4. Our findings provide a molecular explanation for the potentially pathological heart rate adaptation to exercise training. PMID:24825544
D'Souza, Alicia; Bucchi, Annalisa; Johnsen, Anne Berit; Logantha, Sunil Jit R J; Monfredi, Oliver; Yanni, Joseph; Prehar, Sukhpal; Hart, George; Cartwright, Elizabeth; Wisloff, Ulrik; Dobryznski, Halina; DiFrancesco, Dario; Morris, Gwilym M; Boyett, Mark R
The primary purpose of this research is to study the physiological mechanisms associated with the exercise performance of rats subjected to conditions of simulated weightlessness. A secondary purpose is to study related physiological changes associated with other systems. To facilitate these goals, a rodent suspension model was developed (Overton-Tipton) and a VO2 max testing procedure was perfected. Three methodological developments occurred during this past year deserving of mention. The first was the refinement of the tail suspension model so that (1) the heat dissipation functions of the caudal artery can be better utilized, and (2) the blood flow distribution to the tail would have less external constriction. The second was the development on a one-leg weight bearing model for use in simulated weightlessness studies concerned with change in muscle mass, muscle enzyme activity, and hind limb blood flow. The chemical body composition of 30 rats was determined and used to develop a prediction equation for percent fat using underwater weighing procedures to measure carcass specific gravity and to calculate body density, body fat, and fat free mass.
Tipton, Charles M.
To understand the effects of a resistive vibration exercise (RVE) countermeasure on changes in lumbo-pelvic muscle motor control during prolonged bed-rest, 20 male subjects took part in the Berlin Bed-Rest Study (in 2003-2005) and were randomised to a RVE group or an inactive control group. Surface electromyographic signals recorded from five superficial lumbo-pelvic muscles during a repetitive knee movement task. The task, which required stabilisation of the lumbo-pelvic region, was performed at multiple movement speeds and at multiple time points during and after bed-rest. After excluding effects that could be attributed to increases in subcutaneous fat changes and improvements in movement skill, we found that the RVE intervention ameliorated the generalised increases in activity ratios between movement speeds (p?0.012), reductions in lumbo-pelvic extensor and flexor co-contraction (p=0.058) and increases in root-mean-square electromyographic amplitude (p=0.001) of the lumbar erector spinae muscles. Effects of RVE on preventing increases in amplitude-modulation (p=0.23) of the lumbar erector spinae muscles were not significant. Few significant changes in activation-timing were seen. The RVE intervention during bed-rest, with indirect loading of the spine during exercise, was capable of reducing some, but not all, motor control changes in the lumbo-pelvic musculature during and after bed-rest. PMID:22018458
Belavý, Daniel L; Wilson, Stephen J; Armbrecht, Gabriele; Rittweger, Jörn; Felsenberg, Dieter; Richardson, Carolyn A
Background Methylsulfonylmethane (MSM) has been reported to provide anti-inflammatory and antioxidant effects in both animal and man. Strenuous resistance exercise has the potential to induce both inflammation and oxidative stress. Using a pilot (proof of concept) study design, we determined the influence of MSM on markers of exercise recovery and performance in healthy men. Methods Eight, healthy men (27.1?±?6.9 yrs old) who were considered to be moderately exercise-trained (exercising <150 minutes per week) were randomly assigned to ingest MSM at either 1.5 grams per day or 3.0 grams per day for 30 days (28 days before and 2 days following exercise). Before and after the 28 day intervention period, subjects performed 18 sets of knee extension exercise in an attempt to induce muscle damage (and to be used partly as a measure of exercise performance). Sets 1–15 were performed at a predetermined weight for 10 repetitions each, while sets 16–18 were performed to muscular failure. Muscle soreness (using a 5-point Likert scale), fatigue (using the fatigue-inertia subset of the Profile of Mood States), blood antioxidant status (glutathione and Trolox Equivalent Antioxidant Capacity [TEAC]), and blood homocysteine were measured before and after exercise, pre and post intervention. Exercise performance (total work performed during sets 16–18 of knee extension testing) was also measured pre and post intervention. Results Muscle soreness increased following exercise and a trend was noted for a reduction in muscle soreness with 3.0 grams versus 1.5 grams of MSM (p?=?0.080), with a 1.0 point difference between dosages. Fatigue was slightly reduced with MSM (p?=?0.073 with 3.0 grams; p?=?0.087 for both dosages combined). TEAC increased significantly following exercise with 3.0 grams of MSM (p?=?0.035), while homocysteine decreased following exercise for both dosages combined (p?=?0.007). No significant effects were noted for glutathione or total work performed during knee extension testing (p?>?0.05). Conclusion MSM, especially when provided at 3.0 grams per day, may favorably influence selected markers of exercise recovery. More work is needed to extend these findings, in particular using a larger sample of subjects and the inclusion of additional markers of exercise recovery and performance.
Our objective was to determine the prevalence and distribution of fasciculations in healthy adults and to assess the effect of age, caffeine and exercise. Fasciculations were studied with ultrasonography in 58 healthy adults in various age categories. Questionnaires were used to determine effect of caffeine and regular exercise on the presence of fasciculations. Finally, we tested the effect of strenuous exercise on fasciculations in 10 healthy adults. Twenty-five subjects (43%) showed fasciculations on ultrasonography, mostly in the abductor hallucis longus muscle. Fasciculations were only sporadically encountered in muscle groups above the knee. Subjects with fasciculations were significantly older than those without. Caffeine and regular physical exercise did not influence the prevalence of fasciculations. However, strenuous physical exercise caused a temporary increase in fasciculations, but only in lower leg muscles. Fasciculations above the knee should raise suspicion and may warrant further investigation. PMID:19533451
Fermont, Jiske; Arts, Ilse M P; Overeem, Sebastiaan; Kleine, Bert U; Schelhaas, H Jurgen; Zwarts, Machiel J
Ten highly trained endurance athletes were studied to determine the effects of exposure to low ozone (O/sub 3/) concentrations on simulated competitive endurance performance and associated physiological and subjective symptom responses. Each subject was randomly exposed to filtered air (FA), and to 0.12, 0.18, and 0.24 ppm O/sub 3/ while performing a 1 h competitive simulation protocol on a bicycle ergometer. Endurance performance was evaluated by the number of subjects unable to complete rides (last 30 min at an intense work load of approximately 86% VO/sub 2/max). All subjects completed the FA exposure, whereas one, five, and seven subjects did not complete the 0.12, 0.18, and 0.24 ppm O/sub 3/ exposures, respectively. Statistical analysis indicated a significant (P less than 0.05) increase in the inability of subjects to complete the competitive simulations with increasing O/sub 3/ concentration, including a significant difference between the 0.24 ppm O/sub 3/ and FA exposure. Significant decreases (P less than 0.05) were also observed following the 0.18 and 0.24 ppm O/sub 3/ exposures, respectively, in forced vital capacity (-7.8 and -9.9%), and forced expiratory volume in 1 s (-5.8 and -10.5%). No significant O/sub 3/ effect was observed for exercise respiratory metabolism or ventilatory pattern responses. However, the number of reported subjective symptoms increased significantly following the 0.18 and 0.24 ppm O/sub 3/ protocols. These data demonstrate significant decrements in simulated competitive endurance performance and in pulmonary function, with accompanying enhanced subjective symptoms, following exposure to low O/sub 3/ levels commonly observed in numerous metropolitan environments during the summer months.
Schelegle, E.S.; Adams, W.C.
Examined whether stages of change of exercise adoption appropriately addressed strenuous, moderate, and mild intensities of physical activity. Secondary analysis of four data sets (adolescents, college students, adults, and seniors) investigated transtheoretical model constructs for exercise adoption. Results supported the construct validity of…
Schumann, Anja; Nigg, Claudio R.; Rossi, Joseph S.; Jordan, Patricia J.; Norman, Gregory J.; Garber, Carol Ewing; Riebe, Deborah; Benisovich, Sonya V.
Objective To describe the physical activity (PA) levels and counseling attitudes of Canadian undergraduate medical students. Design Online or paper survey. Setting The University of British Columbia (UBC). Participants Fourth-year medical students at UBC from 2007 to 2010. Main outcome measures Physical activity levels, relationship between exercise behaviour and attitudes toward counseling, and student perception of training in the area of exercise prescription. Results A total of 546 out of 883 students participated in the survey (62% response rate). Sixty-four percent of students met the Canadian Society for Exercise Physiology 2011 recommendations for PA. Attitudes toward healthy living were related to PA levels, but the rate of counseling patients about exercise was not; however, students who engaged in more strenuous PA were more likely to perceive exercise counseling as being highly relevant to future clinical practice (P = .018). Overall, 69% of students perceived exercise counseling to be highly relevant to clinical practice, but 86% thought that their training in this area was less than extensive. Conclusion Fourth-year UBC medical students engage in more strenuous PA than average age-matched Canadians, which affects their attitudes toward perceived future counseling practices. Encouraging more student participation in strenuous PA and encouraging academic training in the area of exercise counseling might be important next steps in preparing future physicians to effectively prescribe exercise to their patients.
Holtz, Kaila A.; Kokotilo, Kristen J.; Fitzgerald, Barbara E.; Frank, Erica
The effect of acute alcohol intake on muscular performance in both the exercising and non-exercising legs in the days following strenuous eccentric exercise was investigated to ascertain whether an interaction between post-exercise alcohol use and muscle damage causes an increase in damage-related weakness. Ten healthy males performed 300 maximal eccentric contractions of the quadriceps muscles of one leg on an isokinetic dynamometer. They then consumed either a beverage containing 1 g of ethanol per kg bodyweight ethanol (as vodka and orange juice; ALC) or a non-alcoholic beverage (OJ). At least 2 weeks later they performed an equivalent bout of eccentric exercise on the contralateral leg after which they consumed the other beverage. Measurement of peak and average peak isokinetic (concentric and eccentric) and isometric torque produced by the quadriceps of both exercising and non-exercising legs was made before and 36 and 60 h post-exercise. Greatest decreases in exercising leg performance were observed at 36 h with losses of 28.7, 31.9 and 25.9% occurring for OJ average peak isometric, concentric, and eccentric torques, respectively. However, average peak torque loss was significantly greater in ALC with the same performance measures decreasing by 40.9, 42.8 and 44.8% (all p < 0.05). Performance of the non-exercising leg did not change significantly under either treatment. Therefore, consumption of moderate amounts of alcohol after damaging exercise magnifies the loss of force associated with strenuous eccentric exercise. This weakness appears to be due to an interaction between muscle damage and alcohol rather than the systemic effects of acute alcohol consumption. PMID:20012446
Barnes, Matthew J; Mündel, Toby; Stannard, Stephen R
Phosphodiesterase type 5 inhibitors may influence human physiology, health, and performance by also modulating endocrine pathways. We evaluated the effects of a 2-day tadalafil administration on adenohypophyseal and adrenal hormone adaptation to exercise in humans. Fourteen healthy males were included in a double-blind crossover trial. Each volunteer randomly received two tablets of placebo or tadalafil (20 mg/day with a 36-h interval) before a maximal exercise was performed. After a 2-wk washout, the volunteers were crossed over. Blood samples were collected at -30 and -15 min and immediately before exercise, immediately after, and during recovery (+15, +30, +60, and +90 min) for adrenocorticotropin (ACTH), ?-endorphin, growth hormone (GH), prolactin, cortisol (C), corticosterone, dehydroepiandrosterone-sulfate (DHEAS), and cortisol binding globulin (CBG) assays. C-to-CBG (free cortisol index, FCI) and DHEAS-to-C ratios were calculated. Exercise intensity, perceived exertion rate, O? consumption, and CO? and blood lactate concentration were evaluated. ACTH, GH, C, corticosterone, and CBG absolute concentrations and/or areas under the curve (AUC) increased after exercise after both placebo and tadalafil. Exercise increased DHEAS only after placebo. Compared with placebo, tadalafil administration reduced the ACTH, C, corticosterone, and FCI responses to exercise and was associated with higher ?-endorphin AUC and DHEAS-to-C ratio during recovery, without influencing cardiorespiratory and performance parameters. Tadalafil reduced the activation of the hypothalamus-pituitary-adrenal axis during exercise by probably influencing the brain's nitric oxide- and cGMP-mediated pathways. Further studies are necessary to confirm our results and to identify the involved mechanisms, possible health risks, and potential clinical uses. PMID:22318947
Di Luigi, Luigi; Sgrò, Paolo; Baldari, Carlo; Gallotta, Maria Chiara; Emerenziani, Gian Pietro; Crescioli, Clara; Bianchini, Serena; Romanelli, Francesco; Lenzi, Andrea; Guidetti, Laura
Context: Several recovery strategies have been used, with limited effectiveness, to reduce the muscle discomfort or pain and the diminished muscle performance following a bout of unaccustomed physical activity, a condition known as delayed onset of muscle soreness (DOMS). Muscle damage in this condition is associated with mechanical disruption of the muscle and connective tissue and inflammation and increased oxidative
Daniel H. Serravite
The effect of a strenuous tennis match was studied in 9 young (21.2 +/- 1.9 yr) and 10 veteran women players (46.5 +/- 1.3 yr) of equivalent skill. Each match was carried out during the summer (ambient temperature 27 +/- 1 degree C), as an official competition, under conditions as similar as possible. Heart rate (HR) was monitored throughout the match, weight loss was evaluated and pre- and post-match values of haematocrit, plasma lactate, free fatty acid (FFA), glycemia, ionogram, norepinephrine (NOR), epinephrine, arginine vasopressin (AV) concentrations and plasma renin activity (PRA) were measured. Plasma volume was calculated. While mean HR remained steady in young players, it increased progressively in veteran players as the match went on and reached a very high level towards the end of the match. When post-match values were compared to pre-match values, the mean results were: no substantial changes in plasma lactate and electrolyte concentrations, a large increase in FFA, no increase in epinephrine, a moderate rise in NOR and a large increase in PRA and AV. Despite a similar weight loss, a large drop in plasma volume occurred only in veteran players, who also showed FFA and AV values greater than in young players. During these strenuous matches the large response of hormones which control body fluid probably contributed to the limiting of changes in water and electrolyte balances. However, under similar conditions marked differences occurred as a function of ageing concerning the control of plasma volume.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2030052
Therminarias, A; Dansou, P; Chirpaz-Oddou, M F; Gharib, C; Quirion, A
Two levels of protein (200 and 100 gm/day) were fed to two groups of young adults who exercised strenuously for 40 days. From body volume, total body water mass, 40 K whole body counting, and potassium balances, it was determined that the 2.10 kg gain in ...
H. J. Krzywicki C. F. Consolazio H. L. Johnson N. F. Witt
Glutamine is an important fuel for some cells of the immune system. In situations of stress, such as clinical trauma, starvation, or prolonged, strenuous exercise, the concentration of glutamine in blood is decreased, often substantially. In endurance athletes this decrease occurs concomitantly with relatively transient immunodepression. Provision of glutamine or a glutamine precursor has been found to decrease the incidence
Linda M Castell
This study examined the feasibility of reducing free-living sedentary time (ST) and the convergent validity of various tools to measure ST. Twenty overweight/obese participants wore the activPAL (AP) (criterion measure) and ActiGraph (AG; 100 and 150 count/minute cut-points) for a 7-day baseline period. Next, they received a simple intervention targeting free-living ST reductions (7-day intervention period). ST was measured using two questionnaires following each period. ST significantly decreased from 67% of wear time (baseline period) to 62.7% of wear time (intervention period) according to AP (n = 14, P < 0.01). No other measurement tool detected a reduction in ST. The AG measures were more accurate (lower bias) and more precise (smaller confidence intervals) than the questionnaires. Participants reduced ST by ~5%, which is equivalent to a 48_min reduction over a 16-hour waking day. These data describe ST measurement properties from wearable monitors and self-report tools to inform sample-size estimates for future ST interventions.
Kozey-Keadle, Sarah; Libertine, Amanda; Staudenmayer, John; Freedson, Patty
BackgroundCannabis dependence is a significant public health problem. Because there are no approved medications for this condition, treatment must rely on behavioral approaches empirically complemented by such lifestyle change as exercise.AimsTo examine the effects of moderate aerobic exercise on cannabis craving and use in cannabis dependent adults under normal living conditions.DesignParticipants attended 10 supervised 30-min treadmill exercise sessions standardized using
Maciej S. Buchowski; Natalie N. Meade; Evonne Charboneau; Sohee Park; Mary S. Dietrich; Ronald L. Cowan; Peter R. Martin; Antonio Verdejo García
Declining mobility is a major concern, as well as a major source of health care costs, among the elderly population. Lack of mobility is a primary cause of entry into managed care facilities, and a contributing factor to the frequency of damaging falls. Exercise-based therapies have shown great promise in sustaining mobility in elderly patients, as well as in rodent models. However, the genetic basis of the changing physiological responses to exercise during aging is not well understood. Here, we describe the first exercise-training paradigm in an invertebrate genetic model system. Flies are exercised by a mechanized platform, known as the Power Tower, that rapidly, repeatedly, induces their innate instinct for negative geotaxis. When young flies are subjected to a carefully controlled, ramped paradigm of exercise-training, they display significant reduction in age-related decline in mobility and cardiac performance. Fly lines with improved mitochondrial efficiency display some of the phenotypes observed in wild-type exercised flies. The exercise response in flies is influenced by the amount of protein and lipid, but not carbohydrate, in the diet. The development of an exercise-training model in Drosophila melanogaster opens the way to direct testing of single-gene based genetic therapies for improved mobility in aged animals, as well as unbiased genetic screens for loci involved in the changing response to exercise during aging.
Piazza, Nicole; Gosangi, Babina; Devilla, Shawn; Arking, Robert; Wessells, Robert
OBJECTIVE: To assess exercise habits and their relation to smoking habits and social and medical factors in postmenopausal women. METHODS: A cross-sectional study with a questionnaire to all 1324 55-56 year old women in Linköping, Sweden. RESULTS: Response rate was 85%. About a third of the women took part in some kind of quite strenuous exercise for at least one hour a week. After a quarter worked out once a week; fewer did swimming and jogging. One in four women smoked. Women who used hormone replacement therapy, who were not smoking and who had a physically light occupation more often took part in strenuous sports. Women who had been treated for malignancies or with back problems exercised to the same extent as women in the general population. CONCLUSION: About a third of the post-menopausal women exercised on a regular basis, if exercise involved in getting to and from work was not counted. Since regular physical exercise has many health benefits, more women should be encouraged to take part in regular physical exercise. Factors probably associated with level of education and general awareness of the importance of a healthy lifestyle positively influenced the likelihood of these women to be physically active on a regular basis. A previous malignant disease or current back problems did not prevent women from taking part in exercise on a regular basis. Images Figure 1
Frisk, J; Brynhildsen, J; Ivarsson, T; Persson, P; Hammar, M
Objectives. We examined a community-based participatory diabetes interven- tion to identify facilitators of and barriers to sustained community efforts to ad- dress social factors that contribute to health. Methods. We conducted a case study description and analysis of the Healthy Eating and Exercising to Reduce Diabetes project in the theoretical context of a conceptual model of social determinants of health.
Amy J. Schulz; Shannon Zenk; Angela Odoms-Young; Teretha Hollis-Neely; William Ridella; Srimathi Kannan
INTRODUCTION The development of chylous ascites is usually associated with trauma, iatrogenic or otherwise. Blunt abdominal trauma producing hyperextension or hyperflexion may cause disruption to lymphatic vessels causing chylous ascites. PRESENTATION OF CASE This report describes the case of a 38-year-old gentleman who presented to the emergency department with severe abdominal pain after completing a triathlon. As the patient was in severe pain, an abdominal CT was performed which demonstrated a possible mid gut volvulus. Subsequent laparotomy noted a significant volume of intra-abdominal chyle with no other abnormalities. DISCUSSION This is the first report of chylous ascites occurring without associated abdominal pathology after a period of strenuous exercise. CONCLUSION Chylous ascites can occur as a result of hyperreflexion and hyperextension injuries sustained during strenuous exercise.
Tewari, N.; Bhalla, A.; Iftikhar, S.
Background It has been hypothesized that obese and reduced-obese individuals have decreased oxidative capacity, which contributes to weight gain and regain. Recent data have challenged this concept. Objective To determine (1) whether total and dietary fat oxidation are decreased in obese and reduced-obese adults compared to lean but increase in response to an acute exercise bout and (2) whether regular physical activity attenuates these metabolic alterations. Design We measured 24-hr total (whole-room calorimetry) and dietary fat (14C-oleate) oxidation in Sedentary Lean (BMI?=?21.5±1.6; n?=?10), Sedentary Obese (BMI?=?33.6±2.5; n?=?9), Sedentary Reduced-Obese (RED-SED; BMI?=?26.9±3.7; n?=?7) and in Physically Active Reduced-Obese (RED-EX; BMI?=?27.3±2.8; n?=?12) men and women with or without an acute exercise bout where energy expended during exercise was not replaced. Results Although Red-SED and Red-EX had a similar level of fatness, aerobic capacity and metabolic profiles were better in Red-EX only compared to Obese subjects. No significant between-group differences were seen in 24-hr respiratory quotient (RQ, Lean: 0.831±0.044, Obese: 0.852±0.023, Red-SED: 0.864±0.037, Red-EX: 0.842±0.039), total and dietary fat oxidation. A single bout of exercise increased total (+27.8%, p<0.0001) and dietary (+6.6%, p?=?0.048) fat oxidation across groups. Although exercise did not impact RQ during the day, it decreased RQ during sleep (p?=?0.01) in all groups. Red-EX oxidized more fat overnight than Red-SED subjects under both resting (p?=?0.036) and negative energy balance (p?=?0.003) conditions, even after adjustment for fat-free mass. Conclusion Obese and reduced-obese individuals oxidize as much fat as lean both under eucaloric and negative energy balance conditions, which does not support the hypothesis of reduced oxidative capacity in these groups. Reduced-obese individuals who exercise regularly have markers of metabolic health similar to those seen in lean adults. Both the acute and chronic effects of exercise were primarily observed at night suggesting an important role of sleep in the regulation of lipid metabolism.
Bergouignan, Audrey; Kealey, Elizabeth H.; Schmidt, Stacy L.; Jackman, Matthew R.; Bessesen, Daniel H.
Inadequate cerebral O? availability has been proposed to be an important contributing factor to the development of central fatigue during strenuous exercise. Here we tested the hypothesis that supraspinal processes of fatigue would be increased after locomotor exercise in acute hypoxia compared to normoxia, and that such change would be related to reductions in cerebral O? delivery and tissue oxygenation. Nine endurance-trained cyclists completed three constant-load cycling exercise trials at ?80% of maximal work rate: (1) to the limit of tolerance in acute hypoxia; (2) for the same duration but in normoxia (control); and (3) to the limit of tolerance in normoxia. Throughout each trial, prefrontal cortex tissue oxygenation and middle cerebral artery blood velocity (MCAV) were assessed using near-infrared spectroscopy and trans-cranial Doppler sonography, respectively. Cerebral O? delivery was calculated as the product of arterial O? content and MCAV. Before and immediately after each trial, twitch responses to supramaximal femoral nerve stimulation and transcranial magnetic stimulation were obtained to assess neuromuscular and cortical function, respectively. Exercise time was reduced by 54%in hypoxia compared to normoxia (3.6 ± 1.3 vs. 8.1 ± 2.9 min; P<0.001). Cerebral O? delivery,cerebral oxygenation and maximum O? uptake were reduced whereas muscle electromyographic activity was increased in hypoxia compared to control (P <0.05).Maximum voluntary force and potentiated quadriceps twitch force were decreased below baseline after exercise in each trial;the decreases were greater in hypoxia compared to control (P<0.001), but were not different in the exhaustive trials (P>0.05). Cortical voluntary activation was also decreased after exercise in all trials, but the decline in hypoxia (?18%) was greater than in the normoxic trials (?5-9%)(P <0.05). The reductions in cortical voluntary activation were paralleled by reductions in cerebral O? delivery. The results suggest that curtailment of exercise performance in acute severe hypoxia is due, in part, to failure of drive from the motor cortex, possibly as a consequence of diminished O? availability in the brain. PMID:22473785
Goodall, Stuart; González-Alonso, José; Ali, Leena; Ross, Emma Z; Romer, Lee M
It is well known that strenuous eccentric exercise may result in muscle damage. We proposed that vigorous eccentric exercise (EE) would impair myoelectric activity of the biceps brachii. This study utilised a 7-day prospective time-series design. Ten healthy males performed a session of 70 maximal EE elbow flexion contractions. Analysis of surface electromyography activity (sEMG) was performed on the signals
Sirous Ahmadi; Peter J. Sinclair; Nasim Foroughi; Glen M. Davis
Endothelin-1 (ET-1) and circulating hormones play important roles in maintaining cardiovascular function. Tai Chi Chuan (TCC) is known to be good for health. This study evaluated the effect of 3 months of TCC training on serum ET-1, blood lipids, and other circulating hormones in the elderly. Twenty-two TCC trainees and 20 normal subjects were included in this study. The TCC trainees practiced classical Yang's TCC 40 min per session, 7 times per week, for 3 months. The hemodynamics and serum ET-1 and lipids before and after TCC were compared. The percentage change in serum ET-1 and triglyceride (TG) were decreased significantly after 3 months of TCC, as compared to the control group. In the TCC group, the percentage decrease in serum ET-1 and TG after 3 months of TCC were -36.6 (-63.4 to -14.0)% and -22.5 (-30.7 to 4.9)%, respectively. TCC exercise for 3 months can reduce serum ET-1 and TG in the elderly. PMID:24199974
Lu, Wan-An; Kuo, Cheng-Deng
Background Physical exercise can modify subsequent energy intake and appetite and may thus be of particular interest in terms of obesity treatment. However, it is still unclear whether an intensive bout of exercise can affect the energy consumption of obese children and adolescents. Objective To compare the impact of high vs. moderate intensity exercises on subsequent 24-h energy intake, macronutrient preferences, appetite sensations, energy expenditure and balance in obese adolescent. Design This randomized cross-over trial involves 15 obese adolescent boys who were asked to randomly complete three 24-h sessions in a metabolic chamber, each separated by at least 7 days: (1) sedentary (SED); (2) Low-Intensity Exercise (LIE) (40% maximal oxygen uptake, VO2max); (3) High-Intensity Exercise (HIE) (75%VO2max). Results Despite unchanged appetite sensations, 24-h total energy intake following HIE was 6–11% lower compared to LIE and SED (p<0.05), whereas no differences appeared between SED and LIE. Energy intake at lunch was 9.4% and 8.4% lower after HIE compared to SED and LIE, respectively (p<0.05). At dinner time, it was 20.5% and 19.7% lower after HIE compared to SED and LIE, respectively (p<0.01). 24-h energy expenditure was not significantly altered. Thus, the 24-h energy balance was significantly reduced during HIE compared to SED and LIE (p<0.01), whereas those of SED and LIE did not differ. Conclusions In obese adolescent boys, HIE has a beneficial impact on 24-h energy balance, mainly due to the spontaneous decrease in energy intake during lunch and dinner following the exercise bout. Prescribing high-intensity exercises to promote weight loss may therefore provide effective results without affecting appetite sensations and, as a result, food frustrations. Trial Registration ClinicalTrial.gov NCT01036360
Thivel, David; Isacco, Laurie; Montaurier, Christophe; Boirie, Yves
High-intensity interval training (HIT) has been proposed as a time-efficient alternative to traditional cardiorespiratory exercise training, but is very fatiguing. In this study, we investigated the effects of a reduced-exertion HIT (REHIT) exercise intervention on insulin sensitivity and aerobic capacity. Twenty-nine healthy but sedentary young men and women were randomly assigned to the REHIT intervention (men, n = 7; women, n = 8) or a control group (men, n = 6; women, n = 8). Subjects assigned to the control groups maintained their normal sedentary lifestyle, whilst subjects in the training groups completed three exercise sessions per week for 6 weeks. The 10-min exercise sessions consisted of low-intensity cycling (60 W) and one (first session) or two (all other sessions) brief 'all-out' sprints (10 s in week 1, 15 s in weeks 2-3 and 20 s in the final 3 weeks). Aerobic capacity ([Formula: see text]) and the glucose and insulin response to a 75-g glucose load (OGTT) were determined before and 3 days after the exercise program. Despite relatively low ratings of perceived exertion (RPE 13 ± 1), insulin sensitivity significantly increased by 28% in the male training group following the REHIT intervention (P < 0.05). [Formula: see text] increased in the male training (+15%) and female training (+12%) groups (P < 0.01). In conclusion we show that a novel, feasible exercise intervention can improve metabolic health and aerobic capacity. REHIT may offer a genuinely time-efficient alternative to HIT and conventional cardiorespiratory exercise training for improving risk factors of T2D. PMID:22124524
Metcalfe, Richard S; Babraj, John A; Fawkner, Samantha G; Vollaard, Niels B J
The levels of circulatory inflammatory markers, including interleukin (IL) IL-1?, IL-6, tumor necrosis factor-? (TNF-?) and interferon (INF-?), are known to increase associated to aging. Caffeine has been reported to produce many beneficial effects for health. Exercise is considered to be a safe medicine to attenuate inflammation and cellular senescence. The purpose of the present study was to investigate the effects of a moderate-intensity swimming exercise (3 % of body weight, 20 min per day, 4 weeks) and sub-chronic supplementation with caffeine (30 mg/kg, 4 weeks) on the serum cytokine levels in middle-aged (18 months) Wistar rats. The effects of swimming exercise and caffeine on oxidative stress in muscle and liver of middle-aged rats were also investigated. The two-way ANOVA of pro-inflammatory cytokine levels demonstrated a significant exercise x caffeine interaction for IL-1? (F (1, 16) = 9.5772; p = 0.0069), IL-6 (F (1, 16) = 8.0463; p = 0.0119) and INF-? (F (1, 16) = 15.078; p = 0.0013). The two-way ANOVA of TNF-? levels revealed a significant exercise × caffeine interaction (F (1, 16) = 9.6881; p = 0.00670). Swimming exercise and caffeine supplementation increased the ratio of reduced glutathione/oxidized glutathione in the rat liver and gastrocnemius muscle. Hepatic and renal markers of damage were not modified. In conclusion, a moderate-intensity swimming exercise protocol and caffeine supplementation induced positive adaptations in modulating cytokine levels without causing oxidative stress in muscle and liver of middle-aged rats. PMID:24481487
Cechella, José L; Leite, Marlon R; Dobrachinski, Fernando; da Rocha, Juliana T; Carvalho, Nelson R; Duarte, Marta M M F; Soares, Félix A A; Bresciani, Guilherme; Royes, Luiz F F; Zeni, Gilson
OBJECTIVE In type 1 diabetes, small studies have found that resistance exercise (weight lifting) reduces HbA1c. In the current study, we examined the acute impacts of resistance exercise on glycemia during exercise and in the subsequent 24 h compared with aerobic exercise and no exercise. RESEARCH DESIGN AND METHODS Twelve physically active individuals with type 1 diabetes (HbA1c 7.1 ± 1.0%) performed 45 min of resistance exercise (three sets of seven exercises at eight repetitions maximum), 45 min of aerobic exercise (running at 60% of Vo2max), or no exercise on separate days. Plasma glucose was measured during and for 60 min after exercise. Interstitial glucose was measured by continuous glucose monitoring 24 h before, during, and 24 h after exercise. RESULTS Treatment-by-time interactions (P < 0.001) were found for changes in plasma glucose during and after exercise. Plasma glucose decreased from 8.4 ± 2.7 to 6.8 ± 2.3 mmol/L (P = 0.008) during resistance exercise and from 9.2 ± 3.4 to 5.8 ± 2.0 mmol/L (P = 0.001) during aerobic exercise. No significant changes were seen during the no-exercise control session. During recovery, glucose levels did not change significantly after resistance exercise but increased by 2.2 ± 0.6 mmol/L (P = 0.023) after aerobic exercise. Mean interstitial glucose from 4.5 to 6.0 h postexercise was significantly lower after resistance exercise versus aerobic exercise. CONCLUSIONS Resistance exercise causes less initial decline in blood glucose during the activity but is associated with more prolonged reductions in postexercise glycemia than aerobic exercise. This might account for HbA1c reductions found in studies of resistance exercise but not aerobic exercise in type 1 diabetes.
Yardley, Jane E.; Kenny, Glen P.; Perkins, Bruce A.; Riddell, Michael C.; Balaa, Nadia; Malcolm, Janine; Boulay, Pierre; Khandwala, Farah; Sigal, Ronald J.
We have tested the hypothesis that training with moderate- (MT), strenuous- (ST), or over- (OT) load can cause alterations in memory, lipid peroxidation, protein oxidation, DNA damage, activity of 8-oxoG-DNA glycosylase (OGG1) and brain-derived neurotrophic factor (BDNF), in rat brain. Rat memory was assessed by a passive avoidance test and the ST and OT group demonstrated improved memory. The content
Helga Ogonovszky; István Berkes; Shuzo Kumagai; Takao Kaneko; Shoichi Tahara; Sataro Goto; Zsolt Radák
It has been suggested that during repeated long-term stretch-shortening cycle (SSC) exercise the decreased neuromuscular\\u000a function may result partly from alterations in stiffness regulation. Therefore, interaction between the short latency stretch-reflex\\u000a component (M1) and muscle stiffness and their influences on muscle performance were investigated before and after long lasting SSC exercise.\\u000a The test protocol included various jumps on a sledge
Janne Avela; Paavo V. Komi
Background: Automobile exhaust contains precursors to ozone and fine particulate matter (PM ? 2.5 µm in aerodynamic diameter; PM2.5), posing health risks. Dependency on car commuting also reduces physical fitness opportunities. Objective: In this study we sought to quantify benefits from reducing automobile usage for short urban and suburban trips. Methods: We simulated census-tract level changes in hourly pollutant concentrations from the elimination of automobile round trips ? 8 km in 11 metropolitan areas in the upper midwestern United States using the Community Multiscale Air Quality (CMAQ) model. Next, we estimated annual changes in health outcomes and monetary costs expected from pollution changes using the U.S. Environmental Protection Agency Benefits Mapping Analysis Program (BenMAP). In addition, we used the World Health Organization Health Economic Assessment Tool (HEAT) to calculate benefits of increased physical activity if 50% of short trips were made by bicycle. Results: We estimate that, by eliminating these short automobile trips, annual average urban PM2.5 would decline by 0.1 µg/m3 and that summer ozone (O3) would increase slightly in cities but decline regionally, resulting in net health bene-fits of $4.94 billion/year [95% confidence interval (CI): $0.2 billion, $13.5 billion), with 25% of PM2.5 and most O3 bene-fits to populations outside metropolitan areas. Across the study region of approximately 31.3 million people and 37,000 total square miles, mortality would decline by approximately 1,295 deaths/year (95% CI: 912, 1,636) because of improved air quality and increased exercise. Making 50% of short trips by bicycle would yield savings of approximately $3.8 billion/year from avoided mortality and reduced health care costs (95% CI: $2.7 billion, $5.0 billion]. We estimate that the combined benefits of improved air quality and physical fitness would exceed $8 billion/year. Conclusion: Our findings suggest that significant health and economic benefits are possible if bicycling replaces short car trips. Less dependence on automobiles in urban areas would also improve health in downwind rural settings.
Spak, Scott N.; Holloway, Tracey; Stone, Brian; Mednick, Adam C.; Patz, Jonathan A.
Strenuous bouts of prolonged exercise and heavy training are associated with depressed immune cell function. Furthermore, inadequate or inappropriate nutrition can compound the negative influence of heavy exertion on immunocompetence. Dietary deficiencies of protein and specific micronutrients have long been associated with immune dysfunction. An adequate intake of iron, zinc and vitamins A, E, B6 and B12 is particularly important for the maintenance of immune function, but excess intakes of some micronutrients can also impair immune function and have other adverse effects on health. Immune system depression has also been associated with an excess intake of fat. To maintain immune function, athletes should eat a well-balanced diet sufficient to meet their energy requirements. An athlete exercising in a carbohydrate-depleted state experiences larger increases in circulating stress hormones and a greater perturbation of several immune function indices. Conversely, consuming 30-60 g carbohydrate x h(-1) during sustained intensive exercise attenuates rises in stress hormones such as cortisol and appears to limit the degree of exercise-induced immune depression. Convincing evidence that so-called 'immune-boosting' supplements, including high doses of antioxidant vitamins, glutamine, zinc, probiotics and Echinacea, prevent exercise-induced immune impairment is currently lacking. PMID:14971437
Gleeson, Michael; Nieman, David C; Pedersen, Bente K
It was demonstrated that the dynamics of muscle oxygen utilization can readily be measured using dual wavelength hemoglobin oximetry. This method can be used for muscle training exercise and also for evaluation of exercise performance where the anaerobic threshold must be avoided. It was shown that CW imaging technology gives images along the surface of the muscle while the time resolved spectroscopy gives images transverse to the muscle.
Chance, Britton; Nioka, Shoko; Long, Hong; Xie, Chunhua; Ma, XuHui; Ntziachristos, Vasilis; Luo, Qingming
Although the type and duration of activity during decompression was well documented, the metabolic cost of 1665 subject-exposures with 8 activity profiles from 17 altitude decompression sickness (DCS) protocols at Brooks City-Base, TX from 1983-2005 was not determined. Female and male human volunteers (30 planned, 4 completed) performed activity profiles matching those 8 activity profiles at ground level with continuous monitoring of metabolic cost. A Cosmed K4b2 Cardio Pulmonary Exercise Testing device was used to measure oxygen uptake (VO2) during the profiles. The results show levels of metabolic cost to the females for the profiles tested varied from 4.3 to 25.5 ml/kg/min and from 3.0 to 12.0 ml/kg/min to the males. The increase in VO2 from seated rest to the most strenuous of the 8 activity profiles was 3.6-fold for the females and 2.8-fold for the males. These preliminary data on 4 subjects indicate close agreement of oxygen uptake for activity performed during many subject-exposures as published earlier. The relatively low average oxygen uptake required to perform the most strenuous activity may imply the need for adjustment of modeling efforts using metabolic cost as a risk factor. Better definition of metabolic cost during exposure to altitude, a critical factor in DCS risk, may allow refinement of DCS prediction models.
Webb, James T.; Gernhardt, Michael L.
The purpose of this study was to investigate the possible role of moderate and strenuous swimming training on plasma and cerebrospinal fluid (CSF) IL-6 (interleukin-6) levels during recovery from exhaustive exercise in rats. Wistar rats were divided into three groups: sedentary control (C), moderately trained (MT) and strenuously trained (ST). MT rats underwent swimming exercise for one hour/day and 5 days/week for 8 weeks. Animals in the ST group began swimming with 1 h/day and swimming duration was progressively increased by 30 min/wk, reaching 2.5 h/day by week 4 and stayed constant for an additional 4 weeks. After all animals underwent an acute exhaustive swimming exercise, animals were divided into 3 groups, and decapitated immediately, 24 and 48 hours after exhaustion to obtain tissue samples. Muscle citrate synthase activity, plasma and CSF IL-6 levels were determined. The citrate synthase activity was found to be higher in MT and ST groups compared to the C group. Although plasma IL-6 levels were found unaltered among all groups, the CSF IL-6 concentration was found to be increased 24 hours after exhaustive exercise of the ST group. We conclude that exercise training intensity is an important factor determining cerebrospinal IL-6 concentration after exhaustive exercise. PMID:24311225
K?l?ç, M; Ulusoy, O; C?rr?k, S; Hindistan, I E; Ozkaya, Y Gül
Assess the effects of exercise-training on resting arterial pressure and heart rate, placental fetuses morphologic alterations in pregnant spontaneously hypertensive rats (SHRs).Twenty SHRs and their respective control normotensive rats (WKY) were submitted or not to a swimming protocol during 9 weeks, resulting in four pregnant experimental groups: sedentary hypertensive (PSH), trained hypertensive (PTH), sedentary normotensive (PSN), and trained normotensive (PTN). Exercise-training by swimming attenuates arterial pressure in pregnant SHRs, and can contribute to an increase in the length of fetuses and the percentage of the vessels in the placenta. PMID:22506932
Abate, Débora Tavares de Resende e Silva; Barbosa Neto, Octavio; Rossi e Silva, Renata Calciolari; Faleiros, Ana Carolina Guimarães; Correa, Rosana Rosa Miranda; da Silva, Valdo José Dias; Castro, Eumênia Costa da Cunha; Reis, Marlene Antônia
This study evaluated the effectiveness of a 10-week active intervention program (AIP), which incorporates dietary education with exercise training, among 30 healthy Mexican American male children, aged 8-12 years, in Laredo, Texas. Participants were randomly divided into 3 groups: education (EDU), dietary education to participants and parents and…
Lee, Sukho; Misra, Ranjita; Kaster, Elizabeth
We tested the hypothesis that the inability to increase cardiac output during exercise would explain the decreased rate of oxygen uptake (VO2) in recent onset, ischemia-induced heart failure rats. Nine nor- mal control rats and 6 rats with ischemic heart failure were studied. Myocardial infarction was induced by coronary ligation. VO2 was measured during a ramp protocol test on a
N. P. L. Rolim; K. C. Mattos; P. C. Brum; M. V. C. Baldo; H. R. Middlekauff; C. E. Negrão
Aims and Methods: This study investigated the effect of Allium vegetable intake on the antioxidative activity and on the plasma cholesterol profile during exercise in rats. Ninety rats were fed either a control diet or a diet with added Allium sativum (AS), Allium cepa (AC), Allium fistulosum (AF), or Allium tuberosum (AT) for 4 weeks and were then subdivided into
Eun-Young Choi; Youn-Ok Cho
Intense exercise is associated with a reduction in cerebral blood flow (CBF), but regulation of CBF during strenuous exercise in the heat with dehydration is unclear. We assessed internal (ICA) and common carotid artery (CCA) haemodynamics (indicative of CBF and extra-cranial blood flow), middle cerebral artery velocity (MCA Vmean), arterial-venous differences and blood temperature in 10 trained males during incremental cycling to exhaustion in the heat (35°C) in control, dehydrated and rehydrated states. Dehydration reduced body mass (75.8 ± 3 vs. 78.2 ± 3 kg), increased internal temperature (38.3 ± 0.1 vs. 36.8 ± 0.1°C), impaired exercise capacity (269 ± 11 vs. 336 ± 14 W), and lowered ICA and MCA Vmean by 12-23% without compromising CCA blood flow. During euhydrated incremental exercise on a separate day, however, exercise capacity and ICA, MCA Vmean and CCA dynamics were preserved. The fast decline in cerebral perfusion with dehydration was accompanied by increased O2 extraction (P < 0.05), resulting in a maintained cerebral metabolic rate for oxygen (CMRO2). In all conditions, reductions in ICA and MCA Vmean were associated with declining cerebral vascular conductance, increasing jugular venous noradrenaline, and falling arterial carbon dioxide tension (P aCO 2) (R(2) ? 0.41, P ? 0.01) whereas CCA flow and conductance were related to elevated blood temperature. In conclusion, dehydration accelerated the decline in CBF by decreasing P aCO 2 and enhancing vasoconstrictor activity. However, the circulatory strain on the human brain during maximal exercise does not compromise CMRO2 because of compensatory increases in O2 extraction. PMID:24835170
Trangmar, Steven J; Chiesa, Scott T; Stock, Christopher G; Kalsi, Kameljit K; Secher, Niels H; González-Alonso, José
Liposuction is the most popular aesthetic surgery performed in Brazil and worldwide. Evidence showing that adipose tissue is a metabolically active tissue has led to the suggestion that liposuction could be a viable method for improving metabolic profile through the immediate loss of adipose tissue. However, the immediate liposuction-induced increase in the proportion of visceral to subcutaneous adipose tissue could be detrimental to metabolism, because a high proportion of visceral to subcutaneous adipose tissue is associated with risk factors for cardiovascular disease. The results of studies investigating the effects of liposuction on the metabolic profile are inconsistent, however, with most studies reporting either no change or improvements in one or more cardiovascular risk factors. In addition, animal studies have demonstrated a compensatory growth of intact adipose tissue in response to lipectomy, although studies with humans have reported inconsistent results. Exercise training improves insulin sensitivity, inflammatory balance, lipid oxidation, and adipose tissue distribution; increases or preserves the fat-free mass; and increases total energy expenditure. Thus, liposuction and exercise appear to directly affect metabolism in similar ways, which suggests a possible interaction between these two strategies. To our knowledge, no studies have reported the associated effects of liposuction and exercise in humans. Nonetheless, one could suggest that exercise training associated with liposuction could attenuate or even block the possible compensatory fat deposition in intact depots or regrowth of the fat mass and exert an additive or even a synergistic effect to liposuction on improving insulin sensitivity and the inflammatory balance, resulting in an improvement of cardiovascular risk factors. Consequently, one could suggest that liposuction and exercise appear to be safe and effective strategies for either the treatment of metabolic disorders or aesthetic purposes. PMID:21779146
Benatti, Fabiana Braga; Lira, Fábio Santos; Oyama, Lila Missae; do Nascimento, Cláudia Maria da Penha Oller; Lancha, Antonio Herbert
Liposuction is the most popular aesthetic surgery performed in Brazil and worldwide. Evidence showing that adipose tissue is a metabolically active tissue has led to the suggestion that liposuction could be a viable method for improving metabolic profile through the immediate loss of adipose tissue. However, the immediate liposuction-induced increase in the proportion of visceral to subcutaneous adipose tissue could be detrimental to metabolism, because a high proportion of visceral to subcutaneous adipose tissue is associated with risk factors for cardiovascular disease. The results of studies investigating the effects of liposuction on the metabolic profile are inconsistent, however, with most studies reporting either no change or improvements in one or more cardiovascular risk factors. In addition, animal studies have demonstrated a compensatory growth of intact adipose tissue in response to lipectomy, although studies with humans have reported inconsistent results. Exercise training improves insulin sensitivity, inflammatory balance, lipid oxidation, and adipose tissue distribution; increases or preserves the fat-free mass; and increases total energy expenditure. Thus, liposuction and exercise appear to directly affect metabolism in similar ways, which suggests a possible interaction between these two strategies. To our knowledge, no studies have reported the associated effects of liposuction and exercise in humans. Nonetheless, one could suggest that exercise training associated with liposuction could attenuate or even block the possible compensatory fat deposition in intact depots or regrowth of the fat mass and exert an additive or even a synergistic effect to liposuction on improving insulin sensitivity and the inflammatory balance, resulting in an improvement of cardiovascular risk factors. Consequently, one could suggest that liposuction and exercise appear to be safe and effective strategies for either the treatment of metabolic disorders or aesthetic purposes.
Benatti, Fabiana Braga; Lira, Fabio Santos; Oyama, Lila Missae; do Nascimento, Claudia Maria da Penha Oller; Lancha, Antonio Herbert
Many patients with coronary artery disease treated by percutaneous transluminal coronary angioplasty (PTCA) have a history of previous myocardial injury resulting in a reduced left ventricular ejection fraction (EF). The effects of successful PTCA on myocardial perfusion and left ventricular function in these patients were compared to treatment in patients with normal left ventricular EF. There were 21 patients with a normal EF (mean EF 59 +/- 2%) (Group I) and 15 patients with reduced EF (mean EF 43 +/- 1%) (Group II). Before PTCA a similar degree of reversible myocardial ischemia was present on thallium scintigraphy. At peak exercise left ventricular EF in the Group I patients decreased by 4 +/- 1% compared to 8 +/- 1% in Group II. At one month following successful PTCA there was resolution of reversible myocardial ischemia in both groups. No changes in EF at rest were observed. At the same level of exercise as before PTCA the mean EF was 5 +/- 1% higher than the pretreatment value in Group I and 10 +/- 1% higher in Group II. Thus in this study reversible myocardial ischemia was associated with severe compromise in the left ventricular response to exercise which was substantially improved by PTCA.
Singh, A.; Chandler, S.; Pears, D.; Perry, R.; Murray, R.G.; Shiu, M.F.
In terms of cardiovascular, endocrine and immune responses, acute high-intensity aerobic exercise stress may be considered as a subcategory of stressful active coping. The cardiorespiratory responses of both include increases in heart rate, cardiac output, systolic blood pressure, skeletal muscle vasodilation and oxygen consumption. Neurohormonal responses include increases in catecholamines as well as elevations in cortisol under high but relatively low sympathetic activation. Immune system responses include increases in natural killer (NK) cell number and cytotoxicity and suppressor/cytotoxic lymphocytes as well as decreased proliferative response to mitogens. Task and recovery periods for both acute psychological stress or exercise show biphasic changes in immune response such that immune status is negatively impacted during recovery. Chronic life stressors influence acute cardiovascular, endocrine and immune responses to acute stressors. In addition, both chronic stress and unusually heavy chronic exercise can negatively impact immune status. Given impaired immune status following chronic stress and interactive effects of acute and chronic stressors (e.g. blunted acute NK responses to acute stressors), it is suggested that these factors may extend the window of vulnerability for infectious agents to act following acute psychological (e.g. examinations) or strenuous exercise (competitive athletics) stressors. PMID:9129266
Perna, F M; Schneiderman, N; LaPerriere, A
Strenuous exercise, such as running a marathon, is known to suppress mucosal immunity for up to 24 hr, which can increase the risk of developing an upper respiratory tract infection (URTI) and reduced performance capacity (Allgrove JE, Geneen L, Latif S, Gleeson M. Influence of a fed or fasted state on the s-IgA response to prolonged cycling in active men and women. Int J Sport Nutr Exerc Metab. 2009;19(3):209-221; Barrett B, Locken K, Maberry R, Schwamman J, Brown R, Bobula J, Stauffacher EA. The Wisconsin Upper Respiratory Symptom Survey (WURSS): a new research instrument for assessing the common cold. J Fam Pract. 2002;51(3):265; Carpenter KC, Breslin WL, Davidson T, Adams A, McFarlin BK. Baker's yeast beta glucan supplementation increases monocytes and cytokines post-exercise: implications for infection risk? Br J Nutr. 2012;1-9). While many dietary interventions have been used to combat postexercise immune suppression, most have been ineffective. The key purpose of this study was to determine if baker's yeast ?-glucan (BG) could positively affect the immune system of individuals undergoing intense exercise stress using two experiments. In the first (E1; N = 182 men and women), BG was compared to placebo supplementation for the incidence of URTI symptoms for 28 days postmarathon. In the second (E2; N = 60 men and women) changes in salivary immunoglobulin A (IgA) were evaluated after 50-min of strenuous cycling when participants had been supplemented for 10 days with either BG (250 mg/day) or placebo (rice flour). For E1, subjects reported URTI symptoms using a daily health log. For E2, saliva was collected prior to, immediately, and 2-hr postexercise using a salivette. Data for E1 and E2 were analyzed using separate analyses of variance (ANOVAs) with repeated measures (p < .05). In E1, BG was associated with a 37% reduction in the number of cold/flu symptom days postmarathon compared to placebo (p = .026). In E2, BG was associated with a 32% increase in salivary IgA (p = .048) at 2 hr after exercise compared to placebo. In summary, the present study demonstrates that BG may reduce URTI symptomatic days and improve mucosal immunity (salivary IgA) postexercise. PMID:23927572
McFarlin, Brian K; Carpenter, Katie C; Davidson, Tiffany; McFarlin, Meredith A
Dynamic collapse of the upper respiratory tract (URT) is a common cause of poor performance in horses. These conditions occur predominantly during strenuous exercise when the URT is unable to maintain dilation in the face of high inspiratory pressures. In most cases, these disorders cannot be accurately diagnosed during a resting endoscopic examination. To date, a definitive diagnosis of dynamic URT obstructions has been possible only by performing an endoscopic examination during high-speed treadmill exercise. However, recent technological advances now enable URT endoscopy to be performed while the horse is exercising in its normal environment. PMID:19165944
Franklin, H; Burnt, J F; Allen, K J
Skeletal muscle insulin resistance has been implicated in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and atherogenic dyslipidemia associated with the metabolic syndrome by altering the distribution pattern of postprandial energy storage. We conducted a study to examine this hypothesis by reversing muscle insulin resistance with a single bout of exercise and measuring hepatic de novo lipogenesis and hepatic triglyceride synthesis after a carbohydrate-rich meal. We studied 12 healthy, young, lean, insulin resistant individuals in an interventional, randomized cross-over trial. The response to the ingestion of a carbohydrate-rich meal was studied at rest and after one 45-min bout of exercise on an elliptical trainer. Hepatic de novo lipogenesis was assessed by using 2H2O, and changes in glycogen and fat content in liver and muscle were measured by 13C and 1H magnetic resonance spectroscopy, respectively. Exercise resulted in a greater than threefold increase in postprandial net muscle glycogen synthesis (P < 0.001), reflecting improved muscle insulin responsiveness, and a ?40% reduction (P < 0.05) in net hepatic triglyceride synthesis. These changes in whole body energy storage were accompanied by a ?30% decrease in hepatic de novo lipogenesis (P < 0.01) and were independent of changes in fasting or postprandial plasma glucose and insulin concentrations. These data demonstrate that skeletal muscle insulin resistance is an early therapeutic target for the treatment and prevention of atherogenic dyslipidemia and NAFLD in young insulin resistant individuals who are prone to develop the metabolic syndrome and type 2 diabetes.
Rab?l, Rasmus; Petersen, Kitt Falk; Dufour, Sylvie; Flannery, Clare; Shulman, Gerald I.
Skeletal muscle insulin resistance has been implicated in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and atherogenic dyslipidemia associated with the metabolic syndrome by altering the distribution pattern of postprandial energy storage. We conducted a study to examine this hypothesis by reversing muscle insulin resistance with a single bout of exercise and measuring hepatic de novo lipogenesis and hepatic triglyceride synthesis after a carbohydrate-rich meal. We studied 12 healthy, young, lean, insulin resistant individuals in an interventional, randomized cross-over trial. The response to the ingestion of a carbohydrate-rich meal was studied at rest and after one 45-min bout of exercise on an elliptical trainer. Hepatic de novo lipogenesis was assessed by using (2)H(2)O, and changes in glycogen and fat content in liver and muscle were measured by (13)C and (1)H magnetic resonance spectroscopy, respectively. Exercise resulted in a greater than threefold increase in postprandial net muscle glycogen synthesis (P < 0.001), reflecting improved muscle insulin responsiveness, and a ?40% reduction (P < 0.05) in net hepatic triglyceride synthesis. These changes in whole body energy storage were accompanied by a ?30% decrease in hepatic de novo lipogenesis (P < 0.01) and were independent of changes in fasting or postprandial plasma glucose and insulin concentrations. These data demonstrate that skeletal muscle insulin resistance is an early therapeutic target for the treatment and prevention of atherogenic dyslipidemia and NAFLD in young insulin resistant individuals who are prone to develop the metabolic syndrome and type 2 diabetes. PMID:21808028
Rabøl, Rasmus; Petersen, Kitt Falk; Dufour, Sylvie; Flannery, Clare; Shulman, Gerald I
\\u000a \\u000a Key Points \\u000a \\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a Exercise-induced asthma (EIA) occurs in 90% of individuals with asthma.\\u000a \\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a The prevalence of EIA among athletes ranges between 3 and 11%.\\u000a \\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a EIA is characterized by transient airway obstruction occurring after strenuous exertion.\\u000a \\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a Pathophysiological mechanisms that could possibly explain the phenomenon of EIA include respiratory, heat or water loss (or\\u000a both), hyperventilation leading to the
The purpose of this study was to investigate the relationship of light and strenuous exercise, and self-reported change in exercise status, with different components of cognitive function, and gender differences in this relation, in a large, representative sample included in the Swedish National study on Aging and Care (SNAC). Eight-hundred-and-thirteen participants in age-cohorts from 60–96 years completed a wide range
Magnus Lindwall; Mikael Rennemark; Tomas Berggren
Aging results in chronic low grade inflammation that is associated with increased risk for disease, poor physical functioning and mortality. Strategies that reduce age-related inflammation may improve the quality of life in older adults. Regular exercise is recommended for older people for a variety of reasons including increasing muscle mass and reducing risk for chronic diseases of the heart and metabolic systems. Only recently has exercise been examined in the context of inflammation. This review will highlight key randomized clinical trial evidence regarding the influence of exercise training on inflammatory biomarkers in the elderly. Potential mechanisms will be presented that might explain why exercise may exert an anti-inflammatory effect.
Woods, Jeffrey A.; Wilund, Kenneth R.; Martin, Stephen A.; Kistler, Brandon M.
To test whether isoprostanes could be used as markers of oxidative stress in horses, their concentration was determined in plasma and in pulmonary epithelial lining fluid (PELF) in 3 models of oxidative stress: (1) strenuous exercise, (2) acute COPD crisis and (3) exercise combined with COPD crisis. Four horses were investigated twice, once in crisis and once in remission. The animals underwent a standardised treadmill exercise test. Isoprostane assessment was performed in plasma and bronchoalveolar lavage fluid 24 h before and 1 h after exercise and in plasma also immediately after exercise. Exercise in remission induced a significant increase of isoprostanes in plasma and in PELF. In horses in crisis, the isoprostane concentrations did not increase in plasma, while they did increase in PELF. Lastly, exercise in crisis increased plasma levels of isoprostanes, but did not change PELF isoprostanes. In conclusion, 1) isoprostanes are increased by systemic oxidative stress induced by strenuous exercise in COPD horses in remission either in PELF or in plasma; 2) only PELF and not plasma isoprostanes are increased by pulmonary oxidative stress induced by COPD crisis and 3) unexpectedly, exercise in crisis increased plasma but not PELF isoprostanes. PMID:10659229
Kirschvink, N; Art, T; Smith, N; Lekeux, P
Massage is commonly believed to be the best modality for relieving muscle soreness. However, actively warming up the muscles with exercise may be an effective alternative. The purpose of this study was to compare the acute effect of massage with active exercise for relieving muscle soreness. Twenty healthy female volunteers (mean age 32 years) participated in this examiner-blind randomized controlled trial (ClinicalTrials.gov NCT01478451). The participants performed eccentric contractions for the upper trapezius muscle on a Biodex dynamometer. Delayed onset muscle soreness (DOMS) presented 48 hours later, at which the participants (a) received 10 minutes of massage of the trapezius muscle or (b) performed 10 minutes of active exercise (shoulder shrugs 10 × 10 reps) with increasing elastic resistance (Thera-Band). First, 1 treatment was randomly applied to 1 shoulder while the contralateral shoulder served as a passive control. Two hours later, the contralateral resting shoulder received the other treatment. The participants rated the intensity of soreness (scale 0-10), and a blinded examiner took measures of pressure pain threshold (PPT) of the upper trapezius immediately before treatment and 0, 10, 20, and 60 minutes after treatment 48 hours posteccentric exercise. Immediately before treatment, the intensity of soreness was 5.0 (SD 2.2) and PPT was 138 (SD 78) kPa. In response to treatment, a significant treatment by time interaction was found for the intensity of soreness (p < 0.001) and PPT (p < 0.05). Compared with control, both active exercise and massage significantly reduced the intensity of soreness and increased PPT (i.e., reduced pain sensitivity). For both types of treatment, the greatest effect on perceived soreness occurred immediately after treatment, whereas the effect on PPT peaked 20 minutes after treatment. In conclusion, active exercise using elastic resistance provides similar acute relief of muscle soreness as compared with that using massage. Coaches, therapists, and athletes can use either active warm-up or massage to reduce DOMS acutely, for example, to prepare for competition or strenuous work, but should be aware that the effect is temporary, that is, the greatest effects occurs during the first 20 minutes after treatment and diminishes within an hour. PMID:23524365
Andersen, Lars L; Jay, Kenneth; Andersen, Christoffer H; Jakobsen, Markus D; Sundstrup, Emil; Topp, Robert; Behm, David G
It is important to individualize exercise programs to safely achieve exercise goals. The article reviews several key points to help exercise leaders individualize new exercise programs or rejuvenate routine workouts, focusing on cardiorespiratory and muscular training. The article emphasizes that individualizing exercise programs reduces injury,…
Browder, Kathy D.; Darby, Lynn A.
Study Design?This case report describes an acute Schmorl's node (SN) in an elite monofin athlete during exercise. The patient presented with severe back pain and leg numbness and was managed successfully with conservative treatment. Objective?The aim of our communication was to describe a rare presentation of a common pathological condition during an intense sport. Background?Swimming is not generally considered to be a sport activity that leads to spinal injuries. SNs are usually asymptomatic lesions, incidentally found on imaging studies. There is no correlation between swimming and symptomatic SN formation. Case Report?A 16-year-old monofin elite athlete suffered from an acute nonradiating back pain during extreme exercise. His back pain was associated with a fracture of the superior L5 end plate and an acute SN at the L5 vertebral body with perilesional bone marrow edema. The pain resolved with nonsteroidal anti-inflammatory drugs and bed rest. The athlete had an excellent outcome and returned to his training activities 6 months after his incident. Conclusion?SN should be considered in the differential diagnosis of severe back pain, especially in sport-related injuries. SNs present with characteristic imaging findings. Due to the benign nature of these lesions, surveillance-only management may be the best course of action. PMID:24353963
Paterakis, Konstantinos N; Brotis, Alexandros G; Dardiotis, Efthimios; Hadjigeorgiou, Georgios M; Karachalios, Theofilos; Fountas, Kostas N; Karantanas, Apostolos
Study Design?This case report describes an acute Schmorl's node (SN) in an elite monofin athlete during exercise. The patient presented with severe back pain and leg numbness and was managed successfully with conservative treatment. Objective?The aim of our communication was to describe a rare presentation of a common pathological condition during an intense sport. Background?Swimming is not generally considered to be a sport activity that leads to spinal injuries. SNs are usually asymptomatic lesions, incidentally found on imaging studies. There is no correlation between swimming and symptomatic SN formation. Case Report?A 16-year-old monofin elite athlete suffered from an acute nonradiating back pain during extreme exercise. His back pain was associated with a fracture of the superior L5 end plate and an acute SN at the L5 vertebral body with perilesional bone marrow edema. The pain resolved with nonsteroidal anti-inflammatory drugs and bed rest. The athlete had an excellent outcome and returned to his training activities 6 months after his incident. Conclusion?SN should be considered in the differential diagnosis of severe back pain, especially in sport-related injuries. SNs present with characteristic imaging findings. Due to the benign nature of these lesions, surveillance-only management may be the best course of action.
Paterakis, Konstantinos N.; Brotis, Alexandros G.; Dardiotis, Efthimios; Hadjigeorgiou, Georgios M.; Karachalios, Theofilos; Fountas, Kostas N.; Karantanas, Apostolos
A review of epidemiological studies suggesting that exercise reduces the risk of cancer concludes that exercise may help defend against cancer by preventing obesity, stimulating lymphokines, and/or facilitating other healthful changes in behavior. (Author/CB)
Eichner, Edward R.
Fibromyalgia syndrome, a chronic condition typically characterized by widespread pain, nonrestorative sleep, fatigue, cognitive dysfunction, and other somatic symptoms, negatively impacts physical and emotional function and reduces quality of life. Exercise is commonly recommended in the management of people with fibromyalgia, and interest in examining exercise benefits for those with the syndrome has grown substantially over the past 25 years. Research supports aerobic and strength training to improve physical fitness and function, reduce fibromyalgia symptoms, and improve quality of life. However, other forms of exercise (e.g., tai chi, yoga, Nordic walking, vibration techniques) and lifestyle physical activity also have been investigated to determine their effects. This paper highlights findings from recent randomized controlled trials and reviews of exercise for people with fibromyalgia, and includes information regarding factors that influence response and adherence to exercise to assist clinicians with exercise and physical activity prescription decision-making to optimize health and well-being. PMID:21725900
Busch, Angela J; Webber, Sandra C; Brachaniec, Mary; Bidonde, Julia; Bello-Haas, Vanina Dal; Danyliw, Adrienne D; Overend, Tom J; Richards, Rachel S; Sawant, Anuradha; Schachter, Candice L
Background: Automobile exhaust contains precursors to ozone and fine particulate matter (PM 2.5 µrn in aerodynamic diameter; PM?.?), posing health risks. Dependency on car commuting also reduces physical fitness opportunities. Objective: In this study we sought to quantify benefits from reducing automobile usage for short urban and suburban trips. Methods: We simulated census-tract level changes in hourly pollutant concentrations
Maggie L. Grabow; Scott N. Spak; Tracey Holloway; Brian Stone Jr.; Adam C. Mednick; Jonathan A. Patz
Physical activity is a potent therapy for both the prevention and treatment of cardiovascular disease. Exercise appears to most benefit people who are the least active. There is some evidence to suggest that a curvilinear relationship exists between exercise and survival, whereby beyond an optimal level of fitness, the principle of diminishing returns applies. Indeed, some go further in suggesting that there is evidence that extreme athletic training may be harmful in some individuals. The incidence of sudden cardiac death in athletes is greater than in matched, nonathletic counterparts, and this finding is driven by the provocation of an underlying cardiac abnormality by strenuous exertion. The task of detecting pathological myocardial substrate in athletes is made difficult by physiological adaptations to exercise that can mimic the appearance of cardiomyopathies and ion channelopathies in some individuals. This article details the clinical evaluation of the athlete with reference limits for cardiac physiological remodeling and discusses the diagnostic dilemmas that arise. PMID:24875977
D'Silva, Andrew; Sharma, Sanjay; D'Silva, Andrew; Sharma, Sanjay; D'Silva, Andrew; Sharma, Sanjay; D'Silva, Andrew; Sharma, Sanjay
1. Exercise provokes changes in the immune system, including macrophage activity. Chemotaxis is a necessary function of macrophages if they are to reach the focus of infection and strenuous acute exercise may modulate chemotaxis. However, the precise mechanisms remain unknown. 2. Three experiments were performed in the present study. (1) The effect of strenuous acute exercise (swimming until exhaustion) on the chemotactic capacity of macrophages was evaluated. (2) Peritoneal macrophages from control mice were incubated with plasma from exercised mice or control (no exercise) mice. The differences in the resulting chemotactic capacity were measured. (3) Changes in the concentration of plasma corticosterone and prolactin after exercise were also measured, and the effect of incubation with the post-exercise levels of plasma corticosterone and prolactin on the chemotactic capacity of the peritoneal macrophages was then studied in vitro. 3. Exercise induced an increase in the macrophage chemotaxis index (103 +/- 8 vs. 47 +/- 11 in controls). Incubation with plasma from exercised mice led to an increased level of chemotaxis (68 +/- 18 vs. 40 +/- 6 with plasma from controls). Incubation with concentrations of corticosterone and prolactin similar to those observed in plasma immediately after exercise (corticosterone, 0.72 mumol l-1; prolactin, 88 pmol l-1) raised the chemotactic capacity with respect to that following incubation with the basal concentrations of the hormones in control animals (90 +/- 9 vs. 37 +/- 4 for corticosterone; 72 +/- 9 vs. 41 +/- 4 for prolactin). 4. It is concluded that corticosterone and prolactin may mediate the increased chemotaxis of peritoneal macrophages induced by exercise. Images Figure 3 Figure 4
Ortega, E; Forner, M A; Barriga, C
The primary goals of childhood are optimal growth and maturation. These developmental processes demand positive energy and nitrogen balance. Regular physical activity can enhance childhood development; however, strenuous physical training may reduce the body’s stores of energy and nitrogen, both of which must be replaced through the diet. Physically active adolescents are susceptible to disordered eating, which can lead to
C. L. Zanker
Magnesium is involved in numerous processes that affect muscle function including oxygen uptake, energy production and electrolyte balance. Thus, the relationship between magnesium status and exercise has received significant research attention. This research has shown that exercise induces a redistribution of magnesium in the body to accommodate metabolic needs. There is evidence that marginal magnesium deficiency impairs exercise performance and amplifies the negative consequences of strenuous exercise (e.g., oxidative stress). Strenuous exercise apparently increases urinary and sweat losses that may increase magnesium requirements by 10-20%. Based on dietary surveys and recent human experiments, a magnesium intake less than 260 mg/day for male and 220 mg/day for female athletes may result in a magnesium-deficient status. Recent surveys also indicate that a significant number of individuals routinely have magnesium intakes that may result in a deficient status. Athletes participating in sports requiring weight control (e.g., wrestling, gymnastics) are apparently especially vulnerable to an inadequate magnesium status. Magnesium supplementation or increased dietary intake of magnesium will have beneficial effects on exercise performance in magnesium-deficient individuals. Magnesium supplementation of physically active individuals with adequate magnesium status has not been shown to enhance physical performance. An activity-linked RNI or RDA based on long-term balance data from well-controlled human experiments should be determined so that physically active individuals can ascertain whether they have a magnesium intake that may affect their performance or enhance their risk to adverse health consequences (e.g., immunosuppression, oxidative damage, arrhythmias). PMID:17172008
Nielsen, F H; Lukaski, H C
In cardiac rehabilitation programs, patients learn how to adopt a healthier lifestyle, including regular, strenuous physical\\u000a activity. Long-term success is only modest despite good intentions. To improve exercise adherence, a 3-group experiment was\\u000a designed that included innovative psychological interventions. All 3 groups underwent a standard care rehabilitation program.\\u000a Patients in the 2 treatment groups were instructed not only to produce
Falko F. Sniehotta; Urte Scholz; Ralf Schwarzer; Bärbel Fuhrmann; Ulrich Kiwus; Heinz Völler
Acute and chronic smoking reduces peripheral blood flow and shear stress, contributing to the increased incidence of peripheral arterial disease in smokers. Currently, it is not known whether physical activity status influences peripheral blood flow among chronic smokers. Blood flow was measured using Doppler ultrasound on the common femoral artery in nine young otherwise healthy sedentary smokers (eight males/one female) and nine physically-active smokers (six males/three females). Physically-active smokers performed strenuous exercise 4.4 times/week for 8 h/week. No significant differences in body fat, blood pressure, and total cholesterol were observed between groups. Basal femoral artery blood flow was approximately 50% higher in physically-active smokers compared with sedentary smokers (259+/-108 ml min(-1) versus 173+/-47 ml min(-1), P<0.05). The higher basal femoral artery blood flow in physically-active smokers compared with sedentary smokers was associated with a 47% higher femoral artery vascular conductance (2.99+/-1.2 U versus 2.03+/-0.5 U, P<0.05) and a 39% lower vascular resistance (0.38+/-0.13 U versus 0.53+/-0.15 U, P<0.05). Cardiac output, systemic vascular resistance, femoral intima-media thickness, and plasma norepinephrine concentration were not different between the groups. We concluded that smokers who habitually perform physical activity demonstrate greater levels of peripheral blood flow and peripheral vascular conductance. The findings from the present cross-sectional study suggest that chronic smokers may be able to negate, at least in part, the adverse effects of chronic smoking on the peripheral vasculature by performing regular physical activity. PMID:16046216
Anton, Maria M; Cortez-Cooper, Miriam Y; DeVan, Allison E; Neidre, Daria B; Cook, Jill N; Tanaka, Hirofumi
The present study examined the hyponociceptive effect of swimming exercise in a chemical behavioral model of nociception and the mechanisms involved in this effect. Male mice were submitted to swimming sessions (30 min\\/d for 5 days). Twenty-four hours after the last session, we noticed that swimming exercise decreased the number of abdominal constriction responses caused by acetic acid compared with
Leidiane Mazzardo-Martins; Daniel F. Martins; Rodrigo Marcon; Ubirajara D. dos Santos; Breno Speckhann; Vinícius M. Gadotti; André Roberto Sigwalt; Luiz Guilherme A. Guglielmo; Adair Roberto Soares Santos
The early diastolic transmitral velocity/tissue Doppler imaging mitral annular early diastolic velocity (E/e') ratio is used to estimate left ventricular (LV) filling pressures at rest. However, there are only limited data that validate its use during exercise. Accordingly, the aim of this study was to test the ability of E/e' to estimate pulmonary capillary wedge pressure (PCWP) during symptom-limited exercise in patients with LV systolic dysfunction. Forty patients with severe LV dysfunction and heart failure symptoms (54 ± 12 years, 28 men) underwent simultaneous Doppler assessment of E/e' and right-sided cardiac catheterization at rest and during a symptom-limited exercise test, at steady state levels of 30%, 60%, and 90% of their maximal exercise capacity. During exercise, all 40 patients successfully completed stage 1, yielding 40 pairs of data for comparison. Eighteen patients also successfully completed stage 2, and 5 patients also made it through stage 3, yielding 23 additional data pairs. In total, there were thus 63 pairs of data available during exercise. With exercise, heart rate increased from 77 ± 14 to 112 ± 21 beats/min. Septal E/e' at rest correlated well with PCWP at rest (r = 0.75, p <0.01). PCWP at rest also correlated with resting mitral deceleration time (r = 0.32, p <0.01) and with the transmitral E/A ratio (r = 0.74, p <0.01). During exercise, the correlation between septal E/e' and PCWP was weaker (r = 0.57, p <0.01) and was shifted to the right. This rightward shift was observed in patients with both separated or merged E and A velocities. In conclusion, in patients with severe LV dysfunction, although E/e' allows accurate estimation of PCWP at rest, it appears less reliable for estimating LV filing pressure during exercise. PMID:24786358
Marchandise, Sébastien; Vanoverschelde, Jean-Louis; D'Hondt, Anne Marie; Gurne, Olivier; Vancraeynest, David; Gerber, Berhnard; Pasquet, Agnès
Design of the Physical exercise during Adjuvant Chemotherapy Effectiveness Study (PACES):A randomized controlled trial to evaluate effectiveness and cost-effectiveness of physical exercise in improving physical fitness and reducing fatigue
Background Cancer chemotherapy is frequently associated with a decline in general physical condition, exercise tolerance, and muscle strength and with an increase in fatigue. While accumulating evidence suggests that physical activity and exercise interventions during chemotherapy treatment may contribute to maintaining cardiorespiratory fitness and strength, the results of studies conducted to date have not been consistent. Additional research is needed to determine the optimal intensity of exercise training programs in general and in particular the relative effectiveness of supervised, outpatient (hospital- or physical therapy practice-based) versus home-based programs. Methods This multicenter, prospective, randomized trial will evaluate the effectiveness of a low to moderate intensity, home-based, self-management physical activity program, and a high intensity, structured, supervised exercise program, in maintaining or enhancing physical fitness (cardiorespiratory fitness and muscle strength), in minimizing fatigue and in enhancing the health-related quality of life (HRQoL). Patients receiving adjuvant chemotherapy for breast or colon cancer (n = 360) are being recruited from twelve hospitals in the Netherlands, and randomly allocated to one of the two treatment groups or to a 'usual care' control group. Performance-based and self-reported outcomes are assessed at baseline, at the end of chemotherapy and at six month follow-up. Discussion This large, multicenter, randomized clinical trial will provide additional empirical evidence regarding the effectiveness of physical exercise during adjuvant chemotherapy in enhancing physical fitness, minimizing fatigue, and maintaining or enhancing patients' quality of life. If demonstrated to be effective, exercise intervention programs will be a welcome addition to the standard program of care offered to patients with cancer receiving chemotherapy. Trial registration This study is registered at the Netherlands Trial Register (NTR 2159)
The purpose of the study was to investigate whether acute strenuous exercise (1600- to 2500-m race) would elicit an acute phase response (APR) in Standardbred trotters. Blood levels of several inflammatory markers [serum amyloid A (SAA), haptoglobin, fibrinogen, white blood cell count (WBC), and iron], muscle enzymes [creatinine kinase (CK) and aspartate transaminase (AST)], and hemoglobin were assessed in 58 Standardbred trotters before and after racing. Hemoglobin levels increased and iron levels decreased 12 to 14 h after racing and haptoglobin concentrations, white blood cell counts, and iron levels were decreased 2 and/or 7 d after racing. Concentrations of CK, AST, SAA, and fibrinogen were unaltered in response to racing. Acute strenuous exercise did not elicit an acute phase reaction. The observed acute increase in hemoglobin levels and decreases in haptoglobin and iron levels may have been caused by exercise-induced hemolysis, which indicates that horses might experience a condition similar to athlete's anemia in humans. The pathogenesis and clinical implications of the hematological and blood-biochemical changes elicited by acute exercise in Standardbred trotters in the present study warrant further investigation. PMID:24688170
Kristensen, Lena; Buhl, Rikke; Nostell, Katarina; Bak, Lars; Petersen, Ellen; Lindholm, Maria; Jacobsen, Stine
This study was designed to test the hypothesis that performing repeated bouts of eccentric exercise when muscles were not recovered from previous exercise would exacerbate muscle damage. Twelve nonweight-trained males (21.7 +/- 2.4 yr) performed three sets of 10 eccentric actions of the elbow flexors (ECC) using a dumbbell that was set at 80% of the preexercise maximal isometric force level. This same exercise was repeated 3 and 6 d after the first exercise. Maximal isometric force, relaxed and flexed elbow joint angle, muscle soreness, plasma creatine kinase, and glutamic-oxaloacetic transaminase activities were assessed. Ultrasound images were taken from the upper arm. These measures (except soreness) were assessed immediately before and after each eccentric exercise bout (ECC1, ECC2, and ECC3) and 3 d after ECC3. Soreness was assessed prior to ECC1 and once a day for 9 d thereafter. All criterion measures changed significantly (P < 0.01) after ECC1. ECC2 and ECC3 performed 3 and 6 d after ECC1 did not exacerbate damage and did not appear to slow the recovery rate. Increased echointensity in ultrasound images was demonstrated following ECC1, but no indication of increased damage was found after ECC2 and ECC3. Strenuous exercise performed with "damaged" muscles did not exacerbate damage or affect the repair process. PMID:8531624
Nosaka, K; Clarkson, P M
The exercise-induced changes in the equine breathing pattern were studied by analyzing tidal breathing flow-volume loops recorded in ten ponies both at rest and during a standardized exercise. Airflow, tidal volume, esophageal pressure and mask pressure were simultaneously recorded before, during and after a treadmill exercise. From the collected data, respiratory frequency and total pulmonary resistance were calculated, tidal breathing flow-volume loops were retraced using a computerized method and loop indices were measured for each period of the experimental protocol. For each pony, results of three consecutive daily measurements were averaged. The exercise loop indices were compared with the corresponding resting values using a one-way analysis of variance. The significantly changed indices were correlated with respiratory frequency and total pulmonary resistance. Several types of respiratory patterns were observed at rest as well as during exercise, although each pony was relatively constant in its own pattern of breathing. Most resting inspiratory and expiratory airflow curves were found to be biphasic. When ponies started running, the airflow developed an increasingly rectangular pattern. During strenuous exercise, both inspiratory and expiratory airflow curves showed a substantial increase of the volume acceleration and tended to a plateau. The loop indices relating the expiratory to the inspiratory airflow were significantly increased compared with their rest values. Correlations of these indices with respiratory frequency and total pulmonary resistance were weak.(ABSTRACT TRUNCATED AT 250 WORDS)
Art, T; Lekeux, P
Fibromyalgia syndrome, a chronic condition typically characterized by widespread pain, nonrestorative sleep, fatigue, cognitive\\u000a dysfunction, and other somatic symptoms, negatively impacts physical and emotional function and reduces quality of life. Exercise\\u000a is commonly recommended in the management of people with fibromyalgia, and interest in examining exercise benefits for those\\u000a with the syndrome has grown substantially over the past 25 years. Research
Angela J. Busch; Sandra C. Webber; Mary Brachaniec; Julia Bidonde; Vanina Dal Bello-Haas; Adrienne D. Danyliw; Tom J. Overend; Rachel S. Richards; Anuradha Sawant; Candice L. Schachter
Summary Microvascular dysfunction is frequently seen in patients with Type 1 (insulin-dependent) diabetes. The present study was undertaken to examine whether skeletal muscle microcirculation in Type 1 diabetic patients is influenced by C-peptide. Forearm blood flow, capillary diffusion capacity and substrate exchange were studied during strenuous rhythmic forearm exercise on a hand ergometer. Measurements were made before and during i.v. infusion
B.-L. Johansson; B. Linde; J. Wahren
Summary Epidemiologic investigations have shown that exercise reduces morbidity and mortality from coronary artery disease. In this study, using a rat model, we attempted to determine whether exercise can reduce ischemic injury to the heart and elucidate a mechanism for the cardiopro- tective effect of exercise. Results showed that exercise significantly reduced the magnitude of a myocardial infarction in biphasic
Nobushige Yamashita; Shiro Hoshida; Kinya Otsu; Michio Asahi; Tsunehiko Kuzuya; Masatsugu Hori
The chemiluminescence response of granulocytes to serum opsonized zymosan particles (SOZ) ex vivo was investigated during\\u000a two ranger training courses lasting 7 days with continuous moderate physical activities corresponding to about 32% of maximal\\u000a oxygen uptake or 35 000 kJ · 24 h?1, with energy deficiency (energy supply 0-4000 kJ · 24 h?1), and less than 3-h sleep during the
P. Wiik; P. K. Opstad; A. Bøyum
Some exercises to introduce students to the concept of green chemistry are given. By doing these exercises, students develop an appreciation for the role of green chemistry on feedstock substitution, milder reaction conditions, reduced environmental exposure, and resource conservation.
Song, Yu-Min; Wang, Yong-Cheng; Geng, Zhi-Yuan
Attention deficit/hyperactivity disorder (ADHD) is a neurobehavioral disorder of cognition. We investigated the effects of treadmill exercise on Purkinje cell and astrocytic reaction in the cerebellum of the ADHD rat. Adult male spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKYR) weighing 210± 10 g were used. The animals were randomly divided into four groups (n= 15): control group, ADHD group, ADHD and methylphenidate (MPH)-treated group, ADHD and treadmill exercise group. The rats in the MPH-treated group as a positive control received 1 mg/kg MPH orally once a day for 28 consecutive days. The rats in the treadmill exercise group were made to run on a treadmill for 30 min once a day for 28 days. Motor coordination and balance were determined by vertical pole test. Immunohistochemistry for the expression of calbindinD-28 and glial fibrillary acidic protein (GFAP) in the cerebellar vermis and Western blot for GFAP, Bax, and Bcl-2 were conducted. In the present results, ADHD significantly decreased balance and the number of calbindin-positive cells, while GFAP expression and Bax/Bcl-2 ratio in the cerebellum were significantly increased in the ADHD group compared to the control group (P< 0.05, respectively). In contrast, treadmill exercise and MPH alleviated the ADHD-induced the decrease of balance and the number of calbindine-positive cells, and the increase of GFAP expression and Bax/Bcl-2 ratio in the cerebellum (P< 0.05, respectively). Therefore, the present results suggested that treadmill exercise might exert ameliorating effect on ADHD through reduction of Purkinje cell loss and astrocytic reaction in the cerebellum.
Yun, Hyo-Soon; Park, Mi-Sook; Ji, Eun-Sang; Kim, Tae-Woon; Ko, Il-Gyu; Kim, Hyun-Bae; Kim, Hong
Attention deficit/hyperactivity disorder (ADHD) is a neurobehavioral disorder of cognition. We investigated the effects of treadmill exercise on Purkinje cell and astrocytic reaction in the cerebellum of the ADHD rat. Adult male spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKYR) weighing 210± 10 g were used. The animals were randomly divided into four groups (n= 15): control group, ADHD group, ADHD and methylphenidate (MPH)-treated group, ADHD and treadmill exercise group. The rats in the MPH-treated group as a positive control received 1 mg/kg MPH orally once a day for 28 consecutive days. The rats in the treadmill exercise group were made to run on a treadmill for 30 min once a day for 28 days. Motor coordination and balance were determined by vertical pole test. Immunohistochemistry for the expression of calbindinD-28 and glial fibrillary acidic protein (GFAP) in the cerebellar vermis and Western blot for GFAP, Bax, and Bcl-2 were conducted. In the present results, ADHD significantly decreased balance and the number of calbindin-positive cells, while GFAP expression and Bax/Bcl-2 ratio in the cerebellum were significantly increased in the ADHD group compared to the control group (P< 0.05, respectively). In contrast, treadmill exercise and MPH alleviated the ADHD-induced the decrease of balance and the number of calbindine-positive cells, and the increase of GFAP expression and Bax/Bcl-2 ratio in the cerebellum (P< 0.05, respectively). Therefore, the present results suggested that treadmill exercise might exert ameliorating effect on ADHD through reduction of Purkinje cell loss and astrocytic reaction in the cerebellum. PMID:24678501
Yun, Hyo-Soon; Park, Mi-Sook; Ji, Eun-Sang; Kim, Tae-Woon; Ko, Il-Gyu; Kim, Hyun-Bae; Kim, Hong
This homework exercise, which builds on knowledge gained in previous homework exercises located at the same site, asks students in an undergraduate class at Tulane University to answer some basic questions about volcanoes, and to determine the volcanic hazards associated with Mt. Rainier, Washington; Montserrat, West Indies; and Long Valley Caldera, California by searching the World Wide Web.
The integrity of the pulmonary blood-gas barrier is vulnerable to intense exercise in elite athletes, similar to the phenomenon of exercise-induced pulmonary hemorrhage in thoroughbred racehorses. A 50-year-old previously healthy man presented with acute onset shortness of breath, dry cough, and hypoxemia after engaging in an extremely vigorous game of handball. CT scan of the chest showed diffuse patchy air-space disease. Bronchoalveolar lavage revealed diffuse alveolar hemorrhage. Infectious etiologies and bleeding diatheses were excluded by laboratory testing. Serological tests for ANCA-associated vasculitis, lupus, and Goodpasture's disease also were negative. A transthoracic echocardiogram was normal. The patient recovered completely on supportive therapy in less than 72 h. This case demonstrates strenuous exercise as a cause of diffuse alveolar hemorrhage in a previously healthy male with no apparent underlying cardiopulmonary disease. PMID:24532148
Diwakar, Amit; Schmidt, Gregory A
Exercise training in patients with chronic stable heart failure (HF) is a recommended and broadly accepted treatment strategy that is an integral part of an evidence-based management involving pharmacological and non-pharmacological therapies. There is ample scientific evidence that exercise training in HF with reduced (HFrEF) and with preserved ejection fraction (HFpEF) improves exercise capacity, HF symptoms and quality of life. This is due to an improvement of central hemodynamics, endothelial function, neurohumoral activation, skeletal muscle structure and function as well as a decrease in inflammatory markers. The largest randomized, controlled HF-ACTION study (Heart Failure-A Controlled Trial Investigating Outcomes of exercise TraiNing) demonstrated that exercise training results in a modest improvement of all-cause mortality and hospitalizations in HFrEF, depending on adequate compliance. Outcome data in HFpEF are lacking. Besides compliance, efficacy of exercise training is dependent on the intensity and type of exercise. Resistance and high intensity endurance training in addition to a standard aerobic exercise seem to be superior in improving the clinical status of HF patients. In the future, individualized exercise programs will help to improve long-term adherence to exercise training. PMID:24817538
Edelmann, F; Grabs, V; Halle, M
The time-course of plasma noradrenaline (NA) and adrenaline (A) concentrations and their dissipation profiles were examined concomitantly with heart rate changes after strenuous exercise in eight normal subjects receiving either placebo or carteolol, a beta-adrenoceptor blocker. Post-exercise NA concentrations declined with time in a biexponential manner, while A disappearance curves were apparently monophasic. Plasma NA concentrations and their peak value attained within 3 min after exercise were higher in the carteolol than in the placebo phase, whereas there were no significant differences in the first and second disappearance t1/2 between the two trials. The monoexponential t1/2 of A in the carteolol trial was significantly longer than in the placebo trial. Our results suggest that the dissipation profiles of catecholamines released by exercise appear to be affected by beta-adrenoceptor blockade.
Ohnishi, A; Minegishi, A; Sasaki, T; Suganuma, T; Ishizaki, T
Exercise deconditioning during space flight may impact a crewmember's ability to perform strenuous or prolonged tasks during and after a spaceflight mission. In this paper, we review the cardiovascular exercise data from U.S. spaceflights from the Mercury Project through International Space Station (ISS) expeditions and potential implications upon current and future missions. During shorter spaceflights (<16 days), the heart rate (HR) response to exercise testing and maximum oxygen consumption (VO 2 max) are not changed. The submaximal exercise HR responses during longer duration flights are less consistent, and VO 2 max has not been measured. Skylab data demonstrated no change in the exercise HR response during flight which would be consistent with no change in VO 2 max; however, during ISS flight exercise HR is elevated early in the mission, but approaches preflight levels later during the missions, perhaps due to performance of exercise countermeasures. An elevated exercise HR is consistently observed after both short and long duration spaceflight, and crewmembers appear to recover at rates which are affected by the length of the mission.
Moore, Alan D.; Lee, Stuart M. C.; Stenger, Michael B.; Platts, Steven H.
OBJECTIVESThe goal of this study was to determine if cardiac cycle-dependent changes in proximal thoracic aortic area and distensibility are associated with exercise intolerance in elderly patients with diastolic heart failure (DHF).BACKGROUNDAortic compliance declines substantially with age. We hypothesized that a reduction in cardiac cycle-dependent changes in thoracic aortic area and distensibility (above that which occurs with aging) could be
W. Gregory Hundley; Dalane W. Kitzman; Timothy M. Morgan; Craig A. Hamilton; Stephen N. Darty; Kathryn P. Stewart; David M. Herrington; Kerry M. Link; William C. Little
ABSTRACT Purpose: Damage to the spinal accessory nerve (SAN) can result in denervation of the trapezius muscle in patients undergoing surgery for head and neck cancer. Trapezius denervation leads to muscle weakness and dysfunction that, for some patients, persists despite the return of conduction along the SAN. This prospective case series describes an intervention involving a combination of a novel type of neuromuscular electrical stimulation (NMES) with bilateral exercise. Methods: Three survivors of head and neck cancer participated in the 6-week program. NMES was applied over the region of the SAN on the affected side while subjects performed bilateral voluntary scapular retraction and elevation exercises against resistance. The NMES was delivered using relatively wide pulse widths and high frequencies to enhance the electrically evoked sensory volley and was triggered by the onset of trapezius muscle activity on the non-affected side. Shoulder range of motion (ROM) assessments and patient-rated outcomes were administered at baseline and 6 weeks. Results: All patients showed improvements in shoulder flexion and abduction ROM and reported reductions in pain and disability. Conclusions: This combination of NMES and bilateral exercise may prove to be an effective component of a comprehensive shoulder rehabilitation program for patients with persistent trapezius muscle dysfunction as a result of SAN damage.
Baldwin, Evan R.L.; Baldwin, Terri D.; Lancaster, Josh S.; McNeely, Margaret L.
The present study evaluated ventilatory, cardiovascular and metabolic parameters during recovery from strenuous exercise in horses suffering from a crisis of chronic obstructive pulmonary disease (COPD) and to determine whether ipratropium dry powder inhalation (DPI) before exercise has an effect on these parameters. When 6 saddle horses, affected with COPD, developed airway obstruction, they inhaled placebo and ipratropium (2400 microg/horse), the order being randomly chosen. Pulmonary function tests were then recorded 15 min after inhalation. Following these tests, the horses underwent a strenuous treadmill exercise, followed by a recovery period that consisted of a 10 min walk. Measurements were made at the first and tenth min of recovery. Respiratory flow, O2 and CO2 fractions in the respired gas, pleural pressure changes and heart rate were recorded. Arterial and mixed venous blood samples were analysed for gas tensions, haemoglobin and plasma lactate concentrations. Oxygen consumption (VO2), CO2 production, tidal volume, alveolar oxygen tension (PAO2), alveolar ventilation, the alveolar-pulmonary capillary oxygen difference ((A-a)dO2) and total pulmonary resistance (RL) were measured. The PAO2 was the only parameter significantly improved during recovery following ipratropium DPI. This improvement was not accompanied by evidence of improvement of other ventilatory or cardiorespiratory parameters. The results showed that in horses suffering from a crisis of COPD, recovery is characterised by an exercise-induced bronchodilation. Secondly, ipratropium DPI at a dose of 2400 microg/horse is an effective bronchodilator in these horses at rest but it has little effect on the airway calibre during the recovery period. It is suggested that the short term recovery period is still influenced by exercise-induced adjustments that may exceed the bronchodilatory effect of inhaled ipratropium that are observed before exercise. PMID:9952325
Duvivier, D H; Bayly, W M; Votion, D; Vandenput, S; Art, T; Farnir, F; Lekeux, P
The present study examined the effects of timed ingestion of supplemental protein (20-g servings of whey protein, 3×/day), added to the habitual diet of free-living overweight/obese adults and subsequently randomized to either whey protein only (P; n = 24), whey protein and resistance exercise (P + RT; n = 27), or a whey protein and multimode exercise training program [protein and resistance exercise, intervals, stretching/yoga/Pilates, endurance exercise (PRISE); n = 28]. Total and regional body composition and visceral adipose tissue (VAT) mass (dual-energy X-ray absorptiometry), insulin sensitivity [homeostasis model assessment-estimated insulin resistance (HOMA-IR)], plasma lipids and adipokines, and feelings of hunger and satiety (visual analog scales) were measured before and after the 16-wk intervention. All groups lost body weight, fat mass (FM), and abdominal fat; however, PRISE lost significantly (P < 0.01) more body weight (3.3 ± 0.7 vs. 1.1 ± 0.7 kg, P + RT) and FM (2.8 ± 0.7 vs. 0.9 ± 0.5 kg, P + RT) and gained (P < 0.05) a greater percentage of lean body mass (2 ± 0.5 vs. 0.9 ± 0.3 and 0.6 ± 0.4%, P + RT and P, respectively). Only P + RT (0.1 ± 0.04 kg) and PRISE (0.21 ± 0.07 kg) lost VAT mass (P < 0.05). Fasting glucose decreased only in P + RT (5.1 ± 2.5 mg/dl) and PRISE (15.3 ± 2.1 mg/dl), with the greatest decline occurring in PRISE (P < 0.05). Similarly, HOMA-IR improved (0.6 ± 0.3, 0.6 ± 0.4 units), and leptin decreased (4.7 ± 2.2, 4.7 ± 3.1 ng/dl), and adiponectin increased (3.8 ± 1.1, 2.4 ± 1.1 ?g/ml) only in P + RT and PRISE, respectively, with no change in P. In conclusion, we find evidence to support exercise training and timed ingestion of whey protein added to the habitual diet of free-living overweight/obese adults, independent of caloric restriction on total and regional body fat distribution, insulin resistance, and adipokines. PMID:24833780
Arciero, Paul J; Baur, Daniel; Connelly, Scott; Ormsbee, Michael J
Physical activity during and after cancer treatment can alleviate symptoms such as fatigue, help patients retain their independence and reduce the risk of cancer recurrence and mortality. Nurses should encourage patients and survivors to keep active and prescribe exercise where appropriate. PMID:24191810
Practical guidelines for physical education teachers concerning the right amount of exercise to develop and maintain health-related fitness among students are outlined, along with some techniques for developing student motivation. (JMF)
Pollock, Michael L.; Blair, Steven N.
This homework exercise, which was designed for an undergraduate level geology class at Tulane University, asks the student to make evaluations about the Loma Prieta Earthquake and other earthquakes using seismograms, time travel curves, maps and other information.
These exercises help students understand how the code of the Insertion Sort and the Selection Sort work. It also compares how efficient several different algorithms are. Advanced Exercise 1 - Understanding the Insertion Sort code Remember that the Insertion Sort sort works by making sure everything to the left of the pointer is sorted. The variable j of the for loop represents this pointer, and therefore it starts at 1 and continues to the end of the ...
The bicycle ergometer and a graded stress protocol were used to conduct exercise stress tests for the Apollo project. The graded exercise tests permitted a progressive evaluation of physiological control system response and provided a better understanding of safe stress limits; heart rate was used for determining stress levels. During each test, workload, heart rate, blood pressure, and respiratory gas exchange (oxygen consumption, carbon dioxide production, and minute volume) measurements were made. The results are presented and discussed.
Rummel, J. A.; Sawin, C. F.; Michel, E. L.
The purpose of the present study was to determine the effects of short-term supplementation with the free acid form of b-hydroxyb-methylbutyrate (HMB-FA) on indices of muscle damage, protein breakdown, recovery and hormone status following a high-volume resistance training session in trained athletes. A total of twenty resistance-trained males were recruited to participate in a high-volume resistance training session centred on full squats, bench presses and dead lifts. Subjects were randomly assigned to receive either 3 g/d of HMB-FA or a placebo. Immediately before the exercise session and 48 h post-exercise, serum creatine kinase (CK), urinary 3-methylhistadine (3-MH), testosterone, cortisol and perceived recovery status (PRS) scale measurements were taken. The results showed that CK increased to a greater extent in the placebo (329%) than in the HMB-FA group (104%) (P¼0·004, d ¼ 1·6). There was also a significant change for PRS, which decreased to a greater extent in the placebo (9·1 (SEM 0·4) to 4·6 (SEM 0·5)) than in the HMB-FA group (9·1 (SEM 0·3) to 6·3 (SEM 0·3)) (P¼0·005, d ¼ 20·48). Muscle protein breakdown, measured by 3-MH analysis, numerically decreased with HMB-FA supplementation and approached significance (P¼0·08, d ¼ 0·12). There were no acute changes in plasma total or free testosterone, cortisol or C-reactive protein. In conclusion, these results suggest that an HMB-FA supplement given to trained athletes before exercise can blunt increases in muscle damage and prevent declines in perceived readiness to train following a high-volume, muscle-damaging resistance-training session. PMID:23286834
Wilson, Jacob M; Lowery, Ryan P; Joy, Jordan M; Walters, Joe A; Baier, Shawn M; Fuller, John C; Stout, Jeffrey R; Norton, Layne E; Sikorski, Eric M; Wilson, Stephanie M C; Duncan, Nevine M; Zanchi, Nelo E; Rathmacher, John
The requirements for exercise in space by means of locomotion are established and addressed with prototype treadmills for use during long-duration spaceflight. The adaptation of the human body to microgravity is described in terms of 1-G locomotor biomechanics, the effects of reduced activity, and effective activity-replacement techniques. The treadmill is introduced as a complement to other techniques of force replacement with reference given to the angle required for exercise. A motor-driven unit is proposed that can operate at a variety of controlled speeds and equivalent grades. The treadmills permit locomotor exercise as required for long-duration space travel to sustain locomotor and cardiorespiratory capacity at a level consistent with postflight needs.
Thornton, W.; Whitmore, H.
[Purpose] Cigarette smoking increases oxidative stress, which is a risk factor for several diseases. Moreover, strenuous exercise has been shown to induce plasma and pulmonary oxidative stress in young cigarette smokers. However, no previous reports have demonstrated whether plasma and pulmonary oxidative stress occur after moderate-intensity exercise. Therefore, the aim of this study was to clarify whether moderate-intensity exercise induces pulmonary and plasma oxidative stress in smokers. [Subjects] Ten young male smokers and 10 young male nonsmokers participated in this study. [Methods] Plasma hydroperoxide concentrations were measured at baseline and then immediately and 15?min after moderate-intensity exercise. Hydrogen peroxide concentrations in exhaled breath condensate were measured at baseline and after exercise. [Results] No significant interactions were found between smokers and nonsmokers in terms of hydroperoxide or hydrogen peroxide concentrations following moderate-intensity exercise at any time point. [Conclusion] These findings suggested that moderate-intensity exercise did not induce plasma or pulmonary oxidative stress in young cigarette smokers. PMID:24707095
Taito, Shunsuke; Domen, Sayaka; Sekikawa, Kiyokazu; Kamikawa, Norimichi; Oura, Keisuke; Kimura, Tatsushi; Takahashi, Makoto; Hamada, Hironobu
[Purpose] Cigarette smoking increases oxidative stress, which is a risk factor for several diseases. Moreover, strenuous exercise has been shown to induce plasma and pulmonary oxidative stress in young cigarette smokers. However, no previous reports have demonstrated whether plasma and pulmonary oxidative stress occur after moderate-intensity exercise. Therefore, the aim of this study was to clarify whether moderate-intensity exercise induces pulmonary and plasma oxidative stress in smokers. [Subjects] Ten young male smokers and 10 young male nonsmokers participated in this study. [Methods] Plasma hydroperoxide concentrations were measured at baseline and then immediately and 15?min after moderate-intensity exercise. Hydrogen peroxide concentrations in exhaled breath condensate were measured at baseline and after exercise. [Results] No significant interactions were found between smokers and nonsmokers in terms of hydroperoxide or hydrogen peroxide concentrations following moderate-intensity exercise at any time point. [Conclusion] These findings suggested that moderate-intensity exercise did not induce plasma or pulmonary oxidative stress in young cigarette smokers.
Taito, Shunsuke; Domen, Sayaka; Sekikawa, Kiyokazu; Kamikawa, Norimichi; Oura, Keisuke; Kimura, Tatsushi; Takahashi, Makoto; Hamada, Hironobu
It is widely accepted that regular physical exercise helps diabetic patients control blood glucose, reduce cardiovascular risk factors, and prevent other related complications. In spite of the undoubted benefits of regular physical exercise, diabetic patients with chronic complications should be aware of potential hazards of practicing exercise. To avoid some harmful consequences of acute exercise, it is necessary to adopt
C. Nakhanakhup; P. Moungmee; H. J. Appell; J. A. Duarte
OBJECTIVE To determine the effect of metformin on the acute metabolic response to submaximal exercise, the effect of exercise on plasma metformin concentrations, and the interaction between metformin and exercise on the subsequent response to a standardized meal. RESEARCH DESIGN AND METHODS Ten participants with type 2 diabetes were recruited for this randomized crossover study. Metformin or placebo was given for 28 days, followed by the alternate condition for 28 days. On the last 2 days of each condition, participants were assessed during a nonexercise and a subsequent exercise day. Exercise took place in the morning and involved a total of 35 min performed at three different submaximal intensities. RESULTS Metformin increased heart rate and plasma lactate during exercise (both P ? 0.01) but lowered respiratory exchange ratio (P = 0.03) without affecting total energy expenditure, which suggests increased fat oxidation. Metformin plasma concentrations were greater at several, but not all, time points on the exercise day compared with the nonexercise day. The glycemic response to a standardized meal was reduced by metformin, but the reduction was attenuated when exercise was added (metformin × exercise interaction, P = 0.05). Glucagon levels were highest in the combined exercise and metformin condition. CONCLUSIONS This study reveals several ways by which metformin and exercise therapies can affect each other. By increasing heart rate, metformin could lead to the prescription of lower exercise workloads. Furthermore, under the tested conditions, exercise interfered with the glucose-lowering effect of metformin.
Boule, Normand G.; Robert, Cheri; Bell, Gordon J.; Johnson, Steven T.; Bell, Rhonda C.; Lewanczuk, Richard Z.; Gabr, Raniah Q.; Brocks, Dion R.
Exercise echocardiography has been used for 30 years. It is now considered a consolidated technique for the diagnosis and risk stratification of patients with known or suspected coronary artery disease (CAD). Of the stress echocardiography techniques, it represents the first choice for patients who are able to exercise. Given that the cost-effectiveness and safety of stress echocardiography are higher than those of other imaging techniques, its use is likely to be expanded further. Recent research has also proposed this technique for the evaluation of cardiac pathology beyond CAD. Although the role of new technology is promising, the assessment of cardiac function relies on good quality black and white harmonic images.
Peteiro, Jesus; Bouzas-Mosquera, Alberto
Viewgraphs on daily exercise routines are presented. Topics covered include: daily exercise and periodic stress testings; exercise equipment; physiological monitors; exercise protocols; physiological levels; equipment control; control systems; and fuzzy logic control.
Anderson, Patrick L.; Amoroso, Michael T.
It has previously been shown that females incur less muscle damage than males after strenuous exercise, but limited data are available for humans. To determine possible differences between the sexes in humans, the response to high-force eccentric exercise was examined in a large sample of women (n = 83) and men (n = 82). The participants performed a bout of eccentric exercise of the elbow flexors consisting of 70 maximal repetitions. Isometric strength, resting elbow angle and muscle soreness were measured before, immediately after (except soreness) and then daily for 7 days after exercise. There was a significant loss in strength among both groups (69% for women and 63% for men) (P < 0.01) immediately after exercise; at 168 h post-exercise, women still had a 27% strength loss and men had a 24% strength loss. No significant difference in strength loss or recovery rate was found between men and women. Soreness reached peak values 32-48 h post-exercise (P < 0.01), with no significant difference between men and women. Range of motion decreased significantly until 3 days after exercise (14.6 degrees or 0.255 rad loss for women; 12.2 degrees or 0.213 rad loss for men) (P < 0.01); at 168 h post-exercise, the women and men still showed a loss of 4.8 degrees (0.084 rad) and 4.0 degrees (0.07 rad), respectively. There was a significant interaction of sex x time (P < 0.01); a post-hoc test indicated that the women experienced a greater loss in range of motion at 72 h than men and this difference was maintained to 168 h post-exercise (P < 0.01). Thus, our results do not support the contention that women have a lower response to eccentric exercise than men. PMID:10824639
Rinard, J; Clarkson, P M; Smith, L L; Grossman, M
Normal children achieve the same increase of oxygen uptake (VO2) in response to exercise even though resting and submaximal exercise heart rates vary greatly as a function of age, body size and physical conditioning. To determine whether the VO2 response to exercise is altered when heart rate is significantly reduced by heart disease, we compared 78 children who achieved a
I. M. Schulze-Neick; H. U. Wessel; M. H. Paul
"Study shows reducing carbs after exercise is more important for enhancing insulin sensitivity than reducing calories." This press release describes the study design and findings from the published study "Energy deficit after exercise augments lipid mobilization but does not contribute to the exercise-induced increase in insulin sensitivity" by Sean A. Newsom, Simon Schenk, Kristin M. Tomas, Matthew P. Harber, Nicolas D. Knuth, Naila Goldenberg, and Jeffrey F. Horowitz published in the Journal of Applied Physiology, March 2010.
APS Communications Office (American Physiological Society Communications Office)
An apparatus and method for exercising whereby the user is supported by various mechanisms in such as way that the user's shoulder area is free to translate and rotate; the user's pelvic area is free to translate and rotate; or in any combination.
Schaffner, Grant (Inventor); Bentley, Jason R. (Inventor); Loehr, James A. (Inventor); Gundo, Daniel P. (Inventor)
... such as muscles, tendons, bursae, cartilage, bones, and nerves. Repetitive stress can leads to microtraumas — minor injuries that would typically heal with enough rest. When you exercise too frequently, your body never has a chance to repair these microtraumas. As microtraumas build up over time, ...
This homework exercise, developed for an undergraduate geology course at Tulane University, leads students through the steps involved in determining the probability that a flood of a given discharge will occur in any given year. Students retrieve discharge data from U.S. Geological Services Internet sites for Dry Creek, LA, Rapid Creek, SD and Red River, ND to make their calculations.
Hypoxia due to altitude diminishes performance and alters exercise oxidative stress responses. While oxidative stress and exercise are well studied, the independent impact of hypoxia on exercise recovery remains unknown. Accordingly, we investigated hypoxic recovery effects on post-exercise oxidative stress. Physically active males (n = 12) performed normoxic cycle ergometer exercise consisting of ten high:low intensity intervals, 20 min at moderate intensity, and 6 h recovery at 975 m (normoxic) or simulated 5,000 m (hypoxic chamber) in a randomized counter-balanced cross-over design. Oxygen saturation was monitored via finger pulse oximetry. Blood plasma obtained pre- (Pre), post- (Post), 2 h post- (2Hr), 4 h post- (4Hr), and 6 h (6Hr) post-exercise was assayed for Ferric Reducing Ability of Plasma (FRAP), Trolox Equivalent Antioxidant Capacity (TEAC), Lipid Hydroperoxides (LOOH), and Protein Carbonyls (PC). Biopsies from the vastus lateralis obtained Pre and 6Hr were analyzed by real-time PCR quantify expression of Heme oxygenase 1 (HMOX1), Superoxide Dismutase 2 (SOD2), and Nuclear factor (euthyroid-derived2)-like factor (NFE2L2). PCs were not altered between trials, but a time effect (13 % Post-2Hr increase, p = 0.044) indicated exercise-induced blood oxidative stress. Plasma LOOH revealed only a time effect (p = 0.041), including a 120 % Post-4Hr increase. TEAC values were elevated in normoxic recovery versus hypoxic recovery. FRAP values were higher 6Hr (p = 0.045) in normoxic versus hypoxic recovery. Exercise elevated gene expression of NFE2L2 (20 % increase, p = 0.001) and SOD2 (42 % increase, p = 0.003), but hypoxic recovery abolished this response. Data indicate that recovery in a hypoxic environment, independent of exercise, may alter exercise adaptations to oxidative stress and metabolism. PMID:24384982
Ballmann, Christopher; McGinnis, Graham; Peters, Bridget; Slivka, Dustin; Cuddy, John; Hailes, Walter; Dumke, Charles; Ruby, Brent; Quindry, John
Achilles tendinopathy is a common disorder and is more prevalent in men. Although differences in tendon mechanics between men and women have been reported, understanding of tendon mechanics in young active people is limited. Moreover, there is limited understanding of changes in tendon mechanics in response to acute exercise. Our purpose was to compare Achilles tendon mechanics in active young adult men and women at rest and after light and strenuous activity in the form of repeated jumping with an added load. Participants consisted of 17 men and 14 women (18-30 years) who were classified as being at least moderately physically active as defined by the International Physical Activity Questionnaire. Tendon force/elongation measures were obtained during an isometric plantarflexion contraction on an isokinetic dynamometer with simultaneous ultrasound imaging of the Achilles tendon approximate to the soleus myotendinous junction. Data were collected at rest, after a 10-minute treadmill walk, and after a fatigue protocol of 100 toe jumps performed in a Smith machine, with a load equaling 20% of body mass. We found greater tendon elongation, decreased stiffness, and lower Young's modulus only in women after the jumping exercise. Force and stress were not different between groups but decreased subsequent to the jumping exercise bout. In general, women had greater elongation and strain, less stiffness, and a lower Young's modulus during plantarflexor contraction. These data demonstrate differences in tendon mechanics between men and women and suggest a potential protective mechanism explaining the lower incidence of Achilles tendinopathy in women. PMID:24552794
Joseph, Michael F; Lillie, Kurtis R; Bergeron, Daniel J; Cota, Kevin C; Yoon, Joseph S; Kraemer, William J; Denegar, Craig R
Complex mechanisms exist in the human to defend against adverse effects of negative energy balance. These include alterations of hormone secretion affecting the growth hormone/insulin-like growth factor system, the adrenal axis, and the reproductive system, particularly in females. Energy deficits are least partially offset by neuroendocrine mechanisms regulating appetite and satiety. The complex feedback mechanisms reporting peripheral fat and energy stores to the central nervous system involve secretion of the peptide hormones leptin and ghrelin, which act centrally on neurons in the arcuate nucleus and anteroventral periventricular area. In addition to appetite regulation, these hormones exert influences on spatially and functionally-related mechanisms regulating reproductive function, such as the kisspeptin-gonadotropin releasing hormone system. Negative energy balance often occurs partially as a result of strenuous and repetitive physical exercise. Exercise stress leads to increased cortisol secretion, but this action is mediated through the induced negative energy balance. In healthy adults with energy deficits, this exercise-induced stress appears to be more important than pure psychological stress in impairing reproductive function. Estrogen deficiency resulting from negative energy balance has important adverse effects on bone density as well as bone microarchitecture, and it may also adversely affect markers of cardiovascular disease. PMID:23415825
Fuqua, John S; Rogol, Alan D
Extravehicular activity (EVA) from the Space Shuttle involves one hour of prebreath with 100% oxygen, decompression of the entire Shuttle to 10.2 psia for at least 12 hours, and another prebreath for 40 minutes before decompression to the 4.3 psia suit pressure. We are investigating the use of a one-hour prebreathe with 100% oxygen beginning with a ten-minute strenuous exercise period as an alternative for the staged decompression schedule described above. The 10-minute exercise consists of dual-cycle ergometry performed at 75% of the subject's peak oxygen uptake to increase denitrogenation efficiency by increasing ventilation and perfusion. The control exposures were preceded by a one-hour prebreathe with 100% oxygen while resting in a supine position. The twenty-two male subjects were exposed to 4.3 psia for 4 hours while performing light to moderate exercise. Preliminary results from 22 of the planned 26 subjects indicate 76% DCS following supine, resting prebreathe and 38% following prebreathe with exercise. The staged decompression schedule has been shown to result in 23% DCS which is not significantly different from the exercise-enhanced prebreathe results. Prebreathe including exercise appears to be comparable to the protection afforded by the more lengthy staged decompression schedule. Completion of the study later this year will enable planned statistical analysis of the results.
Webb, James T.; Fischer, Michele D.; Heaps, Cristine L.; Pilmanis, Andrew A.
The effort to gain best achievement in sports by means of exercise has two dilemmatic sides, both for the coaches and sport promoters. On one side, exercise should be done intensely and maximally, but on the other side, it is a known fact that excessive and maximal exercises can damage the body organs. The purposes of this study were to
Alprodit Galatang; Jahja Alex Pangkahila; I Gusti; Ngurah Nal; Ketut Tirtayasa
AIMS Dietary supplements (DS) promoted to enhance athletic performance often contain herbal sympathomimetics such as Citrus aurantium (synephrine) and caffeine. We aimed to characterize the pharmacology of a performance-enhancing DS in the setting of exercise. METHODS Ten healthy adults (three women) aged 20–31 years participated in a three-arm, double-blind, placebo-controlled, crossover study. Subjects ingested one dose of DS (Ripped Fuel Extreme Cut® with 21 mg synephrine and 304 mg caffeine by analysis) under resting conditions and 1 h prior to moderately intense exercise (30 min on cycle ergometer at 75–80% HRmax), with a placebo (PLC)/exercise control. Plasma synephrine and caffeine concentrations were measured over 12 h, and vital signs, serum electrolytes, oxygen consumption and perceived exercise exertion were monitored. RESULTS No significant adverse events occurred. Synephrine and caffeine pharmacokinetics were unaffected by exercise. Post-exercise diastolic blood pressure was higher after DS (peak mean 71.7 ± 8.7 mmHg) than PLC (63.0 ± 4.9 mmHg) (p = 0.007). There were no substantial treatment-related differences in post-exercise HR, systolic blood pressure, or temperature. Postprandial plasma glucose increased to 121.0 ± 31.6 mg dl?1 with DS and exercise vs. 103.7 ± 25.5 mg dl?1 with PLC and exercise (P = 0.004). No treatment differences in exercise-related oxygen consumption, serum lactate, or insulin were observed. Exercise was rated less difficult with DS than PLC (P = 0.001). CONCLUSIONS Blood pressure and plasma glucose increased post-exercise with DS use, which could be detrimental in some people. Exercise was perceived as less strenuous after DS, presumably due to the stimulant effects of caffeine. WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT Performance-enhancing dietary supplements have not been clinically tested for safety or efficacy. In clinical trials performed under resting conditions, performance-enhancing supplements raise blood pressure and affect glucose homeostasis. The effect of exercise on the pharmacokinetics and pharmacodynamics of stimulant herbals is unknown. WHAT THIS STUDY ADDS Supplement-induced effects on blood pressure and glucose levels are not ameliorated by exercise.Exercise does not affect the kinetics of stimulant ingredients, caffeine and synephrine.Performance-enhancing supplement use modestly improves exercise tolerance.
Haller, Christine A; Duan, Minjing; Jacob, Peyton; Benowitz, Neal
Background: Exercise capacity is reduced in obese patients due to disadvantageous respiratory mechanics that lead to dyspnea. Proportional assist ventilation (PAV) has the potential to unload resistive and elastic burdens of the ventilatory system. Objectives: The present study aimed to test if PAV can increase endurance and reduce exercise-related dyspnea in obese patients. Methods: Two symptom-limited exercise tests were performed
Michael Dreher; Hans-Joachim Kabitz; Verena Burgardt; Stephan Walterspacher; Wolfram Windisch
The American College of Sports Medicine and the United States Department of Health and Human Services advocate core training as a means to improve stability, reduce injury, and maintain mobility. There are countless exercises that target the primary core trunk muscles (abdominal and lumbar) with the aim of providing these benefits. However, it is unknown as to which exercises elicit the greatest activation thereby maximizing functional gains and peak performance. Thus, our purpose was to determine whether integration core exercises that require activation of the distal trunk muscles (deltoid and gluteal) elicit greater activation of primary trunk muscles in comparison with isolation core exercises that only require activation of the proximal trunk muscles. Twenty participants, 10 men and 10 women, completed 16 randomly assigned exercises (e.g., crunch, upper body extension, and hover variations). We measured muscle activity with surface electromyography of the anterior deltoid, rectus abdominus, external abdominal oblique, lumbar erector spinae, thoracic erector spinae, and gluteus maximus. Our results indicate that the activation of the abdominal and lumbar muscles was the greatest during the exercises that required deltoid and gluteal recruitment. In conclusion, when completing the core strength guidelines, an integrated routine that incorporates the activation of distal trunk musculature would be optimal in terms of maximizing strength, improving endurance, enhancing stability, reducing injury, and maintaining mobility. PMID:22580983
Gottschall, Jinger S; Mills, Jackie; Hastings, Bryce
This paper aims to highlight the importance of exercise in patients with rheumatoid arthritis (RA) and to demonstrate the multitude of beneficial effects that properly designed exercise training has in this population. RA is a chronic, systemic, autoimmune disease characterised by decrements to joint health including joint pain and inflammation, fatigue, increased incidence and progression of cardiovascular disease, and accelerated loss of muscle mass, that is, “rheumatoid cachexia”. These factors contribute to functional limitation, disability, comorbidities, and reduced quality of life. Exercise training for RA patients has been shown to be efficacious in reversing cachexia and substantially improving function without exacerbating disease activity and is likely to reduce cardiovascular risk. Thus, all RA patients should be encouraged to include aerobic and resistance exercise training as part of routine care. Understanding the perceptions of RA patients and health professionals to exercise is key to patients initiating and adhering to effective exercise training.
Cooney, Jennifer K.; Law, Rebecca-Jane; Matschke, Verena; Lemmey, Andrew B.; Moore, Jonathan P.; Ahmad, Yasmeen; Jones, Jeremy G.; Maddison, Peter; Thom, Jeanette M.
This paper aims to highlight the importance of exercise in patients with rheumatoid arthritis (RA) and to demonstrate the multitude of beneficial effects that properly designed exercise training has in this population. RA is a chronic, systemic, autoimmune disease characterised by decrements to joint health including joint pain and inflammation, fatigue, increased incidence and progression of cardiovascular disease, and accelerated loss of muscle mass, that is, "rheumatoid cachexia". These factors contribute to functional limitation, disability, comorbidities, and reduced quality of life. Exercise training for RA patients has been shown to be efficacious in reversing cachexia and substantially improving function without exacerbating disease activity and is likely to reduce cardiovascular risk. Thus, all RA patients should be encouraged to include aerobic and resistance exercise training as part of routine care. Understanding the perceptions of RA patients and health professionals to exercise is key to patients initiating and adhering to effective exercise training. PMID:21403833
Cooney, Jennifer K; Law, Rebecca-Jane; Matschke, Verena; Lemmey, Andrew B; Moore, Jonathan P; Ahmad, Yasmeen; Jones, Jeremy G; Maddison, Peter; Thom, Jeanette M
Skeletal muscle inducible nitric oxide synthase (NOS) protein is greatly elevated in people with type 2 diabetes mellitus, whereas endothelial NOS is at normal levels. Diabetic rat studies suggest that skeletal muscle neuronal NOS (nNOS) ? protein expression may be reduced in human insulin resistance. The aim of this study was to determine whether skeletal muscle nNOS? protein expression is
Scott J. Bradley; Bronwyn A. Kingwell; Benedict J. Canny; Glenn K. McConell
There are two major problems here that are not independent. One is the more practically oriented problem of determining the effect of various modes of exercise training on gravitational tolerances, i.e., the point of syncope (unconsciousness) usually estimated from the time of appearance of presyncopal signs and symptoms. The other is more theoretical and concerns the mechanism of blood pressure failure that results in syncope. In many experimental designs these two problems or purposes have been intermingled, with equivocal results.
Geelen, G.; Greenleaf, J. E.
Fatigue is synonymous with a wide spectrum of familiar physiological conditions, from pathology and general health, to sport and physical exercise. Strenuous, prolonged exercise training causes fatigue. Although several studies have investigated the effects of electrical stimulation frequency on muscle fatigue, the effects of percutaneous pulse current stimulation on fatigue in the hepatic tissue of trained rats is still unclear. In order to find an effective strategy to prevent fatigue or enhance recovery, the effects of pulse current on endurance exercise and its anti-fatigue properties in exercised rats were studied. Rats were subjected to one, three or five weeks of swimming exercise training. After exercise training, rats in the treated group received daily applications of pulse current. All rats were sacrificed after one, three or five weeks of swimming exercise, and the major biochemical indexes were measured in serum and liver. The results demonstrate that pulse current could prolong the exhaustion swimming time, as well as decrease serum ALT, AST and LD levels and liver MDA content. It also elevated serum LDH activity, liver SOD activity and glycogen content. Furthermore, pulse current increased the expression of Bcl-2 and decreased the expression of Bax. Taken together, these results show that pulse current can elevate endurance capacity and facilitate recovery from fatigue.
Ju, Xiaowei; Zhu, Lvgang; Huang, Changlin; Huang, Tao; Zuo, Xincheng; Gao, Chunfang
Extracellular ATP and ADP trigger vasodilatatory and prothrombotic signalling events in the vasculature. Here, we tested the hypothesis that nucleotide turnover is activated in the bloodstream of exercising humans thus contributing to the enhanced platelet reactivity and haemostasis. Right atrial, arterial and venous blood samples were collected from endurance-trained athletes at rest, during submaximal and maximal cycle ergometer exercise, and after early recovery. ATP-specific bioluminescent assay, together with high-performance liquid chromatographic analysis, revealed that plasma ATP and ADP concentrations increased up to 2.5-fold during maximal exercise. Subsequent flow cytometric analysis showed that plasma from exercising subjects significantly up-regulated the surface expression of P-selectin in human platelets and these prothrombotic effects were diminished after scavenging plasma nucleotides with exogenous apyrase. Next, using thin layer chromatographic assays with [?-32P]ATP and 3H/14C-labelled nucleotides, we showed that two soluble nucleotide-inactivating enzymes, nucleotide pyrophosphatase/phosphodiesterase and nucleoside triphosphate diphosphohydrolase, constitutively circulate in human bloodstream. Strikingly, serum nucleotide pyrophosphatase and hydrolase activities rose during maximal exercise by 20–25 and 80–100%, respectively, and then declined after 30 min recovery. Likewise, soluble nucleotidases were transiently up-regulated in the venous blood of sedentary subjects during exhaustive exercise. Human serum also contains 5?-nucleotidase, adenylate kinase and nucleoside diphosphate (NDP) kinase; however, these activities remain unchanged during exercise. In conclusion, intravascular ADP significantly augments platelet activity during strenuous exercise and these prothrombotic responses are counteracted by concurrent release of soluble nucleotide-inactivating enzymes. These findings provide a novel insight into the mechanisms underlying the enhanced risk of occlusive thrombus formation under exercising conditions.
Yegutkin, Gennady G; Samburski, Sergei S; Mortensen, Stefan P; Jalkanen, Sirpa; Gonzalez-Alonso, Jose
BACKGROUND--The inability to match lung perfusion to ventilation because of a reduced cardiac output on exercise contributes to reduced exercise capacity in chronic heart failure. OBJECTIVE--To quantify ventilation to perfusion matching at rest and at peak exercise in patients with chronic heart failure and relate this to haemodynamic and ventilatory variables of exercise capacity. DESIGN--Eight men in New York Heart
N G Uren; S W Davies; J E Agnew; A G Irwin; S L Jordan; A J Hilson; D P Lipkin
High-intensity exercise leads to an increased risk of upper respiratory tract infections in athletes, which had been related to an exercise-induced impairment of neutrophil function. In this study, several indices of neutrophil function were analysed before and after a biathlon and the effect of oral vitamin C on neutrophil function was determined. Six athletes took 2 g vitamin C daily for 1 week prior to a biathlon and four athletes did not take any supplementation. Neutrophil phagocytosis was analysed by fluorescence microscopy and flow cytometry. Cytosolic calcium kinetics were assessed fluorometrically and neutrophil bactericidal ability was assessed by fluorescence microscopy. Reactive oxygen production was analysed by flow cytometry. Catecholamines were analysed by high-performance liquid chromatography. After high-intensity exercise there were significant reductions in the number of phagocytosed Escherichia coli per neutrophil and in neutrophil bactericidal ability. There was a significant exercise-dependent increase of catecholamines. There was no difference between the two groups of athletes. These results do not support the concept that vitamin C supplementation corrects neutrophil dysfunction after strenuous exercise. PMID:11264655
Krause, R; Patruta, S; Daxböck, F; Fladerer, P; Biegelmayer, C; Wenisch, C
Preservation of locomotor capacity by earth equivalent, exercise in space is the crucial component of inflight exercise. At this time the treadmill appears to be the only way possible to do this. Work is underway on appropriate hardware but this and a proposed protocol to reduce exercise time must be tested. Such exercise will preserve muscle, bone Ca(++) and cardiovascular-respiratory capacity. In addition, reasonable upper body exercise can be supplied by a new force generator/measurement system-optional exercise might include a rowing machine and bicycle ergometer. A subject centered monitoring-evaluation program will allow real time adjustments as required. Absolute protection for any astronaut will not be possible and those with hypertrophied capacities such as marathoners or weight lifters will suffer significant loss. However, the program described should return the crew to earth with adequate capacity of typical activity on earth including immediate ambulation and minimal recovery time and without permanent change. An understanding of the practical mechanics and biomechanics involved is essential to a solution of the problem.
Competence for proper response to hazardous materials emergencies is enhanced and effectively measured by exercises which test plans and procedures and validate training. Emergency exercises are most effective when realistic criteria is used and a sequence of events is followed. The scenario is developed from pre-determined exercise objectives based on hazard analyses, actual plans and procedures. The scenario should address findings from previous exercises and actual emergencies. Exercise rules establish the extent of play and address contingencies during the exercise. All exercise personnel are assigned roles as players, controllers or evaluators. These participants should receive specialized training in advance. A methodology for writing an emergency exercise plan will be detailed.
Competence for proper response to hazardous materials emergencies is enhanced and effectively measured by exercises which test plans and procedures and validate training. Emergency exercises are most effective when realistic criteria is used and a sequence of events is followed. The scenario is developed from pre-determined exercise objectives based on hazard analyses, actual plans and procedures. The scenario should address findings from previous exercises and actual emergencies. Exercise rules establish the extent of play and address contingencies during the exercise. All exercise personnel are assigned roles as players, controllers or evaluators. These participants should receive specialized training in advance. A methodology for writing an emergency exercise plan will be detailed.
The exercise response after bed rest inactivity is a reduction in the physical work capacity and is manifested by significant decreases in oxygen uptake. The magnitude of decrease in maximal oxygen intake V(dot)O2max is related to the duration of confinement and the pre-bed-rest level of aerobic fitness; these relationships are relatively independent of age and gender. The reduced exercise performance and V(dot)O2max following bed rest are associated with various physiological adaptations including reductions in blood volume, submaximal and maximal stroke volume, maximal cardiac output, sceletal muscle tone and strength, and aerobic enzyme capacities, as well as increases in venous compliance and submaximal and maximal heart rate. This reduction in physiological capacity can be partially restored by specific countermeasures that provide regular muscular activity or orhtostatic stress or both during the bed rest exposure. The understanding of these physiological and physical responses to exercise following bed rest inactivity has important implications for the solution to safety and health problems that arise in clinical medicine, aerospace medicine, sedentary living, and aging.
Convertino, Victor A.
The purpose of the present investigation was to study the influence of free versus constant pace on perceived exertion (RPE) and estimated time Limit (ETL). Ten athletes performed a graded test aimed to determine maximal oxygen uptake (VO2max) and the velocity associated with VO2max (vVO2max), a constant run to exhaustion at 90 % vVO2max to determine the time and distance to exhaustion at this relative velocity, a free paced run over the distance to exhaustion set by the time to exhaustion at 90 % vVO2max. Oxygen uptake and velocity during constant pace and free pace runs were both averaged throughout the entire period of exercise and without the last lap. The results did not show any significant effect of free versus constant pace on RPE and ETL. Averaged oxygen uptake between free and constant pace runs was not significantly different, whereas averaged vVO2max, % vVO2max and time to exhaustion was significantly higher for free pace runs only for the entire exercise. Consequently, compared to the constant pace run, the free pace one only allowed athletes to finish the run by a sprint which was effective in increasing performance, but not to perceive the free pacing run as being less strenuous than the constant pace one. PMID:18004686
Garcin, M; Danel, M; Billat, V
Among athletes strenuous exercise, dehydration and gastric emptying (GE) delay are the main causes of gastrointestinal (GI) complaints, whereas gut ischemia is the main cause of their nausea, vomiting, abdominal pain and (blood) diarrhea. Additionally any factor that limits sweat evaporation, such as a hot and humid environment and/or body dehydration, has profound effects on muscle glycogen depletion and risk for heat illness. A serious underperfusion of the gut often leads to mucosal damage and enhanced permeability so as to hide blood loss, microbiota invasion (or endotoxemia) and food-born allergen absorption (with anaphylaxis). The goal of exercise rehydration is to intake more fluid orally than what is being lost in sweat. Sports drinks provide the addition of sodium and carbohydrates to assist with intestinal absorption of water and muscle-glycogen replenishment, respectively. However GE is proportionally slowed by carbohydrate-rich (hyperosmolar) solutions. On the other hand, in order to prevent hyponatremia, avoiding overhydration is recommended. Caregiver's responsibility would be to inform athletes about potential dangers of drinking too much water and also advise them to refrain from using hypertonic fluid replacements.
Current recommendations are that people with Type 1 and Type 2 diabetes mellitus exercise regularly. However, in cases in which insulin or insulin secretagogues are used to manage diabetes, patients have an increased risk of developing hypoglycemia, which is amplified during and after exercise. Repeated episodes of hypoglycemia blunt autonomic nervous system, neuroendocrine and metabolic defenses (counter-regulatory responses) against subsequent episodes of falling blood glucose levels during exercise. Likewise, antecedent exercise blunts counter-regulatory responses to subsequent hypoglycemia. This can lead to a vicious cycle, by which each episode of either exercise or hypoglycemia further blunts counter-regulatory responses. Although contemporary insulin therapies cannot fully mimic physiologic changes in insulin secretion, people with diabetes have several management options to avoid hypoglycemia during and after exercise, including regularly monitoring blood glucose, reducing basal and/or bolus insulin, and consuming supplemental carbohydrates.
Younk, Lisa M; Mikeladze, Maia; Tate, Donna; Davis, Stephen N
Cardio-vascular exercise has been used to mitigate the muscle and cardiac atrophy associated with adaptation to micro-gravity environments. Several hours per day may be required. In confined spaces and long duration missions this kind of exercise is inevitably repetitive and rapidly becomes uninteresting. At the same time, there are pressures to accomplish as much as possible given the cost- per-hour for humans occupying orbiting or interplanetary. Media augmentation provides a the means to overlap activities in time by supplementing the exercise with social, recreational, training or collaborative activities and thereby reducing time pressures. In addition, the machine functions as an interface to a wide range of digital environments allowing for spatial variety in an otherwise confined environment. We hypothesize that the adoption of media augmented exercise machines will have a positive effect on psycho-social well-being on long duration missions. By organizing and supplementing exercise machines, data acquisition hardware, computers and displays into an interacting system this proposal increases functionality with limited additional mass. This paper reviews preliminary work on a project to augment exercise equipment in a manner that addresses these issues and at the same time opens possibilities for additional benefits. A testbed augmented exercise machine uses a specialty built cycle trainer as both input to a virtual environment and as an output device from it using spatialized sound, and visual displays, vibration transducers and variable resistance. The resulting interactivity increases a sense of engagement in the exercise, provides a rich experience of the digital environments. Activities in the virtual environment and accompanying physiological and psychological indicators may be correlated to track and evaluate the health of the crew.
Classic studies on exercise hemorheology evidenced that blood fluidity is impaired during exercise (short term exercise-induced hyperviscosity) and is improved as a result of regular exercise practice (hemorheologic fitness). Extensive description of these events led to the concepts of "the triphasic effects of exercise", "the paradox of hematocrit", and "the hemorheological paradox of lactate". However, some results obtained in training studies do not fit with this classical picture and cannot be explained by a simplistic paradigm based on the Hagen-Poiseuille law. Taking into account the non-linearity of the effects of viscosity factors on blood flow and oxygen delivery helps to elaborate another picture. For example, moderately high values of hematocrit and erythrocyte rigidity induced by high intensity exercise are likely to trigger a physiological vasodilation improving circulatory adaptation (rather than limiting performance as was previously assumed). This may apply to the acute rise in red cell rigidity observed during strenuous exercise, and also to the paradoxical rise in hematocrit or red cell rigidity observed after some training protocols and that did not fit with the previous (simplistic) paradigms. The "healthy primitive lifestyle" hypothesis assumes that evolution has selected genetic polymorphisms leading to insulin resistance as an adaptative strategy to cope with continuous low intensity physical activity and a special alimentation based on lean meat and wild herbs (i.e., moderately high in protein, rich in low glycemic index carbohydrates, and poor in saturated fat). We propose here that this model may help to explain on an evolutionary perspective these apparently inconsistent findings. The pivotal explanation is that the true physiological picture would be that of an individual whose exercise and nutritional habits are close from this lifestyle, both sedentary subjects and trained athletes representing situations on the edge of this model. PMID:23478223
Brun, Jean-Frédéric; Varlet-Marie, Emmanuelle; Romain, Ahmed-Jérôme; Guiraudou, M; Raynaud de Mauverger, Eric
Decreased working capacity and "orthostatic" intolerance are two major problems for astronauts during and after landing from spaceflight in a return vehicle. The purpose was to test the hypotheses that (1) supine-passive-acceleration training, supine-interval-exercise plus acceleration training, and supine exercise plus acceleration training will improve orthostatic tolerance (OT) in ambulatory men; and that (2) addition of aerobic exercise conditioning will not influence this enhanced OT from that of passive-acceleration training. Seven untrained men (24-38 yr) underwent 3 training regimens (30 min/d x 5d/wk x 3wk on the human-powered centrifuge - HPC): (a) Passive acceleration (alternating +1.0 Gz to 50% Gzmax); (b) Exercise acceleration (alternating 40% - 90% V02max leg cycle exercise plus 50% of HPCmax acceleration); and (c) Combined intermittent exercise-acceleration at 40% to 90% HPCmax. Maximal supine exercise workloads increased (P < 0.05) by 8.3% with Passive, by 12.6% with Exercise, and by 15.4% with Combined; but maximal V02 and HR were unchanged in all groups. Maximal endurance (time to cessation) was unchanged with Passive, but increased (P < 0.05) with Exercise and Combined. Resting pre-tilt HR was elevated by 12.9% (P < 0.05) only after Passive training, suggesting that exercise training attenuated this HR response. All resting pre-tilt blood pressures (SBP, DBP, MAP) were not different pre- vs. post-training. Post-training tilt-tolerance time and HR were increased (P < 0.05) only with Passive training by 37.8% and by 29.1%, respectively. Thus, addition of exercise training attenuated the increased Passive tilt tolerance. Resting (pre-tilt) and post-tilt cardiac R-R interval, stroke volume, end-diastolic volume, and cardiac output were all uniformly reduced (P < 0.05) while peripheral resistance was uniformly increased (P < 0.05) pre-and post-training for the three regimens indicating no effect of any training regimen on those cardiovascular variables. Plasma volume (% delta) was uniformly decreased by 8% to 14% (P < 0.05) at tilt-tolerance pre- vs. post-training for all regimens indicating no effect of these training regimens on the level of vascular fluid shifts.
Greenleaf, John E.; Simonson, S. R.; Stocks, J. M.; Evans, J. M.; Knapp, C. F.; Dalton, Bonnie P. (Technical Monitor)
OBJECTIVE? To investigate the effect of atorvastatin on exercise tolerance in patients with diastolic dysfunction and exercise-induced hypertension. METHODS? A randomized? double-blind? placebo-controlled prospective study was performed. Sixty patients with diastolic dysfunction ?mitral flow velocity E/A <1? and exercise-induced hypertension ?SBP>200 mm Hg? treated with atorvastatin ?20 mg q.d? or placebo for 1 year. Cardiopulmonary exercise test and exercise blood pressure measurement were performed. Plasma B-natriuretic peptide ?BNP? concentration at rest and at peak exercise? plasma high sensitive-C reaction protein ?hs-CRP? and endothelin ?ET? concentration were determined at baseline and after treatment. RESULTS? After treatment by atorvastatin? the resting SBP? pulse pressure? the peak exercise SBP and BNP were significantly decreased; and the exercise time? metabolic equivalent? maximal oxygen uptake and anaerobic threshold were increased. All of these parameters had significant differences with baseline levels ?P<0.05?? and the rest pulse pressure? the peak exercise SBP and BNP? and the exercise time had significant differences compared with placebo treatment ?P<0.05?. Plasma concentrations of hs-CRP and ET were markedly reduced by atorvastatin treatment compared with baseline and placebo ?P<0.05?. No difference in above parameters was found before and after placebo treatment ?P>0.05?. CONCLUSION? In patients with diastolic dysfunction at rest and exercise-induced hypertension? atorvastatin can effectively reduce plasma hs-CRP and ET level? lower blood pressure and peak exercise SBP? decrease peak exercise plasma BNP concentration? and ultimately improve exercise tolerance? PMID:24998653
Ye, Ping-Xian; Ye, Ping-Zhen; Zhu, Jian-Hua; Chen, Wei; Gao, Dan Chen
Diabetes mellitus (DM) is a great public health problem, which attacks part of the world population, being characterized by an imbalance in body glucose homeostasis. Physical exercise is pointed as a protective agent and is also recommended to people with DM. As pancreatic islets present an important role in glucose homeostasis, we aim to study the role of physical exercise (chronic adaptations and acute responses) in pancreatic islets functionality in Wistar male rats. First, animals were divided into two groups: sedentary (S) and aerobic trained (T). At the end of 8 weeks, half of them (S and T) were submitted to an acute exercise session (exercise until exhaustion), being subdivided as acute sedentary (AS) and acute trained (AT). After the experimental period, periepididymal, retroperitoneal and subcutaneous fat pads, blood, soleus muscle and pancreatic islets were collected and prepared for further analysis. From the pancreatic islets, total insulin content, insulin secretion stimulated by glucose, leucine, arginine and carbachol were analyzed. Our results pointed that body adiposity and glucose homeostasis improved with chronic physical exercise. In addition, total insulin content was reduced in group AT, insulin secretion stimulated by glucose was reduced in trained groups (T and AT) and insulin secretion stimulated by carbachol was increased in group AT. There were no significant differences in insulin secretion stimulated by arginine and leucine. We identified a possible modulating action on insulin secretion, probably related to the association of chronic adaptation with an acute response on cholinergic activity in pancreatic islets.
Almeida, Felipe N.; Proenca, Andre R.G.; Chimin, Patricia; Marcal, Anderson C.; Bessa-Lima, Fabio; Carvalho, Carla R.O.
Background\\/Aims: Hemodialyzed patients (HD) demonstrate elevated oxidative stress (OXS) levels. Exercise effects on OXS response and antioxidant status of HD was investigated in the present study. Methods: Twelve HD and 12 healthy controls (HC) performed a graded exercise protocol. Blood samples, collected prior to and following exercise, were analyzed for lactate, thiobarbituric acid-reactive substances (TBARS), protein carbonyls (PC), reduced (GSH)
Ioannis G. Fatouros; Ploumis Pasadakis; Apostolos Sovatzidis; Athanasios Chatzinikolaou; Stylianos Panagoutsos; Dimitrios Sivridis; Ioannis Michailidis; Ioannis Douroudos; Kiriakos Taxildaris; Vasilios Vargemezis
The pathophysiology of stroke, a leading cause of morbidity and mortality, is still in the process of being understood. Pre-ischemic exercise has been known to be beneficial in reducing the severity of stroke-induced brain injury in animal models. Forced exercise with a stressful component, rather than voluntary exercise, was better able to induce neuroprotection. This study further determined the changes
Harish Kinni; Miao Guo; Jamie Y. Ding; Sanjay Konakondla; David Dornbos; Raymond Tran; Murali Guthikonda; Yuchuan Ding
Asthma patients can benefit from 20 to 30 minutes of exercise at 60 to 85% of maximum heart rate several times a week. Improved fitness can reduce airway reactivity and medication use. The capacity to exercise requires good general control of asthma. Patients must learn to prevent exercise-induced bronchoconstriction by using inhaled medications…
Disabella, Vincent; Sherman, Carl
Muscle glycogen and blood glucose are important substrates for contracting skeletal muscle during exercise and fatigue often coincides with depletion of these carbohydrate reserves. Carbohydrate utilization during exercise is influenced by several factors including exercise intensity and duration, training status, diet, environment and gender. In view of the importance of carbohydrates for exercise performance, active individuals should ensure their diet
Suggests that exercise should be the first-line therapy for preventing and treating many common diseases; however, physicians need more training in how best to use exercise therapy. The paper explains the power of exercise and discusses how to motivate individuals to start safe, enjoyable, and life-saving exercise routines. (SM)
Precipitation data for Macomb (Illinois) for the period 1912-1981 were the bases for developing classroom exercises that offered college students experience in collecting such data. After students collected the data, they reduced them to manageable proportions, and then examined average long-term relations which may have emerged among yearly,…
Hypertension, diabetes and obesity cause cardiac diastolic dysfunction (DD) which could reduce exercise capacity. Our aim was to determine if 10% weight loss by exercise at 60% VO2max five days\\/week (~-375 kcal\\/session) and caloric restriction (~-600 kcal\\/d) over 6 months improves exercise capacity and DD in Metabolic syndrome (MetS). Eighteen subjects (40 ± 1y, women = 6, BMI = 33.5
Anand Chockalingam; Melissa A. Linden; Marc Del Rosario; Gurushankar Govindarajan; Kevin C. Dellsperger; Tom R. Thomas
To minimize the effects of weightlessness and partial gravity, astronauts use several counter measures to maintain health and fitness. One counter measure is exercise to help reduce or eliminate muscle atrophy and bone loss, and to improve altered cardiovascular function. This video shows astronauts on the International Space Station (ISS) using the stationary Cycle/ Ergometer Vibration Isolation System (CVIS), the Treadmill Vibration Isolation System (TVIS), and the resistance exercise device. These technologies and activities will be crucial to keeping astronauts healthy and productive during the long missions to the Moon. Mars, and beyond.
Ingestion of carbohydrate and reducing core body temperature pre-exercise, either separately or combined, may have ergogenic\\u000a effects during prolonged intermittent exercise in hot conditions. The aim of this investigation was to examine the effect\\u000a of carbohydrate ingestion and pre-cooling on the physiological responses to soccer-specific intermittent exercise and the\\u000a impact on subsequent high-intensity exercise performance in the heat. Twelve male
N. D. Clarke; D. P. M. Maclaren; T. Reilly; B. Drust
Increased oxidative stress during prolonged endurance exercise may end up with muscle damage, fatigue and decreased physical performance. We have recently shown that acute exercise at moderate intensity induced lipid peroxidation, protein oxidation and oxygen radical absorbance capacity (ORAC) in trained trotters. The aim of this study was to measure the changes in oxidative stress and antioxidant defense following an 80-km ride in the blood of endurance horses. Blood samples were collected before and immediately after the ride. Unlike to our previous studies performed on trotters, in endurance horses there were no measurable changes in antioxidants or oxidative stress marker lipid hydroperoxides (LPO) after prolonged exercise. ORAC, vitamin E and lipid hydroperoxide (LPO) concentration or glutathione related enzyme activities were not altered due to the 80-km ride. However, the base line levels of oxidative stress marker were higher in endurance horses compared to trotters. A positive correlation between the pre-ride LPO concentration and erythrocyte glutathione peroxidase (GPx) activity after the ride was observed, which may indicate a protective response of glutathione peroxidase against exercise-induced oxidative stress. Our results suggest that endurance horses have higher oxidative stress levels compared to trotters and a single 80-km ride probably did not suffice to induce oxidative stress and to activate antioxidant defense mechanisms. Key PointsReactive oxygen species (ROS) at lower concentrations have physiological role in the signal transduction and in the regulation of cellular functions. However, the overproduction of ROS results in oxidative stress, an imbalance favoring pro-oxidants over antioxidants.Increased oxidative stress which occurred during prolonged and strenuous physical exercise may end up with muscle damage, fatigue and decreased performance.Prolonged exercise at moderate intensity does not induce oxidative stress in endurance horses.Endurance horses have higher oxidative stress at rest compared to trotters which were trained for short bouts of exercise.
Kinnunen, Susanna; Atalay, Mustafa; Hyyppa, Seppo; Lehmuskero, Arja; Hanninen, Osmo; Oksala, Niku
Sedentary and trained men respond differently to the same intensity of exercise, this is probably related to their platelet reactivity and antioxidant capacity. There is growing interest in the utilization of antioxidant-rich plant extracts as dietary food supplements. The aim of this study was to investigate the effect of an acute bout of sub maximal exercise on platelet count and differential response of platelet activation in trained and sedentary subjects and to observe if cocoa polyphenols reverse the effect of exercise on platelet function. The practical significance of this study was that many sedentary people engage in occasional strenuous exercise that may predispose them to risk of heart disease. Fasting blood samples were collected from 16 male subjects, pre and post 1-h cycling exercise at 70% of maximal aerobic power (VO2max) before and after consumption of cocoa or placebo. Agonist stimulated citrated whole blood was utilized for measuring platelet aggregation, adenosine triphosphate (ATP) release and platelet activation. Baseline platelet count (221 +/- 33 x 10(9)/L) and ATP release (1.4 +/- 0.6 nmol) increased significantly (P < 0.05) after exercise in all subjects. Baseline platelet numbers in the trained were higher (P < 0.05) than in the sedentary (235 +/- 37 vs. 208 +/- 34 x 10(9)/L), where as platelet activation in trained was lower (P < 0.05) than sedentary (51 +/- 6 vs. 59 +/- 5%). Seven days of cocoa polyphenol supplementation had little effect on any of the parameters measured. We conclude that trained subjects show decreased activation of stimulated platelets when compared to the sedentary subjects and short-term cocoa polyphenol supplementation did not decrease platelet activity in response to exercise independent of prior training status. PMID:16973496
Singh, I; Quinn, H; Mok, M; Southgate, R J; Turner, A H; Li, D; Sinclair, A J; Hawley, J A
Regular exercise is positively associated with health. It has also been suggested to exert anti-inflammatory effects. In healthy subjects, a single exercise session results in immune cell activation, which is characterized by production of immune modulatory peptides (e.g. IL-6, IL-8), a leukocytosis and enhanced immune cell functions. Upon cessation of exercise, immune activation is followed by a tolerizing phase, characterized by a reduced responsiveness of immune cells. Regular exercise of moderate intensity and duration has been shown to exert anti-inflammatory effects and is associated with a reduced disease incidence and viral infection susceptibility. Specific exercise programs may therefore be used to modify the course of chronic inflammatory and infectious diseases such as cystic fibrosis (CF). Patients with CF suffer from severe and chronic pulmonary infections and inflammation, leading to obstructive and restrictive pulmonary disease, exercise intolerance and muscle cachexia. Inflammation is characterized by a hyper-inflammatory phenotype. Patients are encouraged to engage in exercise programs to maintain physical fitness, quality of life, pulmonary function and health. In this review, we present an overview of available literature describing the association between regular exercise, inflammation and infection susceptibility and discuss the implications of these observations for prevention and treatment of inflammation and infection susceptibility in patients with CF.
It is well recognized that acute strenuous exercise is accompanied by an increase in free-radical production and subsequent oxidative stress, in addition to changes in blood antioxidant status. Chronic exercise provides protection against exercise-induced oxidative stress by upregulating endogenous antioxidant defense systems. Little is known regarding the protective effect afforded by judo exercise. Therefore, we determined antioxidant and oxidative stress biomarkers at rest and in response to acute exercise in 10 competitive judokas and 10 sedentary subjects after mixed exercise (anaerobic followed by aerobic). The subjects performed a Wingate test, followed by 30 minutes of aerobic exercise performed at 60% of maximal aerobic power. Blood samples were taken, by an intravenous catheter, at rest (R), immediately after the physical exercise (P0), and at 5 (P5), 10 (P10), and 20 (P20) minutes postexercise. The measured parameters included the activity of the antioxidant enzymes superoxide dismutase, glutathione peroxidase, and glutathione reductase, in addition to ?-tocopherol, and total antioxidant status. Malondialdehyde was measured as a representation of lipid peroxidation. At rest, the judokas had higher values for all antioxidant and oxidative stress markers as compared to the sedentary subjects (p < 0.05). Plasma concentrations of all parameters except for ?-tocopherol increased significantly above resting values for both the judokas and sedentary subjects (p < 0.05) and remained elevated at 20 minutes postexercise. A significant postexercise decrease was observed for ?-tocopherol (p < 0.05) at P20 for judokas and at P5 for sedentary subjects. These data indicate that competitive judo athletes have higher endogenous antioxidant protection compared to sedentary subjects. However, both groups of subjects experience an increase in exercise-induced oxidative stress that is not different. PMID:21869626
El Abed, Kaïs; Rebai, Haitham; Bloomer, Richard J; Trabelsi, Khaled; Masmoudi, Liwa; Zbidi, Abdelkarim; Sahnoun, Zouhaier; Hakim, Ahmed; Tabka, Zouhaier
Peripheral blood mononuclear cells (PBMCs) are stimulated by exercise and contribute not only to host defense, but also to growth, repair, and disease pathogenesis. Whether PBMC gene expression is altered by exercise in children is not known. 10 early pubertal boys (8-12 y) and 10 late pubertal boys (15-18 y) performed 10, 2-min bouts of strenuous, constant work rate exercise with 1-min rest intervals. PBMCs were isolated before and after exercise and microarray (Affymetrix U133+2 chips) analyzed. Statistical criterion to identify gene expression changes was less than 5% false discovery rate with 95% confidence. 1246 genes were altered in older boys (517 up, 729 down), but only 109 in the younger group (79 up, 30 down). In older boys, 13 gene pathways (using EASE p<0.05) were found (e.g., natural killer cell cytoxicity, apoptosis). Epiregulin gene expression (EREG, a growth factor involved in wound healing) increased in older boys. In older boys exercise altered genes such as TBX21, GZMA, PGTDR, and CCL5 that also play roles in pediatric inflammatory diseases like asthma. 66 genes changed significantly in both groups. The pattern of PBMC gene expression suggests the initiation of an immunological “danger” signal associated with a sudden change in energy expenditure.
Radom-Aizik, Shlomit; Zaldivar, Frank; Leu, Szu-Yun; Cooper, Dan M.
Physical training exposes the various systems of the body to potent physiologic stimuli. These stimuli induce specific adaptations that enhance an individual's tolerance for the type of exercise encountered in training. The level of adaptation and the magnitude of improvement in exercise tolerance is proportional to the potency of the physical training stimuli. Likewise, our bodies are stimulated by gravity, which promotes adaptations of both the cardiovascular and skeletal muscles. Exposure to microgravity removes normal stimuli to these systems, and the body adapts to these reduced demands. In many respects the cessation of physical training in athletes and the transition from normal gravity to microgravity represent similar paradigms. Inherent to these situations is the concept of the reversibility of the adaptations induced by training or by exposure to normal gravity. The reversibility concept holds that when physical training is stopped (i.e., detraining) or reduced, or a person goes from normal gravity to microgravity, the bodily systems readjust in accordance with the diminished physiologic stimuli. The focus of this chapter is on the time course of loss of the adaptations to endurance training as well as on the possibility that certain adaptations persist, to some extent, when training is stopped. Because endurance exercise training generally improves cardiovascular function and promotes metabolic adaptations within the exercising skeletal musculature, the reversibility of these specific adaptations is considered. These observations have some applicability to the transition from normal to microgravity.
Coyle, Edward F.
Purpose An active lifestyle is widely recognized as having a beneficial effect on cardiovascular health. However, no clear consensus exists as to whether exercise training increases overall physical activity energy expenditure (PAEE) or whether individuals participating in regular exercise compensate by reducing their off-exercise physical activity. The purpose of this study was to evaluate changes in PAEE in response to aerobic training (AT), resistance training (RT), or combined aerobic and resistance training (AT/RT). Methods Data are from 82 participants in the Studies of Targeted Risk Reduction Interventions through Defined Exercise—Aerobic Training versus Resistance Training study, a randomized trial of overweight (body mass index = 25–35 kg·m?2) adults, in which participants were randomized to receive 8 months of AT, RT, or AT/RT. All subjects completed a 4-month control period before randomization. PAEE was measured using triaxial RT3 accelerometers, which subjects wore for a 5- to 7-d period before and after the exercise intervention. Data reduction was performed with a previously published computer-based algorithm. Results There was no significant change in off-exercise PAEE in any of the exercise training groups. We observed a significant increase in total PAEE that included the exercise training, in both AT and AT/RT but not in RT. Conclusions Eight months of exercise training was not associated with a compensatory reduction in off-exercise physical activity, regardless of exercise modality. The absence of compensation is particularly notable for AT/RT subjects, who performed a larger volume of exercise than did AT or RT subjects. We believe that the extended duration of our exercise training program was the key factor in allowing subjects to reach a new steady-state level of physical activity within their daily lives.
RANGAN, VIKRAM V.; WILLIS, LESLIE H.; SLENTZ, CRIS A.; BATEMAN, LORI A.; SHIELDS, A. TAMLYN; HOUMARD, JOSEPH A.; KRAUS, WILLIAM E.
Maximal exercise vasodilatation results from the balance between vasoconstricting and vasodilating signals combined with the vascular reactivity to these signals. During maximal exercise with a small muscle mass the skeletal muscle vascular bed is fully vasodilated. During maximal whole body exercise, however, vasodilatation is restrained by the sympathetic system. This is necessary to avoid hypotension since the maximal vascular conductance of the musculature exceeds the maximal pumping capacity of the heart. Endurance training and high-intensity intermittent knee extension training increase the capacity for maximal exercise vasodilatation by 20–30%, mainly due to an enhanced vasodilatory capacity, as maximal exercise perfusion pressure changes little with training. The increase in maximal exercise vascular conductance is to a large extent explained by skeletal muscle hypertrophy and vascular remodelling. The vasodilatory capacity during maximal exercise is reduced or blunted with ageing, as well as in chronic heart failure patients and chronically hypoxic humans; reduced vasodilatory responsiveness and increased sympathetic activity (and probably, altered sympatholysis) are potential mechanisms accounting for this effect. Pharmacological counteraction of the sympathetic restraint may result in lower perfusion pressure and reduced oxygen extraction by the exercising muscles. However, at the same time fast inhibition of the chemoreflex in maximally exercising humans may result in increased vasodilatation, further confirming a restraining role of the sympathetic nervous system on exercise-induced vasodilatation. This is likely to be critical for the maintenance of blood pressure in exercising patients with a limited heart pump capacity.
Calbet, Jose A L; Lundby, Carsten
Oxidation of the BCAA leucine is increased during a bout of exhaustive exercise. The purpose of this study was to determine the effects of exercise training on leu oxidation during aerobic exercise. Female Sprague-Dawley rats were fed a commercial diet ad lib and divided into sedentary and two trained groups. Animals were trained to run on a treadmill with a 10/sup 0/ incline at 28 m/min for 5 wks for either 50 or 120 min/day. There were no differences in food intake or body weight. After a 12 hr fast, animals were run for 50 or 120 min and changes in leu catabolism determined by measurement of in vivo leu oxidation and activity of branched chain keto acid dehydrogenase (BCKAD). For measurement of leu oxidation, rats were injected IP with 4 ..mu..Ci 1-/sup 14/C-leu during the last 15 min of exercise, placed in glass metabolic chambers, and /sup 14/CO/sub 2/ collected in 1 N NaOH for 30 min periods. Leu oxidation was increased by 40% after 50 min of exercise and by 79% after 120 min of exercise. Five weeks of training reduced the rate of leu oxidation during an exercise bout. The activity of the BCKAD was not increased in the trained animals after either 50 or 120 min of exercise. These data indicate that the rate of leu oxidation during exercises is dependent on the duration of the exercise and that training will reduce the magnitude of this effect.
Hendrix, M.K.; Layman, D.K.
Patients with chronic conditions such as coronary artery disease, hypertension, diabetes, and obesity might benefit from prescribed exercise. Although exercise does not reverse pathologic changes, it may play a role in disease management. (JD)
The cardiopulmonary exercise test (CPET) is an important physiological investigation that can aid clinicians in their evaluation of exercise intolerance and dyspnea. Maximal oxygen consumption (V?O2max) is the gold-standard measure of aerobic fitness and is determined by the variables that define oxygen delivery in the Fick equation (V?O2 = cardiac output × arterial-venous O2 content difference). In healthy subjects, of the variables involved in oxygen delivery, it is the limitations of the cardiovascular system that are most responsible for limiting exercise, as ventilation and gas exchange are sufficient to maintain arterial O2 content up to peak exercise. Patients with lung disease can develop a pulmonary limitation to exercise which can contribute to exercise intolerance and dyspnea. In these patients, ventilation may be insufficient for metabolic demand, as demonstrated by an inadequate breathing reserve, expiratory flow limitation, dynamic hyperinflation, and/or retention of arterial CO2. Lung disease patients can also develop gas exchange impairments with exercise as demonstrated by an increased alveolar-to-arterial O2 pressure difference. CPET testing data, when combined with other clinical/investigation studies, can provide the clinician with an objective method to evaluate cardiopulmonary physiology and determination of exercise intolerance.
Stickland, Michael K.; Butcher, Scott J.; Marciniuk, Darcy D.; Bhutani, Mohit
Diet, physical exercise and cognitive behavioral training as a combined workplace based intervention to reduce body weight and increase physical capacity in health care workers - a randomized controlled trial
Background Health care workers comprise a high-risk workgroup with respect to deterioration and early retirement. There is high prevalence of obesity and many of the workers are overweight. Together, these factors play a significant role in the health-related problems within this sector. The present study evaluates the effects of the first 3-months of a cluster randomized controlled lifestyle intervention among health care workers. The intervention addresses body weight, general health variables, physical capacity and musculoskeletal pain. Methods 98 female, overweight health care workers were cluster-randomized to an intervention group or a reference group. The intervention consisted of an individually dietary plan with an energy deficit of 1200 kcal/day (15 min/hour), strengthening exercises (15 min/hour) and cognitive behavioral training (30 min/hour) during working hours 1 hour/week. Leisure time aerobic fitness was planned for 2 hour/week. The reference group was offered monthly oral presentations. Body weight, BMI, body fat percentage (bioimpedance), waist circumference, blood pressure, musculoskeletal pain, maximal oxygen uptake (maximal bicycle test), and isometric maximal muscle strength of 3 body regions were measured before and after the intervention period. Results In an intention-to-treat analysis from pre to post tests, the intervention group significantly reduced body weight with 3.6 kg (p < 0.001), BMI from 30.5 to 29.2 (p < 0.001), body fat percentage from 40.9 to 39.3 (p < 0.001), waist circumference from 99.7 to 95.5 cm (p < 0.001) and blood pressure from 134/85 to 127/80 mmHg (p < 0.001), with significant difference between the intervention and control group (p < 0.001) on all measures. No effect of intervention was found in musculoskeletal pain, maximal oxygen uptake and muscle strength, but on aerobic fitness. Conclusion The significantly reduced body weight, body fat, waist circumference and blood pressure as well as increased aerobic fitness in the intervention group show the great potential of workplace health promotion among this high-risk workgroup. Long-term effects of the intervention remain to be investigated. Trial registration ClinicalTrials.gov: NCT01015716
Background Major Depressive Disorder (MDD) in pregnancy, or antenatal depression poses unique treatment challenges and has serious consequences for mothers, unborn babies, and families when untreated. This review presents current knowledge on exercise during pregnancy, antidepressant effects of exercise, and the rationale for the specific study of exercise for antenatal depression. Method A systematic literature review was performed using English language articles published in Medline, PsycINFO, CINAHL, and the Cochrane Library from 1985 to January 2010. Results There is a broad literature supporting the antidepressant effects of exercise, but a paucity of studies specifically for antenatal depression. A small number of observational studies have reported that regular physical activities improve self-esteem and reduce symptoms of anxiety and depression during pregnancy. To date, there have not been randomized controlled studies of exercise for the treatment of MDD in pregnant women. Conclusions Systematic studies are needed to assess exercise as a treatment alternative for MDD during pregnancy. In consideration of the benefits of exercise for the mother and baby, and the burden of depression, studies are needed to determine the role of exercise for pregnant women with depression.
Shivakumar, Geetha; Brandon, Anna R.; Snell, Peter G.; Santiago-Munoz, Patricia; Johnson, Neysa L.; Trivedi, Madhukar H.; Freeman, Marlene P.
Background: In adults, exercise is a powerful and natural stimulator of immune cells and adhesion molecules. Far less is known about exercise responses during childhood and adolescence and whether or not exercise in "real life" activities of healthy adolescents influences immune responses. Objective: To determine if strenuous exercise leads to significant changes in leucocyte number and adhesion molecule expression in adolescent boys. Methods: Eleven healthy, high school boys, aged 14–18.5 years, performed a single, typical, 1.5 hour wrestling practice session. Blood was sampled before and after the session. Flow cytometry was used to evaluate changes in immune responses. Results: The exercise led to significant (p<0.05) and robust increases in granulocytes, monocytes, and all lymphocyte subpopulations. The most significant changes were observed for natural killer cells (p<0.0005). The number of T cytotoxic and T helper cells expressing CD62L increased significantly (p<0.002 and p<0.0005 respectively), as did the number of T cytotoxic and T helper cells not expressing CD62L (p<0.003 and p<0.009 respectively). The density of CD62L on lymphocytes decreased significantly with exercise (p<0.0005), whereas CD11a (p<0.01) and CD54 (p<0.01) increased. Conclusions: The data show that an intense wrestling bout in adolescent boys leads to profound stimulation of the immune system. The role of these common changes in overall immune status and the development of the immune and haemopoietic systems has yet to be determined.
Nemet, D; Mills, P; Cooper, D
This article discusses how to use stretch bands for improving total body fitness and quality of life. A stretch band exercise program offers a versatile and inexpensive option to motivate participants to exercise. The authors suggest practical exercises that can be used in physical education to improve or maintain muscular strength and endurance,…
Skirka, Nicholas; Hume, Donald
The present invention relates to an exercise device, which includes a vacuum cylinder and a flywheel. The flywheel provides an inertial component to the load, which is particularly well suited for use in space as it simulates exercising under normal gravity conditions. Also, the present invention relates to an exercise device, which has a vacuum cylinder and a load adjusting armbase assembly.
Raboin, Jasen L. (Inventor); Niebuhr, Jason (Inventor); Cruz, Santana F. (Inventor); Lamoreaux, Christopher D. (Inventor)
Lack of physical activity in the general population is a public health problem and is recognized as an independent risk factor for the development of coronary disease. The relative risk of inactivity is similar to that of hypertension, hypercholesterolemia, and smoking. Consequently, a sedentary lifestyle is associated with a concurrent increase in cardiovascular disease. Engaging regularly in mild-to-moderate physical exercise results in a range of physiological adaptations that are beneficial for health. Various studies have demonstrated that there is an inverse relationship between regular exercise and the risk of coronary heart disease, cardiac events, and death. Exercise improves the lipid profile and glycemic control, reduces or prevents hypertension, obesity, and stress, and promotes fitness and longevity. However, most evidence for the benefits of exercise comes from observational studies and, although maximum oxygen uptake and the duration of exercise on an exercise stress test are powerful predictors of mortality, there is no agreement on the quantity or intensity of the physical activity needed for primary or secondary prevention. On the other hand, although there is a temporarily increased risk of acute myocardial infarction during exhaustive exercise, the balance of risks and benefits is strongly in favor of the benefits because there is a minimum threshold for the weekly energy expenditure required to reduce cardiovascular risk. PMID:24776002
Pérez, Araceli Boraita
Objective To review the effects of core stability exercise or general exercise for patients with chronic low back pain (LBP). Summary of Background Data Exercise therapy appears to be effective at decreasing pain and improving function for patients with chronic LBP in practice guidelines. Core stability exercise is becoming increasingly popular for LBP. However, it is currently unknown whether core stability exercise produces more beneficial effects than general exercise in patients with chronic LBP. Methods Published articles from 1970 to October 2011 were identified using electronic searches. For this meta-analysis, two reviewers independently selected relevant randomized controlled trials (RCTs) investigating core stability exercise versus general exercise for the treatment of patients with chronic LBP. Data were extracted independently by the same two individuals who selected the studies. Results From the 28 potentially relevant trials, a total of 5 trials involving 414 participants were included in the current analysis. The pooling revealed that core stability exercise was better than general exercise for reducing pain [mean difference (?1.29); 95% confidence interval (?2.47, ?0.11); P?=?0.003] and disability [mean difference (?7.14); 95% confidence interval (?11.64, ?2.65); P?=?0.002] at the time of the short-term follow-up. However, no significant differences were observed between core stability exercise and general exercise in reducing pain at 6 months [mean difference (?0.50); 95% confidence interval (?1.36, 0.36); P?=?0.26] and 12 months [mean difference (?0.32); 95% confidence interval (?0.87, 0.23); P?=?0.25]. Conclusions Compared to general exercise, core stability exercise is more effective in decreasing pain and may improve physical function in patients with chronic LBP in the short term. However, no significant long-term differences in pain severity were observed between patients who engaged in core stability exercise versus those who engaged in general exercise. Systematic Review Registration http://www.crd.york.ac.uk/PROSPERO PROSPERO registration number: CRD42011001717.
Wang, Xue-Qiang; Zheng, Jie-Jiao; Yu, Zhuo-Wei; Bi, Xia; Lou, Shu-Jie; Liu, Jing; Cai, Bin; Hua, Ying-Hui; Wu, Mark; Wei, Mao-Ling; Shen, Hai-Min; Chen, Yi; Pan, Yu-Jian; Xu, Guo-Hui; Chen, Pei-Jie
Habitual physical activity reduces coronary heart disease events, but vig- orous activity can also acutely and transiently increase the risk of sudden cardiac death and acute myocardial infarction in susceptible persons. This scientific statement discusses the potential cardiovascular complications of exercise, their pathological substrate, and their incidence and suggests strategies to reduce these complications. Exercise-associated acute cardiac events generally occur
Paul D. Thompson; Barry A. Franklin; Gary J. Balady; Steven N. Blair; Domenico Corrado; N. A. Mark Estes III; Janet E. Fulton; Neil F. Gordon; William L. Haskell; Mark S. Link; Barry J. Maron; Murray A. Mittleman; Antonio Pelliccia; Nanette K. Wenger; Stefan N. Willich; Fernando Costa
This site contains model class exercises which instructors may find useful as class assignments to accompany class trips to the Wallace Creek site. These exercises are designed for college-level students who have had some background in geology and a general background of fault mechanics and earthquake geology. Particular questions in these exercises requires the students to conduct certain exercises or participate in appropriate discussions regarding geomorphology and slip rates. Five figures necessary to complete certain parts of the exercises are available for downloading.
In this activity you will learn about components of a basic exercise program. You will also find some tips for making exercise a regular part of your life. Finally you will create a simple exercise program that includes the FIT formula. Doggonit!! You really wanted to just sit on the couch, watch another TV program, and eat a bag of chips. Your conscience, on the other hand, is telling you that you really need to get some exercise. What will you do? Hopefully, you are thinking seriously about some exercise. There are ...
Objectives: To determine the effects of exercise training on physical condition in 25 college rugby players during a summer training camp, and to compare these variables by the different players' positions. Methods: Changes in body composition parameters and blood biochemistry were examined before and after a summer training camp. Results: Body weight and percentage body fat did not change significantly during the camp. There were significant decreases in levels of serum total cholesterol, triglycerides, phosphate, uric acid, and immunoglobulin G and M. In contrast, there were significant increases in levels of serum potassium, markers of renal, hepatic, and muscular damage (BUN, GOT, GPT, LDH, CK), and complement C4. Comparison of the changes in biochemical parameters between rugby players playing in different positions showed a significant increase in serum albumin level in the forwards, and significant decreases in serum triglyceride and sodium levels in the backs. The magnitude of change in serum LDH during the camp was significantly greater (p<0.05) for the forwards than for the backs. Conclusions: These data suggest that, in rugby players attending a 20 day camp, exercise training resulted in muscular damage, loss of electrolytes due to sweating, and changes in immune function. Backs exhibited a higher rate of fat metabolism and loss of electrolytes than forwards, possibly because they did more running during the camp. In contrast, forwards experienced more physical contact, performed more physically strenuous exercise, and exhibited higher levels of muscular damage and tissue protein degradation.
Mashiko, T; Umeda, T; Nakaji, S; Sugawara, K
Background: Strenuous exercise is associated with tissue damage. This activates the innate immune system and local inflammation. Interaction between innate and adaptive immunity is essential for maintaining health, suggesting that the adaptive immune system may also be altered by exercise. Objectives: To determine exercise induced changes in the adaptive immune system by measuring the immunoglobulin isotype and subclass response to an ultra-marathon. Methods: Venepuncture was performed on 11 experienced volunteers (six men, five women; mean (SD) age 43 (9.8) years) 24 hours before the projected finishing time and immediately after and 3, 24, and 72 hours after an ultra-marathon (90 km). Serum was stored at –80°C. IgM, IgD, IgA, IgG, IgG1, 2, 3, and 4, and total IgE were measured. Results: The following immunoglobulins were significantly (p?0.05) altered after the race: IgD, immediately (–51%) and 24 hours (–41%) after; IgM 24 hours after (–23%); total IgG immediately after (+12%). There were no reports of symptoms of upper respiratory tract infections after the ultra-marathon. Conclusions: In experienced ultra-endurance runners, alterations in immunoglobulin concentrations after a race suggest an enhanced immune response, including isotype switching, interactions with the innate immune system, and a secondary antibody response. These alterations may have a role in the maintenance of subject health after an ultra-marathon.
McKune, A; Smith, L; Semple, S; Wadee, A
Opinion statement Regular and vigorous physical exercise has been scientifically established as providing strong preventative medicine against\\u000a cancer with the potential to reduce incidence by 40%. The effect is strongest for breast and colorectal cancer; however, evidence\\u000a is accumulating for the protective influence on prostate cancer, although predominantly for more advanced disease and in older\\u000a men. Following cancer diagnosis, exercise prescription
Robert U. Newton; Daniel A. Galvão
Exposure to microgravity or bed rest reduces upright exercise capacity. Exercise modes, durations, and intensities which will effectively and efficiently counteract such deconditioning are presently unresolved. We that daily supine treadmill interval training with lower body negative pressure (LBNP) would prevent reduction in upright exercise capacity during 14 days of 6 deg. head-down bed rest (BR). Eight healthy male subjects underwent two 14 day BR protocols separated by 3 months. In a crossover design, subjects either remained at strict BR or performed 40 min of daily exercise consisting of supine walking and running at intensities varying from 40-80% of pre-BR upright peak oxygen uptake (VO2). LBNP during supine exercise was used to provide 1.0 to 1.2 times body weight of footward force. An incremental upright treadmill test to measure submaximal and peak exercise responses was given pre- and post-BR. In the non-exercise condition, peak VO2 and time to exhaustion were reduced 16 +/- 4% and 10 +/- 1% (p less than 0.05), respectively, from pre-BR. With LBNP exercise these variables were not significantly different (NS) from pre-BR. During submaximal treadmill speeds after BR, heart rate was higher (11 +/- 11 bpm, p less than 0.05) and respiratory exchange ratio was elevated (p less than 0.05) in the no exercise condition. Both were maintained at pre-BR levels in the LBNP exercise condition (NS from pre-BR). Since this supine treadmill interval training with addition of LBNP maintained upright exercise responses and capacity during BR, this countermeasure may also be effective during space flight.
Ertl, Andy C.; Watenpaugh, D. E.; Hargens, Alan R.; Fortney, S. M.; Lee, S. M. C.; Ballard, R. E.; William, J. M.
\\u000a PCa is the second most commonly diagnosed cancer in men. Though often curable or treatable with an excellent long-term survival,\\u000a many therapeutic options reduce health-related QoL. Exercise and regular PA have been demonstrated as beneficial throughout\\u000a the continuum of the disease. Clinically important benefits have been observed particularly during the active treatment phase.\\u000a Several recent intervention trials have investigated the
Daniel Santa Mina; Paul Ritvo; Roanne Segal; N. Culos-Reed; Shabbir M. H. Alibhai
BACKGROUND—Hyperinsulinism in childhood is often caused by genetic defects involving the regulation of insulin secretion leading to recurrent episodes of hypoglycaemia. We report two patients with exercise induced hypoglycaemia.?METHODS—Standardised short exercise tests with frequent blood glucose and plasma insulin measurements were performed in the patients and young healthy controls.?RESULTS—Short term exercise resulted in insulin induced hypoglycaemia 15 to 50 minutes after the end of exercise. A massive burst of insulin secretion was observed within a few minutes of the start of exercise in both patients. By contrast glucose and insulin concentrations remained unchanged in healthy controls.?CONCLUSIONS—Hyperinsulinaemic hypoglycaemia after moderate physical exercise represents a rarely described phenotype of hyperinsulinism with an as yet unknown defect in the regulation of insulin secretion. It should be suspected in individuals with recurrent exercise related syncope or disturbance of consciousness.??
Meissner, T; Otonkoski, T; Feneberg, R; Beinbrech, B; Apostolidou, S; Sipila, I; Schaefer, F; Mayatepek, E
This study examined the effects of exercise-induced muscle damage on tremor and proprioception components of neuromuscular function. Six male and six female volunteers (aged 18-30 yr) performed 50 maximal eccentric muscle actions using the forearm flexors of the nondominant arm. Forearm flexor tremor and perception of voluntary force and joint position were monitored to assess changes in neuromuscular function. Data were analyzed using REANOVA. Serum creatine kinase activity increased from a baseline value of 68 +/- 13 IU.l-1 to 2849 +/- 852 IU.l-1 5 d after exercise (P < 0.05). This was accompanied by prolonged impaired joint range of motion (P < 0.01) and reduced maximum strength (P < 0.01). Muscle soreness peaked 3 d postexercise (P < 0.01; Wilcoxon test). Tremor amplitude was increased (P < 0.01) until 48 h after exercise, whereas the power frequency spectrum was unaffected. Perception of joint position at elbow angles of 1.57 rad (P < 0.01) and 2.09 rad (P < 0.05) and perception of force (P < 0.01) were significantly impaired when the control arm acted as the reference. Joint positions were more accurately reproduced when the experimental arm acted as its own reference. The increase in tremor amplitude and loss of proprioceptive function in the days after damage-inducing eccentric exercise suggest significant impairment of neuromuscular function. PMID:7476064
Saxton, J M; Clarkson, P M; James, R; Miles, M; Westerfer, M; Clark, S; Donnelly, A E
Background: The effects of oxygen on recovery from exercise in patients with chronic obstructive pulmonary disease (COPD) are not clearly known. A study was undertaken to determine whether oxygen given after maximal exercise reduced the degree of dynamic hyperinflation and so reduced the perception of breathlessness.Methods: Eighteen patients with moderate to severe COPD performed maximal symptom limited exercise on a
N J Stevenson; P M A Calverley
The aim of this study was to investigate whether variation in estrogen levels during the menstrual cycle influences susceptibility to exercise-induced muscle damage after stretch-shortening cycle exercise. Physically active women (n = 18; age = 20.2 ± 1.7?yr) participated in this research. The subjects performed one session of 100 maximal drop jumps on day 1 or 2 of the follicular phase and another identical session on day 1 or 2 of the ovulatory phase; the order of the sessions was randomized. Quadriceps femoris muscle peak torque evoked by electrical stimulation and maximal voluntary contraction, muscle pain, and CK activity were measured before and at various times up to 72?h after exercise. It was found that the high estrogen level during the ovulatory phase might be related to an earlier return to baseline muscle strength after strenuous stretch-shortening cycle exercise in that phase compared with the follicular phase. The estrogen effect appears to be highly specific to the damaged site because the differences in most EIMD markers (CK, soreness, and low-frequency fatigue) between the two menstrual cycle phases were small.
Sipaviciene, Saule; Daniuseviciute, Laura; Kliziene, Irina; Kamandulis, Sigitas; Skurvydas, Albertas
The aim of this study was to investigate whether variation in estrogen levels during the menstrual cycle influences susceptibility to exercise-induced muscle damage after stretch-shortening cycle exercise. Physically active women (n = 18; age = 20.2 ± 1.7 yr) participated in this research. The subjects performed one session of 100 maximal drop jumps on day 1 or 2 of the follicular phase and another identical session on day 1 or 2 of the ovulatory phase; the order of the sessions was randomized. Quadriceps femoris muscle peak torque evoked by electrical stimulation and maximal voluntary contraction, muscle pain, and CK activity were measured before and at various times up to 72 h after exercise. It was found that the high estrogen level during the ovulatory phase might be related to an earlier return to baseline muscle strength after strenuous stretch-shortening cycle exercise in that phase compared with the follicular phase. The estrogen effect appears to be highly specific to the damaged site because the differences in most EIMD markers (CK, soreness, and low-frequency fatigue) between the two menstrual cycle phases were small. PMID:24151587
Sipavi?ien?, Saul?; Daniusevi?iut?, Laura; Klizien?, Irina; Kamandulis, Sigitas; Skurvydas, Albertas
BACKGROUND—Impaired exercise capacity and oxygen consumption are common in cirrhosis.?AIM—To explore the relationship between possible myocardial dysfunction and exercise tolerance in cirrhosis.?METHODS—Cardiac responses to exercise, using radionuclide angiography and graded upright cycle ergometry with oxygen consumption, were assessed before and after exercise in 39 cirrhotics patients and compared with 12 age and sex matched healthy volunteers. Baseline cardiac chamber dimensions and wall thickness, ejection fraction, and diastolic function were measured using two dimensional echocardiography is all subjects.?RESULTS—Baseline diastolic dysfunction with prolonged isovolumic relaxation times (p=0.02), left atrial enlargement, and left ventricular wall thickening were present in all cirrhotics (p=0.02), despite increased mean ejection fraction. With graded exercise, cirrhotics achieved 71 (4)% (p=0.03) (pre-ascitics) and 46 (3)% (p<0.001) (ascitics) of predicted work loads, respectively, without significant increases in ejection fraction. The smaller absolute and percentage increases in cardiac output (p=0.003) in the cirrhotics were associated with significantly reduced oxygen consumption (p=0.003) and anaerobic threshold (p<0.001), and correlated significantly with work and metabolic parameters.?CONCLUSIONS—Impaired exercise capacity in cirrhosis is associated with myocardial thickening and ventricular stiffness leading to decreased diastolic function, inotropic and chronotropic incompetence under conditions of stress, with metabolic consequences. This picture is compatible with the condition now known as cirrhotic cardiomyopathy.???Keywords: cirrhosis; exercise tolerance; myocardial function; oxygen consumption
Wong, F; Girgrah, N; Graba, J; Allidina, Y; Liu, P; Blendis, L
Resistance exercise has been suggested to increase blood volume, increase the sensitivity of the carotid baroreceptor cardiac reflex response (BARO), and decrease leg compliance, all factors that are expected to improve orthostatic tolerance. To further test these hypotheses, cardiovascular responses to standing and to pre-syncopal limited lower body negative pressure (LBNP) were measured in two groups of sedentary men before and after a 12-week period of either exercise (n = 10) or no exercise (control, n = 9). Resistance exercise training consisted of nine isotonic exercises, four sets of each, 3 days per week, stressing all major muscle groups. After exercise training, leg muscle volumes increased (P < 0.05) by 4-14%, lean body mass increased (P = 0.00) by 2.0 (0.5) kg, leg compliance and BARO were not significantly altered, and the maximal LBNP tolerated without pre-syncope was not significantly different. Supine resting heart rate was reduced (P = 0.03) without attenuating the heart rate or blood pressure responses during the stand test or LBNP. Also, blood volume (125I and 51Cr) and red cell mass were increased (P < 0.02) by 2.8% and 3.9%, respectively. These findings indicate that intense resistance exercise increases blood volume but does not consistently improve orthostatic tolerance.
McCarthy, J. P.; Bamman, M. M.; Yelle, J. M.; LeBlanc, A. D.; Rowe, R. M.; Greenisen, M. C.; Lee, S. M.; Spector, E. R.; Fortney, S. M.
Regular physical exercise seems to have protective effects against diseases that involve inflammatory processes since it induces an increase in the systemic levels of cytokines with anti-inflammatory and antioxidant properties and also acts by reducing estrogen levels. Evidence has suggested that the symptoms associated with endometriosis result from a local inflammatory peritoneal reaction caused by ectopic endometrial implants. Thus, the objective of the present review was to assess the relationship between physical exercise and the prevalence and/or improvement of the symptoms associated with endometriosis. To this end, data available in PubMed (1985-2012) were surveyed using the terms "endometriosis and physical exercises", "endometriosis and life style and physical exercises" in the English language literature. Only 6 of the 935 articles detected were included in the study. These studies tried establish a possible relationship between the practice of physical exercise and the prevalence of endometriosis. The data available are inconclusive regarding the benefits of physical exercise as a risk factor for the disease and no data exist about the potential impact of exercise on the course of the endometriosis. In addition, randomized studies are necessary. PMID:24393293
Bonocher, Camila M; Montenegro, Mary L; Rosa E Silva, Julio C; Ferriani, Rui A; Meola, Juliana
This study determined the effects of exercise on the ability of macrophages (Mphi) to present antigen to T cells. Pathogen-free male Balb/c mice (8 +/- 2 wk of age) were randomly assigned to either home cage control, moderate exercise (Mod; 18 m/min, 5% grade, 0.5 h/day), exhaustive exercise (Exh, 18-30 m/min, 3 h/day), or treadmill control groups. The mice underwent treatments for 4 days during peritoneal thioglycolate inflammation. Peritoneal Mphi were harvested, purified, and incubated with chicken ovalbumin (C-OVA; 0-10 mg/ml) for 18 h. Mphi were then cocultured with C-OVA-specific T cells for 48 h, and the supernatants were analyzed via ELISA for interleukin-2 as an indication of Mphi antigen presentation (AP). Exh exhibited suppressed ( approximately 25-34%) Mphi AP across a wide range of C-OVA doses when measured immediately, 3, and 24 h postexercise. In contrast, Mod had reduced Mphi AP only at 3 h postexercise. Mphi AP was also lower in the treadmill control (4-27%) compared with the home cage control group, but was significantly higher than Exh. The reduction in Mphi AP was not due to exercise-induced differences in Mphi number, percentage, or expression of intercellular adhesion molecule-1, B7-2, or major histocompatability complex II, molecules important in AP. In conclusion, our data lend evidence that may help explain the increased incidence of infection observed after prolonged exhaustive exercise or overtraining. PMID:10601175
Ceddia, M A; Woods, J A
Researchers generally agree that high aerobic fitness achieved through physical training will reduce the physiological strain to exercise in the heat, but does not replace the benefits of an exercise-heat acclimation program. In addition, high aerobic fit...
K. B. Pandolf M. N. Sawka Y. Shapiro
Abstract Short, middle, and long-term exercise, as well as the relative intensity of the physical effort, may influence a broad array of laboratory results, and it is thereby of pivotal importance to appropriately differentiate the 'physiologic' from the 'pathological' effects of exercise. Therefore, the values of some biomarkers in physically active subjects may be cautiously interpreted since the results may fall outside the conventional reference ranges. It has been demonstrated that middle and long-term endurance and/or strenuous exercise triggers transient elevations of muscular and cardiac biomarkers. However, no data have been published about the effect of short-term maximal exercise test on the most useful muscular, hepatic and cardiovascular biomarkers. The aim of the present study was to assess the baseline concentrations of muscular, hepatic, and cardiovascular makers between trained and untrained subjects, along with changes induced by maximal exercise test. We measured C reactive protein (CRP), procalcitonin (PCT), gamma glutamyltransferase (GGT), creatine kinase-MB isoenzyme (CK-MB), Hs-TnT, NT-proBNP, CK, LDH, AST, and ALT in serum samples of physically active (trained) and physically inactive (sedentary) male collected before, immediately after a maximal exercise test and after a 30-min recovery period. Trained subjects tend to have significantly raised base concentrations of CK, CK-MB, ALT, and LDH compared to sedentary individuals, and this can be clearly interpreted as a mild injury of skeletal muscle. A single maximal exercise was also effective to transiently increase the concentrations of NT-proBNP, but not those of Hs-TnT, thus suggesting that the cardiac involvement is mostly benign in nature. PMID:24484196
Romagnoli, Marco; Alis, Rafael; Aloe, Rosalia; Salvagno, Gian Luca; Basterra, Javier; Pareja-Galeano, Helios; Sanchis-Gomar, Fabian; Lippi, Giuseppe
Purpose The purpose of this study was to compare the effects of high, moderate and low intensity plyometric exercise on the post-exercise systolic and diastolic blood pressure and heart rate responses. Methods Ten healthy normotensive men (age, 21.1±0.9 years; height, 175.8±6 cm; and body mass, 69.1±13.6 kg) volunteered to participate in this study and were evaluated for three non-consecutive days in depth jump exercise from 20-cm box (low intensity [LI]), 40-cm box (moderate intensity [MI]) and 60-cm box (high intensity [HI]) for 5 sets of 20 repetitions. After each exercise session, systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured every 10 min for a period of 90 min. Results No significant differences were observed among post-exercise SBP, DBP and HR when the protocols (LI, MI and HI) were compared. The LI and HI protocols showed greater reduction in SBP at 40th-70th min of post-exercise (~9%), whereas the LI and MI protocols indicated greater reduction in DBP at 10th-50th min of post exercise (~10%). In addition, the change in the DBP for HI was not significant and the increases in the HR were similar for all intensities. Conclusion It can be concluded that a plyometric exercise (PE) can reduce SBP and DBP post-exercise and therefore we can say that PE has significant effects for reducing BP and HR or post-exercise hypotension.
Arazi, Hamid; Asadi, Abbas; Rahimzadeh, Mehdi; Moradkhani, Amir-Hossein
This slide presentation reviews potential exercise technologies to counter the effects of space flight. It includes a overview of the exercise countermeasures project, a review of some of the candidate exercise technologies being considered and a few of the analog exercise hardware devices, and a review of new studies that are designed to optimize the current and future exercise protocols.
Loerch, Linda H.
Exercise can help patients maintain lean body mass during weight loss. Although exercise is not extremely useful in shedding excess pounds, it helps keep off weight lost through calorie restriction. This article discusses the specifics of exercise prescription, types of exercise, motivation to exercise, and special problems such as diabetes. (SM)
Work, Janis A.
Exercise has been shown to reduce age-related losses in cognitive function including learning and memory, but the mechanisms underlying this effect remain poorly understood. Memory formation occurs in stages that include an initial acquisition phase, an intermediate labile phase, and then a process of consolidation which leads to long-term memory formation. An effective way to examine the mechanism by which exercise improves memory is to introduce the intervention (exercise), post-acquisition, making it possible to selectively examine memory storage and consolidation. Accordingly we evaluated the effects of post-trial exercise (10 min on a treadmill) on memory consolidation in aged canines both right after, an hour after, and 24 h after acute exercise training in concurrent discrimination, object location memory (OLM), and novel object recognition tasks. Our study shows that post-trial exercise facilitates memory function by improving memory consolidation in aged animals in a time-dependent manner. The improvements were significant at 24 h post-exercise and not right after or 1 h after exercise. Aged animals were also tested following chronic exercise (10 min/day for 14 consecutive days) on OLM or till criterion were reached (for reversal learning task). We found improvements from a chronic exercise design in both the object location and reversal learning tasks. Our studies suggest that mechanisms to improve overall consolidation and cognitive function remain accessible even with progressing age and can be re-engaged by both acute and chronic exercise. PMID:24550824
Snigdha, Shikha; de Rivera, Christina; Milgram, Norton W; Cotman, Carl W
The advanced resistive exercise device (ARED), now at the prototype stage of development, is a versatile machine that can be used to perform different customized exercises for which, heretofore, it has been necessary to use different machines. Conceived as a means of helping astronauts and others to maintain muscle and bone strength and endurance in low-gravity environments, the ARED could also prove advantageous in terrestrial settings (e.g., health clubs and military training facilities) in which many users are exercising simultaneously and there is heavy demand for use of exercise machines.
Raboin, Jasen; Niebuhr, Jason; Cruz, Santana; Lamoreaux, chris
Evidence-based medicine (EBM) has come to be regarded as essential in all fields of medical sciences and practical medicine. In the field of diabetes and exercise, among the epidemiological studies of physical exercise, recent mega-trials such as the Diabetes Prevention Program (DPP) in the U.S. have shown that lifestyle intervention programs involving diet and\\/or exercise reduce the progression of impaired
Yuzo Sato; Masaru Nagasaki; Masakazu Kubota; Tomoko Uno; Naoya Nakai
The metabolic syndrome is a clustering of obesity, diabetes, hyperlipidemia, and hypertension that is occurring in increasing frequency across the global population. Although there is some controversy about its diagnostic criteria, oxidative stress, which is defined as imbalance between the production and inactivation of reactive oxygen species, has a major pathophysiological role in all the components of this disease. Oxidative stress and consequent inflammation induce insulin resistance, which likely links the various components of this disease. We briefly review the role of oxidative stress as a major component of the metabolic syndrome and then discuss the impact of exercise on these pathophysiological pathways. Included in this paper is the effect of exercise in reducing fat-induced inflammation, blood pressure, and improving muscular metabolism.
Golbidi, Saeid; Mesdaghinia, Azam; Laher, Ismail
Carbohydrate consumption during strenuous aerobic exercise reportedly minimizes post-exercise suppression of the innate immune system. One of the most common measurements of innate immunity is natural killer cell activity (NKCA). It is not known whether actual carbohydrate consumption or merely the knowledge of carbohydrate consumption mediates alteration in NKCA. The purpose of the present investigation was to determine if knowledge of carbohydrate beverage could result in alteration of RPE and NKCA, independent of actual carbohydrate intake. We recruited 11 male and female endurance athletes and randomly assigned them to either a correct or false knowledge of carbohydrate intake, such that in the false group, subjects were informed that they were receiving the carbohydrate beverage (CHO), but actually received a placebo (PLA) beverage. CHO and PLA beverages were matched to be similar in taste and appearance. Subjects completed 60 min of cycle ergometry (74% of VO2 peak). Venous blood samples were collected before (PRE), immediately after (POST), and 2 h after (2H) exercise and used to determine plasma glucose concentration, leukocyte total and differential counts, and NKCA. Data were statistically analyzed using a 3-factor analysis of variance (ANOVA) (p < 0.05). We did not find a significant effect of knowledge of drink type on leukocyte count, leukocyte differential, or NKCA. Drink type did not significantly alter leukocyte total, differential counts, or NKCA. There was a significant effect of exercise on NKCA. Knowledge of drink type does not alter innate immunity following exercise as assessed by leukocyte counts and NKCA. PMID:18923577
McFarlin, Brian K; Hutchison, Alexander T; Kueht, Michael L
This slide presentation reviews potential exercise technologies to counter the effects of space flight. It includes a overview of the exercise countermeasures project, a review of some of the candidate exercise technologies being considered and a few of t...
L. H. Loerch
Aerobic exercise at approximately 70% of maximal aerobic capacity moderately reduces pain sensitivity and attenuates pain, even after a single session. If the analgesic effects depend on exercise intensity, then high-intensity interval exercise at 85% of maximal aerobic capacity should further reduce pain. The aim of this study was to explore the exercise-induced analgesic effects of high-intensity interval aerobic exercise and to compare them with the analgesic effects of moderate continuous aerobic exercise. Twenty-nine young untrained healthy males were randomly assigned to aerobic-continuous (70% heart rate reserve (HRR)) and interval (4 × 4 min at 85% HRR and 2 min at 60% HRR between cycles) exercise modes, each lasting 30 min. Psychophysical pain tests, pressure and heat pain thresholds (HPT), and tonic heat pain (THP) were conducted before and after exercise sessions. Repeated measures ANOVA was used for data analysis. HPT increased (p = 0.056) and THP decreased (p = 0.013) following exercise unrelated to exercise type. However, the main time effect (pre-/postexercise) was a trend of increased HPT (45.6 ± 1.9 °C to 46.2 ± 1.8 °C; p = 0.082) and a significant reduction in THP (from 50.7 ± 25 to 45.9 ± 25.4 numeric pain scale; p = 0.043) following interval exercise. No significant change was found for the pressure pain threshold following either exercise type. In conclusion, interval exercise (85% HRR) has analgesic effects on experimental pain perception. This, in addition to its cardiovascular, muscular, and metabolic advantages may promote its inclusion in pain management programs. PMID:24773287
Kodesh, Einat; Weissman-Fogel, Irit
This monograph presents descriptions of various exercises and athletic activities with a kinesiological and biomechanical analysis of the muscle systems involved. It is intended as examples of laboratory activities and projects in a college course in kinesiology. A listing of the required laboratory exercises precedes the examples. Specific…
Mills, Brett D.; And Others
This class exercise from Kirk Garrison is intended for construction students learning about home insulation and heating. The class will learn to calculate heat loss in a home by using an online home heat loss calculator. This exercise document includes student worksheets. This document may be downloaded in PDF file format.
Students will investigate the process of respiration by investigating the question: How does exercise affect the amount of carbon dioxide exhaled? They will use bromothymol blue to time how fast it changes color before and after exercising. They will be guided into an understanding of the process of cellular respiration.
This paper first reviews muscle growth and then considers the influence of exercise in growth. Knowledge about how muscle cells grow and some factors that may influence the growth pattern are discussed first since these effects must be considered before the influence of exercise becomes clear. Growth of muscle can occur in three ways: (1) by an increase in muscle
A. M. Pearson
Describes an exercise that helps students in an interpersonal communication class to identify and understand their preferred style of bargaining while also coming to understand the ideals and practices behind other styles of bargaining. Suggests the exercise enhances their bargaining skills. (SG)
Voluntary physical activity and exercise training can favorably influence brain plasticity by facilitating neurogenerative, neuroadaptive, and neuroprotective processes. At least some of the processes are mediated by neurotrophic factors. Motor skill training and regular exercise enhance executive functions of cognition and some types of learning, including motor learning in the spinal cord. These adaptations in the central nervous system have
Rod K. Dishman; Hans-Rudolf Berthoud; Frank W. Booth; Carl W. Cotman; V. Reggie Edgerton; Monika R. Fleshner; Simon C. Gandevia; Fernando Gomez-Pinilla; Benjamin N. Greenwood; Charles H. Hillman; Arthur F. Kramer; Barry E. Levin; Timothy H. Moran; Amelia A. Russo-Neustadt; John D. Salamone; Jacqueline D. Van Hoomissen; Charles E. Wade; David A. York; Michael J. Zigmond
Physical activity is associated with reduced risk of several cancers, including aggressive prostate cancer. The mechanisms mediating the effects are not yet understood; among the candidates are modifications of endogenous hormone levels. Long-term exercise is known to reduce serum levels of growth stimulating hormones. In contrast, the endocrine effects of acute endurance exercise include increased levels of mitogenic factors such as GH and IGF-1. It can be speculated that the elevation of serum growth factors may be detrimental to prostate cancer progression into malignancy. The incentive of the current study is to evaluate the effect of acute exercise serum on prostate cancer cell growth. We designed an exercise intervention where 10 male individuals performed 60 minutes of bicycle exercise at increasing intensity. Serum samples were obtained before (rest serum) and after completed exercise (exercise serum). The established prostate cancer cell line LNCaP was exposed to exercise or rest serum. Exercise serum from 9 out of 10 individuals had a growth inhibitory effect on LNCaP cells. Incubation with pooled exercise serum resulted in a 31% inhibition of LNCaP growth and pre-incubation before subcutaneous injection into SCID mice caused a delay in tumor formation. Serum analyses indicated two possible candidates for the effect; increased levels of IGFBP-1 and reduced levels of EGF. In conclusion, despite the fear of possible detrimental effects of acute exercise serum on tumor cell growth, we show that even the short-term effects seem to add to the overall beneficial influence of exercise on neoplasia.
Rundqvist, Helene; Augsten, Martin; Stromberg, Anna; Rullman, Eric; Mijwel, Sara; Kharaziha, Pedram; Panaretakis, Theocharis; Gustafsson, Thomas; Ostman, Arne
Falls are a common geriatric syndrome and are the third leading cause of chonic disability worldwide. Falls are not random events and occur, at least in part, due to impaired physiological function, such as impaired balance, and cognitive impairment. The clinical syndrome of falls is important for Sports and Exercise Medicine Clinicians as there is Level 1 evidence that targeted exercise prescription is an effective intervention strategy. The widely accepted dogma is that improved physical function, balance and muscle strength, underlies the effectiveness of the exercise in reducing falls. However, findings from randomised controlled trials suggest that exercise reduce falls via mechanisms other than improved physiological function. The authors propose that improved cognitive function - specifically, executive functions - and associated functional plasticity may be an important yet underappreciated mechanism by which the exercise reduces falls in older adults. PMID:22522589
Liu-Ambrose, Teresa; Nagamatsu, Lindsay S; Hsu, Chun Liang; Bolandzadeh, Niousha
Appropriate nutrition is an essential prerequisite for effective improvement of athletic performance, conditioning, recovery from fatigue after exercise, and avoidance of injury. Nutritional supplements containing carbohydrates, proteins, vitamins, and minerals have been widely used in various sporting fields to provide a boost to the recommended daily allowance. In addition, several natural food components have been found to show physiological effects, and some of them are considered to be useful for promoting exercise performance or for prevention of injury. However, these foods should only be used when there is clear scientific evidence and with understanding of the physiological changes caused by exercise. This article describes various "functional foods" that have been reported to be effective for improving exercise performance or health promotion, along with the relevant physiological changes that occur during exercise.
Aoi, Wataru; Naito, Yuji; Yoshikawa, Toshikazu
The volume of literature attesting to the clinical benefits of exercise training in patients with stable chronic heart failure (CHF) is substantial. Training can improve symptoms and exercise capacity, as well as reducing morbidity, mortality, and rates of emergency hospitalization. These benefits are apparent in all patients with stable CHF, irrespective of age or sex, or the etiology or severity
Andrew J. Stewart Coats
Exercise can be definitive therapy for some, and adjunctive therapy for many, people with hypertension, though people with secondary hypertension may not derive as much benefit. Low-to- moderate-intensity aerobic exercise can help with mild hypertension and reduce drug dosages in more severe cases. For active patients requiring medication,…
This investigation examined whether gating related deficits among individuals with high trait anxiety could be moderated by an acute bout of exercise. Low (LA) and high (HA) trait anxious participants engaged in either a quiet rest or an exercise session on separate occasions. Replicating previous findings, HA participants exhibited significantly reduced PPI at lead intervals of 30 and 60 ms relative
Aaron R. Duley; Charles H. Hillman; Stephen Coombes; Christopher M. Janelle
Context: Whether muscle warming protects against exercise-induced muscle damage is unknown. Objective: To determine the effect of leg immersion in warm water before stretch-shortening exercise on the time course of indirect markers of exercise-induced muscle damage. Design: Crossover trial. Setting: Human kinetics laboratory. Patients or Other Participants: Eleven healthy, untrained men (age ?=? 21.5 ± 1.7 years). Intervention(s): Participants' legs were immersed in a water bath at 44 ± 1°C for 45 minutes. Main Outcome Measure(s): Creatine kinase changes in the blood, muscle soreness, prolonged (within 72 hours) impairment in maximal voluntary contraction force and height of drop jump, and electrically evoked muscle force at low and high stimulation frequencies at short and long muscle lengths. Results: Leg immersion in warm water before stretch-shortening exercise reduced most of the indirect markers of exercise-induced muscle damage, including creatine kinase activity in the blood, muscle soreness, maximal voluntary contraction force, and jump height. The values for maximal voluntary contraction force and jump height, however, were higher during prewarming than for the control condition at 48 hours after stretch-shortening exercise, but this difference was only minor at other time points. Muscle prewarming did not bring about any changes in the dynamics of low-frequency fatigue, registered at either short or long muscle length, within 72 hours of stretch-shortening exercise. Conclusions: Leg immersion in warm water before stretch-shortening exercise reduced most of the indirect markers of exercise-induced muscle damage. However, the clinical application of muscle prewarming may be limited, because decreasing muscle damage did not necessarily lead to improved voluntary performance.
Skurvydas, Albertas; Kamandulis, Sigitas; Stanislovaitis, Aleksas; Streckis, Vytautas; Mamkus, Gediminas; Drazdauskas, Adomas
Exercise evokes sympathetic activation and increases blood pressure and heart rate (HR). Two neural mechanisms that cause the exercise-induced increase in sympathetic discharge are central command and the exercise pressor reflex (EPR). The former suggests that a volitional signal emanating from central motor areas leads to increased sympathetic activation during exercise. The latter is a reflex originating in skeletal muscle which contributes significantly to the regulation of the cardiovascular and respiratory systems during exercise. The afferent arm of this reflex is composed of metabolically sensitive (predominantly group IV, C-fibers) and mechanically sensitive (predominately group III, A-delta fibers) afferent fibers. Activation of these receptors and their associated afferent fibers reflexively adjusts sympathetic and parasympathetic nerve activity during exercise. In heart failure, the sympathetic activation during exercise is exaggerated, which potentially increases cardiovascular risk and contributes to exercise intolerance during physical activity in chronic heart failure (CHF) patients. A therapeutic strategy for preventing or slowing the progression of the exaggerated EPR may be of benefit in CHF patients. Long-term exercise training (ExT), as a non-pharmacological treatment for CHF increases exercise capacity, reduces sympatho-excitation and improves cardiovascular function in CHF animals and patients. In this review, we will discuss the effects of ExT and the mechanisms that contribute to the exaggerated EPR in the CHF state.
Wang, Han-Jun; Zucker, Irving H.; Wang, Wei
The exercise pressor reflex (a peripheral neural reflex originating in skeletal muscle) contributes significantly to the regulation of the cardiovascular system during exercise. Exercise-induced signals that comprise the afferent arm of the reflex are generated by activation of mechanically (muscle mechanoreflex) and chemically sensitive (muscle metaboreflex) skeletal muscle receptors. Activation of these receptors and their associated afferent fibres reflexively adjusts sympathetic and parasympathetic nerve activity during exercise. In heart failure, the cardiovascular response to exercise is augmented. Owing to the peripheral skeletal myopathy that develops in heart failure (e.g. muscle atrophy, decreased peripheral blood flow, fibre-type transformation and reduced oxidative capacity), the exercise pressor reflex has been implicated as a possible mechanism by which the cardiovascular response to physical activity is exaggerated in this disease. Accumulating evidence supports this conclusion. This review therefore focuses on the role of the exercise pressor reflex in regulating the cardiovascular system during exercise in both health and disease. Updates on our current understanding of the exercise pressor reflex neural pathway as well as experimental models used to study this reflex are presented. In addition, special emphasis is placed on the changes in exercise pressor reflex activity that develop in heart failure, including the contributions of the muscle mechanoreflex and metaboreflex to this pressor reflex dysfunction. PMID:16282366
Smith, Scott A; Mitchell, Jere H; Garry, Mary G
Bilateral vocal fold paralysis (BVCP) is a life threatening condition and appears to be a good candidate for therapy using functional electrical stimulation (FES). Developing a working FES system has been technically difficult due to the inaccessible location and small size of the sole arytenoid abductor, the posterior cricoarytenoid (PCA) muscle. A naturally-occurring disease in horses shares many functional and etiological features with BVCP. In this study, the feasibility of FES for equine vocal fold paralysis was explored by testing arytenoid abduction evoked by electrical stimulation of the PCA muscle. Rheobase and chronaxie were determined for innervated PCA muscle. We then tested the hypothesis that direct muscle stimulation can maintain airway patency during strenuous exercise in horses with induced transient conduction block of the laryngeal motor nerve. Six adult horses were instrumented with a single bipolar intra-muscular electrode in the left PCA muscle. Rheobase and chronaxie were within the normal range for innervated muscle at 0.55±0.38 v and 0.38±0.19 ms respectively. Intramuscular stimulation of the PCA muscle significantly improved arytenoid abduction at all levels of exercise intensity and there was no significant difference between the level of abduction achieved with stimulation and control values under moderate loads. The equine larynx may provide a useful model for the study of bilateral fold paralysis.
Cheetham, Jon; Regner, Abby; Jarvis, Jonathan C.; Priest, David; Sanders, Ira; Soderholm, Leo V.; Mitchell, Lisa M.; Ducharme, Norm G.
In an aging population with increasing incidence of dementia and cognitive impairment, strategies are needed to slow age-related decline and reduce disease-related cognitive impairment in older adults. Physical exercise that targets modifiable risk factors and neuroprotective mechanisms may reduce declines in cognitive performance attributed to the normal aging process and protect against changes related to neurodegenerative diseases such as Alzheimer’s disease and other types of dementia. In this review we summarize the role of exercise in neuroprotection and cognitive performance, and provide information related to implementation of physical exercise programs for older adults. Evidence from both animal and human studies supports the role of physical exercise in modifying metabolic, structural, and functional dimensions of the brain and preserving cognitive performance in older adults. The results of observational studies support a dose-dependent neuroprotective relationship between physical exercise and cognitive performance in older adults. Although some clinical trials of exercise interventions demonstrate positive effects of exercise on cognitive performance, other trials show minimal to no effect. Although further research is needed, physical exercise interventions aimed at improving brain health through neuroprotective mechanisms show promise for preserving cognitive performance. Exercise programs that are structured, individualized, higher intensity, longer duration, and multicomponent show promise for preserving cognitive performance in older adults.
Kirk-Sanchez, Neva J; McGough, Ellen L
In an aging population with increasing incidence of dementia and cognitive impairment, strategies are needed to slow age-related decline and reduce disease-related cognitive impairment in older adults. Physical exercise that targets modifiable risk factors and neuroprotective mechanisms may reduce declines in cognitive performance attributed to the normal aging process and protect against changes related to neurodegenerative diseases such as Alzheimer's disease and other types of dementia. In this review we summarize the role of exercise in neuroprotection and cognitive performance, and provide information related to implementation of physical exercise programs for older adults. Evidence from both animal and human studies supports the role of physical exercise in modifying metabolic, structural, and functional dimensions of the brain and preserving cognitive performance in older adults. The results of observational studies support a dose-dependent neuroprotective relationship between physical exercise and cognitive performance in older adults. Although some clinical trials of exercise interventions demonstrate positive effects of exercise on cognitive performance, other trials show minimal to no effect. Although further research is needed, physical exercise interventions aimed at improving brain health through neuroprotective mechanisms show promise for preserving cognitive performance. Exercise programs that are structured, individualized, higher intensity, longer duration, and multicomponent show promise for preserving cognitive performance in older adults. PMID:24379659
Kirk-Sanchez, Neva J; McGough, Ellen L
Objectives—To explore, using qualitative methods, the concept of exercise dependence. Semistructured interviews were undertaken with subjects screened for exercise dependence and eating disorders. Methods—Female exercisers, four in each case, were allocated a priori to four groups: primary exercise dependent; secondary exercise dependent, where there was a coincidence of exercise dependence and an eating disorder; eating disordered; control, where there was no evidence of either exercise dependence or eating disorder. They were asked about their exercise and eating attitudes and behaviour, as well as about any history of psychological distress. Their narratives were taped, transcribed, and analysed from a social constructionist perspective using QSR NUD*IST. Results—Participants classified as primary exercise dependent either showed no evidence of exercise dependent attitudes and behaviour or, if they exhibited features of exercise dependence, displayed symptoms of an eating disorder. Only the latter reported a history of psychological distress, similar to that exhibited by women classified as secondary exercise dependent or eating disordered. For secondary exercise dependent and eating disordered women, as well as for controls, the narratives largely confirmed the a priori classification. Conclusions—Where exercise dependence was manifest, it was always in the context of an eating disorder, and it was this co-morbidity, in addition to eating disorders per se, that was associated with psychological distress. As such, these qualitative data support the concept of secondary, but not primary, exercise dependence. Key Words: exercise dependence; eating disorders; psychological distress; anorexia; bulimia
Bamber, D; Cockerill, I; Rodgers, S; Carroll, D
Parkinson disease (PD) is progressive, with dementia and medication-refractory motor problems common reasons for late-stage nursing-home placement. Increasing evidence suggests that ongoing vigorous exercise/physical fitness may favorably influence this progression. Parkinsonian animal models reveal exercise-related protection from dopaminergic neurotoxins, apparently mediated by brain neurotrophic factors and neuroplasticity (predicted from in vitro studies). Similarly, exercise consistently improves cognition in animals, also linked to enhanced neuroplasticity and increased neurotrophic factor expression. In these animal models, immobilization has the opposite effect. Brain-derived neurotrophic factor (BDNF) may mediate at least some of this exercise benefit. In humans, exercise increases serum BDNF, and this is known to cross the blood-brain barrier. PD risk in humans is significantly reduced by midlife exercise, documented in large prospective studies. No studies have addressed whether exercise influences dementia risk in PD, but exercised patients with PD improve cognitive scores. Among seniors in general, exercise or physical fitness has not only been associated with better cognitive scores, but midlife exercise significantly reduces the later risk of both dementia and mild cognitive impairment. Finally, numerous studies in seniors with and without dementia have reported increased cerebral gray matter volumes associated with physical fitness or exercise. These findings have several implications for PD clinicians. (1) Ongoing vigorous exercise and physical fitness should be highly encouraged. (2) PD physical therapy programs should include structured, graduated fitness instruction and guidance for deconditioned patients with PD. (3) Levodopa and other forms of dopamine replenishment therapy should be utilized to achieve the maximum capability and motivation for patients to maintain fitness. PMID:21768599
Ahlskog, J Eric
The purpose of this study was to investigate the effects of exercise on myocardial glucose uptake and whether the pattern of glucose uptake is the same as in skeletal muscle. Glucose uptake was measured using positron emission tomography (PET) and 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG). Twelve healthy men were studied during rest, while 14 subjects were studied after 35 min of bicycle exercise corresponding to 30, 55 and 75 % of maximal oxygen consumption (V?O2,max) on three separate days. [18F]FDG was injected 10 min after the start of exercise and exercise continued for a further 25 min. Myocardial and skeletal muscle PET scanning was commenced directly after the completion of the exercise bout. As compared to the resting state, exercise doubled myocardial glucose uptake at the 30 % (P = 0.056) and 55 % intensity levels (P < 0.05), while at the 75 % intensity level glucose uptake was reduced significantly compared to the lower exercise intensities. There was no significant difference between the highest intensity level and the resting state (P = 0.18). At rest and during low-intensity exercise, myocardial glucose uptake was inversely associated with circulating levels of free fatty acids. However, during higher exercise intensities when plasma lactate concentrations increased significantly, this association disappeared. In contrast to myocardial responses, skeletal muscle glucose uptake rose in parallel with exercise intensity from rest to 30 % and then 55 % V?O2,max (P < 0.001) and tended to increase further at the intensity of 75 % V?O2,max (P = 0.065). In conclusion, these results demonstrate that myocardial glucose uptake is increased during mild- and moderate-intensity exercise, but is decreased during high-intensity exercise. This finding suggests that the increased myocardial energy that is needed during high-intensity exercise is supplied by substrates other than glucose.
Kemppainen, Jukka; Fujimoto, Toshihiko; Kalliokoski, Kari K; Viljanen, Tapio; Nuutila, Pirjo; Knuuti, Juhani
This exercise is designed to simulate how a basic geological investigation of a site takes place. A basic geological investigation includes familiarizing yourself with the unconsolidated sediments, rocks, structural geology, and groundwater present at your site. As part of this exercise you will have to properly identify a variety of rock types and sediments, create maps that represent data you collected at each location, and complete a basic report of your findings (optional). Once completed, this exercise should give students a basic understanding of how the various concepts used throughout the semester are applied in the real world in the form of a geological investigation.
Exercise is an important "medication" that healthcare providers can prescribe for their geriatric patients. Increasing physical fitness by participating in regular exercise can reduce the effects of aging that lead to functional declines and poor health. Modest regular exercise can substantially lower the risk of death from coronary artery…
Brennan, Fred H., Jr.
Short-term exercise in growing rodents provided lifelong benefits to bone structure, strength, and fatigue resistance. Consequently, exercise when young may reduce the risk for fractures later in life, and the old exercise adage of 'use it or lose it' may not be entirely applicable to the skeleton.
Warden,S.; Fuchs, R.; Castillo, A.; Nelson, I.; Turner, C.
Exercise thermoregulation exercise is dependent on heat loss by increased skin blood flow (convective and conductive heat loss) and through enhanced sweating (evaporative heat loss). Reduction of plasma volume (PV), increased plasma osmolality, physical deconditioning, and duration of exposure to simulated and actual microgravity reduces the ability to thermoregulate during exercise.
Ertl, A. C.; Dearborn, A. S.; Weldhofer, A. R.; Bernauer, E. M.; Greenleaf, J. E.
Exercise has been shown to enhance hippocampus-related cognition and slow the progression of Alzheimer's disease (AD). However, whether voluntary exercise directly decreases the neurotoxicity of amyloid peptide (A?) needs to be determined. In the present study, two-month old male C57bl/6 mice were intracerebroventricularly injected with A?25-35, and then allowed for voluntary exercise for 12 days. Y-maze test revealed that voluntary exercise mitigated spatial memory impairment induced by A?25-35. Consistently, A?25-35 treated mice with exercise showed reduced neuronal degeneration and synaptic protein loss in the hippocampus compared with sedentary controls. Moreover, voluntary exercise significantly ameliorated oxidative stress markers and increased vessel branches in the hippocampus of A?25-35 treated mice. Our results suggest that voluntary exercise counteracts the neurotoxicity of A? by reducing oxidative stress and increasing angiogenesis, which may underlie the beneficial effect of exercise on AD. PMID:24055357
Wang, Qin; Xu, Zhiqiang; Tang, Jinrong; Sun, Jianguo; Gao, Junying; Wu, Ting; Xiao, Ming
Exercise is a fundamental component of good health. The American College of Sports Medicine and "Exercise is Medicine" recommend treating exercise as a vital sign, and assessing and prescribing physical activity at every medical visit. Meeting the recommended goals of physical activity results in a significant reduction in all-cause mortality. Physicians can improve health by prescribing exercise. PMID:24209719
Research has not yet identified the best combination of estrogen replacement, calcium, and exercise for fighting osteoporosis, but clinical experience indicates all are needed to prevent the rapid bone loss that occurs in postmenopausal women. Physicians must encourage women to reduce their risk using all available options. (SM)
Previous studies have demonstrated a renal Na+ conservation during repeated days of exercise in the heat. The present study was intended to describe the role of plasma aldosterone (PAC) in reducing urine Na+ losses during and after 60 min of exercise (60% VO2max) in a warm environment (30 degrees C, 50-53% relative humidity). Additional measurements were made of plasma renin activity (PRA) in an effort to demonstrate the relationship between PRA and PAC. This study shows that a single bout of exercise can significantly reduce urine Na+, Cl-, and H20 excretions for up to 48 hours. Both PRA and PAC were significantly elevated during and immediately after exercise and returned to the pre-exercise level within 6-12 hours of recovery. Subsequently, ingestion of 180 mEq of Na+ each day with ad libitum water intake results in an increased NaCl storage and an expansion of the extracellular volume. PMID:1011955
Costill, D L; Branam, G; Fink, W; Nelson, R
Exercise training remains a cornerstone of pulmonary rehabilitation (PR) in patients with chronic respiratory disease. The choice of type of exercise training depends on the physiologic requirements and goals of the individual patient as well as the available equipment at the PR center. Current evidence suggests that, at ground walking exercise training, Nordic walking exercise training, resistance training, water-based exercise training, tai chi, and nonlinear periodized exercise are all feasible and effective in (subgroups) of patients with chronic obstructive pulmonary disease. In turn, these exercise training modalities can be considered as part of a comprehensive, interdisciplinary PR program. PMID:24874127
Andrianopoulos, Vasileios; Klijn, Peter; Franssen, Frits M E; Spruit, Martijn A
This site from Flinders University in Australia features two sets of exercises that accompany a course on physical oceanography. The basic exercises were originally intended to replace the need for the teacher's presence, but have since also proved useful in distance learning. Topics for these exercises include map projections ocean floor topography, properties of sea water, and water masses and tides. The advanced exercises were designed to give deeper insight into the material and to encourage investigation. Advanced topics include coastal upwelling, graphic display methods for ocean currents, averaging methods for vector time series, geostrophic currents, Rossby wave propagation, the depth of the permanent thermocline (the Sverdrup balance), Ekman layer dynamics, and the outflow of Mediterranean Water into the Atlantic Ocean. The site also features links to other oceanography websites.
Tomczak, Matthias; Flinders University, Australia
The author altered the format of an exercise physiology course from traditional lecture to emphasizing daily reading quizzes and group problem-solving activities. The SALGains evaluation was used to compare the two approaches and significant improvements
Fitzpatrick, Kathleen A.
Physiological effects of restricted activity (RA) and subsequent retraining have been studied. Ten male mongrel dogs performed a submaximal exercise endurance test on a treadmill during kennel control, after 8 weeks of cage confinement and after eight weeks of retraining using the same treadmill protocol 1 h/d for 6 d/week. Data obtained show that RA reduces exercise endurance, the effectiveness of exercise thermoregulation, muscle glycogen stores, and the lipolytic response to exercise and to noradrenaline stimulation.
Nazar, K.; Greenleaf, J. E.; Pohoska, E.; Turlejska, E.; Kaciuba-Uscilko, H.; Kozlowski, S.
The risk of accidental falls and fall-related injuries increases with age. Regular physical exercises can delay the age-related changes affecting postural balance and reduce the risk of falls. Although Tai Chi (TC) has become a popular exercise among the elderly, does regular TC exercise lead to fewer falls and fall-related injuries? Who would receive the most benefit from TC exercise?
Molly M. Schleicher; Lauren Wedam; Ge Wu
Exercise-induced anaphylaxis has been recognized with increasing frequency since its original description in 1980. Recent\\u000a studies suggest food-induced reactions may occur frequently in this syndrome, which is a mast cell-dependent phenomenon. In\\u000a this article, the clinical manifestations of exercise-induced anaphylaxis are reviewed, and food related factors contributing\\u000a to the disorder are considered.
Mariana C. Castells; Richard F. Horan; Albert L. Sheffer
This exercise flollows the progression of a winter weather event across the Central Plains states beginning 1200 UTC on 7 March 1999. Each forecast question is accompanied by Eta model data and includes a forecast discussion by Phil Schumacher, NWS Sioux Falls, South Dakota. This exercise compliments the Webcast, Inverted Troughs and their Associated Precipitation Regimes, based on a presentation by Phil Schumacher at the MSC Winter Weather Course, December 2002, in Boulder Colorado.