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Chihiro Kojima Hiroto Sasaki Yoshifumi Tsuchiya Kazushige Goto 《Journal of physiological anthropology》2015,34(1)
Background
Acute exercise in the heat has been shown to reduce appetite. However, the influence of exercise in the cold on appetite regulation remains unclear. The aim of this study was to compare exercise-induced appetite regulation under three different environmental temperatures.Methods
Eleven male participants completed three experimental trials on the following separate days: exercise in the heat (36°C), exercise at neutral temperature (24°C), and exercise in the cold (12°C). The exercise trials consisted of pedaling exercises for 30 min at 65% of maximal oxygen uptake (VO2max). Blood samples were collected repeatedly to determine plasma ghrelin, peptide YY (PYY) and other hormonal concentrations. Subjective feelings of hunger and tympanic temperature were also monitored.Results
Tympanic temperature was significantly higher in the 36°C trial than that of the other two trials (P < 0.05). The subjective feelings of hunger in the 36°C and 24°C trials were significantly lower than those in the 12°C trial (P < 0.05). Plasma ghrelin concentration decreased significantly with exercise in all conditions (P < 0.05), and the responses were not significantly different among the three conditions. Plasma PYY concentration increased significantly after the exercise in the 24°C trial only (P < 0.05), with no significant difference among the three trials.Conclusions
These results suggest that exposure to hot or cold temperatures during exercise did not affect exercise-induced plasma ghrelin and PYY responses. However, the exercise-induced reduction of subjective hunger was significantly attenuated in a cold environment. 相似文献3.
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Marcin Kurowski Janusz Jurczyk Marzanna Jarz?bska Sylwia Moskwa Joanna S Makowska Hubert Krysztofiak Marek L Kowalski 《Respiratory research》2014,15(1):45
Background
Respiratory epithelium integrity impairment caused by intensive exercise may lead to exercise-induced bronchoconstriction. Clara cell protein (CC16) has anti-inflammatory properties and its serum level reflects changes in epithelium integrity and airway inflammation. This study aimed to investigate serum CC16 in elite athletes and to seek associations of CC16 with asthma or allergy, respiratory tract infections (RTIs) and immune response to respiratory pathogens.Methods
The study was performed in 203 Olympic athletes. Control groups comprised 53 healthy subjects and 49 mild allergic asthmatics. Serum levels of CC16 and IgG against respiratory viruses and Mycoplasma pneumoniae were assessed. Allergy questionnaire for athletes was used to determine symptoms and exercise pattern. Current versions of ARIA and GINA guidelines were used when diagnosing allergic rhinitis and asthma, respectively.Results
Asthma was diagnosed in 13.3% athletes, of whom 55.6% had concomitant allergic rhinitis. Allergic rhinitis without asthma was diagnosed in 14.8% of athletes. Mean CC16 concentration was significantly lower in athletes versus healthy controls and mild asthmatics. Athletes reporting frequent RTIs had significantly lower serum CC16 and the risk of frequent RTIs was more than 2-fold higher in athletes with low serum CC16 (defined as equal to or less than 4.99 ng/ml). Athletes had significantly higher anti-adenovirus IgG than healthy controls while only non-atopic athletes had anti-parainfluenza virus IgG significantly lower than controls. In all athletes weak correlation of serum CC16 and anti-parainfluenza virus IgG was present (R = 0.20, p < 0.01). In atopic athletes a weak positive correlations of CC16 with IgG specific for respiratory syncytial virus (R = 0.29, p = 0.009), parainfluenza virus (R = 0.31, p = 0.01) and adenovirus (R = 0.27, p = 0.02) were seen as well.Conclusions
Regular high-load exercise is associated with decrease in serum CC16 levels. Athletes with decreased CC16 are more susceptible to respiratory infections. Atopy may be an additional factor modifying susceptibility to infections in subjects performing regular high-load exercise. 相似文献5.
Background
In humans, ageing causes skeletal muscles to become atrophied, weak, and easily fatigued. In rodent studies, ageing has been associated with significant muscle atrophy and changes in the contractile properties of the muscles. However, it is not entirely clear whether these changes in contractile properties can occur before there is significant atrophy, and whether males and females are affected differently.Methods and Results
We investigated various contractile properties of whole isolated fast-twitch EDL muscles from adult (2–6 months-old) and aged (12–22 months-old) male and female mice. Atrophy was not present in the aged mice. Compared with adult mice, EDL muscles of aged mice had significantly lower specific force, longer tetanus relaxation times, and lower fatiguability. In the properties of absolute force and muscle relaxation times, females were affected by ageing to a greater extent than males. Additionally, EDL muscles from a separate group of male mice were subjected to eccentric contractions of 15% strain, and larger force deficits were found in aged than in adult mice.Conclusion
Our findings provide further insight into the muscle atrophy, weakness and fatiguability experienced by the elderly. We have shown that even in the absence of muscle atrophy, there are definite alterations in the physiological properties of whole fast-twitch muscle from ageing mice, and for some of these properties the alterations are more pronounced in female mice than in male mice. 相似文献6.
Palstra AP Tudorache C Rovira M Brittijn SA Burgerhout E van den Thillart GE Spaink HP Planas JV 《PloS one》2010,5(12):e14483
Background
Zebrafish has been largely accepted as a vertebrate multidisciplinary model but its usefulness as a model for exercise physiology has been hampered by the scarce knowledge on its swimming economy, optimal swimming speeds and cost of transport. Therefore, we have performed individual and group-wise swimming experiments to quantify swimming economy and to demonstrate the exercise effects on growth in adult zebrafish.Methodology/Principal Findings
Individual zebrafish (n = 10) were able to swim at a critical swimming speed (Ucrit) of 0.548±0.007 m s−1 or 18.0 standard body lengths (BL) s−1. The optimal swimming speed (Uopt) at which energetic efficiency is highest was 0.396±0.019 m s−1 (13.0 BL s−1) corresponding to 72.26±0.29% of Ucrit. The cost of transport at optimal swimming speed (COTopt) was 25.23±4.03 µmol g−1 m−1. A group-wise experiment was conducted with zebrafish (n = 83) swimming at Uopt for 6 h day−1 for 5 days week−1 for 4 weeks vs. zebrafish (n = 84) that rested during this period. Swimming zebrafish increased their total body length by 5.6% and body weight by 41.1% as compared to resting fish. For the first time, a highly significant exercise-induced growth is demonstrated in adult zebrafish. Expression analysis of a set of muscle growth marker genes revealed clear regulatory roles in relation to swimming-enhanced growth for genes such as growth hormone receptor b (ghrb), insulin-like growth factor 1 receptor a (igf1ra), troponin C (stnnc), slow myosin heavy chain 1 (smyhc1), troponin I2 (tnni2), myosin heavy polypeptide 2 (myhz2) and myostatin (mstnb).Conclusions/Significance
From the results of our study we can conclude that zebrafish can be used as an exercise model for enhanced growth, with implications in basic, biomedical and applied sciences, such as aquaculture. 相似文献7.
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Hiroyasu Mori 《Journal of physiological anthropology》2014,33(1):24
Background
Resistance exercise alters the post-exercise response of anabolic and catabolic hormones. A previous study indicated that the turnover of muscle protein in trained individuals is reduced due to alterations in endocrine factors caused by resistance training, and that muscle protein accumulation varies between trained and untrained individuals due to differences in the timing of protein and carbohydrate intake. We investigated the effect of the timing of protein and carbohydrate intake after resistance exercise on nitrogen balance in trained and untrained young men.Methods
Subjects were 10 trained healthy men (mean age, 23 ± 4 years; height, 173.8 ± 3.1 cm; weight, 72.3 ± 4.3 kg) and 10 untrained healthy men (mean age, 23 ± 1 years; height, 171.8 ± 5.0 cm; weight, 64.5 ± 5.0 kg). All subjects performed four sets of 8 to 10 repetitions of a resistance exercise (comprising bench press, shoulder press, triceps pushdown, leg extension, leg press, leg curl, lat pulldown, rowing, and biceps curl) at 80% one-repetition maximum. After each resistance exercise session, subjects were randomly divided into two groups with respect to intake of protein (0.3 g/kg body weight) and carbohydrate (0.8 g/kg body weight) immediately after (P0) or 6 h (P6) after the session. All subjects were on an experimental diet that met their individual total energy requirement. We assessed whole-body protein metabolism by measuring nitrogen balance at P0 and P6 on the last 3 days of exercise training.Results
The nitrogen balance was significantly lower in the trained men than in the untrained men at both P0 (P <0.05) and P6 (P <0.01). The nitrogen balance in trained men was significantly higher at P0 than at P6 (P <0.01), whereas that in the untrained men was not significantly different between the two periods.Conclusion
The timing of protein and carbohydrate intake after resistance exercise influences nitrogen balance differently in trained and untrained young men. 相似文献9.
Andrea Egger Roland Kreis Sabin Allemann Christoph Stettler Peter Diem Tania Buehler Chris Boesch Emanuel R. Christ 《PloS one》2013,8(8)
Background
Intrahepatocellular (IHCL) and intramyocellular (IMCL) lipids are ectopic lipid stores. Aerobic exercise results in IMCL utilization in subjects over a broad range of exercise capacity. IMCL and IHCL have been related to impaired insulin action at the skeletal muscle and hepatic level, respectively. The acute effect of aerobic exercise on IHCL is unknown. Possible regulatory factors include exercise capacity, insulin sensitivity and fat availability subcutaneous and visceral fat mass).Aim
To concomitantly investigate the effect of aerobic exercise on IHCL and IMCL in healthy subjects, using Magnetic Resonance spectroscopy.Methods
Normal weight, healthy subjects were included. Visit 1 consisted of a determination of VO2max on a treadmill. Visit 2 comprised the assessment of hepatic and peripheral insulin sensitivity by a two-step hyperinsulinaemic euglycaemic clamp. At Visit 3, subcutaneous and visceral fat mass were assessed by whole body MRI, IHCL and IMCL before and after a 2-hours aerobic exercise (50% of VO2max) using 1H-MR-spectroscopy.Results
Eighteen volunteers (12M, 6F) were enrolled in the study (age, 37.6±3.2 years, mean±SEM; VO2max, 53.4±2.9 mL/kg/min). Two hours aerobic exercise resulted in a significant decrease in IMCL (−22.6±3.3, % from baseline) and increase in IHCL (+34.9±7.6, % from baseline). There was no significant correlation between the exercise-induced changes in IMCL and IHCL and exercise capacity, subcutaneous and visceral fat mass and hepatic or peripheral insulin sensitivity.Conclusions
IMCL and IHCL are flexible ectopic lipid stores that are acutely influenced by physical exercise, albeit in different directions.Trial Registration
ClinicalTrial.gov NCT00491582相似文献10.
Chris Burtin Hans Van Remoortel Bart Vrijsen Daniel Langer Kristine Colpaert Rik Gosselink Marc Decramer Lieven Dupont Thierry Troosters 《Respiratory research》2013,14(1):46
Background
Adult patients with cystic fibrosis have peripheral muscle weakness, which is related to exercise intolerance and poor prognosis. The influence of acute exacerbations on muscle strength has been poorly studied. This study aimed to investigate whether quadriceps force (QF), as assessed with an involuntary technique, changes during intravenous antibiotics therapy (IVAT) for an exacerbation.Methods
QF was measured in 20 patients using twitch stimulation of the femoral nerve at the day of hospitalization (day 1) and at termination (day 14) of the IVAT. Physical activity was monitored during IVAT using a SenseWear armband. Ten stable patients served as control subjects.Results
QF did not change during exacerbation (potentiated twitch force at day 1: 140 ± 42 N, at day 14: 140 ± 47 N), but a decrease was observed in individual patients. Changes in twitch force during exacerbation were correlated with time spent in activities of at least moderate intensity (r = 0.61, p = 0.007).Conclusions
QF does not systematically decrease during exacerbations of cystic fibrosis. Individual changes in QF are well correlated with daily time spent in activities of at least moderate intensity. 相似文献11.
Timm Greulich Katharina Kehr Christoph Nell Janine Koepke Daniel Haid Ulrich Koehler Kay Koehler Silke Filipovic Klaus Kenn Claus Vogelmeier Andreas-Rembert Koczulla 《Respiratory research》2014,15(1):36
Introduction
Pulmonary rehabilitation has been demonstrated to improve exercise capacity, dyspnoea, quality of life and to reduce the adverse effects of acute exacerbations. Current guidelines recommend exercise training in patients with mild to very severe disease. However, there is insufficient data comparing the efficacy of different training approaches and intensities.Methods
Between January 2009 and December 2012, 105 COPD patients were screened to participate in the study. 61 patients were randomly assigned into an individualized training group or into a non-individualized training group. Both groups exercised once a week for 60 minutes over a time period of three months. At the beginning and after three months, the following measurements were performed: 6-minute walking test (6-MWT), health-related quality of life (St. Georges Respiratory Questionnaire; SGRQ and COPD-Assessment-Test; CAT), M. rectus femoris cross-sectional area, and inflammatory markers in peripheral blood.Results
Only in the individualized training group we observed a significant change of the 6-MWT (increase of 32.47 m; p = 0.012) and the cross-sectional area of the M. rectus fermoris (increase of 0.57 cm2; p = 0.049), while no significant changes occurred in the non-individualized training group. Peroxisome-proliferator-activated receptor-γ coactivator 1α increased in the individualized training only after the three months training period (increase of 0.43 relative copies; p = 0.017), all other myokines and inflammatory markers were not influenced by either of the programs. The total drop-out-rate was 44.3%.Conclusion
A low frequency outpatient training program may induce modest improvements in exercise capacity and muscle mass only if it is performed on an individualized basis. 相似文献12.
Soon Mi Kwon Hee Geun Park Jong Kui Jun Wang Lok Lee 《Journal of Exercise Nutrition & Biochemistry》2014,18(1):51-60
[Purpose]
The purpose of this study was to investigate whether moderate exercise and quercetin intake with a low fat diet contribute to inflammatory cytokine production, mitochondrial biogenesis, and lipid metabolism in skeletal muscle after strenuous exercise by high-fat diet mice.[Methods]
Male C57BL/6 mice were randomly divided into four groups: (1) High-fat for 12 weeks and low-fat diet control (C; n = 6); (2) high-fat diet for 12 weeks and low-fat diet with quercetin (Q; n = 4); (3) high-fat diet for 12 weeks and low-fat diet with exercise (E; n = 4); or (4) high-fat diet for 12 weeks and low-fat diet with exercise and quercetin (EQ; n = 5). Quercetin (10 mg/kg) was administered once per day, 5 day/week for 8 weeks. Exercise training was performed at moderate intensity for 8 weeks, 5 days/week for 30–60 min/day. Mice were subjected to a strenuous exercise bout of 60 min at a speed of 25 m/min (VO2 max 85%) conducted as an exercise-induced fatigue just before sacrifice.[Results]
As results, body weights were significantly different among the groups. Exercise training significantly reduced inflammatory cytokines after strenuous exercise in skeletal muscle of high-fat diet mice. Exercise training increased Tfam mRNA in the soleus muscle after strenuous exercise. Exercise training significantly decreased lipogenesis markers in skeletal muscle of obese mice after strenuous exercise. Moderate exercise significantly increased lipolysis markers in the tibialis anterior muscle.[Conclusion]
These findings suggest that exercise training reduced inflammatory cytokine levels and improved mitochondrial biogenesis and lipid metabolism. However quercetin supplementation did not affect these parameters. Thus, long-term moderate exercise training has positive effects on obesity. 相似文献13.
Background
Since activation of the PI3K/(protein kinase B; PKB/akt) pathway has been shown to alter muscle mass and growth, the aim of this study was to determine whether resistance exercise increased insulin like growth factor (IGF) I/phosphoinositide 3-kinase (PI3K) signalling and whether altering PI(3,4,5)P3 metabolism genetically would increase load induced muscle growth.Methodology/Principal Findings
Acute and chronic resistance exercise in wild type and muscle specific PTEN knockout mice were used to address the role of PI(3,4,5)P3 regulation in the development of skeletal muscle hypertrophy. Acute resistance exercise did not increase either IGF-1 receptor phosphorylation or IRS1/2 associated p85. Since insulin/IGF signalling to PI3K was unchanged, we next sought to determine whether inactivation of PTEN played a role in load-induced muscle growth. Muscle specific knockout of PTEN resulted in small but significant increases in heart (PTEN+/+ = 5.00±0.02 mg/g, PTEN−/− = 5.50±0.09 mg/g), and TA (PTEN+/+ = 1.74±0.04 mg/g, PTEN−/− = 1.89 ±0.03) muscle mass, while the GTN, SOL, EDL and PLN remain unchanged. Following ablation, hypertrophy of the PLN, SOL or EDL muscles was similar between PTEN−/− and PTEN+/+ animals. Even though there were some changes in overload-induced PKB and S6K1 phosphorylation, 1 hr following acute resistance exercise there was no difference in the phosphorylation state of S6K1 Thr389 between genotypes.Conclusions/Significance
These data suggest that physiological loading does not lead to the enhanced activation of the PI3K/PKB/mTORC1 axis and that neither PI3K activation nor PTEN, and by extension PI(3,4,5)P3 levels, play a significant role in adult skeletal muscle growth. 相似文献14.
Mikael Andersson Frode Slinde Anne Marie Gr?nberg Ulla Svantesson Christer Janson Margareta Emtner 《Respiratory research》2013,14(1):128
Background
Decreased physical activity is associated with higher mortality in subjects with COPD. The aim of this study was to assess clinical characteristics and physical activity levels (PALs) in subjects with COPD.Methods
Seventy-three subjects with COPD (67 ± 7 yrs, 44 female) with one-second forced expiratory volume percentage (FEV1%) predicted values of 43 ± 16 were included. The ratio of total energy expenditure (TEE) and resting metabolic rate (RMR) was used to define the physical activity level (PAL) (PAL = TEE/RMR). TEE was assessed with an activity monitor (ActiReg), and RMR was measured by indirect calorimetry. Walking speed (measured over 30-meters), maximal quadriceps muscle strength, fat-free mass and systemic inflammation were measured as clinical characteristics. Hierarchical linear regression was applied to investigate the explanatory values of the clinical correlates to PAL.Results
The mean PAL was 1.47 ± 0.19, and 92% of subjects were classified as physically very inactive or sedentary. The walking speed was 1.02 ± 0.23 m/s, the quadriceps strength was 31.3 ± 11.2 kg, and the fat-free mass index (FFMI) was 15.7 ± 2.3 kg/m2, identifying 42% of subjects as slow walkers, 21% as muscle-weak and 49% as FFM-depleted. The regression model explained 45.5% (p < 0.001) of the variance in PAL. The FEV1% predicted explained the largest proportion (22.5%), with further improvements in the model from walking speed (10.1%), muscle strength (7.0%) and FFMI (3.0%). Neither age, gender nor systemic inflammation contributed to the model.Conclusions
Apart from lung function, walking speed and muscle strength are important correlates of physical activity. Further explorations of the longitudinal effects of the factors characterizing the most inactive subjects are warranted. 相似文献15.
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Igor Lucas Gomes-Santos Tiago Fernandes Gisele Kruger Couto Julio César Ayres Ferreira-Filho Vera Maria Cury Salemi Fernanda Barrinha Fernandes Dulce Elena Casarini Patricia Chakur Brum Luciana Venturini Rossoni Edilamar Menezes de Oliveira Carlos Eduardo Negrao 《PloS one》2014,9(5)
Background
Accumulated evidence shows that the ACE-AngII-AT1 axis of the renin-angiotensin system (RAS) is markedly activated in chronic heart failure (CHF). Recent studies provide information that Angiotensin (Ang)-(1–7), a metabolite of AngII, counteracts the effects of AngII. However, this balance between AngII and Ang-(1–7) is still little understood in CHF. We investigated the effects of exercise training on circulating and skeletal muscle RAS in the ischemic model of CHF.Methods/Main Results
Male Wistar rats underwent left coronary artery ligation or a Sham operation. They were divided into four groups: 1) Sedentary Sham (Sham-S), 2) exercise-trained Sham (Sham-Ex), sedentary CHF (CHF-S), and exercise-trained CHF (CHF-Ex). Angiotensin concentrations and ACE and ACE2 activity in the circulation and skeletal muscle (soleus and plantaris) were quantified. Skeletal muscle ACE and ACE2 protein expression, and AT1, AT2, and Mas receptor gene expression were also evaluated. CHF reduced ACE2 serum activity. Exercise training restored ACE2 and reduced ACE activity in CHF. Exercise training reduced plasma AngII concentration in both Sham and CHF rats and increased the Ang-(1–7)/AngII ratio in CHF rats. CHF and exercise training did not change skeletal muscle ACE and ACE2 activity and protein expression. CHF increased AngII levels in both soleus and plantaris muscle, and exercise training normalized them. Exercise training increased Ang-(1–7) in the plantaris muscle of CHF rats. The AT1 receptor was only increased in the soleus muscle of CHF rats, and exercise training normalized it. Exercise training increased the expression of the Mas receptor in the soleus muscle of both exercise-trained groups, and normalized it in plantaris muscle.Conclusions
Exercise training causes a shift in RAS towards the Ang-(1–7)-Mas axis in skeletal muscle, which can be influenced by skeletal muscle metabolic characteristics. The changes in RAS circulation do not necessarily reflect the changes occurring in the RAS of skeletal muscle. 相似文献17.
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Marcus D. Goncalves Emidio E. Pistilli Anthony Balduzzi Morris J. Birnbaum Jennifer Lachey Tejvir S. Khurana Rexford S. Ahima 《PloS one》2010,5(9)
Background
Akt is a critical mediator of developmental skeletal muscle growth. Treatment with a soluble ActRIIB fusion protein (ActRIIB-mFc) increases skeletal muscle mass and strength by inhibiting myostatin and related peptides. Recent in vitro studies have suggested that Akt signaling is necessary for the ability of ActRIIB inhibition to induce muscle hypertrophy. Thus, we hypothesized that mice deficient in either Akt1 or Akt2 would not respond to in vivo inhibition of ActRIIB with ActRIIB-mFc treatment.Methodology and Principal Findings
We analyzed body composition and muscle parameters in wild-type C57BL/6J and Akt1 and Akt2 knockout mice, and compared the responses to blockade of ActRIIB signaling via ActRIIB-mFc treatment. Mice lacking Akt1 or Akt2 had reduced muscle mass, grip strength and contractile force. However, deficiency of Akt1 or Akt2 did not prevent the ability of ActRIIB-mFc treatment to induce muscle hypertrophy, or increase grip strength and contractile force. Akt1 and Akt2 deficient mice responded similarly as wild type mice to ActRIIB-mFc treatment by increasing fiber size.Conclusions and Significance
Akt1 and Akt2 are important for the regulation of skeletal muscle mass and function. However, these Akt isoforms are not essential for the ability of ActRIIB inhibition to regulate muscle size, fiber type, strength or contractile force. 相似文献19.
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Jinhyun Kim Ji Yong Choi Sung-Hye Park Seung Hee Yang Ji Ah Park Kichul Shin Eun Young Lee Hiroshi Kawachi Hitoshi Kohsaka Yeong Wook Song 《Arthritis research & therapy》2014,16(3):R126