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Wang B.,University of Texas at Austin | Wang B.,Shanghai Research Institute of Sports Science | Ding Z.,University of Texas at Austin | Wang W.,University of Texas at Austin | And 3 more authors.
European Journal of Applied Physiology

Purpose: We previously reported that an amino acid mixture (AA) was able to lower the glucose response to an oral glucose challenge in both rats and humans. Increased glucose uptake and glycogen storage in muscle might be associated with the faster blood glucose clearance. We therefore tested the effect of two different doses of AA provided with a carbohydrate supplement on blood glucose homeostasis and muscle glycogen replenishment in human subjects after strenuous aerobic exercise.Methods: Ten subjects received a carbohydrate (1.2 g/kg body weight, CHO), CHO/HAA (CHO + 13 g AA), or CHO/LAA (CHO + 6.5 g AA) supplement immediately and 2 h after an intense cycling bout. Muscle biopsies were performed immediately and 4 h after exercise.Results: The glucose responses for CHO/HAA and CHO/LAA during recovery were significantly lower than CHO, as was the glucose area under the curve (CHO/HAA 1259.9 ± 27.7, CHO/LAA 1251.5 ± 47.7, CHO 1376.8 ± 52.9 mmol/L 4 h, p < 0.05). Glycogen storage rate was significantly lower in CHO/HAA compared with CHO, while it did not differ significantly between CHO/LAA or CHO (CHO/HAA 15.4 ± 2.0, CHO/LAA 18.1 ± 2.0, CHO 21.5 ± 1.4 µmol/g wet muscle 4 h). CHO/HAA caused a significantly higher insulin response and a greater effect on mTOR and Akt/PKB phosphorylation compared with CHO. Phosphorylation of AS160 and glycogen synthase did not differ across treatments. Likewise, there were no differences in blood lactate across treatments.Conclusions: The AA lowered the glucose response to a carbohydrate supplement after strenuous exercise. However, it was not effective in facilitating subsequent muscle glycogen storage. © 2015, Springer-Verlag Berlin Heidelberg. Source

Sun M.,Shanghai Research Institute of Sports Science | Qian F.,Shanghai Research Institute of Sports Science | Shen W.,Shanghai JiaoTong University | Shen W.,CAS Shanghai Institutes for Biological Sciences | And 4 more authors.
Scandinavian Journal of Medicine and Science in Sports

The aim of this study was to investigate the effects of a combination of nutrients on physical performance, oxidative stress and mitochondrial biogenesis in rats subjected to exhaustive exercise. Rats were divided into sedentary control (SC), exhaustive exercise (EC) and exhaustive exercise with nutrient supplementation (EN). The nutrients include (mg/kg/day): R-α-lipoic acid 50, acetyl-l-carnitine 100, biotin 0.1, nicotinamide 15, riboflavin 6, pyridoxine 6, creatine 50, CoQ10 5, resveratrol 5 and taurine 100. Examination of running distances over the 4-week period revealed that EN rats ran significantly longer throughout the entire duration of the exhaustive exercise period compared with the EC rats. Nutrient supplementation significantly inhibited the increase in activities of alanine transaminase, lactate dehydrogenase and creatine kinase, reversed increases in malondialdehyde, inhibited decreases in glutathione S-transferase and total antioxidant capacity in plasma, and suppressed the elevation of reactive oxygen species and apoptosis in splenic lymphocytes. Nutrient supplementation increased the protein expression of mitochondrial complexes I, II and III, mtDNA number and transcription factors involved in mitochondrial biogenesis and fusion in skeletal muscle. These findings suggest that mitochondrial nutrient supplementation can reduce exhaustive exercise-induced oxidative damage and mitochondrial dysfunction, thus leading to enhancement of physical performance and of fatigue recovery. © 2011 John Wiley & Sons A/S. Source

Feng X.-H.,Shanghai University of Sport | Feng X.-H.,Shanghai Research Institute of Sports Science | Zheng J.-J.,Fudan University | Li H.-Y.,Fudan University | And 4 more authors.
Journal of Shanghai Jiaotong University (Medical Science)

Objective: To observe the balance control ability of patients with mechanical ankle instability (MAI) and functional ankle instability (FAI).Methods: Patients with MAI (the MAI group, n=12) and FAI (the FAI group, n=12) and normal controls (the control group, n=12) were selected. Single-limb postural sway tests were performed for all participants with eyes closed and opened. Three tests were performed for each leg and each test lasted for 10 s. Parameters relevant to displacements from the center of pressure (COP) were measured, including mensway Y axis (MSY), mensway X axis (MSX), circumference area (CA), path length (PL), unit time path length (UTPL), and unit area path length (UAPL).Results: The difference of age, sex, height, and weight of three groups were not statistically significant (P>0.05). The MSY, CA, PL, and UTPL values of the MAI group with eyes closed were significantly higher than those of the control group (P<0.05 or P<0.01). The differences of each measurement index of the FAI group and control group were not statistically significant (P>0.05). The differences of MSY and CA of the MAI group and control group with eyes opened were statistically significant (P<0.05). The differences of each measurement index of unstable ankles and stable ankles of the MAI group and FAI group were not statistically significant (P>0.05).Conclusion: Significant abnormal balance control ability exists in patients with MAI, while no significant abnormal balance control ability exists in patients with FAI. Source

Liu X.,Shanghai Research Institute of Sports Science | Xu L.,Shanghai Research Institute of Sports Science
Chinese Journal of Rehabilitation Medicine

Objective: To explore whether the swimming or running affect the bone mineral density (BMD) of girls in puberty. Method: A sample of 58 girls with bone age 10-12 years participated in the study: 14 runners (RG), 25 swimmers (SG) and 19 age-matched controls (CG). BMD was determined by Lunar Prodigy DXA; bone age was assessed by CHN-05. Result: (1) After body surface area (BSA) controlled, the BMD of SG (0.552 g/cm2)in arms was higher than that of CG(0.517 g/cm2, 6.8%) and RG (0.511 g/cm2, 8.6%) (P<0.05). The BMD of RG (0.798 g/cm2) in legs was higher than that of SG (0.746 g/cm2, 7.0%) and CG (0.754 g/cm2, 5.8%) (P<0.05), there was no significant differnce among groups in total BMD and total BMD excluded skull. (2) The lean mass (LM) of SG was higher than that of RG and CG in arms, the LM of RG was higher in legs, the LM of CG was lower than that of RG and SG. (3) the extracurricular exercise time of CG was 111.1 min per week, lower than that of RG (661.4 min) and SG (705.6 min), P<0.01. Conclusion: Regular swimming or running can locally affect BMD of female adolescents. The effects are associated with sports-specificity. It suggested that different sports can affect BMD in early stages of the youth. It is recommend that female adolescents should take swimming or running regularly to improve BMD of arms or legs. Source

Sun M.,Shanghai Research Institute of Sports Science | Shen W.,Shanghai JiaoTong University | Zhong M.,Shanghai JiaoTong University | Wu P.,Shanghai JiaoTong University | And 2 more authors.
Cardiovascular Research

Aims In this study, we investigated the interaction between exercise-induced mitochondrial adaptation of large vessels and the effects of chronic anabolic androgenic steroids (AASs). Methods and results Four groups of SpragueDawley rats were studied: (i) sedentary, (ii) sedentary + nandrolone-treated, (iii) aerobic exercise trained, and (iv) trained + nandrolone-treated. Aerobic training increased the levels of aortic endothelial nitric oxide synthase (eNOS) and heme oxygenase-1 (HO-1) in accordance with improved acetylcholine-induced vascular relaxation. These beneficial effects were associated with induction of mitochondrial complexes I and V, increased mitochondrial DNA copy number, and greater expression of transcription factors involved in mitochondrial biogenesis/fusion. We also observed enhanced mitochondrial autophagy pathway activity, including increased conversion of LC3-I to LC3-II and greater expression of beclin1 and autophagy-related protein-7 (ATG7). The levels of thiobarbituric acid-reactive substances and protein carbonyls remained unchanged, whereas significant increases in catalase and mitochondrial manganese superoxide dismutase (MnSOD) levels were observed in the aortas of trained animals, when compared with sedentary controls. Nandrolone increased oxidative stress biomarkers and inhibited exercise-induced increases of eNOS, HO-1, catalase, and MnSOD expression. In addition, it also attenuated elevated peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1a) and mitofusin- 2 expression, and further up-regulated LC3II conversion, beclin1, ATG7, and dynamin-related protein-1 expression. Conclusion These results demonstrate that nandrolone attenuates aortic adaptations to exercise by regulating mitochondrial dynamic remodelling, including down-regulation of mitochondrial biogenesis and intensive autophagy. © 2013 © The Author 2013. Published by Oxford University Press on behalf of the European Society of Cardiology. Source

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