Oral Resveratrol supplementation attenuates exercise-induced Interleukin-6 but not Oxidative Stress after a high intensity cycling challenge in adults.

Previous studies demonstrated that resveratrol (RES) is able to enhance antioxidant, anti-inflammatory and insulin actions in humans. It is unclear whether RES can be used as ergogenic aids to enhance high-intensity cycling exercise performance and attenuate the high-intensity exercise-induced oxidative stress and inflammation. This study investigated the effect of RES supplementation on oxidative stress, inflammation, exercise-induced fatigue, and endurance performance. Eight male athletes participated in this single-blind crossover designed study and randomly instructed to receive four days of either oral RES (480 mg per day, totally 1920mg) or placebo supplementation. The cycling exercise challenge at 80% maximal oxygen consumption with 60 rpm was performed following 4 days of either RES or placebo supplementation. The total cycling performance time was recorded. In addition, blood samples were obtained to analyze the changes in blood glucose, plasma non-esterified fatty acid, serum lactate dehydrogenase, creatine kinase, uric acid, total antioxidant capacity, malondialdehyde, tumor necrosis factor-α, and interleukin-6. The exhausting time of cycling exercise challenge was not significantly increased in RES compared to that in placebo. However, IL-6 response was significantly decreased during exercise challenge in RES trial, and there were no differences in blood biomarkers, fatigue factors, and antioxidative response. Oral RES supplementation can attenuate exercise-induced IL-6 response but not fatigue and oxidative stress, inflammation response. However, we infer that 4-day oral RES supplementation has no ergogenic property on enhancing the high-intensity cycling exercise performance.

Effect of green tea extract supplementation on glycogen replenishment in exercised human skeletal muscle.

The purpose of this study was to investigate the effects of 8-week green tea extract (GTE) supplementation on promoting postexercise muscle glycogen resynthesis and systemic energy substrate utilisation in young college students. A total of eight healthy male participants (age: 22·0 (se 1·0) years, BMI: 24·2 (se 0·7) kg/m2, VO2max: 43·2 (se 2·4) ml/kg per min) participated in this study. GTE (500 mg/d for 8 weeks) was compared with placebo in participants in a double-blind/placebo-controlled and crossover study design with an 8-week washout period. Thereafter, all participants performed a 60-min cycling exercise (75 % VO2max) and consumed a carbohydrate-enriched meal immediately after exercise. Vastus lateralis muscle samples were collected immediately (0 h) and 3 h after exercise, and blood and gaseous samples were collected during the 3-h postexercise recovery period. An 8-week oral GTE supplementation had no effects on further promoting muscle glycogen resynthesis in exercised human skeletal muscle, but the exercise-induced muscle GLUT type 4 (GLUT4) protein content was greater in the GTE supplementation trial (P<0·05). We observed that, during the postexercise recovery period, GTE supplementation elicited an increase in energy reliance on fat oxidation compared with the placebo trial (P<0·05), although there were no differences in blood glucose and insulin responses between the two trials. In summary, 8-week oral GTE supplementation increases postexercise systemic fat oxidation and exercise-induced muscle GLUT4 protein content in response to an acute bout of endurance exercise. However, GTE supplementation has no further benefit on promoting muscle glycogen resynthesis during the postexercise period.

Oral conjugated linoleic acid supplementation enhanced glycogen resynthesis in exercised human skeletal muscle.

Present study examined the effects of conjugated linoleic acid (CLA) supplementation on glycogen resynthesis in exercised human skeletal muscle. Twelve male participants completed a cross-over trial with CLA (3.8 g/day for 8 week) or placebo supplements by separation of 8 weeks. CLA is a mixture of trans-10 cis-12 and cis-9 trans-11 isomers (50:50). On experiment day, all participants performed 60-min cycling exercise at 75% VO2 max, then consumed a carbohydrate meal immediately after exercise and recovered for 3 h. Biopsied muscle samples from vastus lateralis were obtained immediately (0 h) and 3 h following exercise. Simultaneously, blood and gaseous samples were collected for every 30 min during 3-h recovery. Results showed significantly increased muscle glycogen content with CLA after a single bout of exercise (P < 0.05). Muscle glucose transporter type 4 expression was significantly elevated immediately after exercise, and this elevation was continued until 3 h after exercise in CLA trial. However, P-Akt/Akt ratio was not significantly altered, while glucose tolerance was impaired with CLA. Gaseous exchange data showed no beneficial effect of CLA on fat oxidation, instead lower non-esterified fatty acid and glycerol levels were found at 0 h. Our findings conclude that CLA supplementation can enhance the glycogen resynthesis rate in exercised human skeletal muscle.

Oral post-exercise garlic extract supplementation enhances glycogen replenishment but does not up-regulate mitochondria biogenesis mRNA expression in human-exercised skeletal muscle.

PURPOSE: Garlic extract (GA) is purported to enhance antioxidant and anti-inflammatory activity and glucose regulation in humans. The present study investigated the effects of post-exercise GA supplementation on GLUT4 expression, glycogen replenishment, and the transcript factors involved with mitochondrial biosynthesis in exercised human skeletal muscle. METHODS: The single-blinded crossover counterbalanced study was completed by 12 participants. Participants were randomly divided into either GA (2000 mg of GA) or placebo trials immediately after completing a single bout of cycling exercise at 75% Maximal oxygen uptake (VO2max) for 60 minutes. Participants consumed either GA (2000 mg) or placebo capsules with a high glycemic index carbohydrate meal (2 g carb/body weight) immediately after exercise. Muscle samples were collected at 0-h and 3-h post-exercise. Muscle samples were used to measure glycogen levels, GLUT4 protein expression, as well as transcription factors for glucose uptake, and mitochondria biogenesis. Plasma glucose, insulin, glycerol, non-esterified fatty acid (NEFA) concentrations, and respiratory exchange ratio (RER) were also analyzed during the post-exercise recovery periods. RESULTS: Skeletal muscle glycogen replenishment was significantly elevated during the 3-h recovery period for GA concurrent with no difference in GLUT4 protein expression between the garlic and placebo trials. PGC1-α gene expression was up-regulated for both GA and placebo after exercise (p < 0.05). Transcript factors corresponding to muscle mitochondrial biosynthesis were significantly enhanced under acute garlic supplementation as demonstrated by TFAM and FIS1. However, the gene expression of SIRT1, ERRα, NFR1, NFR2, MFN1, MFN2, OPA1, Beclin-1, DRP1 were not enhanced, nor were there any improvements in GLUT4 expression, following post-exercise garlic supplementation. CONCLUSION: Acute post-exercise garlic supplementation may improve the replenishment of muscle glycogen, but this appears to be unrelated to the gene expression for glucose uptake and mitochondrial biosynthesis in exercised human skeletal muscle.

Garlic supplementation attenuates cycling exercise-induced oxidative inflammation but fails to improve time trial performance in healthy adults.

BACKGROUND: Garlic extract has been shown to enhance antioxidant and anti-inflammation activities in humans. The present study investigated the effects of garlic supplementation on 40-km cycling time trial performance, exercise-induced oxidative stress, and inflammatory responses in healthy adults. METHODS: Eleven healthy males were recruited to perform this single-blind crossover study. Participants were randomly assigned to either garlic (garlic extracts 1000 mg/d for 4 weeks) or placebo trials. Following 4-wks of supplementation, participants performed a 40-km cycling challenge. Total cycling performance time and respiratory exchange ratio (RER) were recorded. Blood samples were collected every 10 km to determine exercise-induced oxidative stress, inflammation, and muscle damage. RESULTS: The 40-km cycling time trial performance was not improved following 4 weeks of garlic supplementation. However, 4-wk garlic supplementation significantly increased whole-body antioxidant capacity (total antioxidant capacity, TAC), and subsequently attenuated MDA, TNF-α, and LDH during the 40-km cycling exercise period (p < 0.05). There were no significant differences among the blood biomarkers glucose, NEFA, IL-6, UA, and CK respectively. The respiratory exchange ratio was similar between garlic and placebo trials. CONCLUSION: Four-week oral garlic supplementation attenuates exercise-induced oxidative inflammation and muscle damage during a 40-km bout of cycling. However, it appeared that 4-wk oral garlic had no ergogenic effect on cycling performance in healthy males.

Application of the Motor Abilities Assessment as Part of a Talent Identification System in Tennis Players: A Pilot Study.

In this study, we sought to develop a testing system to scientifically identify tennis talent. This testing system will provide helpful information for players who intend to pursue a professional tennis career. The experimental subjects were 18 college students consisting of 10 tennis players (including 4 soft tennis) and 8 basketball players (all males). The subjects were tested on their vertical jump, 60 m shuttle runs, and shoulder joint mobility to identify tennis talent. To statistically analyze the data, an R package was used to conduct a principal component analysis of the athletic performance indicators of the samples, and the samples were further classified via agglomerative hierarchical clustering. This study found that tennis players required more flexibility than basketball players. Regarding the differences between male and female soft tennis players, the unclassified results showed that there was a significant difference in explosive power. However, there was no significant difference in flexibility between genders. The research methods and results of this study can be used as a reference for others to build a system for identifying athletic performance characteristics in the future, and it is expected that the implementation of this system can provide sports coaches with more information for talent selection and improve the accuracy of their judgments, allowing athletes to play to their strengths.

Short-Term Oral Quercetin Supplementation Improves Post-exercise Insulin Sensitivity, Antioxidant Capacity and Enhances Subsequent Cycling Time to Exhaustion in Healthy Adults: A Pilot Study.

Aim: Quercetin has been reported to have antioxidant and anti-inflammatory properties on health promotion in human studies. The main purpose of this study was to investigate the effect of short-term oral quercetin supplementation on post-exercise whole-body energy metabolism. This study also aimed to determine the effects of supplementation on oxygen stress, inflammation, muscle damage, and high-intensity cycling exercise performance. Method: Twelve healthy participants, physically active students, were recruited to perform a randomized, single-blind crossover study. All subjects completed 7-days of quercetin (quercetin:1,000 mg per day for 7-days) and placebo supplementation in a randomized order. Supplement/placebo was combined with exercise consisting of 70% V̇O2max cycling for 60-min, followed by 3-h of recovery, then a subsequent single bout of cycling exercise with 75% V̇O2max to exhaustion. Time to exhaustion, indicators of muscle damage, as well as blood and gaseous parameters relating to energy metabolism, oxidative stress, inflammatory response, respectively, were determined. Results: The results showed that 7-day quercetin supplementation significantly attenuated the post-exercise glucose-induced insulin response, increased total antioxidant capacity (TAC) and superoxidase dismutase (SOD) activities, and mitigated malondialdehyde (MDA) levels during the recovery period (p < 0.05). While subsequent 75% V̇O2max cycling performance was significantly improved after quercetin treatment and accompanied by lower responses of interleukin 6 and creatine kinase at 24-h. However, it's noted that there were no significant responses in glucose, respiratory exchange rate, tumor necrosis factor-α (TNF-α), myoglobin, and high sensitivity C-reactive protein between quercetin and placebo trials. Conclusion: Our findings concluded that 7-day oral quercetin supplementation enhances high-intensity cycling time to exhaustion, which may be due in part to the increase in whole-body insulin-stimulated glucose uptake and attenuation of exercise-induced oxygen stress and pro-inflammation. Therefore, quercetin may be considered an effective ergogenic aid for enhancing high-intensity cycling performance among young adults.

Effect of Capsinoids Supplementation on Fat Oxidation and Muscle Glycogen Restoration During Post-exercise Recovery in Humans.

BACKGROUND: Capsinoids (CSN), the novel non-pungent capsaicin analogs have been reported to promote metabolic health and exercise tolerance. However, the effect of CSN on fat oxidation and changes in skeletal muscle glycogen levels during post-exercise recovery has not been investigated in humans. PURPOSE: We examined the effect of CSN supplementation on energy reliance, glycogen resynthesis and molecular proteins in the skeletal muscle of young adults during post-exercise recovery. METHODS: In this crossover-designed study, nine healthy adult male volunteers (aged 21.4±0.2 years, BMI 21.9±1.3 kg/m2) completed a 60-min cycling exercise at 70% VO2max. Participants consumed either CSN (12 mg, single dosage) or placebo capsules with a high-carbohydrate meal (2 g carb/kg bodyweight) immediately after exercise. Biopsied muscle samples (vastus lateralis), blood, and gaseous samples were obtained during 3h postexercise recovery period. RESULTS: We found that oral CSN supplementation right after exercise significantly altered the energy reliance on fat oxidation during recovery. This was evidenced by lower respiratory exchange ratio (RER) and higher fat oxidation rate in CSN trial. Despite this, acute CSN dosage does not contribute in enhancing the glycogen replenishment in skeletal muscle during 3h recovery. We identified no significant differences in postprandial glucose and insulin area under the curve in both trials. Western blot data showed an increased muscle GLUT4 expression, but no significant response of p-Akt/Akt ratio with CSN during post-exercise recovery. CONCLUSION: Our findings conclude that acute CSN intake could change energy reliance on fat oxidation but is unable to enhance muscle glycogen resynthesis during post-exercise recovery. Thus, ergogenic properties of CSN in relevance to muscle glycogen restoration following exercise needs to be further investigated in young adults.

Effects of Oral Resveratrol Supplementation on Glycogen Replenishment and Mitochondria Biogenesis in Exercised Human Skeletal Muscle.

The present study aimed to investigate the effect of oral resveratrol supplementation on the key molecular gene expressions involved in mitochondria biogenesis and glycogen resynthesis in human skeletal muscle. Nine young male athletes participated in the single-blind and crossover designed study. All subjects completed a 4-day resveratrol and placebo supplement in a randomized order while performing a single bout of cycling exercise. Immediately after the exercise challenge, the subjects consumed a carbohydrate (CHO) meal (2 g CHO/Kg body mass) with either resveratrol or placebo capsules. Biopsied muscle samples, blood samples and expired gas samples were obtained at 0 h and 3 h after exercise. The muscle samples were measured for gene transcription factor expression by real-time PCR for glucose uptake and mitochondria biogenesis. Plasma glucose, insulin, glycerol, non-esterified fatty acid concentrations and respiratory exchange ratio were analyzed during post-exercise recovery periods. The results showed that the muscle glycogen concentrations were higher at 3 h than at 0 h; however, there were no difference between resveratrol trial and placebo trial. There were no significantly different concentrations in plasma parameters between the two trials. Similarly, no measured gene expressions were significant between the two trials. The evidence concluded that the 4-day oral resveratrol supplementation did not improve post-exercise muscle glycogen resynthesis and related glucose uptake and mitochondrial biosynthesis gene expression in men.