Author(s): LUAN, C., GONG, L., WANG, X., LI, J., WANG, Y., NI, Z. , Institution: BEIJING SPORT UNIVERSITY, Country: CHINA, Abstract-ID: 1399

INTRODUCTION:
BCAAs have a potential role on fat oxidation. However, the impact of supplementation with BCAA during exercise is unknown.This study aims to investigate whether the intake of BCAAs can increase fat oxidation during endurance exercise and enhance endurance performance.

METHODS:
Eleven recreationally active young male participated in this randomized, double-blind, crossover design study. Participants reported to the laboratory on two occasions, BCAA or placebo (0.2g/kg) was supplemented in the morning and evening for 3 consecutive days in each experiment, and exercise was started 30 minutes after supplementation in the morning on the 4th day. Each test started with 60 minutes of cycling at 60%VO2max, followed by time to exhaustion(TTE) cycling at 80%VO2max. During one hour of constant load exercise(CLE),heart rate, rating of perceived exertion(RPE), and visual analogue scores(VAS)were recorded; gas was collected to calculate the rate of carbohydrates(CHO)and fat oxidation, and fingerstick blood was collected to test blood glucose and lactate. Elbow venous blood was collected on an fasting, pre-exercise and post-exercise to measure free fatty acids(FFA), triglycerides(TG), β-hydroxybutyrate(β-HB), insulin, and blood ammonia.

RESULTS:
There were no significant differences in TTE time,HR, RPE, VAS, blood glucose, and blood lactate during the exercise (p>0.05). The VAS value post-exercise of BCAA was significantly lower than placebo (p=0.042). At the 30th, 40th and 50th minutes of 1h CLE, the rate of fat oxidation of BCAA was significantly higher than placebo (p<0.05). During the 60th minute of 1h CLE and throughout the TTE exercise period, the rate of CHO oxidation of BCAA was significantly higher than placebo (p<0.05). There were no significant differences in blood glucose and TG between the two groups over the three time periods (p>0.05). The FFA in the two groups pre-exercise were significantly lower than fasting (P<0.01), and post-exercise the FFA and β-HB were significantly higher than fasting and pre-exercise (P<0.001), but there was no significant difference between the two groups (P>0.05). Post-exercise insulin levels of two groups were significantly higher than fasting and pre-exercise (p<0.001), and the insulin levels of placebo were significantly higher than BCAA post-exercise (p<0.05). The blood ammonia level of BCAA pre-exercise was significantly higher than fasting (p<0.001) and higher than placebo at the same time (p<0.05), and the blood ammonia level of placebo post-exercise was significantly higher than pre-exercise (p<0.01) and higher than BCAA at the same time (p<0.05).

CONCLUSION:
Supplementation with BCAAs doesn’t have a significant effect on endurance performance, but it can increase fat oxidation during exercise, save carbohydrate consumption during exercise, and use more carbohydrates for energy in subsequent sprint exercises. Supplementation with BCAAs can also effectively reduce the level of fatigue immediately after exercise.