This article is part of the supplement: Proceedings of the Sixth International Society of Sports Nutrition (ISSN) Conference and Expo
Poster presentation
The anabolic hormone response to a lower-body resistance exercise bout in conjunction with oral BCAA supplementation
-
* Corresponding author: Bill Campbell Campbell@coedu.usf.edu
1 University of South Florida – Exercise and Performance Nutrition Laboratory, Tampa, FL, USA
2 Baylor University – Exercise and Biochemical Nutrition Laboratory, Waco, TX, USA
3 Texas A&M University – Exercise and Sport Nutrition Laboratory, College Station, TX, USA
Journal of the International Society of Sports Nutrition 2009, 6(Suppl 1):P7 doi:10.1186/1550-2783-6-S1-P7
The electronic version of this article is the complete one and can be found online at: http://www.jissn.com/content/6/S1/P7
| Published: | 31 July 2009 |
© 2009 Campbell et al; licensee BioMed Central Ltd.
Background
BCAAs (leucine, isoleucine, and valine), particularly leucine, activate key enzymes in protein synthesis after physical exercise. Research has demonstrated that BCAAs increase mTOR phosphorylation and activate p70 S6 kinase in human muscle via an Akt-independent pathway. The extent to which BCAAs influence the anabolic hormone response in conjunction with resistance exercise is not well established. A randomized, double-blind, placebo-controlled study was performed to evaluate the effects of BCAA ingestion in conjunction with an acute bout of lower-body resistance exercise (RE) on various anabolic hormones.
Methods
20 recreationally active males ingested a BCAA supplement (120 mg/kg/bw) (n = 10; 24.4 years; 178.3 cm; 85.4 kg) or a placebo (n = 10; 21 years; 176.8 cm; 83 kg) at 3 time points: 30 minutes prior to RE, and immediately pre-RE and immediately post-RE. Subjects performed 4 sets of leg press and 4 sets of leg extension at 80% 1 RM to failure. Rest periods between sets and exercises was approximately 150 seconds. Venous blood was sampled at baseline; 30 min later, immediate postexercise, 30 min post-exercise; 2 hrs post-exercise, and 6 hrs post-exercise for serum insulin, growth hormone (GH), and free insulin-like growth factor-1 (IGF-1). A two-way ANOVA with repeated measures was utilized to analyze the data.
Results
Data are reported as means ± SD at baseline; 30 min later, immediate postexercise, 30 min post-exercise; 2 hrs post-exercise, and 6 hrs post-exercise. Insulin values were 19.2 ± 7.8, 23.0 ± 9.6, 25.3 ± 12.9, 24.8 ± 14.3, 19.0 ± 9.0, 15.8 ± 6.4 and 22.0 ± 10.5, 22.0 ± 10.9, 27.8 ± 9, 24.1 ± 8.7, 17.9 ± 8.8, 21.2 ± 12.8 uIU/mL for the BCAA and Placebo groups, respectively. A significant main effect for time was observed (p < .001), but no significant main effect for group (p = .758) or significant interaction (p = .465) was observed for insulin. GH values were .41 ± .81, .64 ± .97, 1.9 ± 2.2, 1.5 ± 2.6, .23 ± .32, 2.6 ± 4.0 and .07 ± .09, .84 ± 1.3, 2.2 ± 1.9, 2.2 ± 3.8, .28 ± .76, .36 ± .56 ng/ml for the BCAA and Placebo groups, respectively. A significant main effect for time was observed (p = .021), but no significant main effect for group (p = .672) or significant interaction (p = .217) was observed for GH. Free IGF-1 values were 1.3 ± .83, 1.2 ± .72, 1.2 ± .77, 1.4 ± .91, 1.1 ± .74, .95 ± .64 and 1.3 ± .43, 1.2 ± .43, 1.6 ± .54, 1.5 ± .57, 1.4 ± .46, 1.1 ± .53 ng/ml for the BCAA and Placebo groups, respectively. A significant main effect for time was observed (p = .014), but no significant main effect for group (p = .569) or significant interaction (p = .356) was observed for free IGF-1.
Conclusion
An acute bout of lower-body RE significantly increases insulin, GH, and IGF-1 in the immediate post-exercise time period, but oral ingestion of BCAA at a dosage of 120 mg/kg/bw does not impart an additional effect of the hormonal response to the resistance exercise stimulus.