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The anabolic hormone response to a lower-body resistance exercise bout in conjunction with oral BCAA supplementation

  • Bill Campbell
  • Paul La Bounty
  • Austin Oetken
  • Mike Greenwood
  • Richard Kreider
  • Darryn Willoughby
Open Access
Poster presentation
  • 4.5k Downloads

Keywords

Growth Hormone Resistance Exercise Acute Bout Anabolic Hormone mTOR Phosphorylation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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.

Copyright information

© Campbell et al; licensee BioMed Central Ltd. 2009

This article is published under license to BioMed Central Ltd.

Authors and Affiliations

  • Bill Campbell
    • 1
  • Paul La Bounty
    • 2
  • Austin Oetken
    • 2
  • Mike Greenwood
    • 2
  • Richard Kreider
    • 3
  • Darryn Willoughby
    • 2
  1. 1.University of South Florida – Exercise and Performance Nutrition LaboratoryTampaUSA
  2. 2.Baylor University – Exercise and Biochemical Nutrition LaboratoryWacoUSA
  3. 3.Texas A&M University – Exercise and Sport Nutrition LaboratoryCollege StationUSA

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