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The effects of BCAA and leucine supplementation and lower-body resistance exercise on the ERK 1/2 MAPK pathway signal transduction


A randomized, double-blind, placebo-controlled study was performed to evaluate the effects of oral BCAA and leucine supplementation on the ERK1/2 MAP Kinase signal transduction pathway in conjunction with an acute bout of lower-body resistance exercise (RE).


30 males (22.5 yrs; 81.1 kg) ingested either leucine (60 mg/kg/bw), BCAA (120 mg/kg/bw), or placebo. Supplementation was ingested at 3 time points (1/3 of the total dosage at each time point): 30 minutes prior to RE, and immediately pre- and post-RE. The subjects performed 4 sets of leg press and leg extension at 80% 1 RM to failure. Rest periods between sets and exercises were approx. 150 seconds. Muscle biopsies (via the Bergstrom technique) were obtained from the vastus lateralis at four time points: baseline and 30 min, 2 hrs, and 6 hrs post RE and sampled for MEK1 and ERK1/2 activation (via phosphoELISA kits). Participants were fasted for the duration of the investigational period. Other variables (serum markers and other skeletal muscle proteins) were analyzed as part of a larger investigation, but only MEK1 and ERK1/2 and their activation/phosphorylation state are presented here. Skeletal muscle variables (MEK1 and ERK1/2) were transformed to delta values and analyzed via a 3 (group) × 4 (time points) repeated measures MANOVA. Univariate ANOVAs (Bonferroni adjusted) were conducted as follow-up tests to the MANOVA. Post-hoc tests of the interaction effects demonstrated in the ANOVA were investigated via an independent samples T-test.


There was a main effect for time for MEK1 at the 2 hr time point (p = .005). No main effect for group or a group × time interaction was observed for MEK1. Relative to ERK1/2, there were no main effects for time. A main effect for group revealed that the BCAA supplementation significantly elevated ERK1/2 activation as compared to the leucine (p = .001) and placebo groups (p = .001). A group × time interaction revealed that BCAA supplementation significantly elevated ERK1/2 activation at the 2 hr post and 6 hr post time points in comparison with the Leucine (p = .045) and placebo groups (p < .001).


BCAA supplementation increased the phosphorylation status of ERK1/2 in conjunction with RE at 2 and 6 hours post-exercise. Leucine supplementation did not have any effect on ERK1/2 activation.

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Correspondence to Bill Campbell.

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Open Access This article is published under license to BioMed Central Ltd. This is an Open Access article is distributed under the terms of the Creative Commons Attribution 2.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Campbell, B., La Bounty, P., Oetken, A. et al. The effects of BCAA and leucine supplementation and lower-body resistance exercise on the ERK 1/2 MAPK pathway signal transduction. J Int Soc Sports Nutr 5, P19 (2008).

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  • Resistance Exercise
  • Acute Bout
  • Skeletal Muscle Protein
  • Univariate ANOVAs
  • Leucine Supplementation