Abstract

The purpose of the study was to investigate the acute effects of two different quantities of branched-chain amino
acids (BCAA) on the recovery of muscle function following high-intensity resistance training in trained individuals.
Five resistance-trained males were recruited and performed baseline assessments of, countermovement (CMJ) and
squat jump (SJ), peak (PP) and mean (MP) power (6s Cycle Sprint) and perceived muscle soreness (RMS). In a
counterbalanced, single-blind fashion, participants were provided with either, placebo or 6 g or 18 g BCAA 20 min
prior to, and immediately after completion of a high-intensity strength session (ST). At 24 h post ST, all assessments
were completed under all three experimental conditions. Following ST, there were significant decrements in all
measures of muscle function across conditions when compared to baseline values (P<0.05). However, ingestion
of 6 g and 18 g BCAA was shown to significantly attenuate these decrements in comparison to placebo (P<0.05).
A dose-response for BCAA was also present as significant differences (P<0.05) were shown between ingestion of
6 g and 18 g; CMJ (18 g: 59.1 cm, 6 g: 57.7 cm, placebo: 56.6 cm), SJ (18 g: 54.0 cm, 6 g: 52.8 cm, placebo: 51.7
cm), PP (18 g: 1133 W, 6 g: 1107 W, placebo: 1044 W), MP (18 g: 1011 W, 6 g: 986 W, placebo: 972 W), soreness
(18 g: 81 mm, 6 g: 91 mm, placebo: 100 mm). BCAA ingested acutely before, and immediately following intensive
resistance training attenuates the decrement observed in muscle function, while alleviating symptoms of muscle
soreness. These small but significant findings support the proposed ergogenic benefits of BCAA supplementation,
but also highlight a potential dose-response, with a higher dose (18 g) having a significantly greater effect than a
lower dose (6 g) in trained individuals.