The purpose of this study was to examine the role of branched-chain amino acid (BCAA) supplementation during recovery from intense eccentric exercise.Methods:
Twenty-four non-weight-trained males were assigned to one of two groups: one group (supplementary, SUP) ingested BCAA beverages (n = 12); the second group (placebo, PLA) ingested artificially flavored water (n = 12). Diet was controlled throughout the testing period to match habitual intake. The eccentric exercise protocol consisted of 12 × 10 repetitions of unilateral eccentric knee extension exercise at 120% concentric one repetition maximum. On the day of the exercise, supplements were consumed 30 min before exercise, 1.5 h after exercise, between lunch and dinner, and before bed. On the following 2 d, four supplements were consumed between meals. Muscle soreness, muscle function, and putative blood markers of muscle damage were assessed before and after (1, 8, 24, 48, and 72 h) exercise.Results:
Muscle function decreased after the eccentric exercise (P < 0.0001), but the degree of force loss was unaffected by BCAA ingestion (51% ± 3% with SUP vs −48% ± 7% with PLA). A decrease in flexed muscle soreness was observed in SUP compared with PLA at 48 h (21 ± 3 mm vs 32 ± 3 mm, P = 0.02) and 72 h (17 ± 3 mm vs 27 ± 4 mm, P = 0.038). Flexed muscle soreness, expressed as area under the curve, was lower in SUP than in PLA (P = 0.024).Conclusions:
BCAA supplementation may attenuate muscle soreness, but it does not ameliorate eccentric exercise-induced decrements in muscle function or increases in reputed blood markers of muscle damage, when consumed before exercise and for 3 d after an eccentric exercise bout.