Exercise-induced muscle damage is reduced in resistance-trained males by branched chain amino acids: a randomized, double-blind, placebo controlled study

Abstract

BackgroundIt is well documented that exercise-induced muscle damage (EIMD) decreases muscle function and causes soreness and discomfort. Branched-chain amino acid (BCAA) supplementation has been shown to increase protein synthesis and decrease muscle protein breakdown, however, the effects of BCAAs on recovery from damaging resistance training are unclear. Therefore, the aim of this study was to examine the effects of a BCAA supplementation on markers of muscle damage elicited via a sport specific bout of damaging exercise in trained volunteers.MethodsTwelve males (mean ± SD age, 23 ± 2 y; stature, 178.3 ± 3.6 cm and body mass, 79.6 ± 8.4 kg) were randomly assigned to a supplement (n = 6) or placebo (n = 6) group. The damaging exercise consisted of 100 consecutive drop-jumps. Creatine kinase (CK), maximal voluntary contraction (MVC), muscle soreness (DOMS), vertical jump (VJ), thigh circumference (TC) and calf circumference (CC) were measured as markers of muscle damage. All variables were measured immediately before the damaging exercise and at 24, 48, 72 and 96 h post-exercise.ResultsA significant time effect was seen for all variables. There were significant group effects showing a reduction in CK efflux and muscle soreness in the BCAA group compared to the placebo (P<0.05). Furthermore, the recovery of MVC was greater in the BCAA group (P<0.05). The VJ, TC and CC were not different between groups.ConclusionThe present study has shown that BCAA administered before and following damaging resistance exercise reduces indices of muscle damage and accelerates recovery in resistance-trained males. It seems likely that BCAA provided greater bioavailablity of substrate to improve protein synthesis and thereby the extent of secondary muscle damage associated with strenuous resistance exercise. Clinical Trial Registration Number: NCT01529281.

The Acute Effects Different Quantities of Branched-Chain Amino Acids Have On Recovery of Muscle Function

“…The attenuations witnessed after ingestion of BCAA were slightly less prominent than those reported by Howatson et al, [2] (~9%) following repetitive concentrically loaded, eccentric muscle actions. However, this could be attributed to the more 'representative' nature of the ST in this study, as opposed to protocol completed by Howatson et al, [2].…”

“…Statistically significant results have been reported when supplementing varied dosages of BCAA alongside resistance training, from 3 g pre and post exercise to 20 g pre and post exercise [2,13,15]. Although this data has shown that BCAA can be used to reduce the effects of EIMD following resistance training, to date, no scientific research has explored whether a lower dose of BCAA has the same magnitude of effect as a higher dose.…”

“…Participant's RMS was assessed via a 200 mm visual analogue scale, as used previously [2]. While performing a static wall squat, with knees at 90°, participants were instructed to make a line on the scale, depicting their RMS.…”

“…The scale is labelled 'No pain or discomfort' (0 mm) to 'Extreme pain and/ or constant discomfort' (200 mm). The distance between the 0 mm point and the participant's mark was then measured in mm and used to represent perceived soreness [2].…”

“…Adaptations including increased muscular hypertrophy, improved glycolytic capacity and increased neuromuscular power have been well established [1]. However, it is widely acknowledged that intensive resistance training leads to exercise-induced muscle damage (EIMD) that can last several days [2]. Symptoms of EIMD include decreased muscle function, reduced range of functional movement [3,4], increased muscle soreness and swelling [5], and increased serum intramuscular proteins [6].…”