The purpose of this study is to determine if a dietary supplement containing branched chain amino acids will reduce the muscle soreness that sometimes occurs in the days following exercise.

Supplementation with branched chain amino acids (BCAAs) has been used to stimulate muscle protein synthesis following exercise. The purpose of this study was to determine if supplementation with BCAAs in combination with glucose would reduce exercise-induced delayed onset muscle soreness (DOMS). Using a double-blind crossover design, 20 subjects (11 females, 9 males) were randomly assigned to either BCAA (n=10) or placebo (n=10) groups. Subjects performed a squatting exercise to elicit DOMS and rated their muscle soreness every 24 hours for four days following exercise while continuing to consume the BCAA or placebo. Following a three-week recovery period, subjects returned and received the alternate BCAA or placebo treatment, repeating the same exercise and DOMS rating protocol for the next four days. BCAA supplementation in female subjects resulted in a significant decrease in DOMS versus placebo at 24 hours following exercise (p = 0.018). No significant effect of BCAA supplementation versus placebo was noted in male subjects, nor when male and female results were analyzed together. This gender difference may be related to dose per body weight differences between male and female subjects.

Inclusion Criteria:

• Men (n=9) and women (n=11) aged 18-25 who engaged in no more than one hour of light to moderate intensity physical activity per week were recruited from the Greater Burlington, Vermont area.

Exclusion Criteria:

• individuals who engaged in more than one hour per week of light to moderate physical activity
• had been involved in strict athletic competition or weight training in the past six months
• were pregnant or nursing, had a known muscular disease, diabetes mellitus, cardiovascular disease, respiratory disease, and/or were currently taking a protein-based dietary supplement