Influence of Menthol on Recovery From Exercise-Induced Muscle Damage

This study assessed the influence of menthol, a cold receptor agonist, on recovery from exercise-induced muscle damage (EIMD). Forty-seven healthy males were allocated to a Control (CON, n = 18), Placebo (P, n = 14), or 4.0% Menthol (M, n = 15) condition. Participants were familiarized with a testing battery (TB) including: perception of lower-body muscle soreness, hip flexion/abduction range of motion, vertical jump (VJ), and the agility T-test. Muscle damage was induced on day 1 using 40 x 15-m sprints with a 5-m deceleration zone. The TB immediately followed this and was repeated once-daily for 5 days. Over this time, participants in M and P applied gels to the lower body immediately after sprinting and twice-daily thereafter, whereas CON did nothing. Dependent variables were compared by condition using the Kruskal-Wallis test ([alpha] = 0.05), and mean differences with 90% confidence intervals were calculated with small, moderate, and large effects. A significant difference by condition (p < 0.05) in muscle soreness was found, and moderate to large effects were observed in the reduction of muscle soreness with P, compared with M or CON, indicating a placebo effect. A reduction in VJ height across all conditions was observed, with a significant effect (p < 0.05) by condition, and moderate to large effects (1-5 cm) were observed in its preservation with menthol, compared with P or CON. No other differences were observed. These findings raise the possibility that menthol influences recovery of lower-body power after EIMD, and this may have practical implications for menthol's use when recovery of muscle power is important.