Gavel et al. 2024, How cool is that? The effects of menthol mouth rinsing on exercise capacity and performance — a systematic review and meta-analysis

Systematic review and meta-analysis (Sports Med Open 10(1):18), pooling 10 studies, 22 outcomes and 153 participants. Menthol mouth rinsing produced no significant change in exercise capacity or performance overall (SMD 0.12; 95% CI −0.08 to 0.31; P = 0.23). The estimate was slightly larger for endurance activity (SMD 0.14; 95% CI −0.09 to 0.36) than for strength/power (0.05), but the difference was not significant (P = 0.70), and environmental temperature showed no significant moderating effect (P = 0.62). The authors flag a high risk of bias — most trials lacked familiarisation and adequate blinding — and conclude menthol rinsing is unlikely to harm and may, at best, have a small positive influence on endurance performance.