2. Materials and Methods
fatigue
AIDS
Sixteen non-heat-acclimated, trained male and female runners were recruited for this randomized, double-blind, crossover, and placebo-controlled study. An a priori power calculation (G*power, v. 3.1.9.4) indicated 12 participants would be required for a one-way ANOVA analysis with the alpha set at 0.05, power of 0.80, and an effect size of 0.4 for the time trial performance distance covered (km), as derived from a previous study evaluating the effects of menthol mouth rinsing on 3 km running performance [The inclusion criteria for participants were the following: (a) 18–40 years of age, (b) healthy, as assessed by the Exercise and Sport Science Australia adult pre-exercise screening tool [Participants visited the laboratory on three occasions: a preliminary testing and familiarization visit, experimental visit 1, and experimental visit 2. Visits were scheduled at least 72 h apart and at the same time of day (±1 h) to avoid any influence of diurnal variation. Participants were instructed to refrain from exercise and the consumption of alcohol or ergogenic aids for 24 h, and from engaging in behaviors (e.g., sauna bathing) that might otherwise influence body temperature or induce fatigue. The use of mints, chewing gum, mouthwash, or any peppermint-containing products was prohibited within 2 h of each visit. Furthermore, participants were instructed to refrain from strenuous exercise for 48 h prior to each visit and to replicate their sleep regimen the night before each trial. Participants filled out a 24 h dietary recall log before each experimental visit and were instructed to repeat the same dietary intake 24 h before each subsequent visit. Dietary recall logs were compared before the experimental trials to ensure similar dietary intake prior to data collection.