Menthol Mouth Rinsing and Cycling Performance in Females Under Heat Stress
in International Journal of Sports Physiology and PerformancePurpose: The effects of menthol (MEN) mouth rinse (MR) on performance, physiological, and perceptual variables in female cyclists during a 30-km independent time trial (ITT) were tested. Methods: The participants (n = 9) cycled for 30 km in hot conditions (30°C [0.6°C], 70% [1%] relative humidity, 12 [1] km/h wind speed) on 2 test occasions: with a placebo MR and with MEN MR. Handgrip and a 5-second sprint were measured before, following the first MR, and after the ITT. Ratings of perceived exertion Borg 6 to 20, thermal sensation, and thermal pleasantness were recorded every 5 km. Core temperature and heart rate were recorded throughout. Results: The ITT performance significantly improved with MEN MR by 2.3% (2.7%) relative to the placebo (62.6 [5.7] vs 64.0 [4.9] min P = .034; d = 0.85; 95% confidence interval, 0.14 to 2.8 min). The average power output was significantly higher in the MEN trial (P = .031; d = 0.87; 95% confidence interval, 0.9 to 15.0 W). No significant interaction of time and MR for handgrip (P = .581, η2 = .04) or sprint was observed (P = .365, η2 = .103). Core temperature, heart rate, ratings of perceived exertion, and thermal sensation did not significantly differ between trials at set distances (P > .05). Pleasantness significantly differed between the placebo and MEN only at 5 km, with no differences at other TT distances. Conclusion: These results suggest that a nonthermal cooling agent can improve 30-km ITT performance in female cyclists, although the improved performance with MEN MR is not due to altered thermal perception.
Gavel is with the Faculty of Science, Ontario Tech University, Oshawa, ON, Canada. Logan-Sprenger and Good are with the Faculty of Health Sciences, Ontario Tech University, Oshawa, ON, Canada. Jacobs and Thomas are with the Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada. Jacobs is also with the Dept of Pharmacology & Toxicology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
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