Influência da utilização combinada do enxágue bucal e da aplicação tópica de l-mentol na performance e nas respostas afetivas de corredores amadores

Abstract

The objective of the study was to investigate the effects of combined mouthrinse and topical application of L-menthol on perceptual and runner performance under controlled environmental conditions (22 ± 2° C and 30- 60% RH) in a 10-km time trial test on a motorized treadmill. Twelve healthy men (age: 31.7 ± 3.8 years, height: 174 ± 0.1 cm, body mass: 74.5 ± 10.4 kg, maximal oxygen uptake (VO2max): 68.3 ± 7.7 ml/kg/min and body fat percentage (BF%): 15.3 ± 5.7%) participated in this randomized, double-blind, crossover study. Participants performed a familiarization session, a control test (CON) and two randomized experimental trials involving a non-thermal cooling intervention by the combined application of a L-menthol mouthrinse and topical L-menthol gel (MEN), and a combined placebo application simulating both types of cooling interventions (PLA). All perceptual measures (thermal sensation, thermal comfort, ratings of perceived exertion and affective response) were obtained for every km completed of the test. The results showed that performance times were lower in MEN (~ 2.5%, 1.16 min, p = 0.025) and PLA (~ 2.8%, 1.3 min, p = 0.003) compared to the CON condition (46.6 ± 5.5 min), but were not different from each other. All perceptual responses increased over time in all conditions (p < 0.0001), but only the thermal sensation was lower in the MEN condition compared to the other conditions. The present study demonstrated that L-menthol strategies are interesting methods to promote fresh sensations in any environmental condition and exercise model. However, the present study demonstrated that improvements in performance can not be associated with perceptual improvements due to the administration of L-menthol, since the PLA condition was the condition with the shortest test time in the absence of significant psychological modulations. Thus, the ergogenic benefit of MEN may be partially due to the placebo effect.