4. Discussion
MEN
HEAT
This is the first study of its kind to examine the performance and perceptual effects of a menthol-enhanced energy gel during exercise in the heat. The main finding was that the menthol energy gel was not superior to a placebo gel in terms of the 20 min time trial running performance, physiology, perceptions, or cognitive performance in trained runners following 40 min of moderate treadmill running under heat stress. While the results are largely in contrast to previous research on menthol use in sport, the current findings may be limited to indoor exercise scenarios, the protocol employed, and the specific characteristics of the participants (i.e., trained, non-heat-acclimated, recreational runners).The potential benefits of menthol use during endurance exercise in the heat include improved thermal comfort and sensation, reduced RPE, and enhanced time trial/time to exhaustion performance [Unlike previous studies conducted among endurance athletes [There was no significant perceptual benefit for the MEN vs. PLA in terms of TS, TC, RPE, or affect. The perceptual cooling effect of menthol during use in sport has been observed at lower concentrations (i.e., 0.01–0.1% menthol) by previous investigators [Finally, there was no difference in the POMS scores or cognitive performance in terms of the reaction time, accuracy, or cognitive efficiency or when comparing the MEN and PLA during and after exercise. These results agree with previous investigations of the perceptual and cognitive effects of menthol during exercise in the heat. Saldaris and colleagues [The strengths of the current study include a well-controlled laboratory setting and randomized, double-blind, and placebo-controlled study design, although it was not without limitations. The lack of familiarization with the preloaded time trial protocol in the heat chamber may have introduced a learning effect across the two experimental visits, although the subsequent analysis demonstrated that there was no trial order effect on time trial performance between the first and second visits. The maximum speed of the treadmill could also be considered a limitation, which was corrected for by allowing participants to increase the gradient of the incline upon reaching the maximal speed. Therefore, the total vertical distance covered was also measured as a performance outcome. Female participants were scheduled to avoid variation in their menstrual cycle, with the second experimental trial scheduled within three days of the first, and both were scheduled to coincide with the follicular phase, when the TDespite recruiting only trained runners from campus and local area running clubs, the maximal aerobic capacity (VO