# Peppermint's Primary Component, L-Menthol, Increases Physical Power Output and Exercise Time

## Significant Findings:

"Exercise time was an average of 2 minutes greater and average power output increased in the L-Menthol condition."

## Abstract:

### Purpose

The study investigated the effect of a non-thermal cooling agent, L-menthol, on exercise at a fixed subjective rating of perceived exertion (RPE) in a hot environment.

### Method

Eight male participants completed two trials at an exercise intensity between ‘hard’ and ‘very hard’, equating to 16 on the RPE scale at ~35 °C. Participants were instructed to continually adjust their power output to maintain an RPE of 16 throughout the exercise trial, stopping once power output had fallen by 30%. In a randomized crossover design, either L-menthol or placebo mouthwash was administered prior to exercise and at 10 min intervals. Power output, $\stackrel{˙}{V}$O2, heart rate, core and skin temperature was monitored, alongside thermal sensation and thermal comfort. Isokinetic peak power sprints were conducted prior to and immediately after the fixed RPE trial.

### Results

Exercise time was greater (23:23 ± 3:36 vs. 21:44 ± 2:32 min; P = 0.049) and average power output increased (173 ± 24 vs. 167 ± 24 W; P = 0.044) in the L-menthol condition. Peak isokinetic sprint power declined from pre-post trial in the L-menthol l (9.0%; P = 0.015) but not in the placebo condition (3.4%; P = 0.275). Thermal sensation was lower in the L-menthol condition (P = 0.036), despite no changes in skin or core temperature (P > 0.05).

### Conclusion

These results indicate that a non-thermal cooling L-menthol lowered thermal sensation, resulting in an elevated work rate, which extended exercise time in the heat at a fixed RPE.

Published in: European Journal of Applied Physiology, 2017

Authors: Flood T. PhD., Waldron M., & Jeffries O. PhD,

Full Study: https://pubmed.ncbi.nlm.nih.gov/28508114/