Peppermint essential oil ( Mentha piperita L.) increases time to exhaustion in runners

Purpose This study aimed to evaluate the capacity of peppermint essential oil to improve the physical performance of runners in running protocol until exhaustion. Methods In a clinical, randomized, double-blind, cross-over and controlled study, fourteen male recreational runners (37.1 ± 2.0 years; 24 ± 1.1 kg/m 2 ; 53.1 ± 1.7 mL kg min) performed two runs to exhaustion at 70% of VO 2max , after intake of 500 mL of water added with 0.05 mL of peppermint essential oil (PEO) or placebo (PLA), plus 400 mL of the drink during the initial part of the exercise. Records were made of body temperature (BT), thermal sensation (TS), thermal comfort (TC), subjective perception of effort (SPE), sweat rate (SR), and urine volume and density. Results Time to exhaustion was 109.9 ± 6.9 min in PEO and 98.5 ± 6.2 min in PLA ( p = 0.009; effect size: 0.826). No significant changes were observed in the values of BT, TS, TC, SPE, SR, lost body mass, and urine volume and density ( p > 0.05). Conclusion Peppermint essential oil added to water before and during a race significantly increases the time to exhaustion of recreational runners but without altering BT, TS, TC, or hydration status, so the mechanisms involved were not clarified in this study. Brazilian registry of clinical trials (ReBEC) RBR-75zt25z.