Athletes and sports bodies are currently putting extra scrutiny on the possible benefits of using menthol in the anticipation of a sweaty Tokyo 2021 Olympics, which are occurring at hot and humid time of the year. The two main forms of menthol-use in question are topical (through lotions or creams applied to skin) or orally (usually through mouth-rinsing).
However, there is no scientific consensus on the best or safest way to use menthol, which is why researchers published a study in Sports Medicine seeking to provide an expert-based consensus recommendation on the optimal way for athletes, practitioners and researchers to use menthol.
For the study, the researchers gathered 14 expert contributors and had them form an ultimate group consensus on menthol’s best use. To do this, they used the Delphi Method, which is a consensus-making technique designed for groups, where the group anonymously responds to successive rounds of questionnaires where the responses are aggregated and inform the next round of questionnaires to help the group to come to a final representative conclusion.
This study adopted a modified three-round questionnaire process, in which the 14 contributors first voted to agree/disagree on 96 statements based off the existing literature on menthol, and then vote to support/change updated group statements in the next round, finishing with a final round to deliberate the remaining undecided key statements.
The panel arrived at a consensus on a total of 62 statements (38 on topical application and 24 on oral rinsing) which form the basis for a formal understanding of the benefits of menthol use in high temperature sports exercise. The study concludes by giving the green light for elite athletes and teams to explore the use of menthol in preparation for the Tokyo Olympics.
Some key takeaways were:
- Menthol (both topical and oral) is ergogenic in hot environments
- Topical menthol application can improve endurance performance, through both a single high dosage and multiple repeated smaller dosages
- Orally applied menthol improves endurance and time-trial performance when applied repeatedly throughout exercise
- Oral and topical menthol application reliably improve recipients’ heat-stress perception and lowers discomfort when exercising in hot environments - that cooling sensation works!
- It carries a small potential risk of heat-related illness because menthol’s cooling effect may mask heightened body-temperature levels in cases of prolonged exercise in heat
- Menthol application doesn’t confer an unfair advantage in sport and is fair game for everyone, from weekend warriors to elite Olympians
Reference: Barwood, M. J., et al. "Menthol as an ergogenic aid for the Tokyo 2021 Olympic Games: An expert-led consensus statement using the Modified Delphi Method." Sports Medicine50.10 (2020): 1709-1727.