If you’ve watched television anytime in the last 30 years, chances are you’ve seen a commercial for York Peppermint Patties: “When I bite into a York Peppermint Patty, I get the sensation…”of being a Viking king reigning over a mighty tundra, of being on top of a cold and wintry mountain, of riding a luge at over 100 miles per hour. As it turns out, the iconic advertisements aren’t too far off–mint (and specifically, menthol) actually does make us feel cooler, and researchers are discovering fresh ways to apply this to athletic performance.
“Broadly speaking, menthol tends to make us feel cooler, especially when exercising in the heat,” explains Dr. Russ Best of the Waikato Institute of Technology in New Zealand. “This may impact how hard we find the exercise, or how comfortable we are while exercising in a hot environment.”
Mint contains menthol, an aromatic compound with sweet and spicy flavors. Menthol triggers cold-sensitive receptors in the skin, resulting in a cooling sensation that feels super fresh. It also works its magic in the mouth, stimulating the specialized nerve endings that allow you to feel cold. When those nerve endings come into contact with menthol, an electrical impulse travels to the brain, tricking it into believing it’s is up to 40 degrees Fahrenheit cooler than it actually is.
This trickery cascades throughout the body, says Best: “We’ve seen menthol or peppermint supplementation affect how people perceive cooling, ease of breath, and reaction time across a range of activities in the last 40 years or so. Even further back, there is evidence that menthol was used as a treatment for respiratory infections in the late 1800s.”
Now, researchers are getting better at understanding menthol’s effects in a sports performance context. Menthol was first studied as a topical application for pain tolerance and management, but has evolved to better understand its use in temperature management. Topical menthol provides a cooling sensation due to alterations in skin blood flow. Best says menthol also causes lower sweat rates in athletes, becoming more sensitive to cold air flow or increases in core temperature. In one study, this menthol effect was found to increase running performance in hot and humid climates by up to 6%.
Ingestion also makes a difference. In one study, cyclists who swished with a menthol mouth rinsed extended their time to exhaustion by 9%. In another, researchers found menthol ingestion, when paired with beverages of different temperatures (normal water, cool water, ice slushie), can improve performance in tropical conditions–the perceptual cooling effects of menthol were enhanced by the physiological cooling effects of each drink’s temperature.
Though there are options for menthol inhalation (usually in forms designed for stuffy noses), Best says it hasn’t been found to be of benefit from an athletic standpoint: “I wouldn’t recommend inhalation as the effects are perhaps too potent and very short-lasting, so we’re much more likely to cause irritation or detract from performance than enhance it.”
To take a fresh approach to your nutrition strategy for hot and humid races, Best recommends making a mint-water infusion using peppermint or cornmint from the garden. Extra-strong mints or chewing gum with a high menthol concentration can also produce shorter, sharper menthol hits. Best does not advise using mouthwashes, as they tend to contain alcohol or similar chemicals that can dry out the mouth.
It’s important to note, however, that when swilled or ingested, menthol can affect the thirst response. “The same receptors that detect change in our blood osmolality (a measure of water content in the blood) are also stimulated by menthol, so we may inadvertently blunt our thirst response,” explains Best. “If using menthol [water] on its own, I’d recommend it only for sprint or Olympic distances, where hydration may not be as limiting a factor.”