Menthol is an organic compound obtained from mint oils that is known for its cooling taste and feel. Menthol does not actually cool the tongue or the skin when it makes contact with either; it just tricks the brain into perceiving a cooling effect.
Can you see where this one is headed? That’s right: In a 2009 study, researchers found that rinsing the mouth out with a menthol solution every 10 minutes increased cycling endurance in the heat by 9 percent compared to a placebo. In this case, the cyclists were asked to ride at a fixed intensity until they were exhausted. Perceived exertion measurements revealed that menthol made this fixed intensity feel easier to the subjects, and that’s why they sustained it longer.