It’s been previously recommended to place a few drops of peppermint oil into your palms, rub them together, and cup your hands over your mouth and nose to breath in deeply. In a landmark study evaluating the influence of odors on athletic performance, researchers investigated the impact of different scents on perceived performance workload and mood.
The researchers had 40 participants carry out a treadmill test. After this, they took a Task Load Index Test (a subjective measurement of mental and physical workload). All this was done while breathing through a nasal cannula (a device used to deliver supplemental oxygen). During baseline testing, the participants completed the tests with un-odored, low-flow oxygen presented through the nasal cannula. Then in different experimentations separated by 48 hours, the researchers intermittently introduced Peppermint oil, Jasmine oil, and dimethyl sulfide (a compound with a powerful sulfur odor). Analysis of the final data revealed that the introduction of the Peppermint essential oil resulted in participants experiencing reduced perceived physical workload, temporal workload, levels of exertion, and more exceptional self-evaluated performance. In the tests with Jasmine essential oil, results were on par with the baseline control tests, while the introduction of the dimethyl sulfide resulted in significantly increased perceived workload and levels of exertion.
In short, participants reported that their workouts were less stressful (at the same objective levels of intensity) and that they were performing better when Peppermint oil was introduced. The researchers suggested that the variances in perceived workload and levels of exertion may be due to the effects of odors on the nervous system. The smell of Peppermint may have a positive influence on awareness and one’s attention to the environment and task at hand.
In another study, researchers recruited 12 participants to participate in an experiment investigating the influence of ingested Peppermint oil on exercise performance. One day before the beginning of the trial period, baseline evaluations of vital signs and various pulmonary function tests (including forced necessary capacity, peak expiratory flow rate, and peak inspiratory flow) were taken. Next, the participants underwent a Bruce protocol treadmill test. This is a test wherein their metrics of exercise performance were measured as they ran to complete exhaustion while the speed and incline of the treadmill progressively increased.
The participants were then asked to consume one 500 mL bottle of mineral water mixed with .05 mL of Peppermint essential oil for the following ten days. They were also asked to refrain from any high-intensity exercise and to maintain their regular diet. A second Bruce protocol treadmill test was conducted following the 10-day supplementation period. After a one-day rest period, vital signs and pulmonary function tests were repeated. The results were far more extreme than the researchers had hypothesized, with participants experiencing an increase in distance and time to exhaustion on the second treadmill test. Participants also exhibited statistically significant improvements in peak inspiratory flow (the maximum amount of air inhaled in one breath) and post-test heart rate. Although several factors were considered, based upon previous research, it is believed these effects may be due to a combination of Peppermint’s ability to stimulate the central nervous system and reduce the tension of the smooth muscles of the arteries.