Smelling Chocolate May Boost Workout Performance, Study Suggests

Simply smelling dark chocolate before a weightlifting session may help individuals complete significantly more repetitions without increasing their perceived exertion, according to a study published in Frontiers in Physiology. The research suggests that olfactory cues can influence appetite and exercise performance.

In the study, 23 healthy men in their early to mid-20s, who had fasted for at least 10 hours, were divided into three groups. Each group was exposed to the scent of either liquified dark chocolate (90% cocoa), liquified milk chocolate (60% cocoa), or water, which served as a control. Participants then performed leg extension exercises in sets of 10, with 3.5-minute rest intervals between sets.

Volunteers who smelled the dark chocolate aroma completed approximately 18 additional repetitions compared to those who smelled water. The milk chocolate group performed about nine more repetitions than the control group. Notably, participants in both chocolate-scented groups reported feeling less hunger, a reduced desire to eat, and a greater sense of fullness after smelling the respective aromas, compared to the control group. This effect on appetite perception was assessed 30 seconds after the odor exposure.

Researchers theorize that the scent of dark chocolate acts as a learned cue, signaling a rich and satiating food to the brain, thereby creating an anticipatory state of fullness. This psychological shift may allow individuals to focus more on physical exertion and less on hunger signals, leading to increased training volume without a corresponding increase in perceived effort.

The study's senior author, Dr. Mohamed Nashrudin bin Naharudin from the University of Malaya, described the outcome as a fascinating psychobiological phenomenon, where increased repetitions were achieved without subjects feeling they were working harder. While dark chocolate yielded a more pronounced effect, milk chocolate also demonstrated a performance boost, which researchers attribute to its sweeter scent acting as a hedonic reward cue rather than primarily influencing metabolic hunger signals.

The researchers believe that other appealing food odors, particularly those strongly associated with satiety and familiarity, could potentially elicit similar effects. They suggest that the strong, universally recognized reward associations with chocolate make it a particularly effective cue, but other foods with similar learned associations might also influence exercise performance and appetite perception.