Leg day may have an unexpectedly sweet performance boost. In a new study, men who smelled chocolate before and between sets of leg extensions completed significantly more repetitions – without feeling like they were working any harder.
Researchers at the University of Malaya in Malaysia split 23 healthy, moderately trained men in their early to mid-20s into three groups. Each group was exposed to one scent during the session: liquid dark chocolate with 90 percent cocoa, liquid milk chocolate with 60 percent cocoa, or odorless water as a control. All participants had fasted for at least 10 hours before testing, and each rated hunger and appetite ratings around the exposures.
The differences were striking. Sniffing the dark chocolate aroma added about 18 repetitions to the session’s leg extensions, while milk chocolate added about nine, compared with water. Perceived exertion did not budge – participants simply got more work done for the same felt effort. The study was published in the journal Frontiers in Physiology.
The two chocolates seem to work through different routes, the researchers argue. Dark chocolate dampened hunger and increased feelings of fullness before exercise, acting as a learned cue for a rich, satisfying food that “tricks the system into an anticipatory state of fullness,” said senior author Mohamed Nashrudin bin Naharudin. Milk chocolate, which participants rated as the most pleasant smell of the three, appears to have boosted performance simply by making the environment more rewarding.
The study adds to growing evidence that food-related signals can nudge the body in surprising ways – much like a blueberry compound that reprograms muscle cells to burn fat – and that the context around a workout matters nearly as much as the workout itself, a theme also visible in recent head-to-head diet trials.
The authors caution that the sample was small, included only young men, and measured no blood hormones or brain activity, so the mechanism remains speculative. Chocolate may not even be special: other familiar, appealing food smells could plausibly do the same job, though that idea has yet to be tested.
Sources
ScienceDaily: Smelling chocolate helped men complete more reps without feeling more tired
Frontiers in Physiology (journal)
Featured image: Wikimedia Commons, CC0 public domain.