Briefly inhaling the scent of dark chocolate before and during a workout could meaningfully improve a gymgoer’s performance—and even suppress hunger—according to a new peer-reviewed study.

Key Facts

The report in Frontiers in Physiology found that exposing someone working out to chocolate smells immediately before and between weightlifting sets significantly increased the number of repetitions they could do without the participants feeling they were putting forth any greater effort.

The trial’s 23 participants—all male, and averaging 23 years old—had all fasted for at least 10 hours before exercising, and inhaled the smell of chocolate from a jar for 30 seconds between each set of leg extensions at 80% of their max weight.

Dark chocolate was found to be more impactful than milk chocolate, with men who inhaled a 90% cocoa variety able to do about 18 more leg extensions than those using a placebo.

Those who smelled a 60% cocoa milk chocolate scent added about 9 repetitions, according to the study.

Smelling dark chocolate was also found to suppress appetite in trial participants by reducing hunger and increasing feelings of fullness before exercise, while milk chocolate had no impact on appetite (but those studied said it smelled better).

Crucial quote

“Seeing a substantial increase in repetitions without the athletes feeling like they were exerting themselves any harder is a fascinating psychobiological outcome," Mohamed Nashrudin bin Naharudin, the study’s senior author and an assistant professor of sports science at the University of Malaya in Malaysia, said in a statement.

What we don't know

What other smells may boost performance in the gym. The study's authors said they don't think chocolate is the only food with an odor that may help, but said it is pretty universally loved and recognized as a reward.

“A person likely needs to find the odor familiar and appealing— or at least not repulsive—to trigger the psychological shift in appetite that’s needed to see a performance boost,” Nashrudin Naharudin said.