One smell helped people squeeze out more reps in the gym—and it’s probably in your pantry

Move over creatine and protein shakes.

A surprising new gym companion may help boost your next workout: dark chocolate.

A new study published in the https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2026.1834757/full">Frontiers of Physiology journal reveals a link between dark chocolate and improved physical performance.

Participants of the study were tasked with smelling either chocolate or plain water during a leg extension workout routine, with those who smelled dark chocolate completing more repetitions.

The 23 participating men regularly worked out through resistance training, with each one participating in three lab sessions following a night of at least 10-hour fasting.

During each session—which were separated from the others by four days—each participant was exposed to either 90% dark chocolate, 60% milk chocolate, or water.

The study follows research into chocolate’s health benefits, particularly around the flavonoid compound, which some https://www.healthline.com/health-news/sniffing-chocolate-boost-workout-hunger#How-dark-chocolate-and-scent-can-affect-exercise-performance">have linked to improved vascular and brain health.

Each participant had to smell the odor prior to beginning their exercise, and were asked to perform leg extensions until they could no longer continue.

At various points in the exercise, participants would smell the designated odor again for at least 30 seconds, rating the pleasantness of the odor as well as how satiated they felt.

Dark chocolate showed more significant effects on athletic performance.

At 90% dark chocolate, participants performed 18 more leg extension repetitions, and 9 more when smelling 60% milk chocolate.

The repetitions were compared to those completed during the control session, where participants smelled plain water.

Additionally, while dark chocolate was shown to relieve the feeling of hunger, milk chocolate was rated as more pleasurable to smell during the study.

While surprising, the study has several limitations, including the small participant pool and the unclear link between olfactory stimulation and physical endurance and athletic performance, although the line of research is a growing field, with researchers also exploring the effects of  peppermint and lavender.

“Olfactory stimuli may alter appetite, affective responses, and exercise performance through psychobiological processes,” the study explains. “However, whether odor-induced changes in appetite and pleasantness translate into measurable improvements in resistance exercise performance remains unclear.”