Scientists Say Chocolate Could Make Your Workout Easier

Smelling chocolate before and during resistance exercise may slightly improve workout performance, according to a new study published in Frontiers in Physiology.

Researchers found that exposure to dark or milk chocolate odors helped moderately trained men complete more leg extension repetitions without reporting higher perceived effort. The study was exploratory and involved a small group, so the findings should not be treated as broad fitness advice yet.

Chocolate Scents Tested During Leg Exercise

The study included 23 healthy men in their early to mid-20s with moderate resistance training experience.

Participants fasted for at least 10 hours before the test. Researchers then divided them into three groups. One group smelled liquefied dark chocolate with 90% cocoa, another smelled liquefied milk chocolate with 60% cocoa, and the control group smelled odorless water.

The participants performed leg extensions, an exercise where a person sits and straightens the lower legs against weighted resistance.

Before exercise, they reported hunger, fullness, desire to eat, and intention to eat soon. During the workout, they rated hunger and desire to eat after smelling their assigned sample for 30 seconds.

Dark Chocolate Reduced Hunger More

The two chocolate odors had different effects on appetite.

Dark chocolate odor reduced hunger, desire to eat, and intention to eat when compared with milk chocolate and water. It also increased feelings of fullness before exercise.

Milk chocolate smelled more pleasant to participants, but it did not significantly change hunger or appetite.

Both Chocolate Odors Increased Exercise Volume

Both chocolate scents helped participants complete more work.

Senior author Dr Mohamed Nashrudin bin Naharudin said sniffing 90% dark chocolate added about 18 more leg extension repetitions, while 60% milk chocolate added about nine repetitions compared with the water control.

The important finding was that participants did not report feeling like they were working harder, despite completing more repetitions.

Why the Smell May Have Helped

The researchers believe familiar food smells may influence appetite and exercise through learned associations.

Dark chocolate may act as a cue for a rich and filling food, pushing the body into an expected state of fullness before eating. Milk chocolate may work differently by creating a more pleasant training environment rather than reducing hunger directly.

The study suggests that anticipating food through smell may trigger some psychological or physical responses linked to eating, especially after fasting.

Mechanism Still Not Confirmed

The researchers did not measure hormones, digestive responses, or brain activity, so the exact mechanism remains unclear.

The study also had several limits. It included only 23 moderately trained young men, and the chocolate odors may not have been equal in strength. The odorless water control may also have made it clear to some participants that they were in the control group.

Larger studies with more diverse participants are needed before the results can be applied more widely.

Other Food Smells May Also Work

The researchers do not believe chocolate is necessarily unique.

Naharudin said chocolate has strong reward associations, but other familiar and appealing food odors may also produce similar effects. However, this has not been tested yet.

For now, the study shows a narrow but interesting result: chocolate smell may help fasted exercisers complete more resistance exercise volume without making the workout feel harder.