Key Takeaways
- Smelling chocolate before and during exercise could improve workout performance.
- Dark chocolate odour reduced hunger, increased fullness, and helped participants complete more repetitions.
- Milk chocolate odour did not significantly change appetite but made the training environment more pleasant.
A new study published in Frontiers in Physiology suggests that smelling chocolate before and during resistance exercise may enhance workout performance. The research involved a small group of moderately trained young men, who performed leg extensions after being exposed to different odours.
The participants were divided into three groups: one smelled liquefied dark chocolate with 90% cocoa content, another smelled liquefied milk chocolate with 60% cocoa, and the control group smelled odorless water. Before exercise, they reported their hunger levels, fullness, desire to eat, and intention to eat soon.
According to senior author Dr Mohamed Nashrudin bin Naharudin, dark chocolate odour reduced participants' hunger, desire to eat, and intention to eat compared with milk chocolate and water. It also increased feelings of fullness before exercise. Milk chocolate was perceived as more pleasant but did not significantly alter appetite.
The study found that both chocolate scents helped participants complete more work during the leg extension exercise. Dr Nashrudin noted that smelling 90% dark chocolate added about 18 more repetitions, while 60% milk chocolate added about nine repetitions compared with the water control group.
Interestingly, despite completing more repetitions, participants did not report feeling like they were working harder. This finding suggests that 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 might create a more pleasant training environment rather than reducing hunger directly.
The researchers believe that anticipating food through smell may trigger some psychological or physical responses linked to eating, especially after fasting. However, they caution that the exact mechanism remains unclear as no measurements were taken for hormones, digestive responses, or brain activity during the study.
Dr Nashrudin also noted that the study had several limitations, including its small sample size of only 23 moderately trained young men and potential differences in the strength of the chocolate odours. The odorless water control may have made it clear to some participants that they were part of the control group.
While the findings are promising, larger studies with more diverse participants are needed before these results can be applied more widely. Dr Nashrudin does not believe chocolate is necessarily unique and suggests that other familiar and appealing food odours might also produce similar effects.
