TOPLINE

Sniffing chocolate before sets of leg extensions curbed appetite and increased training volume but not perceived exertion, a pilot study found.

METHODOLOGY

• Researchers conducted a randomized, double-blind crossover trial and enrolled 23 healthy, resistance-trained men (mean age, 23.4 years), with participants fasting for at least 10 hours before each trial session.
• Participants were exposed to three odors on separate visits: 90% dark chocolate, 60% milk chocolate, and a water-based control. 
• Appetite (hunger, fullness, desire to eat) and odor pleasantness were assessed using 100-mm visual analog scales, and perceived exertion was measured using the Borg CR10 scale. 
• Participants performed repeated sets of 10-repetition leg extensions at 80% of their 10-repetition maximum to exhaustion, with 3.5-minute rest intervals. 
• Odors were presented before each set, followed by assessments of appetite, pleasantness, and ratings of perceived exertion.

TAKEAWAY

• Total repetitions increased by about 18 when participants were exposed to the dark chocolate odor and by about nine with the milk chocolate odor, compared with the water control.
• The dark chocolate odor lowered pre-exercise hunger and the desire to eat but increased feelings of fullness compared with control.
• The milk chocolate odor increased the perception of odor pleasantness compared with control but didn’t suppress appetite.
• Perceived exertion rose across all sets but did not differ across the different odor conditions.

IN PRACTICE

“These findings indicate that chocolate-related odors can modulate appetite and hedonic responses while increasing resistance-exercise volume, without clear increases in post-set perceived exertion,” the authors wrote. “Chocolate-related odors may offer a nonnutritive approach to support fasted resistance exercise, although further work is needed to confirm the mechanisms and generalizability of these effects.”

SOURCE

The study, led by Mohamed Nashrudin bin Naharudin of the University of Malaya in Kuala Lumpur, Malaysia, was published online in Frontiers in Physiology.

LIMITATIONS

This exploratory study had limitations. The sample size was small and homogeneous, consisting of young resistance-trained men. Claims are inferential because no blood hormones or neural pathways were measured. In addition, there may have been slight variations in smell intensity between the chocolate samples, and the water sample was odorless, which could have given participants clues about whether they were part of the control group.

DISCLOSURES

No funding was provided. The authors declared that this work was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest.