Dark Chocolate Scent Adds 18 Leg-Extension Reps in 23-Man Exploratory Trial

Researchers randomized participants across three sessions separated by at least four days. Each man smelled 90% dark chocolate, 60% milk chocolate, or water for 30 seconds at multiple time points while rating appetite and then performed repeated leg-extension sets to failure. The dark-chocolate condition produced one extra set and 18 additional repetitions; milk chocolate yielded nine extra repetitions. Hunger, desire to eat, and prospective consumption scores fell while fullness rose only with the darker scent.

Related work by Marie-Eve Mathieu has shown peppermint and citrus odors can alter perceived exertion, yet those trials likewise used small, fasted, single-sex samples. The present design cannot separate pharmacological effects of cocoa volatiles from placebo or attentional mechanisms, and the overnight fast may have amplified any appetite-performance interaction not seen under fed conditions.

Evidence quality is low: this is a small, single-exercise, within-subject pilot lacking allocation concealment, female participants, or performance measures beyond one session. Next studies require a registered, adequately powered crossover or parallel RCT that includes both sexes, fed and fasted states, and at least one field-based endurance or strength endpoint measured over multiple weeks.