In a recent study, men who simply smelled chocolate while performing leg extensions completed more repetitions than those who did not, without rating the workout as harder. The effect was strongest for dark chocolate, suggesting the scent alone can influence performance.
The researchers propose that familiar food aromas may shape appetite and motivation through brain mechanisms. Because the men did not perceive the extra work as more tiring, the aroma may have eased the sense of effort rather than changing muscle strength.
The study focused only on men, so it remains unclear whether a similar effect would occur in women.