Smelling chocolate between sets at the gym pushed men to complete far more repetitions than they managed with no scent at all, a new study has found.
The men had not eaten for at least ten hours. Yet the boost showed up anyway, and it was strongest with dark chocolate. They did not feel like they were working any harder, even as their rep counts climbed.
That gap suggests the brain, not the muscles, is where the smell did its work, hinting that a simple sensory trick could help people train on an empty stomach.
How the test worked
The team recruited 23 moderately trained men in their early-to-mid-20s. Each arrived at the lab having skipped food for at least ten hours. They each sat down at a leg-extension machine, a staple of resistance training, and lifted until they could not finish another set.
The work was led by Mohamed Nashrudin bin Naharudin, an assistant professor and the study’s senior author, from the Faculty of Sports and Exercise Science at the University of Malaya (UM) in Kuala Lumpur. He wanted to know whether a smell on its own could change how much a person could lift.
Each man came back for three separate visits, one per scent. Before and between every set, a researcher held a freshly made liquid under his nose. The options were dark chocolate at 90% cocoa, milk chocolate at 60% cocoa, or plain water as a neutral comparison.