Your Genes May Decide If Caffeine Actually Boosts Your Workout

Rise and Grind: Lots of gym goers swear by caffeine to give their workouts an extra boost, while others drink a cup of coffee before lifting and feel nothing. Research has shown that caffeine can improve athletic performance and focus, but if you’re not seeing much of a difference, it may not be all in your head. A new study looked into why caffeine affects people differently during workouts and suggests the answer may trace back to genetics.

The Study: Researchers ran a randomized, placebo-controlled crossover trial with 94 resistance-trained men and women, sorted into three groups based on which version of the CYP1A2 gene they carried, which influences how quickly the liver metabolizes caffeine. Each participant then took three milligrams per kilogram of caffeine or a placebo before bench press and squat tests, and researchers measured how fast they moved the weight. Caffeine improved strength and endurance performance overall, but those with the fast-metabolizing version of the gene saw the biggest gains.

The Takeaway: If your coffee never seems to hit before a workout, that might be your biology talking, not a lack of effort.

Keep in Mind: This research focused on one specific caffeine dose and two specific lifts, so results could look different for endurance sports like running or cycling.