Can coffee improve your workout? The science of caffeine and exercise

Neil Clarke, Coventry University

Caffeine is one of the most researched substances reported to help athletes perform better and train longer and harder. As a result, professional and amateur sportspeople often take it as a performance-enhancing “ergogenic” aids for a wide range of activities. These include intermittent exercise such as football and racket sports, endurance exercise such as running and cycling, and resistance exercise such as weightlifting.

But while most research looks at the effects of pure caffeine consumed as tablets with water, in the real world most people get their caffeine from coffee, energy drinks or other products like special gels or chewing gum. So will drinking a cup of joe before your workout actually make a difference? The answer could depend as much on your genes as what kind of coffee you’re drinking.

Scientists think caffeine affects the body chemical adenosine, which normally promotes sleep and suppresses arousal. Caffeine ties up the receptors in the brain that detect adenosine and so makes it more alert.

But it may also increase stimulation of the central nervous system, making exercise seem like it involves less effort and pain. In high-intensity activities such as resistance training or sprinting, it may increase the number of fibres used in muscle contractions, meaning movements can be more frequent and forceful.

Faster, higher, stronger

Research has shown that pure caffeine can help endurance athletes run faster and cycle for longer. It can help footballers to sprint more often and over greater distances, and basketball players to jump higher