Coffee is historically popular with cyclists. From pros training on fasted rides on just a double espresso, to Sunday riders eagerly anticipating a cafe stop, coffee has become synonymous with cycling.

The (legally) performing enhancing effect of caffeine has been well researched, and as such is employed in everything from short, maximum efforts in time trials to long 100-mile hill-crunching sportives.

At rest, it’s true that caffeine is a diuretic, meaning that your morning espresso at your desk will make you want to visit the toilet much sooner than if you went without it. This is because caffeine stimulates the kidneys to increase the removal of water from your bloodstream.

You don’t need to worry about this effect during exercise though. Exercise itself overrides this diuretic effect, because the body’s effort is going into ensuring you perform as efficiently as possible. This means that you can enjoy the performance-enhancing benefits of caffeine without worrying about whether it will affect your hydration status.

This doesn’t mean you can ignore your hydration, as your body will still expel water and salt through sweat and your raised respiration rate. Needless to say, you should still make sure that you continue to take on board enough water and electrolytes through your training session.

Emma Barraclough is the Senior Sports Nutritionist for Science in Sport
www.scienceinsport.com