Image: @precisionfandh
IT’S ALL ABOUT THE CARBS
When you exercise at high intensity, your body’s primary source of fuel is carbohydrate. At the beginning of an exercise session, this carbohydrate will mostly come from glycogen, stored in your muscles and liver. Roughly speaking, as long as you have eaten recently and sensibly, these stores will last for around 90 to 120 minutes before becoming depleted to such a level that your performance suffers. To continue swimming at high intensity, you need to eat or drink something with more carbohydrate. Energy gels are a convenient – but not the only – way to do this. They are usually supplied in waterproof sachets that are easy to carry (such as inside your costume or the sleeve of your wetsuit) and quick to consume. Solid food, on the other hand, can take too long to chew – and if you’ve ever tried chewing while swimming, you’ll know it isn’t easy.