How can I make sure I take on enough fuel during the bike and run legs of a triathlon?

Joel Enoch explains how to make sure you get all the nutrients you need for completing the bike and run legs

how to make sure you're taking enough fuel on race day

In general, you have enough stored carbohydrates in the form of glycogen for up to 90mins, albeit this can vary by individual and intensity. But when taking on energy products, the classic wisdom is around 60g of carbs per hour in an easily digested form like gels and blocks. That’ll meet the needs of most when it comes to fuelling events up to around 3-4hrs. So do you really need to train your gut to take on more fuel? For most people, arguably not. But if you’re racing long and at a consistently high intensity, then it’s a yes.


There are hurdles to overcome, though. The capacity of the body to absorb carbs during exercise is reduced during exercise as blood’s shunted away from the digestive system to the working muscles. This is individual but can be trained to handle more energy at a given intensity.

Nutritionist Asker Jeukendrup showed that more carbohydrate can be absorbed by taking on more than one type of carbohydrate. It’s for this reason that many manufacturers produce gels with glucose and fructose in combination.

Also, ensure adequate fluid intake (around 100ml for every 8g of carbs) and sodium (around 50mg per 100ml) are taken with carbs as they help to ‘co-transport’ through the gut lining; reduce fat and fibre intake for race time to accelerate gastric emptying; and make sure you find what nutritional products work for you before practising with these at increasing intensities in the eight weeks before your event.

Joel Enoch is a sports scientist and triathlon coach, who’s helped athletes of all abilities reach their multisport goals