If you're taking on any endurance challenge, one thing is certain - your body needs fuel, and lots of it. Whether out on the trails, sat in the saddle, walking an ultra or adding swimming in an Ironman, getting your fuelling right is the difference between thriving and surviving.

Running out of energy mid-event is the nightmare scenario no one wants to face. So, how do you keep your engine running smoothly over hours (or even days) of effort? The answer: carbohydrates.

Let’s break down everything you need to know about fuelling for an ultra-endurance race, from what to eat, when to eat it, and how to train your gut to handle it all.