Achieving Peak Endurance: Fueling Up for Success (2024)

Have you ever wondered how some athletes seem to complete one endurance event after another, without hitting the wall?

Well I have, and it used to baffle me. Especially after I’d hit the wall during a 13 mile run! I mean, some of these people are completing 13 marathons in 13 days, and consecutive ultra ironman events.

I’m here to shed some light on how much nutrition plays a role in fueling for endurance events. Alongside mental strength and resilience, I believe that proper fuel can carry you much further than you think is possible.

Pre-event, during-the-event, and post-event all require slightly different strategies, but for the sake of this piece we are going to look at carbs, protein, water, electrolytes and caffeine.

During an endurance event such as a marathon or 70.3 ironman, your total moving time can be anywhere between 3 - 8 hours, so it’s critical to understand what energy stores the body is tapping into, and how you can replenish these stores to maintain physical activity for an ungodly number of hours.

We store carbs in the form of glycogen, which is found in our muscles and liver. The body seeks these glycogen reserves and uses them to stabilize our blood sugars which allows for optimal muscle function.

Protein is heralded as the muscle building supplement that our favorite Instagram bodybuilders ingest at alarming rates. But you needn’t worry, I’m not here to tell you that you should be eating 1 chicken breast per mile of the Boston, London, or Tokyo marathon. Every cell in our body contains protein, meaning we need it in our diet to help repair broken down cells and make new ones. This is especially the case during an endurance event.

It shouldn’t come as news to you that we all need water. Water is the lubricant for our muscles and joints, and it also helps to keep our core body temperature in check. So when sweating, we need to increase the water we drink. But you can take on too much water if you aren’t careful, and this is where electrolytes come in.

Electrolytes have been amazing for me during endurance events. I have Himalayan salt on almost every meal and consume a SIS hydration tablet every morning. Electrolytes are essential to the normal function of the cells in our body, including muscle function. Sodium is the key ingredient to look out for.

I had to include caffeine, not just because I’m addicted to the stuff, but also because I have felt the benefits of a caffeine hit pre and during long events. This one is a personal preference though, as everyone’s caffeine tolerance will be different. I’ve been a 3-a-day coffee drinker for 10+ years, so to feel the benefits of a caffeine hit when I need it most, I will go cold turkey 7 days before an event.

You’ve heard of carb loading, right? This is a real thing and should be taken seriously.

As we said above, the body turns to carbs for energy, so it’s important that we have enough in storage when it’s needed. From experience, having the largest meal at lunch time the day before a race is better than having a huge meal for dinner (unless you have a later start time), as you want to give your body time to digest. And take it from me, reduce the fiber at least 24 hours before the race. Sipping on an energy drink such as Gatorade is a great way to increase those sodium and potassium stores and they’re easy to digest.

I’ve also been sucked into consuming way too much protein for my 154 pound body! I can now confidently say, after trial and error, that approximately 100 grams per day in the lead up (and every day to be honest) is sufficient for me.

And finally, on race day, it can be tempting to want to eat close to the event so that you have enough energy to keep you fueled, but this is a mistake. You want your last meal about 3 hours prior to the start line, as your body should digest the food and begin to store it. Getting caught out with a heavy stomach on the race course is no fun.

British Cycling recommends taking on around one gram of carbohydrate per kilo of bodyweight per hour during racing – if you weigh 70kg, this would be around 70g of carbs.

The American College of Sports Medicine recommends 30-60g carbohydrates per hour for moderate exercise and up to 90g during ultra-endurance events.

During the race you want easy to digest, convenient snacks that won’t cause brain fog because of a stubborn wrapper. My go-to for years has been energy drinks, gels, and bars. All of which are relatively easy to carry on you and they provide variety for the taste buds - nothing worse than feeling like you’re eating sawdust AGAIN after being on your feet for 6 hours!

And finally, my favorite, my saving grace: coffee. A nice, hot flat white will do wonders for the mental stamina required to complete ultra events. Now of course if you’re running a marathon or doing anytime timed, then stopping to place a coffee order is not really viable, so this one should be saved for the crazy ones who enjoy slower forms of torture, such as a distance walk or ultra event.

On this point, I’ve always found joy in consuming whatever I regard as a treat - mine is coffee, yours may well be a packet of Skittles. Whatever it is, consuming one here and there isn’t going to affect your body during the race itself, so give yourself a boost by chomping down that bag of colorful sweets.

This is when protein starts to play a bigger role, and you can begin to ease off the carbs.

Repairing our broken down, aching and tired muscles should be the priority. And there’s no better source to do that than protein. Shakes, meat, fish, lentils, eggs, beans, quinoa - get it all in (depending on your food preferences of course).

Around 20 grams of protein post-event is enough to stimulate muscle recovery and synthesis. Any more than 30 - 35G per meal will likely be wasted in oxidation or converting excess protein into fat stores.

And as with most things 'endurance’, little and often works here. Try to incorporate 15 - 20G protein per meal post-race.