Experience is as important as science when it comes to Ironman race nutrition. Here, five race winners share their wisdom.
Ironman triathlons are often won and lost on nutrition. They’re not the shorter distance triathlons, where you can get away with being low on blood sugar or short of salts. No matter how fit you are or how hard you’ve trained, the rigours of an Ironman can leave you bereft of all energy, but you can avoid this by fuelling yourself correctly. There’s a lot of information available and most of it is based on scientific research. The only problem is that it’s hard to recreate an Ironman in a scientific lab. Aside from the sheer distance involved there are so many variables, such as the course, aid stations and weather, and that’s before you even factor in each individual’s performances, equipment, strengths and weaknesses. While it’s essential to listen to all the evidence-based advice out there, it’s also worth listening to those with real race experience too.
We have gathered expert opinion from five professional Ironman athletes who’ve won it. For all their race-winning performances, they’ve all had times when they’ve got their nutrition wrong and suffered as a result. These experiences have helped them find solutions and a better way to do things. In this feature they share their secrets, so that you can get it right first time.
Double Ironman World Champion
In his autobiography I’m Here to Win (published by Center Street) McCormack says: “[During an Ironman] your muscles are demanding blood to supply them with oxygen, and your body takes the blood from your digestive tract and shunts it to your quads, calves, and so on. This limits your ability to digest anything complex, which is why you see people throwing up. Simple carbs are the only choice in this situation, but most of the carbohydrate products are maltodextrin based. That’s a simple sugar, but it’s a complex simple sugar, if that makes sense. Remember, to pass across the blood barrier and be used by the cells, all carbohydrates must be broken down to glucose.
“Now, if you break down maltodextrin, instead of getting one glucose molecule you might get five. But the process takes longer, and meanwhile your muscles are screaming for energy. So what I do is take the maltodextrin when my heart rate is at its lowest, because my body can spend more energy breaking down and storing that energy to keep those glycogen stores up. But as my heart rate climbs and the race progresses, I simplify the sugar and get as close to glucose as possible. That’s Coke, as Thomas Hellriegel taught me [when he overtook me] one hot day in Kona.”
Ironman 70.3 winner and European long-distance duathlon champion
To avoid having a bad stomach I cut out fibre for two or three days before a race, which means no fruit and veg or wholemeal foods. Then I make a race day nutrition plan and stick to it. I’ve found writing down a plan makes it easier to get it right on the day. I usually aim for 250 calories per hour, with slightly more on the bike and slightly less on the run. In terms of fluid I alternate High 5 Energy Source with High 5 Zero tablets (electrolyte alone) and get additional calories from gels, a Mars bar and a Bounty bar (sounds silly but I look forward to them and they’re easy to digest). On the run I use gels and a single bottle of the highly caffeinated High 5 Energy Source Xtreme to give me a push in the last 10 miles. If it’s hot I always take a few salt tablets with me on the bike.
Ironman UK winner
The most important thing about Ironman nutrition is keeping it simple. To keep things easy, I take a PowerBar Gel every 20 minutes, and instead of taking 16 gels with me on the course, the night before I empty them all into a water bottle and top it off with water to make it easy to drink.
I have another bottle full of electrolyte drink on the bike and a front aero bottle filled with water, so when I get to an aid station I know to fill the front reservoir with water and replace the electrolyte drink with whatever they offer on the course. At Ironman races they usually have a halfway feed bag so I usually put a bottle of Powerbar Isomax in there with a flapjack, as some solid food to make a change from a gel every 20mins. During the run I grab what I can but I try to aim for at least one litre of drink per hour and three gels, again though it’s really hard to control this when you can’t easily carry them all.
Multiple Ironman 70.3 winner
I have a pre-race breakfast three hours before the start, which is normally porridge, coffee and two slices of white toast. On the way to the race and while setting up in transition I drink 500-750ml of High5 Energy Source and then have two energy gels before the swim start. On the bike I drink 1.25l of High5 Energy Source Xtreme (contains caffeine), and five High5 Isogels. I’ll also look to pick up at least three bottles of water, one from each aid station. If it’s a really hot race, I’ll take salt tablets too. I am always mindful of how I feel on the bike and if I sense my energy levels dropping I’m not afraid to take on more calories. Likewise, if it’s a hot or humid race, I’m not afraid to drink more than normal. I’d typically aim for 600-700ml an hour, but this could be increased to 1l to 1.2l an hour at a race like the Ironman 70.3 World Championships in Las Vegas. I take on fluid little and often rather than gulp down masses in one go.
Multiple Ironman winner and ITU long-distance world champion
There are three things you need to manage on race day – hydration, electrolytes, and calories. In my experience, the order of importance has been, surprisingly: electrolytes, calories and fluid. In racing, if I’m well fuelled with calories and take in some electrolytes, my performance is better, even if – post exercise – I’m a bit short of fluids. This assumes you are adequately hydrated at the outset. The recommended dose has been only 400-600mg of sodium per hour – in my experience, that’s about half what most people seem to find success with. I’ve recommended 1,000mg of sodium (not salt, but sodium chloride) per hour and 750-1l of fluid per hour, though the fluid number seems to vary much more with the atmospheric temperature than the electrolytes. I take in the same amount of electrolytes on a cold day, but less fluid, and on a hot day I’ll take in more fluid.
I also often use salt capsules before a race and the day before the race for sodium
loading – taking on extra electrolytes in advance of competition.
This article was originally published in Triathlon Plus magazine. Save time and money by having every issue delivered to your door or digital device by subscribing to the print edition or buying digitally through Zinio or Apple Newsstand.
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