• Ironman Nutrition – For the Long Haul

    Principally: There is no single nutrition plan or product that will lead to success during an Ironman. Even the world’s best triathletes have had bad races resulting from nutrition. They would all tell you the same thing: Experience is key. An athlete may gain experience three ways. First, consult an expert. Jay McCurdy is not a sports nutritionist but he can recommend some. Second, perform race simulations during training. Do at least one race simulation 3 to 4 weeks out where you wake up early, simulate what you’re going to eat on race morning then get on the bike and go an hour without eating before starting your normal nutrition routine. I like practicing race nutrition during the last 1.5 to 2 hours of a ride. You’re usually pushing hard and you’re already relying on fat metabolism for a large part of your energy. Finally, the third and best way to gain experience is by racing. A half distance race in the two months leading up to your full is a great way to simulate race nutrition for an Ironman.

    Jay’s general plan. To be frank, the biggest challenge is moving food through your gut without clogging during the race. This means eating for a healthy gut in the weeks and especially days prior to the race. Beginning two days prior, really focus on avoiding large heavy meals but eat more throughout the day. Soups are great the night before a race because they are easily digested, but avoid salads and high fiber foods that have a potential to result in stomach upset the next day. I eat a big breakfast and lunch the day before then a light meal before going to bed early. Stay hydrated. Set a bottle of water next to your bed and drink some during the night. The next morning, I rely on coffee and/or First Endurance Pre Race to get the bowels moving again. Other than that, try to follow a pretty normal routine. Too much caffeine can cause real stomach upset and dehydrate you before an already long and dehydrating day.

    Morning of: Coffee. I like oats, but have had problems with the fiber during a hot hard ride. I suggest low fiber but filling foods: rice crispy’s, or puffed rice cereal with milk. Some folks can’t handle milk, but soy, almond, and coconut milk are good substitutes. I like several Hammer Endurolyte tablets with my breakfast. I also eat a chocolate bar and a couple of bananas then have Ultragen for dessert in the car along with maybe another coffee. Totaled, I can consume about 1200 calories over a 30-minute period without much trouble. I also like to stretch and do plyometrics while stuffing myself.

    Pre Race. I like a gel or some energy gummies while I wait for the swim. If it’s going to be a hot swim, I drink some electrolyte drink about 10 to 15 minutes before. You may find you need the toilet again after hydrating, so don’t put it off too late. I don’t eat during the swim, but there’s no reason not to have a gel and some water if it’s a two-loop course.

    On the bike: I generally shoot for 80 to 90 grams of carbohydrates per hour, which is 320 to 360 calories per hour for a 140 lb male doing about 77% of functional threshold power. I get that from a mixture of sources (See Table 1), but almost all of it is from sugar, not protein or fat. Keep in mind fat slows digestion a bit but is about 9 calories per gram of intake. I like chocolate or a Milky-Way bar occasionally. I think the fat helps slow absorption of sugars and keeps me filling satiated.

    I recommend an isotonic (high salt) sports drink during the bike at a rate of 750-1200 ml total fluid intake per hour, depending of course on body size, sweat rate, and the weather. For instance, Ironman Perform is a 20 oz (600 ml) bottle with 17 g carbs, 70 calories, and 190 mg sodium. I then take in a 20-25g carb parcel every 30mins from gel or other semi solid food. Also, my goal in hot weather is getting about 1-1.2g of sodium per hr – that’s unusually high and is not recommended for everyone. Taking a salt stick tab each 30 minutes of the bike on top of the sports drink should get you in the ballpark.

    Tip: your water bottle cage-space is limited. If you have a favorite pre-mix (powder of some sort + Coke + champagne or whatever), mix that at as a concentrate in one bottle then you can gulp and swig water. This works well for a handle bar mounted bottle with a straw or a Speed Fill. So I mix about 4 scoops of EFS, which is around 80 grams of carbs in my down tube bottle. That way I can swig on it the whole way. I have another handlebar bottle cage that is initially just water, and then I can grab water or sports drink along the way to replace it.

    Table 1. Jay’s hourly nutrition plan on the bike might look like this.



    Liquid (ml)


    Carb (g)


    Calories (kCal)


    Na+ (mg)


    IM Perform





    1/5 EFS concentrate





    Gel (~ 2.5 oz EFS Liquid Shot / hour)




    Other (chocolate, chews, etc)

    < 10

    < 40

    1 Salt or electrolyte tablet

    < 600

    1 Bottle Water


    Total (my maximum)





    On the run: Especially in the heat, I’d watch the gel intake. Personally, I just take coke or coke/sports drink every station and tackle any bonking with a gel and water. I don’t take salt on the run unless they’re offered or unless its really hot. Don’t be afraid to walk through every aid station to get what you need. Grab as much as you can get down. If you throw up, keep eating.

    Keep it simple!! If you forget something, grab a replacement on the course. Chances are, you’ll never know the difference. Just don’t clog the system with too much at once. For instance, avoid fibrous energy bars with energy drink. Solid foods help bring some folks back to reality from a bonk very quickly, but others may have a hard time getting it to pass through their gut. Above all, enjoy the experience and challenge. Have fun. 

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