When preparing my athletes and myself for our first Ironman, I had a tough time deciding exactly what the best nutrition strategy was for the race. After really digging into the articles, forums, and research, I finally came up with a strategy that I thought would work best. Luckily, my calculations were correct and these simple steps continue to give my athletes success in endurance races. Before we get started, the most important thing I stress to my athletes after I create their nutrition strategy is that we have to test it. Working out the exact consumption, concentrations, and timing is vital when creating a plan. We all work slightly differently; have different muscle masses, sweat rates, body weights, etc. These variations lead to tweaks in your race day nutrition that can only be determined while experimenting in training.
What and how much of it should you be consuming?
What you eat/drink isn’t really dependent on what activity you are doing. An Ultra Beast, 50k run, and Half-Ironman all take about the same amount of time, therefore the nutrition strategy will be very similar. The first thing you need to look at is time – how long will you be racing for? That number is going to determine the number of calories you need per hour. Then, you need to look at the climate you will be racing in. Hotter races require more fluid and electrolytes than a colder race. These two factors, race length and race climate, are the major factors in creating your race day nutrition strategy.
Now in terms of what you should be consuming, you need three things to have a successful race: Food, Electrolytes, and Water. Let’s first start off with two things you need to avoid: fructose and maltodextrin. These simple sugars cause too rapid of a spike in blood sugar and a large quantity of them may cause GI issues. In smaller quantities, training sessions, or times when the nerves are steady, this may not be a problem. But, when race day comes, nerves are high, and a 5+ hour endurance race requires you to ingest more than 1500 calories worth of this stuff, it may become a problem. Avoid the risk altogether and opt for nutrition that does not have these ingredients. Look for products that cover all of your bases in terms of macronutrient content and include simple carbohydrates, complex carbohydrates, and amino acids. Because of digestibility, you don’t really need to take in any fat during the race and stay away from products with fiber (no need to go to the bathroom during the race!).
Whether you want to consume all your calories via liquid or a mix of liquid and solid foods that is up to you. I opt for both. Just drinking liquids over a 10+ hour Ironman gets old fast. I like to have a little bit of a mixture of things going into my body. The current products I like to use include EFS Liquid Shots, EFS Sports Drink, and a couple Honey Stingers on the bike and maybe transitions, depending on how I am doing with my calorie goals. These EFS products also provide ample electrolytes, so for cooler events, this may be all your body needs. In warmer events, you will need to supplement with additional electrolytes. Salt Sticks are an awesome electrolyte option as they contain the same electrolyte composition as sweat and are one of the few electrolyte supplements that contain the full panel of electrolytes; Sodium, Potassium, Magnesium, Calcium, and Chloride. (I am not endorsed by any of these products; I wish I was because I spend way too much money on them!).
How many calories, per hour, should you be consuming?
Endurance athletes should consume between 300-400 calories per hour. This number varies based on your weight, physical exertion, climate, and fat metabolism. Running alone will burn 600-800 calories per hour. So how, at only 300 calories an hour, is that enough fuel to get you through a race? Two additional factors heavily play into your body’s energy storage. The body has around 2000 calories worth of glucose available at any given time, plus fat storage will help you to the finish line. Your goal in race fueling is not to provide the body all of its fuel, just a nice helping to decrease the metabolic load on the body and keep glucose levels adequate while it is going through fat metabolism.
Take that 300-400 calories per hour and play with it during long training sessions. Use the same products you have decided to use on race day. Begin fine tuning that number. Once you are happy with your energy levels and digestion during training, you have made your nutrition plan. Stick with it. Thinking about and executing your nutrition strategy is a great thing to think about throughout your race. Don’t let your mind wonder too much, stay focused and make sure you are getting your nutrition in when you need it.
How much water, per hour, should you be consuming?
To find out how much water you need, find your sweat rate. Weigh yourself (in lbs) without clothes or shoes on before a one hour outdoor workout and then weigh yourself without clothes or shoes immediately after your workout. Do not consume any food or fluids during this workout. The weight you lost is your sweat rate. Multiply that number by 16 oz and that is the minimum amount of water you should be consuming per hour. For me, that number is 2 lbs x 16 oz giving me 32 oz of water per hour. During long training sessions, I have realized I like to drink more than that, so my average is about 40 oz of water per hour.
Do you need electrolytes?
Yes. Electrolytes affect the amount of water held in your body, blood PH, and muscle function. Without electrolytes you will be peeing out all of the water you take in and quickly pushed to the sidelines cramping. You should also be taking electrolytes in the days and week prior to the event. Just drinking water can cause issues like hyponatremia, or low sodium in the body, which is arguably more of an issue to endurance athletes than dehydration. Electrolytes prior to race day will also help pull hydration intracellularly, which will hydrate your muscle cells for race day. If your nutrition supplement has adequate electrolyte content in it, you might be alright. For warm races you will need electrolytes on top of your nutrition.
When should you be taking your nutrition?
I have found that ingesting your nutrition every 10-15 minutes works very well with my athletes. In triathlon, this would begin immediately after the swim and continue until the race is over. In running, obstacle course, or cycling races, I would begin the nutrition about 30 minutes into the race. Stick to this timeline for the entire race. It will keep your metabolism moving, glucose rates steady, and give your mind something to stay focused on.
Have additional questions? E-Mail me! I would love to answer your questions and help you out. If you are looking to take the guesswork out of your plan, let me create a customized nutrition plan for you! Get in touch with me via e-mail here.
Sean Spire is the Head Coach of ASL. He was a competitive swimmer who discovered CrossFit and Ironman Triathlons. He has his BS in Exercise Science from Florida State University.