By Ben Greenfield

I remember the first time I thought about doing an Ironman. In the early 2000s I was watching the NBC Ironman coverage and I remember seeing some sleepy-eyed guy roll over at 4 a.m. to make his breakfast—a huge mash-up of oatmeal, fruit, toast and scrambled eggs. As he sat there hunched over in his pajamas, jamming forkfuls of calories into his gaping maw, he motioned to a heaping pile of energy bars a few feet away: “That’s breakfast number two.”

At the time I was a competitive bodybuilder. Not only was I used to eating eight to 10 meals per day, but I was also well accustomed to elaborate pre-competition rituals designed to enhance performance and blood flow to the muscles (everything from extreme sodium loading and water depletion to caffeine and red wine backstage). So the idea of waking up in the wee hours to shove fuel into my body certainly wasn’t a foreign concept.

There is a great deal more to race morning breakfast than simply getting as many calories as possible into your body without puking.

Since then, over years of competing, studying and coaching, I’ve learned that there is a great deal more to race morning breakfast than simply getting as many calories as possible into your body without puking. Hopefully this article will help you crack the code on your pre-race meal so that you never have to second-guess yourself while you’re wandering the aisles of the grocery store the night before your big race.

Step 1: Size.

Let’s begin by figuring out the actual size of your meal. Should you eat everything in sight until you’re 100-percent full? Should you painstakingly measure out each portion to the exact gram using a kitchen scale? Should you simply fast so your body magically taps into its stored fat?

The answer is: It depends. And it depends specifically on how big you are, how long your race is, and how much time you have to digest that meal. Armed with just a tiny dose of science, you can easily determine exactly how much you should eat.

Let’s begin with why you should consider eating in the first place. During an overnight fast, you’re not going to burn through much of your muscular glycogen, but your liver glycogen stores are reduced substantially while you sleep. And while glucosyl units may mean jack-squat to you, the big picture is that this equates to a reduction in your liver glycogen stores overnight. Since the average person’s liver stores about 400 calories of glycogen, this means that topping off those stores with around 320 calories is a good goal for the number of carbohydrates to include in your pre-race meal, if your race could exhaust your muscle and liver glycogen stores. In most people, it takes about 1.5–2 hours of hard racing to burn through your stored carbohydrate. This means that for any race that goes longer than 1.5–2 hours, you should consider including somewhere in the range of 320 calories of carbohydrates in your pre-race meal to maximize glycogen storage. Of course, since you’ll be wandering around before the race prepping your bike, warming up, nervously fidgeting and stretching in line at the Porta-Potty, you’re going to be burning an extra 100–150 calories of carbohydrate per hour, so it would be prudent to account for that as well.

Now, bear with me on the math. If you complete your pre-race meal two hours before the race start (a reasonable amount of time as you’ll shortly learn), then in addition to the 320 calories of carbohydrate, you’ll need an extra 100–150 calories of carbohydrate for each hour leading up to the race, which you can do by either consuming that equivalent amount of carbohydrate from a sport bottle before the race start, or by including those calories in your pre-race meal.

Both methods work, but I like to get most of it out of the way at once. Your gut can absorb around 240–280 calories of carbohydrate per hour, so this means that if you consume 320- plus calories of carbohydrates with breakfast two hours before the race, you’ll be able to easily digest that amount over those two hours and still be able to throw in another 100–150 calorie snack in the final hour leading up to the race.

There are a few other things to note about carbohydrates. The first is that a lower glycemic index carbohydrate may cause a slower rise in blood glucose and give you more stable energy levels. Whole grains, barley, rye, rice, quinoa, oatmeal, grapefruits, apples, pears, sweet potatoes and yams are all relatively low on the glycemic index. Next, eating two different types of carbohydrate will allow you to absorb more. So you can combine, for example, a fructose sugar such as fruit or honey with a glucose sugar such as a potato.

Takeaway 1: Include a high-carbohydrate pre-race meal of about 500 calories if you’re racing longer than an hour and a half. For athletes under 150 pounds, this is going to come out to about 400 calories. For athletes over 150 pounds, this is going to come out to about 500 calories. These calories could include two medium-sized sweet potatoes with a couple of tablespoons of honey and a slathering of almond butter, or a banana, a couple of slices of bread and a handful of almonds. Then, in the last hour before the race, consume about 100 calories from a carbohydrate source like an energy bar, sports drink or fruit. If you’re a larger athlete, aim for closer to 150 calories.

Step 2: Composition.

Now that we know how big your breakfast will be, what should go into it? Don’t forget about healthy fats. Consumption of a high-fat meal before exercise has been shown to alter substrate supply before exercise and leads to increased free fatty acid (FFA) levels in the blood, which could then increase lipid metabolism during exercise and either preserve some of your limited glycogen stores or at least attenuate the normal rate of glycogen depletion. It’s important to understand that the effects of consuming a high-fat meal on subsequent exercise performance are not widely acknowledged or proven, with one exception: “fat-adapted” athletes who have followed a high-fat, ketogenic diet for more than six months seem to be able to sustain endurance performance on a high-fat diet, with a significant preservation of glycogen stores during exercise.

One study examined the performance effect of consuming either: 1) a high-fat meal four hours before exercise plus a placebo jelly three minutes before exercise; 2) a high-fat meal four hours before exercise plus maltodextrin jelly three minutes before exercise; or 3) a high-carbohydrate meal four hours before exercise plus a placebo jelly three minutes before exercise. Participants in the high-fat meal plus maltodextrin group showed both a significantly higher fat oxidation rate and a significantly decreased carbohydrate oxidation rate during the first 60 minutes of exercise compared to the other groups, along with a significant increase in their time to exhaustion during exercise. What you can learn from this is that including at least some fat with your pre-race meal is definitely going to be beneficial.

What type of fat is best? The answer is simple: medium-chain triglycerides (MCTs). These fats bypass the long four- to six-hour digestion time of many other fats, and are instead readily available as a form of usable energy. Most athletes can tolerate 100–150 calories of MCTs without gastric distress, and the easiest way to get these is via coconut milk, coconut oil or MCT oil.

Please note that the study referenced above involved eating the pre-workout meal four hours earlier. You should also know that they fed the participants about 1,000 calories in that meal. When you consider that your body can absorb about 250 calories per hour, this makes sense (1,000 calories get absorbed over a four-hour time span). However, I’m a bigger fan of eating a smaller meal, such as the one I recommended earlier, about two hours before the race, and this is because athletes need sleep. Rubbing sleepy eyes at the starting line of an Ironman, and feeling like taking a nap halfway through the marathon because you got up at 3 a.m. to stuff 1,000 calories in your face is simply not worth it.

Takeaway 2: In addition to the meal recommendations earlier, if you’re competing in a long race, especially an Ironman or ultra-endurance event, then consider including 3–6 ounces of full-fat coconut milk, a heaping tablespoon of coconut oil or a level tablespoon of MCT oil with your pre-race meal.

And finally there’s protein.

There’s been quite a bit research done lately investigating the effects of adding protein to carbohydrate drinks or supplements, with many studies finding enhanced exercise performance when amino acids or proteins are included with a pre-exercise meal. There are a few interesting reasons for this. For example, protein lowers the glycemic response to carbohydrates, making it less likely that you’ll have a surge in blood glucose from your pre-race meal followed by a hypoglycemic slump in energy by the time you get to the starting line. The consumption of protein also increases blood levels of amino acids like arginine, leucine and phenylalanine that stimulate cells in your pancreas to release insulin and glucagon. This hormonal response to protein may help to more quickly drive your breakfast into tissues for use as fuel, and may also stimulate glucose output by your liver, which can also help you to avoid hypoglycemia. While it would seem that the presence of insulin might somehow reduce fat oxidation, this is counterbalanced by the fat-burning effect that glucagon can elicit. There is some research to suggest that combining proteins with carbohydrates may speed up pre-exercise fuel storage by enhancing glycogen synthesis, which could lead to even more glycogen sparing during exercise.

Takeaway 3: Smaller athletes can absorb around 20 grams of protein in a meal, while larger athletes can take on closer to 30 grams. However, this amount of protein can take up to four hours to digest, so I recommend using “pre-digested” proteins in the form of amino acid powders. If you use a supplement like this, simply take 5–10 grams of amino acids in a glass of water along with your breakfast. Alternatively, you could take a couple scoops of protein powder in a glass of water with breakfast, but that will take longer to digest.

So let’s summarize all this math and geek speak, shall we? When putting together your pre-race meal, include:

  1. A low glycemic index carbohydrate, preferably from a couple different sources such as fruit and potato, at around 400 calories for smaller athletes and 500 calories for larger athletes. It should be eaten two hours before the race, and accompanied by another 100–150 calories from a sport drink or bar in the two hours leading up to the race.
  2. If the event is longer than 90 minutes, include another 100–150 calories of an easily digestible fat, for example, by throwing a big spoonful of coconut oil on top of your sweet potato.
  3. Whether it’s a long event or a short event, also consider including 20–30 grams of protein with breakfast, or 5–10 grams of amino acids.

Ben Greenfield is an ex-bodybuilder, Ironman triathlete, professional Spartan racer, coach, speaker and author of the book Beyond Training: Mastering Endurance, Health and Life ( In 2008, Ben was voted NSCA’s Personal Trainer of the Year and in both 2013 and 2014 was named by Greatist as one of the top 100 Most Influential People in Health and Fitness. Ben blogs and podcasts at, and lives in Spokane, WA, with his wife and twin boys.

april-2015-coverThis first appeared in the April 2015 issue of LAVA. Get your issue here.

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