Top 5 Tips to Fuel your Next Endurance Race - from a Dietitian and Athlete

April 09, 2019

“At mile 30 aid station, I laid on a cardboard slab for an hour…so long that I had hit the time cut-off and they were pulling people…

….I don’t remember much else, just know that I was in a bonking state the whole rest of the race. I was never able to pull myself out of it and in fact cried the whole last 4 miles into the finish line wanting to be off my bike so bad.”

– bonk stories from Kate Ginsbach

We’ve all been there before, to some extent or another. No matter what, botching your nutrition, especially during an event you’ve spent months training for just sucks. Fortunately, with a solid nutrition plan, bonking doesn’t have to be a part of your race report.

As an endurance athlete and dietitian, I spend a lot of time helping athletes determine the best nutrition strategy to meet their goals. Over the years, while working with athletes setting out to get the course record or simply start their first season of bike racing, I’ve found that a lot of the information is the same, so I’ve compiled it all to share with you.

I’ve used this strategy to complete the six-day Breck Epic, three-day NZ Enduro and plan for every big bike adventure that comes my way. The longer the event, the more real food. This means homemade baked goods instead of dry, hard bars or gels and salty chips or a baguette with cheese and jam instead of, well, flavor fatigue and feeling like I want to puke.

Here are my five best tips to fuel your best endurance efforts and when they are key:


Tip One – Eat your last regularly balanced meal 2.5-3 hours before you start. By balanced meal, I mean a meal that looks like the meals you eat on a regular basis. This means there’s some protein, complex carbohydrate, healthy fats, and vegetables. For example, a simple idea here would be salmon with brown rice and roasted vegetables.

With a balanced meal like this, we have to consider how your body and digestive system is going to deal with it. The main factor is that, once you eat a meal, it takes insulin about 1-1.5 hours to kick into gear and start doing its job. What is that job, exactly? Insulin is responsible for taking the energy (read: carbohydrate) from the meal you just consumed and transporting it from circulation to where it can be used for fuel, in your muscles. Think of insulin as the bus that picks up the circulating energy and delivers it where it needs to go to be used.

Another factor is that it takes protein and fat a relatively long time to digest, especially compared to carbohydrate. Since we’ve just had a complete meal containing these macronutrients, this is why we need more than just 1-1.5 hours of digestion time before we get going. Your goal with eating a balanced meal is to show up on the start line satiated, not stuffed, but not hungry. If this pre-workout meal consisted of primarily carbohydrate, sans protein, fat and some good veggies, it’s likely that you would be hungry come start time.

Tip Two – Be picky about the type of food you consume. As I explained above, carbohydrates digest a lot differently than fats or protein. This is where being picky about the food you consume comes into play.

If you’re used to getting stomach cramps and having digestion problems during a race, it’s typically for one of two reasons. First, it might be because you’re eating too much protein, fat or fiber and your body simply can’t digest it quickly enough. Instead, it sits in your stomach and backloads digestion or it might make you feel “heavy” and start cramping.

On the other end of the spectrum, you could be eating too many simple carbohydrates, aka pure sugars. Think gels, gu, and highly concentrated carbohydrate-based drinks. If this is the case, you might complain of flavor fatigue and a bloated, sloshy stomach. In addition, you can be more prone to dehydration. This happens because there is only so much carbohydrate that our stomach and small intestine can absorb at one time. If that system gets overloaded with carbohydrate, there’s a traffic jam in your small intestine. This means those carbohydrate molecules sit in your stomach and actually draw water INTO your stomach, where it’s not useful for hydrating you. This happens because our natural response is to water down that high concentration of sugar molecules suddenly sitting in our gut. It’s the same reason why gels are often difficult to tolerate. It’s not your fault, this is how your digestion works!

What do you do in either case? Match your food with the intensity of your effort. For high intensity, mostly above lactate threshold effort, primarily carbohydrates are your best option. However, this doesn’t mean they need to be just bars and gels. Bring a piece of banana bread, a homemade cookie bar or Hawaiian rolls with jelly.

For lower intensity efforts below your lactate threshold (LT), it’s okay to pair your carbohydrates with a bit of fat or protein. Instead of a purely carbohydrate baked good, pair your simple carbohydrate with a bit of fat or protein. Options include nut butter, cream cheese or whole wheat instead of white flour based products. A sandwich with peanut butter and honey, or cream cheese and jelly are two examples. Peanut butter stuffed pretzels are one of my favorite carbohydrate, fat, and protein (read: lower intensity) foods. They’ve got it all: salt, carbohydrate and a bit of fat and protein.

Racers take in a gourmet dinner in the Washington state backcountry during the 2018 Trans-Cascadia.
Seasoning some beef before grilling at Trans-Cascadia.
And prepping some whole wheat bread to go with dinner.

During Race

Tip Three – Make your goal to replace 40-50% of the calories you burn every hour with food. For example, if you’re burning 400 calories an hour, aim to consume 200 calories every hour. Now, that’s a lot to stop and eat in one go, so break that down into 15 or 30-minute increments. Eating 50 calories every 15 minutes or 100 calories every 30 minutes is often a lot more logical than sitting, stopping and eating 200 every 60 minutes. Use this as a guideline so that you can plan ahead based on what your workout might look like. Two things to consider: where are your eating opportunities throughout the course and what nutrition are you packing to meet these needs?

Plan the type of macronutrients you consume based on intensity, as explained above in Tip Two.


You get weaker when you workout; you get stronger during recovery. It’s the time when your body adapts from the effort you just completed in order to be stronger the next time you workout. Because of this, I will argue that recovery is the most important time to nail your nutrition strategy. It’s especially critical when you’re doing a multi-day event because your recovery window is limited and you’ve got to optimize it!

Tip Four – For recovery from endurance efforts, focus on carbohydrates first and protein second. Endurance efforts deplete your stored carbohydrate, aka glycogen, more than they break down muscle. For this reason, carbohydrate is your numero uno when it comes to recovery.

The ultimate ratio of carbohydrate to protein is 4 parts carbohydrate and 1 part protein. Total calorie goals change based on the duration of your event, how much you consumed during the event, and your individual status, but the main idea here is the same: make sure you have mostly carbohydrate, and then add some protein.

All of this information can apply to both a multi-day event like Trans-Cascadia or a single day effort like the Dirty Kanza 200. Chances are, with a multi-day event, you have more opportunity to stop and you’re going at a lower intensity. This means there’s more room for proteins and fats in addition to carbohydrate. A good recovery strategy is essential because you have to wake up the next day and do it all over again.

Here’s my Super Fast Recovery Smoothie, which is set on the ideal 4:1 Ratio. It has 43 grams of carbohydrate and 10 grams of protein.

• 1 medium frozen banana
• 2TBS nut butter
• 1TBS cocao powder
• 1-2 cups milk of choice (to reach desired consistency)

Put all ingredients in a blender and blend until smooth.

Consume your recovery meal or snack within one hour of completing your workout. Then, 2-3 hours later, circle back to where it all began: with a regularly balanced meal.

Some examples of real food to fuel I use on adventures.

With an event like DK200, you’re likely going at a higher intensity and don’t have as much time to refine your strategy or bounce back from an upset stomach. This is when your fueling game needs to be on point. Most athletes will do best with primarily carbohydrates, but make sure to vary your flavors and sources so that your gut doesn’t get overwhelmed.

Tip Five – Training shouldn’t just be about training your muscles and your cardiovascular system. You should also practice what you intend to eat while racing at least once a week to determine what is working and what isn’t. There’s nothing worse than training your butt off for a race and then having it ruined by your nutrition or lack thereof.

Lastly, let me close with a disclaimer: the entire category of sports nutrition is very individual. What works for one person most likely doesn’t work just right for the next person. That is the blessing and curse of it all, depending on how you want to look at it. Take this information, treat it as your baseline and go experiment!

As Kate learned, it takes time to get results and figure out what works best for YOU. After her experience laying on a piece of cardboard at mile 30, she, “readjusted a few things and did Leadville about a month later and was able to win {her} age group”. “I learned a lot of lessons that day on the bike.”

It’s all a part of the game. No matter what, enjoy the process and the food that fuels you.

Fueling up between stages of the 2018 Trans-Cascadia.
Aaron Bradford chasing food with water for better digestion while waiting to drop in on a stage.

Side Notes

Simple carbs such as baked goods, white bread, and white rice are primarily sugar and they don’t have any fiber or protein in them to slow down their digestion, but brown rice and whole grain breads are complex in that they have a bit of protein and fiber in them. The latter is great for when you want that carbohydrate energy to last you a bit longer, but potentially too slow digesting when you want to convert your carbohydrate into energy ASAP.

One question I often get is, why do gels and liquid energy foods cause digestive problems? Here’s the least science-laden breakdown I can give you: carbohydrate digestion begins in your mouth, but you have to chew in order to trigger that. There’s an enzyme in our saliva called amylase that is specific to breaking down carbohydrate. If we don’t chew our carbs and instead gulp them down, we risk overwhelming our stomach and small intestine because we bypass that initial step of triggering amylase in our mouth. Suddenly, a dose of carbohydrate ends up in our stomach and it overwhelms our system. Sort of like a highway, there’s only so much it can handle at one time – too many sugar molecules (cars) and you have a traffic jam that leads to sloshy stomach, gut rot or whatever other words you use to explain to your friends that something isn’t right. Plus, the above-mentioned issue with pulling water away from where it needs to be going when racing or training.

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