7 Rules for How To Fuel For Everyday + Extraordinary Endurance

This past week, I rode my bike from Boulder to Aspen with a dear friend. The journey was 210 miles in two days, with over 18k feet of climbing. We covered two mountain passes over 12,000ft, we ate a lot, drank even more and we smiled every single mile because we knew some rules about fueling for endurance.

There was a time when this kind of ride would have completely put me into the ground; when I thought I would need weeks to recover. But these days, rides like this are my bread and butter and I have massive weeks (250-550 miles/week) all the time. Yes – I keep fit and ride my bike frequently, and that helps a bunch.

But moreover, I learned a long time ago how to fueling for endurance – on both everyday and extraordinary efforts – and that has made all the difference.

Before I share my strategy and outlook here, a little disclaimer. I am not a doctor, nutritionist or dietician but I do have over 14 years of training, racing and fueling some of the top athletes in the world under the guidance of renown exercise physiologists. This is what I know: 

There is no one way to fuel for performance or endurance. Every body is different, and every athlete has a different life/physiology cocktail that must be taken into consideration for proper fueling. No doctor, nutritionist, dietician or coach can tell you EXACTLY what to eat. But they can give you some baselines and guidance from which to start. Instead of leaning on others to prescribe a fueling plan, it’s important that you take responsibility for your performance, and commit to listening for as long as it takes to attempt to learn for yourself what works. This means trying new things, and ignoring the shoulds (and, most of the time, the numbers that go with them.) How else would you ever learn whether pizza is your ultimate performance food or not?! 

Now – fueling for everyday and extraordinary endurance!

These seven rules are the ones I follow to guide myself towards balance when I’m tackling something big. It hasn’t failed me yet; not when I was racing triathlon, running ultramarathons or pushing my limits in the marathon. Not at Cape Epic, not climbing 87,000ft in one week through the Swiss Alps on a road bike, and certainly not last week as we paved the way from Boulder to Aspen. These strategies work well, fueling for endurance in both competition and training, but also apply to everyday endurance; the kind that keeps you running through the pressures of everyday life so you can still have the energy to get outside and just breathe. Here we go.

#1: Eat real, whole foods.

The biggest revelation I had with respect to endurance fueling. Once I started jamming almond butter and honey sandwiches in my jersey instead of packaged “energy foods” made with ingredients I couldn’t pronounce, I was able to accurately recognize what my body was craving. Did I need salt? Sugar? Fat? Just something that made my brain think I was “treating myself” on a long-haul ride? I had no way of knowing exactly what I was eating in those packages. No way of knowing exactly when one of the ingredients had upset my stomach and no way of guiding or tracking my cravings.

#2: Listen to your gut.

A little story: on the third day of TransRockies Run that I found myself ready to quit, barely able to stand, completely depleted. I hadn’t slept well in our tent camp, was cold, felt harsh, and had been picking my way through meals all week; attempting to eat “cleanly” to avoid stomach distress. A friend came to the race, took one look at me and drug me kicking and screaming into the nearest pizza joint. He ordered me a deep-dish, meat-lovers pizza and a beer. I reluctantly choked down a few bites and, to my surprise, started to feel better. My body needed that salt, fat, protein and carbohydrate dump. I finished my slices (and the beer,) and hopped back onto the podium the next day.

Just because your running buddy eats entire pizzas during their workout doesn’t mean that this will work for your body.

On the other hand, pizzas might work beautifully for your long efforts and might make you feel right as rain.

Listen to what your body is asking for – be it a pizza, a salad, a cookie, a rest. Find the best ingredients to sate that craving, and then enjoy. That’s fueling for endurance.

#3: Hydrate!

This was my second massive realization; I always figured that “sports drinks” were a little sketchy, and so I used water alone to hydrate on long endurance workouts and in races. It worked just ok – sometimes I felt completely bonked even though I had been eating. I had a lot of brain fog, cramping and digestive distress after my workout.

Come to find out, I was chronically dehydrated and sodium deficient. Once I started consuming more salt, and a bit of salt and sugar in my water during exercise, I found I could ride harder, I felt more clear, and I recovered faster and slept better at night.

Our bodies don’t just need water to replace what we lose in sweat – we also need electrolytes. These come in the form of sodium, magnesium, calcium, and zinc, and are easily uploaded into your body with the help of a bit of carbohydrate. I like using Skratch Labs Exercise Hydration because the ingredients are simple, straightforward and real.

The specific amount of hydration your body will need during exercise has everything to do with your body weight, the intensity of your effort, and just how sweaty you are AND, if you’re a salty sweater.

(If you finish a ride or run covered in chalky salt stains over your clothes, you’re likely a salty sweater, and you needed more hydration during your exercise!) This is a calculation you can run yourself and  this is an excellent article on the topic written by my former colleague, Dr. Allen Lim. 

#4: Check your hunger.

Most coaches, dieticians and nutritionists will give you a number when you ask “what should I eat before, during, or after my event?” I’ve found that it’s helpful to know the numbers; the calories you burn, the grams you consume, the watts you put out.

But, when it comes to really understand my body and how it works and fueling for endurance, the numbers don’t matter much because my body isn’t counting them – its just working. The body wants what it wants.

And, by the way, when you have a stressful day at work, your kids get sick, your boss quits, your car dies and you still have to head out for a long training ride, you’re going to need more calories than you would on a day when you just wake up, ride and then take a nap. Your life cocktail takes energy to manage, not just your workout.

SO – instead of counting the calories and grams, try asking yourself how hungry you are and how you FEEL.

Really listen. When you’re not feeling great, try thinking about how your balance might have been thrown off. For example, on a long, challenging ride through the rain with girlfriends this summer, a few of the ladies started having gut cramps. Instead of continuing to eat and drink what they had in their pockets at random, we picked up some pretzels and hot water at a gas station and sat down to eat them.

The warm water helped their guts to relax, and the salt helped them to rehydrate. I imagine that too much sugar was the culprit here, but we’ll never know for sure – we all rode on to finish 110miles/12k climbing that day!

for every day: When you’re in a period of time when you’re training very little, it’s ok to be a little bit hungry. Pick foods and quantities that make you feel light, but grounded and satisfied.

for training: When it comes to fueling endurance during your workout, you don’t want to be hungry. In fact, during our ride to Aspen, there were times when we were downright FULL. Why did we continue to eat? Because we knew a little secret. Keep reading below…

for racing: When you are getting close to a major event or race, make sure that you aren’t hungry.


#5: Follow a (rough) formula.

Yes, having enough energy is crucial when it comes to maintaining and building endurance. But it’s not so simple as calories in and calories out. Our bodies are only able to absorb about half of the calories they’re burning during exercise – so putting more fuel in doesn’t necessarily mean getting longer, stronger efforts out.

As a general rule, the number of calories you burn in an hour as an endurance athlete falls somewhere between 600-800 calories/hour (depending on your gender, weight, exertion etc.)

This means that most of us ought to aim to consume between 300-400 calories an hour during activity. Preferably from a high-carbohydrate snack that your body can use quickly as fuel. Our bodies have a difficult time burning fats and proteins as immediate fuel. Consuming them means that our bodies have to pull energy away from our activity to make this conversion. It is possible to train your body to make this conversion more quickly. But I believe there’s something brilliant in the design of my body and choose to leave well enough alone. Also, I really only crave cookies when I ride my bike…so.

So, what does that look like? 

You get the picture. More than this amount may leave you having some digestive distress during exercise, so just remember to check your hunger – eat more often, instead of eating more in each instance. Real foods won’t have caloric counts or labels, so learning what your perfect snack is and how big it should be is up to you to learn.


#6: Fueling starts BEFORE your workout.

This means in the weeks, months + years before your big event just as much as it does the hours before you start your ride or run.

It is true that what we eat in the hours before a big event or competition DO impact our performance and endurance, but we forget that unless all the cells in our bodies are mineralized, energized, and functioning at their absolute peak, our pre-race meal doesn’t mean nearly as much.

Eat ALWAYS for peak performance – whether you’re running to work or running a marathon. Fuel your body with the super-nutritious foods you crave every damn day.

And THEN, on the day of your big event focus on fueling for endurance at your peak. Most athletes find that eating something within a 3-hour or 2-hour window before exercise or competition suits them well. And I certainly fall into this camp.

If I’m going on a big ride, I’ll set my alarm 2.5 hours before heading out (and more like 3.5 hours before a race) so I can get in breakfast, coffee and let my body digest.


If you intend to go easy in your first hour of exercise, or if you’re heading out to train or just ride big, you may be able to make this window smaller. This window gives ample time to digest your meal, and to feel satisfied. Some athletes feel best having that pre-workout meal a full three hours before activity, then having a small snack within 30 minutes of heading out.

What to eat pre-workout or race?

I like this to be a lower-glycemic meal, with some carbohydrate, a little extra fat and some protein for staying power. Fat is a vital nutrient that plays a critical role in nearly every bodily function as well as aiding the absorption of vitamins, lubricating neurons, and makes our food more satiating.


#7: Never underestimate the after-party meal.

“If you’re going to be training or racing for more than 4 hours, it’s critical that you eat at least 4 grams of carbohydrate per kilogram of body weight within 30 minutes of finishing.” says my former colleague, Dr. Allen Lim. “For exercise lasting less than 2 hours, the goal is 2 grams of carbohydrate per kilogram of body weight.” he continues.

This is because, within the first hour of finishing exercise, our bodies are extremely sensitive to insulin. Insulin is what brings carbohydrate into our muscles, where it’s stored as glycogen (or immediate energy for your next hard effort.)

Your body seeks to replenish glucose stores burned during your effort in this window, so the nutrients in the snack you eat are stored as energy for your next hard effort – whenever that will be. (In the case of our ride to Aspen, it was the very next morning!)

Makes sense! And yet, is really confusing when you’re talking about foods that don’t have packages or nutrition labels, right?!

This basically amounts to a 500-1000 calorie post-workout snack for a 150-lb athlete.

This can look like:

Notice that I include a few decadent desserts here. If this is a high-glycemic snack, then your body uploads it more quickly than if it’s not, and so immediately exercise is one of the only windows of time when you can truly indulge in sweets and desserts with fewer negative consequences (and even a few positive ones!)

So…that’s it?!

That’s it. By following these rough guidelines, knowing the numbers, using real food to sate cravings, staying hydrated and being unafraid to ignore myths about “good foods” and “bad foods,” and striving to find a sound, science-based system that works for us, we find optimal ways of fueling for endurance.