Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In



Carbs Vs. Fat Fueled Workouts: Which Is Better?

This may make you rethink your next pre-race meal.

It’s dinnertime the night before a big race. What type of food you usually turn to? A giant bowl of angel-hair pasta with grilled chicken? A baked potato with veggies? A turkey sandwich piled onto a dense, crusty baguette?

As runners, we’re constantly told to load up on the carbs before and during long races. But as high-protein, low-carbohydrate diets are becoming more popular among health-conscious athletes, long-distance runners are starting to take different fueling approaches.

Ever heard of Tom Olson? He’s an ultramarathoner  who runs 100 miles at a time. He’s competed in the Western States 100-Mile Endurance Run, the world’s oldest and most prestigious ultramarathon. In 2011, after loading up on carbs, Olson was plagued with cramps and stomach issues that forced him to take dozens of trailside bathroom breaks. A year later? He’d cut wheat and most carbohydrates from his diet. Fueled almost entirely by proteins and fats, he finished the 100-mile race in record time, beating the previous record by 21 minutes.

It’s worth noting that Olson may have been dealing with a gluten intolerance. But not only was he able to function athletically without carbs, but he thrived and improved.

The Paleo Diet

If you’re intrigued by the concept, consider picking up a copy of The Paleo Diet for Athletes, a book written by long-time runner Joe Friel and Dr. Loren Cordain. Friel argued that a carb-heavy diet was superior for high-endurance athletes like himself. Meanwhile Cordain suggested that a Paleo diet would be better. Also known as the caveman diet, Paleo emulates the food eaten by humans during the Paleolithic era by eliminating dairy, grains, legumes, processed oils, and refined sugar.

Friel committed to the Paleo diet to prove his point, and felt awful at first. But after a couple weeks, he found that he was able to hit distances he hadn’t been near in years. He recovered from long runs more quickly than before, as a result of more vitamins, minerals, and proteins from the new diet. A friendly argument and competition with a friend turned into a lifestyle change. It resulted in the publication of their book, which has been converting distance runners to the diet since 2005.

But even Friel and Cordain, who swear by the Paleo lifestyle, encourage runners to abandon the diet’s strict rules and adhere to carb-loading norms around race time, especially for a run more than 10 miles. A protein-rich, natural diet without processed foods could indeed improve your overall health and fitness. But as a runner, you may not want to give up those bowls of pasta and energy gels altogether.

What Works Best For You?

In short, here are a few things to keep in mind regarding high-carb vs. high-protein diets as a runner:

  • Everyone’s body is different and responds to fuel a little differently. Pay attention to what works for you.
  • If you decide to make a big nutritional change, do your research. Be aware of potential side effects and keep an eye on how your body responds to changes.
  • Don’t make any drastic changes right before a race. Let your body get used to a new diet before you tackle a long distance.

Related: The Paleo Diet: Right For Runners