Carbs vs. Keto: Fueling Optimal Performance with Louise Burke, Ph.D.

What’s the most efficient way to fuel human performance during endurance sports? For decades, adherents of keto- and low-carb high-fat diets have battled online with those who favor carbohydrate-burning approaches. In this episode, we have on the global scientific expert whose fascinating studies solved the debate.

Australian Louise Burke is one of the best-known sports nutritionists on the planet, known for her Supernova race-walking studies that showed that keto- and low carb, high fat diets don’t fuel endurance athletes as well as carbohydrate-burning approaches. She also practices what she researches, holding the women’s Australian marathon record in her age group—the age group, she jokes, of “never you mind.”

In this episode Dr. Burke walks Stu and Marty through her research that found carb-based approaches to fueling yield about 5% more of the muscle cell’s energy currency, ATP, compared to fat-burning approaches, with carb-burning also yielding 7-8% better performance. “Even though fat can do the job,” Dr. Burke says, “it’s not going to be able to produce the same amount of ATP so therefore you’re going to be slightly slower even though you’re working at the same relative oxygen utilization.”

She also:

—discusses her own approach to fuelling endurance events, before and during races

—provides tips on carbohydrate periodization for everyone from elite performers to recreational athletes

—explains how to train the body to become a fat- or carb-burning machine

—describes the swings between carb- and fat-fuelled approaches to endurance training

—answers a listener question about carb-loading

—tells the origin story of the important Supernova race-walking studies

—explains why race-walking is so perfect for nutrition studies

—shows that carbs during a race are good not only for muscle but also for the brain