Time after time I’ve read “studies” which purport to show that endurance running and Very Low Carb – Ketogenic Diets are incompatible.  When you delve deeper, you find that the endurance runner was placed on a VLC diet for a relatively short time.  Finally, came across this Article which discusses a recent study.

The study was presented at the American College of Sports Medicine (ACSM) 62nd Annual Meeting: Abstract 1799. May 28, 2015.  Some interesting observations:

Ten of the athletes habitually ate high-carbohydrate diets that were 28% fat, 15% protein, and 58% carbohydrate, and 10 ate low-carbohydrate diets that were 71% fat, 19% protein, and 11% carbohydrate. All had been on these diets for at least 6 months. {Emphasis Added}

This is the first time that I’ve seen a study that actually has the VLC group fully adapted to eating in that manner.

There were no significant differences in the aerobic capacity between the two groups. However, on average, the high-carbohydrate group burned less fat per minute than the low-carbohydrate group (0.67 vs 1.54 g; P < .0001).

“That’s really a profound finding because it indicates they are able to run at a higher intensity for a longer time using mostly fat,” said Dr Davitt.

But then there are the immediate Nay Sayers. Obviously this research must be flawed since it goes against the common belief that the World Is Flat and the Sun revolves around the Earth.

In a joint position statement issued by the ACSM, the American Dietetic Association, and the Dietitians of Canada, it is recommended that athletes replace energy burned during sports with carbohydrates (Med Sci Sports Exerc. 2009;41:709-731).

Even one of the researchers identified a possible draw back – not for endurance running but for competition where a burst of speed is a necessary component.

Adapting to a low-carbohydrate diet might allow endurance athletes to avoid the gastrointestinal symptoms caused by eating during exercise, said Nancy Clark, RD, who is a sports nutritionist in Boston.

However, fats burn more slowly than carbohydrates, which could be a drawback for competitive athletes who need to put on a burst of speed, she explained.

“People on low-carbohydrate diets don’t have the energy for a surge,” she said. “That’s a real problem. You just can’t get into higher gear.”

This disclosure was made:  “The study was supported by Quest Nutrition and the Robert C. and Veronica Atkins Foundation. Dr Davitt and Ms Clark have disclosed no relevant financial relationships.”  No surprises here.