Runners On Low-Carb Diets Burn 50% More Fat Than Those Who 'Carb up'

The debate has been raging for years over an important nutritional issue. Should runners carb up before a run, eat nothing at all or eat protein? New research has shown that a low-carb diet, which is typically higher in protein and fat, may give endurance runners an edge.

A new study provides evidence that endurance athletes particularly can perform at high levels without consuming carbohydrates during competitions, said Patrick Davitt, Ph.D., from Mercy College in Dobbs Ferry, New York.

The myth of carbing up may actually be slowing runners down, he said. That's because while carbohydrates give a burst of quick energy and are metabolized into sugar the body can use, the body prefers them over burning fat because they are easier to utilize. This means the body may have enough carbohydrate energy that it will not burn fat for fuel.

Burning fat is typically a goal of runners and probably not due to the reasons you think. While most people strive to be thinner for aesthetic reasons, runners actually are faster and perform much better when they have very lean muscle and low body fat; a distribution of tissue that low-carb, high-protein, higher fat diets promote. But the carbing up myth has been very hard to put to rest, according to Dr. Davitt.

"We're trying to put all the naysayers to rest. This also will avoid gastrointestinal upset because blood is being shunted away from the gut."
He didn't just surmise this theory; he put it to the test. He recruited twenty experienced ultra-distance (usually marathon) runners from across the United States. All were men, and the average age was 33.5 years. According to Medscape, ten of the athletes consumed 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 during the study.

The researchers then ran the athletes on treadmills and measured consumption of oxygen and production of carbon dioxide concurrently. From these measurements, they extracted the statistical analysis of the maximal aerobic capacity of each athlete, and the amount of fat and carbohydrates burned. What they found may surprise many runners.

There were no differences in the aerobic capacity between the two groups that are statistically significant enough to show much impact. However, on average, the high-carbohydrate group burned less fat per minute than the low-carbohydrate group, meaning that the low-carbohydrate group was burning fat stores in order to fuel their metabolism. Dr. Davitt advises runners to take into consideration what they eat prior to an endurance run.

"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."
[Photo by Scott Olson/Getty Images]

Disclaimer: The Inquisitr strongly recommends you consult your physician before beginning any diet or exercise program. The Inquisitr does not endorse any of the diets or diet techniques mentioned in this article.