OMG UPDATE: Question? Answer.

Updated on Thursday, July 2


QUESTION: I saw a documentary of a mountain runner that claimed he had trained his body to better utilize its fat stores by eating fats rather than carbs prior to his runs. Serious question: is this actually possible?


  1. Ohhh!! I think I saw the same documentary. Ultra runners, was it? It's amazing what he trained his body to do.

  2. yes, its called being metabolically flexible.

  3. yes, this is possible. The body first relies on carbohydrates for fuel from the diet and muscle storage. However, once these carbs sources are depleted, and carbs are no longer in the diet, the body will start converting fat stores into ketone bodies - which pretty much are mock carbohydrates and are a secondary source of energy for the body. This process will naturally occur in starvation, but can also be achieved if minimal carbohydrates are consumed.

    This type of diet cannot promote fast energy release, therefore it is best suited for endurance. Most people feel "sluggish" with this type of diet since the body must first rely on carbs, THEN fat stores to convert to ketones = slower energy source.