Fats As Fuel Help Runner Win 100-Mile Race

credit: Instagram @bigoump305

Still unsure whether a low-carb diet can coincide with an athletic lifestyle? Last month we talked with CrossFit Endurance founder Brian MacKenzie extensively about using fats as the body’s primary source of fuel and turning on  PGC-1α, the gene responsible for the efficiency of the body’s fuel system. Brian shared with us his experiences with his own athletes and how they’ve benefitted from low-carb diets. If this wasn’t enough, we’ve recently caught wind of even more proof that you don’t need extra carbs to fuel for performance.

Ultra-marathoner Tim Olson recently won the Western States 100-mile Endurance Run, and he did it on a low-carb/high-fat diet. Not only did he finish the race 15 minutes before the next competitor, he beat the course record by 21 minutes! Many people were shocked to hear about his diet, and hopefully performances like his will inspire more people to activate their fuel efficiency gene.

Some of the benefits of a low-carb/high-fat diet for endurance athletes include:

  • Training your body to use fats as fuels allows on-going use of the body’s stored fat. For example, Tim Olson has about 7% bodyfat. This equates to at least 30,000 calories of fuel. Compare this to the maximum 2,000 calories you can store in your body from carbs alone.
  • Endurance athletes on high-carb diets often have digestive problems in the middle of long events.
  • Runners racing off of carbs and sugars often encounter ‘bonking,’ where blood sugar and glycogen stores become too low. If they don’t stop at this point, they can slip into a coma.

Steve Phinney and Jeff Volek, authors of The Art and Science of Low Carbohydrate Performance, witnessed Tim Olson’s feat while studying how athletes perform on different diets. Shelley over at Me and My Diabetes interviewed Steve about his study, the benefits of a low-carb/high-fat diet, and how Tim Olson was able to stay ahead of the pack. Check it out using the link below:

Western States 100 – Low Carber Wins Ultramarathon – Steve Phinney and Jeff Volek Study

The posts on this blog are for information only, and are not intended to substitute for a doctor-patient or other healthcare professional-patient relationship nor do they constitute medical or healthcare advice of any kind. Any information in these posts should not be acted upon without consideration of primary source material and professional input from one's own healthcare professionals.

abqandrea says:

Thank you, Ben! Being fat adapted for loooooong steady cardio is one thing, elite athleticism is quite another. I don’t think they are close to being compatible. Kudos to Tim for his *general* lifestyle, though.

Great article. It should be noted, just to avoid confusion, that Tim consumed 1500 calories of pure sugar during this event (and also a very large amount of amino acids, which can technically be converted via gluconeogenesis into sugars). He used a “train low, race high” approach with respect to carbohydrates. Whether an athlete can actually do something like this (fast) in a full fat adapted state on pure ketones is still completely unknown.