Dr. Stephen Phinney: Does ketosis enhance athletic performance?


I think this is something
near and dear to our hearts. – Yeah, wow. Do we have an hour to– – Yeah, I think we could
spend a lot of time on this. Our collaborator, Jeff Volek, that is at Ohio State, and
also a co-founder of Virta, he actually has been looking at this a lot lately in his research. Back at Yukon, a few years ago, he brought in 10 high carb athletes, and 10 keto adapted low carb athletes– – These were elite, ultra runners. – Yeah, elite, ultra runners, that do ultra marathons, or some of them were triathletes. So it was elite, ultra endurance athletes. And 10 of them were keto adapted, and 10 of them were on a high carb diet. He brought them in to run for three hours. And looked at all of their performance during that time, and
then during recovery. Probably not surprisingly, the low carb, keto adapted athletes had higher peak rates of fat oxidation, and a higher mean rate of fat oxidation throughout their run. But the really interesting thing is that, when it comes to athletic performance, people seem to be concerned
about muscle glycogen. And they’re worried that
if your low carbohydrate, and keto adapted that you’re maybe gonna run out of muscle glycogen. Feel like you hit the wall
and not be able to perform. So they did muscle biopsies in this study. And what they found was
that the keto adapted, low carb athletes and
the high carb athletes had the same amount of muscle glycogen. And that it followed the same
pattern even in recovery. So after the three hour run, and then also two hours into recovery, muscle glycogen was all the same. – But the difference between them was because the keto adapted athletes were burning fat at twice the rate, providing 80 to 90% of the fuel during their endurance run at race pace. So as Amy said, they ran them, had them run on a treadmill three hours, in the lab. – In the lab, staring at a blank wall. – The Keto adapted athletes mobilized muscle glycogen at the same rate. But they, it appears
that they recycled it. They didn’t burn it all
the way to CO2 and water. So it’s like, you know, basically recycling that same carbon, so they didn’t need to
eat a lot of carbohydrate in their diet in order to regenerate and maintain muscle glycogen stores. But from a parental perspective, how many ketogenic
enhanced diet performance, one thing that the endurance athlete tells is that when they’re keto adapted they’re much less likely to hit the wall. That is how the central nervous system begins to shut down saying
you aren’t providing me enough glucose to keep
my brain functioning. So A, they can go for
longer periods of time. And it appears to be
that because the brain can function very well on ketones, and is not glucose dependent. And so for events lasting longer than three or four hours, when normally, again a
full iron man triathlon, they have to eat continuously during the running and the cycling
legs of those events. One was that the athletes find they need to eat far less calories in the race in order
to sustain performance. So that’s one aspect that’s beneficial. And the other is what we
call power to weight ratio. That many athletes find, no
matter how hard they train, they can’t train themselves down to an ideal, low level of body fat. Say under 10%. And for some athletes getting under 10% is really important in terms
of the power to weight ratio. And they find that when they
adapt a well formulated, ketogenic diet they’re
better able to achieve that optimum percent body fat that optimizes the ratio of muscle to muscle weight to body fat weight. And again for those athletes, oftentimes they will train on a high fat, low carb diet to get ideal
body composition down. And then they can add back what they call strategic carbs, either
immediately before, or during an event in order
to optimize glycogen as well. And again this tends
to be athlete specific. Each athlete needs to have some guidance, but their own experience in figuring out what works best for them
in terms of the degree of carbohydrate restriction,
and the amount of carbs that can be used strategically to maintain optimum performance. – Yeah, and I think we’ve talked a lot about resistance training, or endurance training, but I think resistance comes up a lot too. I think there was a study recently, I hope I’m not miss remembering this. I think it was out of
Donovan and Stephen’s group, or he was involved in it somehow. But they looked at 10
weeks of western diet compared to a ketogenic diet, and similar gains in terms of strength and power during that time. And also similar losses
of body fat and muscle gain between the two groups. So it doesn’t appear to
impair performance in any way. – And not to get too
far ahead of the data, Professor Volek at OSU is, has completed the data collection from a study they did with a high carb versus a ketogenic diet in a group of student athletes where they did a intensive resistance training program. And hopefully those data
will be reported this year. But it will I think, emphasize the benefit in terms of resistance training, and maintaining lean body mass and optimizing power to weight ratio.

5 thoughts on “Dr. Stephen Phinney: Does ketosis enhance athletic performance?

  1. As a T2 who is controlling blood glucose without medication…I can't get enough information from Stephen Phinney. I'm an avid cyclist and am trying to completely optimize my performance. If you have any more information about athletes and ketosis…please share!

  2. Interesting discussion thanks. Can you direct me to some information regarding high performance endurance training whilst on LCHF and some fueling strategies to use during the event.

  3. This video does not answer the question: Does ketosis enhance athletic performance? Just comment on this article showing differences between keto or not keto athletes. https://www.ncbi.nlm.nih.gov/pubmed/26892521 So, the evidence for this is lacking. If Keto is better for endurance performance, please tell it to the African runners. They have most of the 100 fastest best performance of all times in the marathon. Kenyans or Ethiopians consume 60- 70% of carbs in their diets: https://www.ncbi.nlm.nih.gov/pubmed/21595961 and https://www.ncbi.nlm.nih.gov/pubmed/15657475 This is real athletic performance.

  4. “Athlete specific,” well there’s your fine print and cya right there. 🙄
    Maybe it works for marathon runners but, until I see it working for sprinters, power lifters, football players and wrestlers it gets a big 👎 from me. And you know if it worked for those types of athletes they would all be on Keto religiously, right now.

Leave a Reply

Your email address will not be published. Required fields are marked *