The body stores about 1800 calories of glycogen, give or take. When marathoners hit "the wall" after 15-20 or so miles they have mostly depleted these stores and are having trouble adjusting to burning fat.
If I train in nutritional ketosis, theoretically my body will be used to using fat as a fuel already, right? So then shouldn't I be able to run a marathon without hitting the wall?
I've run 3 marathons in the past eating lots of carbs during training and I'm gearing up for another. Have any experience marathoners played with this?
I know that marathons can be run on a paleo diet just from other PH threads. What I'm asking here is, could it actually advantageous to train in ketosis?
asked bySam_7 (1304)
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on May 03, 2012
at 06:11 AM
Read Volek's new book on exercise performance. He offers the case studies of quite a few ultra-marathoners - folks who do 50, 100 mile runs - who live in ketosis just for the advantage of always have steady fuel during these very long endurance events.
on May 11, 2012
at 10:08 PM
Steve Phinney has shown that keto-adapted athletes utilize muscle glycogen at a lower rate during sub-maximal exercise. Of course, when you are in ketosis your muscle and liver-glycogen stores are much reduced over someone that has carbo-loaded.
It's like having two leaky buckets, a full to the brim carb-loaded bucket with a big hole, and a half-full keto-adapted bucket with a much smaller hole. Even though one is much fuller than the other, they'll both empty out in the same time: http://www.nutritionandmetabolism.com/content/1/1/2
Of course, once your glycogen is exhausted, the keto-adapted athlete is in a better suited to running on stored fat. The alternative title for Phinney and Volek's new book is "the art of avoiding the bonk".
on August 16, 2012
at 12:10 AM
I'm not an "experienced marathoner", but I implemented the Volek/Phinney program and ran a trail marathon in ketosis. I wrote up a report on mark's daily apple:
I'm not convinced that there's a performance advantage, but I don't have an apples to apples comparison. Recovery seems to be improved though, which could be very important.
on May 08, 2012
at 03:42 AM
Take a look at http://www.marksdailyapple.com/how-to-fuel-a-marathon/
Mark talks a bit about "Train Low, Race High"
on May 03, 2012
at 02:28 AM
Honestly, I'd be surprised if training in ketosis does you any good. "Hitting the wall" is not this inevitable occasion, it's just what happens to a lot of people that do marathons.
A better focus, in my opinion, is to build up your muscular strength and endurance. As your muscles get built up, you will be able to go faster and farther using less energy. I just don't think there's as much to this "keto-adapted" thing as people give credit for. Sure, your body will probably become more efficient at it as you do it more, but to the extent that you'd be better off training in ketosis for a marathon is the wrong approach.
If nothing else, the biological mechanism of ketosis and running marathons are completely antagonistic to each other.
on May 03, 2012
at 01:48 AM
I don't do marathons (longest I ever did was a half). I used to do 10k races a bunch, but since switching to Crossfit and paleo full time, I haven't done any long-distance trainings. I still do one 10k a year for fun, and I've been drafted into some 24-hour relay events where the legs are on the order of 10k or so. So take this for what it's worth coming from an anti-endurance mindset and training style.
I have had my best ever 10k races, both in best times, and felt the best during and afterwards, when I've been keto adapted. In fact my last 10k that I did, I ran it in a fasted state. I woke up, drove to the start, ran. I had an awesome feeling of constant energy, never really got tired. I couldn't ever pick up the pace to sprint past anyone but I had a great constant energy. I never felt anything like it. I totally think that it would extend to a marathon if you wanted to try.