Notes on nutrition

After years of trying, I finally ran a PR 2:39 marathon in Houston back in January.  I assess that my marathon performance has never been limited by energy availibility, but rather by muscle damage and central governor regulated muscle fatigue (insert Tim Noakes reference).  However, ultramarathons (both cycling and running) have been limited by my ability to take on calories late in the race.  Thus, I've been experimenting with a very low carbohydrate/ketogenic diet since before the Bull Run Run 50 miler in Apr of 2012.  I had experimented with some fasted long training runs in the fall (as part of fat metabolism adaption for the marathon), but I did not really adopt the very low carb diet until listening to a podcast interview with Dr Peter Attia.

I am your typically lean, long distance runner (5’10”, 140 soaking wet), so I have been experimenting with the very low carbohydrate diet for performance reasons (not weight loss).  In all of the 6 hr+ ultramarathons (both cycling and running) that I’ve done during the last six years, the primary performance limiter has been my ability to take on calories late in the race.  With almost five months of “ketogenic adaption” under my belt, I am pleased with the performance results so far.  I am not any faster (and I’m not any slower either!), but during training runs I have easily completed moderately intense 5-6 hr efforts in the mountains (20-30 miles with 10k ft of elevation gain) fueled only by 2-3 meager packets of almond butter or “cacao bliss” (combination of coconut butter, coconut oil, cocao butter, and agave syrup--5 g carb (4g sugars) per serving).  

My current self experiment is to determine if a very low carbohydrate diet (high fat diet) will improve fat metabolism during long endurance trail running.

Elite athletes openly experimenting with low carb/high fat (LC/HF) diets: Timothy Olson, Devon Crosby-Helms.  In a podcast interview with TalkUltra's Ian Corless, Tim Noakes hinted that he has adopted a low carbohydrate diet as well.  Max King also made similar hints in his interview following his 2012 UROC victory.

Other topics to discuss: calorie restriction, calorie restriction vs carbohydrate restriction, intermittent fasting