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From Fellrnr.com, Running tips
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I used the [[Ketogenic Diet]] for 7 months, running an average of 70 85 miles/week, peaking at 200 miles/week, including over 50 marathon length runs. I was surprised how little impact the Ketogenic Diet had on my running, and I could maintain my training regime without difficulty. However I was not able to race successfully on the Ketogenic Diet and I found the Ketogenic Diet difficult to comply with. This write up should not be considered as scientific in any way; it is simply my anecdotal experience.
=Background=
As an ultrarunner, I've experimented with [[Low Carbohydrate Diets]] (LCD) before with little success. I found that running on LCD let me feeling like I was permanently [[Glycogen]] depleted. However, after reading [http://www.amazon.com/The-Art-Science-Carbohydrate-Performance/dp/0983490716 The Art and Science of Low Carbohydrate Performance] and [http://www.amazon.com/Ketogenic-Diets-Eric-H-Kossoff/dp/1936303108 Ketogenic Diets: Treatments for Epilepsy and Other Disorders] I decided to experiment with a true Ketogenic Diet which is quite different from most general Low Carb Diets.
* I seemed to have more migraines on the Ketogenic Diet, though my migraines are not predictable enough to be sure.
* I had more problems with my skin condition on the Ketogenic Diet, though with hindsight I suspect this was due to an insufficient Vitamin C intake. It's hard to get the macronutrients on a KD, so [[Ketogenic Diet Supplements| supplements are required]].
* There are reports that [[Vespa Gel]] can help performance when on a Ketogenic Diet. The science behind Vespa is extremely poor, with a few animal studies indicating improved performance when taking the equivalent of 100-200 packets of Vespa. However, I performed a simple double blind test on Vespa and found no discernable impact. While I believe that Vespa only acts as a placebo, it's worth remembering that a good placebo can improve performance dramatically.
=Ketone Levels=
One common question I get about my ketogenic experiment is if my ketone levels were actually elevated.
The advice from books like |[http://www.amazon.com/The-Art-Science-Carbohydrate-Performance/dp/0983490716 The Art and Science of Low Carbohydrate Performance] is that [[Ketoadaptation]] takes at least two weeks, and [[The Science of Ketogenic Exercise| the classic study by Phinney]] used four weeks to ensure complete adaptation. My experience fitted in with this guidance and for the first couple of weeks running was much harder. My [[Heart Rate]] (HR) and [[Breathing]] (Respiration Rate, RR) was much higher than I would expect for the given pace. It also seemed like my RR went through cycles; at some points the RR would be what I would expect for the elevated HR, and then increase so that my RR was higher than expected, before lowering again. This would repeat every few minutes. After [[Ketoadaptation]] my running felt similar to how I feel on a high carbohydrate diet. However, an analysis reveals that my HR was higher than it would be on a high carbohydrate diet (see "Running Economy" below.)
=Ketogenic Running=
* I ran an average of 85 miles/week, generally running 4 days/week with an average distance of 20 miles. I ran the marathon distance or longer 58 times.
* I found I had no problems running marathon distance training runs at an easy pace without any fueling on the Ketogenic Diet, but I can also do that on a high carbohydrate diets.
* Taking small amounts of carbohydrate during a long run could be done without impacting my Ketone Levels, but too much would cause the levels to drop precipitously. To my disappointment, the extra carbohydrate did not seem to reduce my fatigue or improve performance. I also tried taking extra fat, or mixtures of fat/carbs/protein, which seemed to help a little.
=Ketogenic Ultramarathons=
I took part in three races while on the Ketogenic Diet; the Midnight Boogie, Laurel Valley and Hinson Lake 24.
* The Midnight Boogie is a 50 mile race in the heat of the North Carolina summer. I started running without calories and felt fine for the first 26 miles, at which point things "went squirrely". I had a few potato chips (crisps in the UK) at mile 26, then I took at a [[Comparison of Energy Gels| peanut butter GU ]] at mile 29, which helped enormously. Over the rest of the race, I had a few more handfuls of chips and I finished two Pocket Fuel gels, the last one about mile 46, finishing the race in 8.54(8th place). That's not a terrible result, but it was slower than I'd have expected (I've won the race in 7:04 previously.) I estimate that from mile 26 to 50 I consumed about 800 calories, 46g fat, 14g protein and 64g carbs. To put that in perspective, my basal metabolic rate for 9 hours is probably around 800 calories, and my total calorie burn for the race would be around 5,000 calories. After the race my Blood Ketones were 3.1 and my Blood Glucose was 105. The high ketones indicate that I was still ketogenic, but the elevated blood glucose is a little odd. I drank my [[DIY Electrolyte Drink]] throughout the race.
* For Laurel Valley (~35 miles) I took things easy, and sadly I made no useful notes in my training log. I recall that I was not attempting to be competitive, and I hung back to look after another runner who had been stung by a bee.
* Hinson Lake 24 Hour was a disastrous race. By mile 24 my blood pressure was low, my breathing was strained, my blood ketones were 0.8, and blood glucose 108. At mile 26 I started to suffer from Nausea, but I continued to push on until mile 42 when my blood pressure was too low to stand. After some medically trained runners took care of me for some time, I recovered enough to walk another lap (~1.5 miles), then run a lap, before retiring from the race. You can read more at [[2013 Hinson Lake 24 Hour]].
=Running Economy=
The graph below is of my [[Relative Running Economy]] over the three year period that includes the time I was on the Ketogenic Diet. As you can see my Running Economy was lower on the Ketogenic Diet than with more carbohydrates. This is what I would expect, has fat requires more oxygen to produce a given amount of energy compared with carbohydrate.
