I was side-lined with injuries much of last year so this was my first attempt at a long distance run in 8 months. I prepped by doing a lot of short, fast runs, a lot of weight work and a very low carb diet. Also a lot of PT for the injury.

I've used lowcarb in the past so I know how it affects me on long runs. I found I need little carb but I do need some. I can't run on body fat alone. The race had the usual assortment of carbs at every aid station: potato chips, lowfat cookies, M&Ms. The available fluid was water or Heed, an electrolyte/sugar mixture similar to gatorade.

As always, the hyper-caffeinated, hyper-glycogenated crowd left me in the dust early. I plodded along, occasionally passing someone with a cramp or strain, but mostly running alone on the trail.

I live in a cold climate. The race was in a warm area. I often have trouble with the heat. Around mile 40 I started having cramps everywhere, not just my legs. For the last 10 miles I mostly walked. I would try to run but that just triggered massive cramps in my legs, back, etc. As I was the last finisher, I was given the pejorative term DFL. Dead fu***** Last! No matter, I'm used to it.

The only problem was the cramping. They seemed to get worse after the race was over. At that point the sun was going down and I was getting quite cold. I was spending the night in a tent and the shivering seemed to trigger worsening cramps. I ended up in my car with the heater blasting while I drank gatorade. After three liters, the cramps subsided.

So this is a new one on me. Does lowcarb affect electrolyte levels? On the positive side, like in the past the muscle soreness was gone in two days. In the old days of marathons on sugar, I suffered muscle soreness for weeks post-race. I don't know whether the lowcarb caused less muscle damage or if running so slowly just didn't enflame the muscles too much.

50 miles in 12.25 hours. DFL. >:-( The winner did it in about 7 hours.

I have no idea what the answer is to your question. I just have to say congrats on finishing a 50 mile race. I think you are crazy , but it is still a huge accomplishment!

First - congratulations! What an accomplishment to finish, even DFL. I'm sure there were more than a few that didn't finish even. I've read about your ultra runs before, quite inspiring.

I'm curious though, I thought you had kind of given up on running low-carb. I thought I'd read posts of yours previously where you said you found you just didn't have the energy for long runs without the carbs. Maybe I'm confused and mixing you up with someone else.

You said you need some carbs to race, did you take some of the carbs offered along the run?

I'm just asking because I'm curious. I'm working on building up to a 10k (nothing compared to your running, I know) and I've pretty much given up on running on low-carb. I can run on maintenance-level carbs, but not really low-carb. I don't bonk running on low-carb obviously, I'm not running long enough, but it's like I start out a little bonked, slow, tired and my legs feeling heavy.

I imagine I could run my 10k that way, but I'd be really slow and I have to confess, half the fun for me is trying to improve my times.

Val

I don't micromanage my diet. I found that without carbs on board my running pace goes down to 12:00 or worse. With some carbs, it goes up to 9:00 or better. So for me it's a matter of finding the lowest amount of carb to get through my daily run. For the past several weeks I was taking in enough carb to be able to do quality speed workouts, which I could never do without carbs.

For a midday run I would have breakfast: oatmeal, peanut butter and syrup in soymilk. If I wasn't running that day, breakfast would be a cheese omelet.

For the 50 miler I was forced to eat whatever was on the aid station tables. In the past I would fill up on carbs for a couple days before the race. This time I didn't. So I think I entered the race on the verge of ketosis. Every 4 or 5 miles there would be an aid table where I could fill my water bottle and eat M&Ms, Pringles, cookies. I ate very little of that. I had a fanny pack filled with nuts that I snacked on all day.

If I had eaten more carbs, I would have finished much sooner. But this was an experiment to push the limits of lowcarb running. What I learned is that I should fill up on carbs a couple days before the race. The goal is fat-burning, but fats burn in a carbohydrate flame. Filling the muscles and liver with glycogen means there is instant energy available to keep the flame burning. I didn't 'carb up' this time because I don't like that bloated feeling. But I learned my lesson. My next race is in early May.

The theory is if I control my heart rate, fat is being burned more than glycogen.

Part of the problem could be that you never allowed your body to become fully adapted to burning only fat for energy. If we give the body any significant amount of carbs, as soon as they are gone, the body will want more. It will never fully adapt to burning fat. Check out the Phinney study, Ketoginic Diets and Physical Performance.

http://www.nutritionandmetabolism.com/content/1/1/2

Trained cyclists were put on ketogenic diets. They found that after sufficient time was given for adaptation, the cyclists performed just as well, if not better than, when they were on the typical high carb diet. And as for fat burning in the flame of carbohydrate: well, they found out that burning calories at a rate of 960 kcal/hr, which is fairly intense exercise, the cyclists were burning virtually all fat.

It's a very interesting read. Anybody who is low-carbing and exercising should read it.

I'd read that report a year or so ago but I reread it anyway. Those athletes who were able to compete with no carbs whatsoever has stayed in my mind. I think what happened there is the body was making sugar (gluconeogenesis) from muscle tissue or ingested protein. So the body still requires glycogen for efficient fat-burning. And the body never gets to the point of being able to work above 90% of maximum heart rate because the body can't manufacture sugar from protein fast enough.

Just a guess.

Perhaps you missed this part of the study:



So, no. Glycogen is not required for efficient fat burning. Also, from personal experience, I can tell you that the body can work above 90% MHR. I do it every time I run.

"virtually all of the substrate for this high energy output was coming from fat" Virtually? It still fits the theory of a carb flame needed to burn fat. Was the 'virtual' component endogenous carb?

A lot of top athletes have tried a ketogenic approach to diet and training. The theory just makes so darn much sense. But I haven't heard of any who were successful. I read one study of cyclists training on a ketogenic diet. They were able to work as well in ketosis as the control group who weren't. But the ketotic group members all said it felt a lot more difficult to work at that level. They saw no need to continue a ketotic diet once the study was done.

Ok, there was a tiny bit of carb was burned along with the fat.
In the study, it said the cyclists were getting less than 3% of their calories from carbs. On a 2500 calorie/day diet, that would be about 20g of carb. It could have came from that.

This is only conjecture, but they were only on the ketogenic diet for 4 weeks. I don't think this is enough time to become fully adapted, and that's where the "virtual' component comes in. My understanding is that it can take anywhere from a few weeks to several months to beome fully keto-adapted.



Unless you believe, like I do, that carbs are bad and the fewer we eat, the better.

The bottom line is, that given time to adapt, these athletes performed just as well without significant carbs as they did on their standard diets, which no doubt contained high amounts of carbs.

I'll admit, although I've used versions of the lowcarb diet for several years now, I've never tried a truly ketotic diet. In periods where urine stix said I was in ketosis, my energy level was usually low. I don't think I could tolerate a ketotic diet because it relies on animal fat intake. I can't make myself eat animal fat. I've tried with vegetarian fats, ie nuts and avocado, but that pales quickly.

My first time on Atkins, I started in Feb 2003. Over the weeks, slowly I started getting cramps - first in my feet and calves in the middle of the night, and then by June I remember I got a charley horse in my hamstring in the middle of the day! My hamstring, it was so painful! I think I started taking potassium ... but I can't remember. I ended up getting pregnant and went off low carb.

I'm currently back to low carb, started again in Feb. In the past few weeks I'm starting to get more charley horses in the middle of the night ... so I'm going to look into more electrolyte replacements, probably will start eating more avocados too!

Don't know if that helps at all, but thought I'd share anyway!

My understanding is that if the urine sticks show ketosis, this means you are not really burning the ketones, you are excreting them. Good for weight loss, but bad for energy. As one becomes adapted, the urine sticks will not show ketosis. That is because you are burning the ketones, not excreting them. Almost every day on this board I read posts saying "I'm eating almost no carbs, but I'm not in ketosis." Well, I just explained why.

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Yes, if you shy away from animal fats then you would have a hard time with a ketogenic diet. Good luck! I admire anybody who can run 50 miles, no matter what they are eating.

I"m sure somebody around here will know for sure, but I believe potassium and/or magnesium will help with the leg cramps.

How long do your legs feel sore? Is it hard to walk for a few days after running 50 miles? Does it make you not want to run for a while or are you still looking forward to it?

I was running two days after the race. Not far and not fast, but running. i did roughly 30 miles the week after the race and 40 miles this week. Next week I'm back up to my 50 miles per week average. That seems to be a feature of lowcarb and exercise. I can't run as fast but the tradeoff is I don't get as sore as I used to when I would 'carbo-load' for days before each race.