Now, if you’ve been following me for a while, you probably know that I recommend a high protein, low carb and a moderately high fat diet, loosely based on what is popularly know as the Paleo diet.  I don’t go as far as eliminating all of the foods that’s suggested by the Paleo diet, for sake of moderation, although I tend to be more stringent than what I recommend.  I do think it’s more realistic and doable for people to go on a diet that isn’t too extreme.  Extreme…that is, relative to the modern American diet that consists of fast foods laden with trans fats, big gulp soft drinks that contain about a bucket of sugar and a population that’s been brain washed into thinking that cereal bars with sugar listed first on the ingredient as healthy because it claims to be low in fat.  Anyway I digress, and I’ll get off my soap box for now and get to the point.

In a diet that consists of low carbohydrates, it’s always a challenge when training your body for longer durations, since more energy is required.  Although, your body has the ability to produce up to 200 g of glycogen, both internally and from dietary sources of protein and fat, it’s quickly depleted when you start training for longer periods of time such as 3 - 4 hours (or longer) a day.

Personally it’s been a long time since I trained for an endurance event, but in the past (in another life it seems) I did train for what now seems like a ludicrously long time…about 3 - 4 hour a day.  And during those long training periods, it seemed that I could pretty much eat what ever I wanted without any fear of gaining weight or other health issues.  The one factor that really stands out is how much carbs I ate.  In fact, carbs was the main focus of all of my meals…breakfast, lunch, dinner and everything in between.  And these were not the healthy carbs that I usually recommend such as fruits and veggies, but rather the calorie dense white flour power carbohydrate foods like bread, rice and pasta.  All the bad grains that I stay away from now, was what constituted 90 % of my diet, but when your training 3 - 4 hours a day, quick available source of energy is what my body needed…or at least that’s what it seemed like that the time.  And so eating 5000 - 6000 or more calorie a day and mostly from carbs didn’t seem like such a big deal.  Although looking back at it now, I wish my coaches knew better about nutrition, since I know how much it effects our body and I do wonder what I may have been able to do if my nutrition was optimized.

So this is where the dilemma arises…knowing what I know now about nutrition, is there a way to keep eating fairly low carbs, sourced mainly from fresh fruits and veggies and not have to eat calorie dense grains…and still train high volumes and long durations without bonking out due to lack of energy.  Well to my surprise, after doing some research I found an interesting article from Nutrition and Metabolism.  It was a review of several studies by Stephen Kinney called “Ketogenic diets and physical performance”.  Here’s the abstract and conclusion from the review:

Abstract:
Impaired physical performance is a common but not obligate result of a low carbohydrate diet. Lessons from traditional Inuit culture indicate that time for adaptation, optimized sodium and potassium nutriture, and constraint of protein to 15–25 % of daily energy expenditure allow unimpaired endurance performance despite nutritional ketosis.

Conclusion:
Both observational and prospectively designed studies support the conclusion that submaximal endurance performance can be sustained despite the virtual exclusion of carbohydrate from the human diet. Clearly this result does not automatically follow the casual implementation of dietary carbohydrate restriction, however, as careful attention to time for keto-adaptation, mineral nutriture, and constraint of the daily protein dose is required. Contradictory results in the scientific literature can be explained by the lack of attention to these lessons learned (and for the most part now forgotten) by the cultures that traditionally lived by hunting. Therapeutic use of ketogenic diets should not require constraint of most forms of physical labor or recreational activity, with the one caveat that anaerobic (ie, weight lifting or sprint) performance is limited by the low muscle glycogen levels induced by a ketogenic diet, and this would strongly discourage its use under most conditions of competitive athletics.

I found the review definitely interesting and something I’d like to look into in more detail.

According to the review there were 3 vital factors that needed to be met in order for an individual to be able to train long durations without any performance compromises.

• Adaptation - It requires anywhere between 2 - 4 weeks for you body to be able to adapt to a ketosis state and be able to optimally provide the necessary energy.  So if you’re thinking about training for endurance event, give yourself plenty of time to adapt to the diet.  In keep in mind that you’ll probably go through quite a bit of ups and downs in your energy, recovery and training performances during this period.

• Sodium and Potassium balance - Your body requires proper balance of sodium and potassium levels in order to maintain proper and optimal bodily functions.  According to the studies reviewed most methods of cooking depleted the meat of their natural sodium and potassium contents and hence their diet had to be supplemented with additional sodium and potassium.  But keep in mind the subjects they studied were on a no carb diet to induce a ketosis state.  Normally, if ample amounts of fruits and veggies are included in your daily diet, you would be getting plenty of sodium and potassium and hence this wouldn’t be something you would have to worry about.

• Sufficient intake of protein - According to the cases reviewed it was evident that sufficient amounts of protein was needed on a daily basis in order to maintain the muscle mass without loss of lean muscles.  The figures that they came up with were somewhere between 90 - 120 grams of protein a day OR about 15 - 25% of the total daily calories.  Anything less than that the body started to lose necessary lean muscle mass and would hinder their physical performance.

Again, it should be noted that the studies they reviewed were extreme case where the individuals were in a state of ketosis, where the intake of carbs was extreme low.  In cases where people were able to eat some carbs from healthy sources such as fruits and veggies, the outcome may be different.  However, that being said, it does bring to light that the possibility of participating in endurance events while keeping a fairly low carb intake from healthy sources of fruits and veggies is possible.  It’s definitely worthy of further investigation and research.  If the diet of Inuit hunters were any indication of what our body’s were meant to do, the prospect of this diet is exciting and it may eventually redefine our traditional mode of carb loading as ineffective and inefficient.

Just as side note, there is a book out there, by the creator of Paleo Diet, Dr, Loren Cordain called “Paleo Diet for Athletes”.  And it looks into how an endurance athlete can train and participate in long endurance events while following the principles of the Paleo Diet.  If you’re an endurance athlete, it’s definitely worth a read.

If you’re currently training for an endurance event, how much carbs are you taking in?

Would you be willing to try going on a low carb diet and see if your body adapts training at higher volumes?

What did you think about the article?  I’d love to know what you think.  Please post you comments below.