There’s more than one way to skin a cat. A terrible expression, isn’t it? I’ve had cats as pets all my life and the phrase is particularly abhorrent to me. However it’s very apropos at the moment, because what I am about to tell you flies directly in the face of conventional wisdom about nutrition. It’s a subject near and dear to my heart, so I think it’s worth discussing. Now, I will add the caveat that I am not a nutrition expert by any means, but these are simply some things I have observed in myself and others.
Conventional nutritional advice suggests that we fuel our runs with carbohydrates. There is, in fact, a bajillion dollar industry based on this idea, with sports drinks, gels, bars, and jellybeans full of carbohydrates out there on the market. For really long runs, the typical advice is to carbo-load starting several days in advance, but even for a 5k, the idea is to take in some easily accessible carbs prior to your run. Let’s consider why this is.
Our bodies store energy in two forms: fat and glycogen. Glycogen is a form of glucose stored in the muscles and the liver, but it can only be stored in limited quantities. It is easily accessible energy for intense exercise. Fat is, well, fat and it can be stored in virtually unlimited quantities in the body. It is a more efficient source of stored energy, but it is also harder for the body to turn fat into energy. Your body will first use up your glycogen stores and then move on to turning fat into energy. So the accepted wisdom says that before runs and races, consuming carbohydrates will top up your glycogen stores and give you more energy.
This is where I am going to turn that wisdom on its head. I am a diabetic, and the kind of carbo-loading that is recommended, where the runner starts increasing their carb intake over the days leading up to a race and then takes in 30 or 40 grams of carbs in the hours before the race, is a dangerous proposition. You might as well tell me I need to go ahead and deliberately cause damage to my feet, eyes and nervous system, not to mention my internal organs. Because that’s what consuming that amount of carbs, along with the subsequent blood sugar rise, would do to my body. Figuring out the nutrition before both regular runs and races has long been a struggle for me.
But it isn’t any longer, because I discovered a remarkable thing. I actually run BETTER when I keep my carbs to the minimum. My best races, both long and short, have been fueled on breakfasts of eggs, cheese and butter. My personal record in the NYC half-marathon was fueled on a 3 egg omelet with cheese about 2 hours before the race, and one mini Luna Bar (11 g of carbs) about 15 minutes prior. As my body has become accustomed to using fat for fuel, it has learned to do so more efficiently and quickly. And I actually get stitches, stomach aches and some gastro-intestinal discomfort if I try to fuel up on carbs. Refined sugar is particularly problematic and I now steer clear of it entirely when training. No Gatorade or running gels for me anymore!
Let me be very clear that I am not advocating a switch over to a low carb diet for everyone, although I do believe that it is a much healthier way of eating. I think what’s most important here is understanding how your body uses the fuel with which you provide it so that you can make smart decisions. You don’t want to start something new just days before a long run or a big race. Your body is used to your current diet and a major change before an event, even if it’s a healthy change, may not sit well on race day. Someone whose body is used to consuming a significant amount of carbohydrate shouldn’t suddenly switch to protein and fat before a race. Likewise, someone who has been eating low carb for several months shouldn’t attempt to carbo-load, hoping to gain more strength and energy. Both of these strategies would inevitably backfire and you could cause yourself some serious intestinal discomfort. You want to finish this race, not be running for the bathroom!
Many of my readers are following a low carb diet, so I say conventional wisdom be damned. You can, in fact, fuel a great race on protein and fat. You can also fuel a great race on carbohydrates. Listen to your body when you run. It will tell you what to do.
For more tips on nutrition and running, please see my post on Red-Faced Runners.