Getting Race Nutrition Right

A theory I have about long-distance racing and nutrition is this: either through superior fitness (think years of base) or being very light in weight or both, it helps to get your body to the point where you can keep going on as FEW calories as possible. And then as many experienced IM'ers know, mostly liquid is easier to process than solids.

I've read that you are doing well in an IM if you're able to replace somewhere around 50-60% of the calories you are burning.

Step 1 of getting it right is knowing how much you are burning. If you are estimating, it can take a few years or so to get this right (in my case, I had my RMR measured and from that and VO2 Max measurement, worked with an exercise physiologist to calculate burn rates for me), but through trial and error, you will eventually (hopefully) figure it out.

Step 2 is to find out what % of the calories you are burning you can tolerate replacing while racing. This will depend on your speed and the distance you are racing. The faster you go, the less calories IN that you can handle, and the slower you go, the MORE. The longer the race, the HIGHER the % of calories burned you need to shoot for, or should--thing is you can make more nutrition errors in shorter races, since you don't have as much time for them to manifest themselves in a big problem.

For example, in a sprint race you can pretty much go without or a few sips of Gatorade here and there. Olympic, you need to be more concerned with hydration and more calorie intake. HIM, most people can get by on maybe 200 calories/hour (assuming you go 6 hours or less). IM--rules of thumb are something like 250-350 calories per hour while on the bike, and then do the best you can on the run. So if you race different distances, your race nutrition is going to be slightly different in terms of how much per hour.

Step 3 is to train in such a way as to make your body an efficient system. The more fit you are, the less calorie intake (as % of burn rate) you can get by on. These are small % variations based on fitness, though, but it does make a difference. The less nutrition your body has to deal with, the more reserves it has available to make your muscles work.

As an N=1 sample, the first 2 years I did triathlon, I was taking in 300+ calories per hour during long rides and long runs or else I would seriously bonk. Now I'm down to maybe 250 on the bike and 200 or less on the run, AND I'm going faster. Maybe that presents a chicken and egg puzzle--not sure. But I can say that even a difference of 25 or 50 calories per hour is significant when you are calibrating race nutrition. It's enlightening to visit the Infinit Nutrition website, answer the questions, and see what they come up with as a personal formula for YOU. When I did this, bang, it was almost dead-on 250 calories per hour.

My definition of "training in such a way as to make your body an efficient system" consists of regular training to maintain or lift AeT (or whatever you want to call it), which also happens to make you faster, and always providing my body with a steady stream of carbs. That latter thing is not scientific, but just my observation. Even if I go out for a 30-minute run, I take some Gatorade with me and will have 1 or 2 sips. My body expects to always have blood sugars available, and I generally don't finish a workout wanting to eat the entire refrigerator contents, which bonus, contributes to weight management.

Step 4 in the nutrition game is to calibrate your race pacing, both planned and by making real-time adjustments, in order to get the nutrition you need. Here's where it gets to be chicken and egg. If you speed up, you must slow down your calorie intake and vice versa. But you have to go into a race with a plan, and then know/learn how to make adjustments due to pacing changes, weather and stress.

Step 5 is to make sure your glycogen stores are topped off before you even begin the race. This ensures you can "fast" while waiting for the race to begin and get through the swim. I personally have 700-800 calories the morning of an IM, and maybe 600 before a 1/2 IM. In the days leading up to the race, I'm not overeating, just emphasizing carbs a bit more, and maybe some extra salt 1-2 days prior.

I'm not going to talk about hydration here, but there are similar issues to consider in terms of body weight, speed, heat and sweat production.

Even if you don't *think* you are experiencing GI issues during a race, you might be slowing yourself down unknowingly by asking your body to either process more or less calories than it needs, or by utilizing inferior energy sources or hard to digest foods. Or, you might be going faster than your GI system can manage (i.e., you didn't adjust your intake up/down as your speed decreased/increased). Which is why, I guess, nutrition is called the "4th discipline" in long-distance racing. Also why it's so easy to slow down significantly during the IM marathon--nutrition and pacing are so closely linked that it can be difficult to separate the two.

Again, remember that liquid wins over solids during a race anytime, even if you use solids in training. Carbs win over proteins and fats. It takes more work for your body to digest solids than liquids, and more work to process protein and fat than pure carbs. Heck, on 100+ mile rides, I will eat all kinds of things--I was even (gasp!) seen eating a custard-filled donut on one ride this summer. But I know that in training I can tolerate just about anything. When I race, though, it's strictly liquids and occasional gels. Even when I think I want something solid, my good sense gets the better of me and the thought passes. I do usually put cheese-peanut-butter crackers in my bike special needs, but I end up putting 2 or 3 in my mouth, taking a big swig of Gatorade and they just sort of melt.