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by Kristen Marchant


Race nutrition is an often talked about topic, especially given the fact that there are so many products out there. There are many articles written to tell you what you should be doing for your race fuel and hydration, which can lead to confusion and generally make things seem a lot more complicated than they need to be. Unfortunately, most studies that look at optimal fueling for racing use young, male, already-fit subjects.  This means that in all likelihood, what the studies conclude to be most effective is not actually most effective for you. Age and gender, along with fitness level and intensity of exercise all play significant roles in your ability to absorb nutrition. As this topic could lead me to write a 20 page essay, I will stick to reporting what I do in a race and a brief rationale.

Typical 70.3 race:

For a race that will take approximately 4.5hrs and done at a moderate intensity (relative to max effort), I consume most calories from food. My choice is to use Clif Shot Bloks (no I’m not sponsored by them, I use it because it works). By consuming something that requires chewing (as opposed to gels), the digestion is slowed down. Also, Shot Bloks use maltodextrin as their sugar/energy source, as opposed to fructose. Fructose has to be taken to the liver first (delaying the time until your body can use the energy), and causes dehydration as when it is in the gut your body needs to draw water from your cells to help with the digestion of the fructose. Maltodextrin is metabolized differently and therefore, as long as it is consumed in moderate amounts, will not have this dehydrating effect.

I believe that hydration should remain almost completely separate to fuelling. Again, there is science to back up this rationale.  Many sports drink companies will tell you that their product is taking care of both your fuel and hydration, but in reality this is not the case. A concentrated fluid solution (typical Gatorade/ Powerade/ etc) needs to be diluted in order to be absorbed. This fluid comes from your body where you actually want the fluid to go, in effect- causing dehydration. The ideal drink will have some (emphasis on some) glucose and/or sucrose and sodium, which drive the transport of fluid into the blood stream. My solution to this, while not perfect, is to drink a very diluted powerade on the bike- approximately 50% powerade/50% water in one bottle and straight water in the other- more water to be obtained on course (on a hot day I will consume up to 4 bottles of fluid during the bike portion).

Caloric intake:  The studies done on fit, young, males show that it is possible to consume 300 calories an hour and be able to absorb and digest this amount. Again, most people do not fit into the ‘fit, young, male’ category, and therefore can probably not eat this much. In a typical 70.3 race I consume about 500-600 calories. On the bike this is about 100 from the Powerade, and 400 from the Shot Bloks. On the run, if needed, I will drink Red Bull or Coke in the second half. One note of caution is that if you start to consume caffeine in a race, you basically need to be able to continue to consume it for the rest of the race. Because of the way that caffeine is absorbed, you will feel like you are bonking if you do not continue to consume it during the race.

I hope that if you are having issues with your race fuelling/hydration plan that there are some nuggets of wisdom you can take from this to better optimize what you are doing.