Nutrition And The Ironman

Central Maryland triathlon coach David Flynn ran an interesting experiment with some of the athletes he advises at the recent ChesapeakeMan iron-distance triathlon in Cambridge, MD. David doesn't put his content online, but sends it out via email, making it next to impossible to link to it, so I'm going to quote liberally and then send you over to David himself.

(T)he goal of this test was to test a calorie model for race intake such that Scott and Patrick would have better performance than their peers. ... In this case, we charted the calories needed for both Scott and Patrick per race hour per event based upon the latest calorie charts using their weight and predicted race speed. They assumed an 11 hour effort, swimming about 30 minute miles, 20 MPH on the bike and 8 minutes per mile in the marathon. ... Our pre-race assumptions were that Scott could carry 1500 calories (90 minutes worth) in stored muscle glycogen, and anything he ate or drank would be useful 1 hour later. Further more, we assumed half of his race calorie need would come from stored fat after his initial 90 minute pre-race store was expired.

We did a post mortem on the race to get the actuals Scott ingested, and created column H. As you can see, Scott was at minus 99 calories just before hour 10 of the event. This is the wall people talk about, but one missed yogurt smoothie at the run transition was what had the wall come so early.

As a result of this test, both Patrick and Scott added significantly to the calories they planned for the race without the chart. Even so, they both fell short of the charts goals, but Scott followed it closest.

Interestingly, Scott had the fastest time of this group of six, and new comer Patrick was second fastest. Those not in the study finished between 15 and 60 minutes after Scott. All are accomplished Triathletes, and I by no means mean to take anything from their accomplishment in finishing a race this long, by implying diet make the key difference in performance.

But, in fact, I believe this kind of detail that I have been using all season is now proven to work on others. I firmly believe after this test that it IS possible to dramatically predict a racers caloric needs, if I have their speed and weight.

Most coaches and nutrition advisers that I'm aware of use weight and time exercising as the only variable in predicting the nutrition needs of athletes in ultradistance events, so adding the twist of the speed is new to me. I'll be interested in seeing further research into this.

Another interesting twist: David's choice in nutritional products.

We planned 260 Calorie Yogurt Smoothies (the highly fortified Yoplait ones I use) which out class any gel on the market.

I'm staring at an empty bottle of peach-flavored Yoplait Nouriche SuperSmoothie on my desk right now. Yup, it's pretty powerful: 260 calories, 0g fat, 55g carbohydrate (42g sugar and 5g dietary fiber), 10g protein, a decent vitamin and mineral profile. The lack of fat tarnishes its star a little bit, particularly for multi-day events. Its top ingredient is milk, however, which would make me nervous using it in a race (plus it needs refrigeration, reducing its usability in a long event in which refrigeration is not feasible). Also contains sugar and high fructose corn syrup, the current vogue demons of the American diet. I can't necessarily criticize it, but there are some warning signs to me.

But beyond that, David has brought to my attention some new things to consider as I try to conquer my own demons in competition nutrition.