3. I Didn't Fuel Up
Distracted by glorious views, rockin' Zydeco bands, or spectators bearing cowbells, I have been known to let more than 13 miles go by before popping my first chews. At one race, I figured I'd save my Turbo Double Espresso shot until I really needed the jolt. But by the time that need reared its head—in the form of a weird, presumably low-blood-sugar-induced tingling in my face—it was too late. (BEWARE: These Top 5 Prerace Nutrition Mistakes may sabotage your results.)
"Once you dig yourself into a hole, it's very hard for your body to catch up," says Kim Mueller, M.S., R.D., C.C.S.D., a 2:52 marathoner and founder of San Diego-based Fuel Factor Nutrition. It's hard to restock your tank because it takes oxygen to digest food and to pump blood to your muscles. "A lot of runners overwhelm the gut and end up with all those calories swishing around in there making them nauseous," Mueller says.
Lesson Learned: Train your eating.
During training, experiment with pre-run and on-the-run fueling. Once you establish what you can handle, stick with what works. Mueller recommends eating 75 to 125 grams of carbs for breakfast (like a white bagel, or low-fiber cream of wheat cereal and a banana). If you will have hours on race morning before the gun goes off, down an energy bar two hours before the start and nurse your sports drink all the way to the corral. The average runner burns roughly two-thirds of her body weight in calories every mile, says Mueller. Take your first fuel at the 10K mark and aim to replace 25 to 30 percent of the total calories you burn between there and the finish. For a 150-pound runner, that's 500 to 600 calories (or 5 to 6 gels).
More: The New Rules of Marathon Nutrition
4. I Arrived Late
En route to an East Coast race, I listened to rain pelt the airport rooftop for seven hours before I caught a connecting red-eye that got me to my hotel just before sunrise the day before the race. I had slept zero hours that night—the night that coaches say matters most, since nerves keep most of us awake on race eve. "People try to cut it too close and end up spending all their pre-race energy being stressed out," says Star Blackford, a Clif Bar pace team leader and veteran of 140 marathons.
Lesson Learned: Get there early.
Traveling to a race? It can take more than 24 hours for your body to recover from the swelling and dehydration that a pressurized airplane cabin can yield, says Guzman. To keep it to a minimum, shun alcohol and caffeine—both diuretics—bring your own water, and wear compression socks on the plane. Arrive at least 48 hours before the start so you have time to do a 30-minute shakeout run, get a good night's sleep, spend a few hours at the expo, and lounge the night before the race. For cheapskates like me, consider staying at an inexpensive hotel by the airport the first night.
Racing close to home? You want to arrive an hour before the start so you can pick up your number, check your gear, hit the porta potty, and be in your corral 20 to 30 minutes before the gun goes off—so you don't waste precious glycogen stores sprinting to the start.
5. I Ate too Much
There's nothing like an all-you-can-eat buffet of cheese-soaked ziti to inspire a sense of calorie entitlement in a marathon runner. "I'm carb-loading," I rationalized before one 26.2-miler. The next day, despite my typically foolproof ritual of strong coffee and morning headlines, the buffet stayed with me, making my stomach slosh and my waistband chafe all the way to the finish line.
No surprise there, says Mueller. Fat (including that in cheese and in creamy or high-fat-meat sauces) slows digestion. "So if you go to bed after a rich, heavy meal, you're going to wake up with nerves and a bunch of undigested food in your gut." At best, it can weigh you down. Or it may require an unplanned pit stop.
Lesson Learned: Load up properly.
After months of training, a runner's glycogen—or blood sugar stores—are depleted to about 50 to 60 percent of normal. In order to sustain energy for three, four, or more hours, they must be topped off—which means carb-loading starting 72 hours out (not the night before). Eat 4 grams of carbohydrates per pound of body weight per day. For a 130-pound woman, that would be 520 grams. Your diet should consist of 80 to 90 percent carbohydrates. (RELATED: Learn the Right Way to Carbo-Load.)
Steer clear of high-fiber foods, like nuts, seeds, fruits with the peel on and juice with pulp—all of which tend to leave a residue in the gut. Choose instead bananas or melons; creamy (not crunchy) peanut butter; pulp-free juice; and white foods like rice, bread and pasta. "Pre-race is the one time I recommend white over wheat because of its low fiber content," says Mueller. Finally, the day before the race, make your lunch your biggest meal so you have plenty of time to digest.