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Race-Day Nutrition

Fueling Faux Pas

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Solutions for runners’ six most dangerous nutrition mistakes

Your race preparation probably involves spending considerable time and energy conditioning your body and discussing race strategy with your training partners, but how much time do you invest in devising a fueling strategy? Only careful planning and pre-race experimentation will ensure you avoid these six common issues during your next big race.

This article appeared in our August 2010 issue.


>Mistake: During a hectic day, you drink coffee, no water, and when it comes time to run, you rush out the door without a water bottle. After about an hour, you feel tired, sluggish and your calf begins to cramp.

>Quick Fix: Before a run, boost your hydration level with 12 to 16 ounces of energy drink (containing electrolytes) and continue to drink while running, even if your run is less than an hour. Immediately afterward, drink 16 to 20 ounces of fluid for every pound of body weight lost during exercise (determined by weighing yourself before and after the run).

>The Lesson: Mild dehydration can cause headaches, fatigue, sluggishness, poor concentration and constipation. Severe dehydration may result in cramps, nausea, vomiting, dizziness and confusion. Sip water frequently throughout the day, and, while running, always carry water or energy drink. “Take four to eight swallows (a swallow is about one ounce) every 20 minutes,” says Cara Marrs, a registered dietitian in Steamboat Springs, Colorado.


>Mistake: Despite drinking copious amounts of water during a long, hot-weather race, your quads begin to cramp, and you feel nauseated and have a piercing headache. Mistaking your condition as dehydration, you guzzle more water. The problem is in fact hyponatremia (or “water intoxication”), a potentially dangerous condition caused by low sodium levels that can even cause seizures, loss of consciousness and kidney damage.

>Quick Fix: Restore your sodium level with supplemental electrolytes (such as salt capsules) or a one-time emergency dose of ordinary table salt in water. “One teaspoon contains 2300 milligrams of sodium,” says Ryan Kohler, a sports nutritionist at Carmichael Training Systems in Colorado Springs, Colorado. Long-distance runners lose between one to two grams of sodium per liter of sweat (and sweat up to a liter per hour), but individual sodium-intake amounts vary significantly. “Athletes may need anywhere from 400 to 1200 milligrams per hour, so experimentation is your best strategy,” says Kohler.

>The Lesson: While hyponatremia can result from consuming too much water, limiting water intake does not entirely protect you from the condition, since dehydration can also trigger hyponatremia. Experts at the Mayo Clinic recommend that athletes drink “only as much fluid as they lose due to sweating—usually no more than about 34 ounces (about one liter) of water an hour during extended exercise.”

Underlying medical conditions (such as hypothyroidism or kidney problems), certain medications (including ibuprofen), recreational drugs (such a ecstasy) or dietary considerations (such as a very low-sodium diet or drinking diuretic beverages such as beer) also make you more susceptible to hyponatremia.

Runner’s Trots

>Mistake: The night before a big race, you load on up on veggies, whole grains and legumes, then have a bowl of steaming oatmeal on race morning, only to find yourself making frequent stops in the bush and port-o-lets.

>Quick Fix: Slow your pace to help you body digest those high-fiber foods. Besides causing the release of gastric hormones that stimulate intestinal movement, running causes the “runs” by jiggling the gut and drawing blood away from the digestive tract to service working muscles, which further slows digestion. Also, temporarily cut back on your sugar intake (but continue to drink water), as ingesting too much sugar also makes digestion difficult.

>The Lesson: While fiber is an important component of a healthy diet, before a long run or race, stick to easily digestible, low-fiber foods (such as a whiteflour bagel with peanut butter and sliced banana or non-whole-wheat pasta with chicken) that pass relatively quickly through the digestive tract (a little coffee may speed the process along).

Bloated Belly

>Mistake: Determined to avoid the dreaded bonk, you squirt a gel into your mouth every 20 minutes and wash it down with a sweet energy drink, but after about an hour, your belly is aching, cramping and distended.

>Quick Fix: Eating more carbohydrates than your gut can absorb results in the accumulation of undigested food that leads to bloating, diarrhea and nausea. Lay off all fuel types and sip only plain water until the excess sugar clears from your stomach, which may take at least a half hour.

>The Lesson: Since you cannot replace all of the 600-plus calories per hour you burn while running, plan to eat about half that number of calories, depending on your body weight, fitness, exertion level and personal tolerance. While most athletes have success with a single energy source in short-duration events, in longer events, avoid stomach distress by eating a variety of calorie sources.

“Always have a nutritional plan B,” suggests Kohler. “If carbohydrate-rich gels start to make you feel bad, switch to protein-rich cheese.”

Hitting the Wall

>Mistake: When the pre-race nerves cause an unsettled stomach, you forgo eating until your energy level nosedives and you’re staggering to the next aid station.

>Quick Fix: As soon as possible, consume a gel or energy drink containing slow-burning complex carbohydrates (such as maltodextrin) and, if you can stomach it, a little solid food. These carbohydrates not only restore blood glucose needed to fuel working muscles, they also boost the central nervous system, which affects your mood and mental alertness. “Bonking means your gas tank is running on fumes,” says Kohler. “Shift your focus to restoring your glycogen levels so you can get back in the race.”

>The Lesson: Your muscles and liver hold about 2000 calories worth of glycogen—enough to fuel a couple of hours’ worth of running, but unless you take in additional calories during exercise (200 to 300 calories or 30 to 60 grams of carbohydrates per hour), that finite amount of energy is used up before your run’s end and you hit the wall.


>Mistake: Your trail marathon was going well until, suddenly, nausea forces you to stop in anticipation of a vomitous event. The awful feeling subsides—until you try running again.

>Quick Fix: Eat ginger candy (such as The Ginger People’s Ginger Chews), crystallized pieces of dried ginger, capsules of powdered ginger root or drink homemade ginger tea made from crushed fresh ginger root. (Most ginger ales do not contain real ginger.) Natural ginger root (dried or fresh) has been proven to alleviate nausea in those undergoing chemotherapy and suffering morning or motion sickness. Ginger’s relief is attributed to its ability to promote the secretion of digestive juices, which neutralizes stomach acid.

>The Lesson: Nausea often accompanies the nutrition issues discussed in previous “Mistakes,” and while frustrating, nausea needn’t be race ending. Since running’s up-down motion often exacerbates the urge to vomit, take a timeout by sitting or lying down and avoiding solid food (soup is a good alternative) until the worst has passed. On the other hand, Tim Twietmeyer, 25-time Western States 100-Mile Endurance Run finisher, says that vomiting is every ultrarunner’s rite of passage. “If you’re going to puke, get it over with and keep moving,” he says.


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