Nothing kills a race like stomach troubles. To avoid them, stick to foods you know and remember that taking in too many calories is a frequent culprit, says Bob Sallis, a doctor of sports medicine with Kaiser Permanente, in a video on Competitor.com. While calorie needs during a race vary for each athlete, 200 to 300 per hour is a good guideline, Sallis says. Consuming more than you need, or too much at one time, can overwhelm your stomach — which isn’t getting as much blood as usual, in favor of your heart, lungs and muscles — and lead to cramps, nausea and even vomiting.
