Endurance athletes -- in particular those who are really pushing themselves -- often suffer cramping, diarrhea or some other form of gastrointestinal distress while they're working out or competing. Natalie Digate Muth of the American Council on Exercise, a physician and registered dietitian, has some tips on how to avoid it.
Her tips "are all very reasonable" and are a valuable contribution, said Paul Lebovitz, chair of the division of gastroenterology at West Penn Allegheny Health System. "I can't remember seeing a lot of evidence-based medicine on how to deal with these problems."
About 60 percent of endurance athletes will suffer from gastroesophageal reflux disease, and about 30 percent of long-distance runners will get diarrhea, said Aaron Mares, a primary care sports medicine physician at UPMC. GERD occurs when stomach acid flows back into the food pipe, irritating the lining of the esophagus.
A smaller number of endurance athletes will experience exercise induced gastrointestinal bleeding, Dr. Mares said.
These ailments are not gender specific, Dr. Lebovitz said. But Dr. Mares said young women seem to be more susceptible.
Dr. Muth's first tip, "get fit," seems surprising, because these are ailments of the physically fit. But the more fit you are, the less likely it is that you'll experience gastrointestinal distress, she said, because "more physically fit athletes have faster gastric emptying which is the process of food and fluid passing from stomach to the small intestines, where most of the nutrient absorption occurs. This translates into quicker energy availability and decreased GI discomfort following fueling."
"Exercise at high levels will increase the motility of the gut," Dr. Lebovitz agreed. "Things that don't make the gut work so hard are helpful."
Stay hydrated, Dr. Muth said. "The more fluid in the stomach, the faster the gastric emptying and the less GI distress."
But stay away from high energy drinks an hour before or after exercise, she said, because they "can slow gastric emptying."
And don't eat much before or during exercise because "the more food you eat, the harder it will be for the stomach to pass all of the food into the small intestine. All that extra food sloshing around in the stomach leads to cramping and heartburn."
You should try to urinate and defecate before exercise because this "will reduce the nerve-induced feelings of having to go and buy you some time before you have to hit the next restroom," Dr. Muth said.
Her other tips are to eat a high carbohydrate diet (they're easier to digest than proteins or fats), avoid high-fiber foods before exercise, and lay off coffee and alcohol before and during exercise. You can read all of Dr. Muth's tips at www.acefitness.org/blog/1601/how-do-i-avoid-gi-upset-during-a-competitive/.
Jack Kelly: email@example.com or 412-263-1476.