July 20, 2011
Maybe you rolled out of bed at sunrise to push through a 60-minute Spinning class and had a side stitch the whole workout after forgetting to prehydrate? Or perhaps you ran a marathon and developed mind- numbing stomach pains after your Gu and Powerade refueling at mile 18? If you’ve participated in a long-distance endurance workout, you’ve probably at some point experienced the gastrointestinal (GI) distress like cramping, diarrhea, vomiting, bloating, heartburn or severe stomach pain that can come from less-than-ideal nutrition and hydration habits before and during exercise. With application of a few general principles and some pre-event practice, you can avoid repeat episodes of the potentially-disabling exercise-induced GI distress. Here’s a few tips:
- Get fit. 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 nutrient absorption occurs. This translates into quicker energy availability and decreased GI discomfort following fueling.
- Stay hydrated. Not only does good hydration improve athletic performance, to a certain extent the more fluid in the stomach, the faster the gastric emptying and the less GI distress.
- Practice drinking during training to improve race-day comfort. One of the most effective ways to minimize surprise GI distress during an important event is to experiment with different fueling snacks and drinks during training.
- Avoid over-nutrition before and during exercise. 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, heart burn, and other pains.
- Avoid high-energy drinks before (within 30-60 min) and after exercise. These foods can all slow gastric emptying. A hypertonic drink has carbohydrate content greater than 6-8% of total weight. Figure this out by dividing the number of grams of carbohydrate by the total number of grams contained in the product.
- Ingest a high-energy, high-carbohydrate diet (and limit protein and fat intake before exercise). Carbohydrates are the most rapidly digested and absorbed of the macronutrients. Protein and fat take longer to digest and absorb which can contribute to GI pains.
- Avoid high-fiber foods before exercise. A bulky high-fiber snack not only decreases gastric emptying but it also increases intestinal distention and water content which contribute to diarrhea and the sudden urge to hit the Port-a-potty.
- Limit nonsteroidal anti-inflammatory drugs, alcohol, caffeine, antibiotics, and nutritional supplements before and during exercise as these can all cause various types of GI ailments. Experiment during training to identify your triggers.
- Urinate and defecate prior to exercise. This will help to reduce the nerves-induced feelings of having to go and buy you some time before you have to hit the next restroom.
- Consult a physician if GI problems persist, especially abdominal pain, diarrhea, or bloody stool. It may be that some underlying problem is causing the GI distress.
By Natalie Digate Muth
Natalie Digate Muth, MD, MPH, RD, FAAPNatalie Digate Muth, MD, MPH, RD, FAAP is the Healthcare Solutions Director for the American Council on Exercise, a board-certified pediatrician and Fellow of the American Academy of Pediatrics, a Diplomat of the American Board of Obesity Medicine, registered dietitian and board-certified specialist in sports dietetics, and ACE-certified health coach. She is the author of "Eat Your Vegetables" and Other Mistakes Parents Make: Redefining How to Raise Healthy Eaters" and the upcoming textbook "Sports Nutrition for Health Professionals". She has been ACE certified since 1998.