Gastrointestinal (GI) problems are very common in endurance athletes. All you need to do is gather a group of long-distance runners and triathletes together and bring up the conversation of GI problems. Athletes will likely begin sharing horror stories of planning training routes with bathrooms available, running with toilet paper, diving into the ditch to relieve yourself before you poop your shorts and even situations of athletes failing to complete a race due to GI problems. It’s a horrible situation to be in, and unfortunately most athletes have experienced it a time or two.
There actually has been quite a bit of research on the link between endurance activity and GI distress. I have sports nutrition books on my bookshelf with entire chapters dedicated to discussing athletes with GI disorders!
The problem is that there is no clear sign as to what causes GI problems in athletes because symptoms are highly individual and there are no clear patterns. Common GI symptoms include heartburn, stomach pains, cramping, bloating, diarrhea, reflux, nausea and vomiting and they can vary in severity, but all symptoms can impact an athlete’s performance.
Factors that can play a role in GI problems:
- Nerves, stress, anxiety, and pre-event jitters can play a role in causing an upset stomach or diarrhea.
- Exercise accelerates intestinal transit time. For people who have trouble with constipation issues, dietitians often recommend exercising to help “move things along.” For people who have normal bowel movements, exercise may cause movements to happen too quickly.
- Physiologically speaking, especially in running-type sports GI problems can occur due the jostling of the intestines and/or reduced blood flow to the intestines as blood is being diverted to muscles.
- Nutritionally speaking, certain foods won’t sit well in an athlete’s stomach or take a long time to digest. Foods high in fiber, fat, protein and concentrated carbohydrate solutions may play a factor. Dehydration may also contribute to the problem.
- Limit foods that contain sugar alcohols such as sorbitol, mannitol, xylitol etc. Sugar alcohols don’t fully digest and can ferment (a.k.a.- cause gas) in the gut.
- If you have an inkling that you may have a sensitivity to gluten or Celiac disease, consult your doctor for testing. Most people with these diagnoses will see a rapid response, showing improvements within weeks when eliminating gluten from their diet.
- Drink extra water to prevent dehydration.
- Limit caffeine. Caffeine is known for having a laxative effect.
- Avoid high-fiber foods for a few days before your competition. Fiber increases fecal bulk and movement. Eating a fiber-rich diet during training is great to keep your bowel movements regular, but for competition day you will want to decrease your need to travel to the bathroom.
—This is my go-to solution for triathlons… Eat a very low-fiber diet for the three days before every event, and the evening prior to the event run for 20-30 minutes. I call this ritual my “colon-cleanse run” and it works almost every time.
- When all else fails, you may want to consult with your doctor about an anti-diarrhea medication such as Imodium. There are potential side effects when taking this type of medication, so educate yourself to weigh the benefits and consequences.
—I’ve done this a couple times in my early triathlon days, but it takes quite a few days afterward to get back on a regular schedule.
As there are so many factors that can contribute to GI problems, it’s important to trial different eating and drinking patterns and types of foods. Creating a list of “safe” foods to eat and a pre-competition ritual will provide you with the confidence to know you won’t lose your race due to an unexpected trip to the porta-toilet.