by Rachel Stuck, RDN
For most runners, running isn't just a way to get in that recommended cardio. Runners run to experience the joys of quiet sunrise jogs by the lake, setting personal records, winning races, and exploring new courses with friends. Of course, there are the less-than-desirable experiences too.
The terms runner’s gut and runner’s trots have been used to describe a spectrum of uncomfortable gut experiences during or after intense cardio-based exercises like running or cycling. If you’ve felt it and identified your symptoms as “runner’s gut,” you’re probably cringing at the thought of experiencing this unpleasant feeling again. But for those of you who have felt it and never really knew what was going on (or were too embarrassed to ask your running buddy) this article will offer advice that might help you avoid or reduce the risk of experiencing that oh-so-awful event again.
About 40–60% of runners—and some studies even note up to 80% of runners—have experienced some sort of gastrointestinal (GI) distress while running. Running-induced GI distress can present as a variety of symptoms depending on how sensitive your system is and the duration and intensity of exercise. For some, it is a short-term cramping sensation that passes once the exercise is over. For others, runner’s gut can include severe cramping, bloating, pain, diarrhea, nausea, vomiting, and in extreme cases, GI ischemia, ischemic colitis, or bleeding.
Runner’s gut occurs during strenuous exercise when blood is pulled from the abdomen and redirected to the leg muscles. Hormones, among a variety of other things, as you’ll see in the list below, also play a role in the onset of runner’s gut. When the body is stressed, it releases the hormones epinephrine (adrenaline), dopamine, and norepinephrine. These hormones not only increase your heart rate, but also initiate blood to be sent to skeletal muscles as a part of your fight-or-flight response. When blood is drawn from the abdomen and away from the intestines, it causes abdominal cramping and fluid to be drawn into the gut. This, coupled with the bouncing and jostling that naturally happens to your organs when you run, can cause food and other substances to move faster through your system.
While it is impossible to completely avoid the natural stress response without hanging up your running shoes, there are steps you can take to reduce the occurrence of runner’s gut. If you struggle with runner’s gut, consider the list below to help you identify what might be causing your symptoms. You might be surprised that one simple change can make your cardio training a lot more pleasant.
Adequate hydration before, during, and after a race is absolutely essential for all athletes, but especially for anyone who experiences runner’s gut. Proper hydration will help you avoid GI distress while you are running, and help combat severe dehydration if vomiting or diarrhea occur. However, it is not a good idea to overload the system with liquid before a race. Too much liquid in the stomach can also cause discomfort. Instead, focus on staying hydrated weeks before a race, and if your race is going to take longer than an hour, consider finding ways to hydrate during your race. Whether it’s simply stopping at the water station or gearing up with your own hydration belt or backpack, staying hydrated needs to be at the top of your list when preparing for a long run or race.
Everyone has a pre-race ritual, including certain stretches, foods, gels, and electrolyte drinks, but you might be surprised to learn the lengthy list of foods and drinks that should be avoided before a big race. A slice of whole grain toast slathered with peanut butter might sound like a healthy breakfast before exercise, but it’s actually just the opposite. Not only can the fat from the peanut butter cause heartburn, but the high-fat and high-fiber content of this meal can initiate or exacerbate GI distress during exercise, especially distance running. High-fat foods, high-fiber foods, caffeine, sugary foods, and artificial sugars are among the most common offenders that should be avoided if you are prone to GI discomfort during or after running. This means that electrolyte drinks, coffee, caffeinated gels and drinks, and sugary energy gummies should be consumed with caution. Consider testing out what electrolyte drinks or gels sit best with your stomach while training. This will help you determine which meals, snacks, and drinks cause distress and which ones are useful. Below you will find a list of foods to consider and foods to avoid
Not only does the type of food matter, but meal timing is just as, if not more, important. If the list of safe foods above doesn’t sound appealing, consider eating your meal a few hours before you start running. The rule of thumb for pre-workout snacks and meals is 2–4 hours before exercise; but, for runners with GI distress it might be helpful to allow more time between fueling and exercise. Consider eating smaller servings or adding time between eating and exercise to help you determine your perfect equation. Trial and error is the best technique for ironing out your pre-race routines.
If fueling swaps don’t seem to ease your GI distress from running, try a different approach. Proper training and a good warm-up are also important. If you start a training program too quickly or add miles too quickly, you might notice a more severe wave of GI distress. Instead, give yourself plenty of time to train before pushing yourself to hit miles and split times before your body is accustomed to longer runs. Gradual progression and a good warm-up will also help you avoid GI distress while running. This allows your body to recognize the start of exercise and will signal the body’s sympathetic nervous system to temporarily halt digestion. This prepares the body for activity and increases your heart rate, breathing, and blood pressure during exercise.
NSAIDs (nonsteroidal anti-inflammatory drugs) are known to cause GI distress even in the absence of exercise. Taking NSAIDs, like ibuprofen, can be hard on the kidneys and on the gut, making them an extra risk for people who are prone to runner’s gut. NSAIDs can increase your blood pressure while also blocking an enzyme in the body that protects the heart and the stomach lining from digestive acids. This potentially increases the risk of heart attack and can also lead to nausea, diarrhea, cramping, and even intestinal bleeding. If you need over-the-counter drugs to relieve joint pain and other aches, consider taking acetaminophen, but only at its proper dosing recommendations.
The best way to stop GI distress while running is to stop running—but not forever. Walk for 5–10 minutes until the pre-bathroom event, pain, and cramping passes. Then, slowly start running again. While this technique won’t push you closer to breaking your PR, it will help you avoid the risk of severe intestinal injury related to strenuous exercise.
3 cups unsweetened coconut water
2-inch cube ginger, sliced thin
6 tablespoons honey
1 cup ice cubes (4–5 cubes)
6 tablespoons lemon or lime juice
¼ - ½ teaspoon salt, optional
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Remember, exercise and running is also good for the gut, especially when it doesn’t push you into some of the symptoms discussed above! Regular exercise benefits the blood flow and motility of the gut, and helps you improve your gut microbiome and avoid sickness.
Registered Dietitian Nutritionist Rachel Stuck has a background in culinary arts and nutrition counseling. Rachel takes a positive approach to nutrition: she avoids recommending restrictive diets and instead focuses on helping people choose foods that promote health and well-being. She is passionate about empowering and assisting Ixcela members as they develop their unique, gut-healthy lifestyles.
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