G.I Issues: Athlete Edition


Warning! We will be dropping the D bomb in this article (diarrhea) and talking about very normal bodily functions. If you are squeamish… deal with it, especially if you are having gastrointestinal (GI) issues during exercise. 

If you are an athlete, then I’m sure that you have experienced some sort of discomfort with your gut during training. This is the most common complaint that we get from our athletes. There are horror stories of jumping behind the nearest tree and using your favorite sock to manage the aftermath. Or, going out for a long Sunday ride and battling your breakfast so you don’t have it for round two. Unfortunately, many of us have stories of our own and many athletes assume this is part of their sport. Because your hardcore, right?

No. It doesn’t have to be this way. 

First, if your overall nutrition is lacking (i.e inadequate protein intakes, excessive intakes of highly processed foods, minimal vegetables, imbalance of fats), then that is step one. These factors can easily create an unhealthy GI environment. If you are confused about what step one entails, feel free to chat with our Registered Dietitian, Abby. If you have step one dialed, let’s move on.

We wish there was a one size fits all recommendation that we can give you, but it’s just not that easy. Every sport is different, and your symptoms will different from your riding buddy or workout partner. But, here are some tips to try if you are starting to run low on socks. 

  • Problem: Nerves. There is so much emerging research linking our guts to our brains. Prolonged physical, mental and emotional stress can play a role in your GI issues. 

    • Solution: Take a chill pill. We know that continuous stress (training, work, families, etc.) can have an impact on our hormones, which control everything in our body. They allow us to wake up, sleep, and maintain normal bodily functions. If our we are too stressed, we often see G.I issues and you may not tolerate certain foods very well. During training, incorporate some low-intensity training days in your program. (Read more about low intensity training here). . Include some time to “down regulate”. Pre-race or workout, take a few breathes before you toe the line. I personally love throwing my headphones in and doing some stretching/activating (you are warming up before running, right?). This helps me get out of my head and more into my body. Take a few deep breathes. Take a walk, warm up jog, or a do pre-race meditation. Overall, if we can start to “de-stress” by either walking, reading, meditating, gently yoga, writing, low intensity training, etc., the body will be better able to digest anded recover.

  • Problem: Transit time. If our food isn’t moving through us, it’s not going to feel great.

    • Solution: The number one recommendation for those who are constipated is to stay hydrated and get moving. Drink some warm beverage in the morning along with a large glass of water. Then, take a walk or do a gentle warm up at home. Also, you can try eating 1-2 prunes at night before bed with about 24oz of water. They are rich in fiber and contain a natural laxative called sorbitol.  

  • Problem: Gut rot anyone? Two words. Blood Flow. Your intestines require blood flow in order to digest food. When you exercise, your body is in a sympathetic state. This is easily referred to as fight or flight. This decreases the blood flow to your intestines because it is focusing on sending blood to your muscles, lungs and heart. 

    • Solution: Limit foods that are difficult to digest. These include high fiber foods, fatty foods and high protein. Before an activity fuel with something easy on your stomach. Try a banana and yogurt. This is much easier to digest than a few eggs with cheese and that yummy seedy bread that you love. 

  • Problem: Dehydration. This one goes with “Gut Rot”. The more dehydrated you are; the less blood volume you have. Therefore, less blood flow you have to your gut. When you have decreased blood flow to your gut, your intestinal walls actually start to breakdown, making it more difficult to process that concentrated gel you just threw down your gullet.

    • Solution: HYDRATE! Multiply your weight in pounds by 0.5 oz. for a lower end and 1.0oz for higher end needs that will give you about how many milliliters you need to drink/day. The average 140# person needs to drink 70-140 oz./day. That is 2-4 liters. This does not take heat, calorie consumption, elevation, or exercise into account. During exercise drink about 400-500ml every 30 minutes. Replace any fluids lost during exercise by weighing yourself before exercise and after. For every pound lose, you should drink 24oz of water. 

  • Problem: Bloating, gas, everything else. The problem may be the artificial sweeteners. These are often found in BCAA powders, hydration mixes and some other sports nutrition supplements. Unfortunately, your gut doesn’t necessarily know how to digest them and they ferment in your causing bloating, gas, diarrhea and overall a very unpleasant training session.

    • Solution: Read your labels! Limit foods that contain sugar alcohols. Looks for the terms mannitol, sorbitol, xylitol, lactilol, and most things ending in “-ol”. Look for ingredients that have real sugars like cane sugar, dextrose, fruit juice etc. “DID A DIETITIAN JUST TELL ME TO EAT SUGAR?” Yep, I did. When exercising your body needs sugar to help maintain energy stores. 

  • Problem Caffeine. Caffeine is known for its laxative effects. It is known to have performance benefits in moderation but in excess it can cause diarrhea and an upset stomach.

    • Solution: Time your coffee intakes pre-race or pre-training session. If you must have coffee to speak or function, then ensure there is adequate time built into your morning to drink your coffee and spend some quality time on your porcelain throne.  Many sports supplements like gels, beans and drinks now have caffeine added to them, READ YOUR LABELS. If you are sensitive to caffeine, try to limit these during training sessions. 

  • Problem: TOO MUCH BULK. Are you finding yourself having multiple bowel movements during your race that look like the salad you ate the night before? Fiber increases fecal bulk and movement. Which is great on a day to day basis, not so great when you are trying to PR. Eating a high fiber diet during training will help keep you regular and feeling fast… butt really. 

    • Solution: Decrease fiber consumption 1-2 days pre-race. This will ensure that you are nice and cleaned out and will decrease the overall fecal bulk. Add a high fiber snack once you are standing on that podium. 

  • Problem: Intolerances. Many of the sports nutrition supplements on the market may contain things that you may not tolerate very well. As we learned previously, high levels of training causes stress. This stresses can cause a disrupt normal G.I function which can lead to some temporary intolerances of some foods.

    • Solution: Understand what it is in your supplements, try out different foods during training to see which ones you tolerate. Maintain a healthy, balanced diet with a good amount of fiber, protein, carbohydrates, fats and water. However, don’t simply try a gluten-free or other type of elimination diet on your own! Especially in athletes, this can easily lead to nutritional deficiencies or hormonal problems. Consult a registered dietitian.

Still have questions or are you still confused about some next steps? Drop us a line. Let’s figure this out and get you back to doing what you love.

Abby Chan