6 Smart Tips for Navigating Runner’s Stomach on the Trail and in Daily Life

Last Updated: May 15, 2024
image of a pile of toilet paper

Hardly a day goes by without me meeting a trail runner, ultra runner, or hiker who is struggling with gastrointestinal issues (GI) such as bloating, acid reflux, or chronic loose stools. It’s safe to say we’ve all been hit by gut issues at least once on the trail; one moment, we’re enjoying the scenery, and the next minute, we’re squatting in the woods using leaves as toilet paper. Many of us also deal with gut issues off the trail in our daily lives.

Gut issues in your daily life and on the trail aren’t merely an inconvenience; a growing body of research indicates that chronic gut issues are a harbinger of future potential health issues, including chronic inflammation, nutrient malabsorption and deficiencies, compromised immune function, and impaired athletic performance and recovery. (Source, Source, Source, Source

While runners often refer to their GI issues as “runner’s stomach,” the problem is rarely related just to the stomach (in fact, I would say it is a pet peeve of mine when active people refer to their issues as “runner’s stomach!”); usually, it also involves other parts of the GI tract, including the small intestine and large intestine. 

In this blog, I’ll discuss six tips for navigating runner’s stomach in your daily life and on the trail so you can run feel and perform your best when training, racing, and in daily life! 

image of a pile of toilet paper

Why Does Your Gut Feel Like Crap (Pun Intended) While Running?

Let me be clear – your gut shouldn’t feel like crap while you are running. While gut issues during running are common, this doesn’t mean they are normal!

Gut issues can occur during running for several reasons. For one, blood is diverted from your gastrointestinal system (stomach, small intestine, and large intestine) during exercise and goes towards your muscles and skin. Less blood flow in the gut means you cannot digest food as effectively as when you’re not exercising. If you ate shortly before your workout, this means you may struggle to digest what you just ate.

Endurance exercise may also transiently increase intestinal permeability (often called “leaky gut”), meaning tiny gaps develop between the cells that line the small intestine. This allows substances to leak from the gut into the systemic circulation. A leaky gut can cause chronic inflammation, possibly contributing to impaired exercise recovery, as well as severe issues like brain fog and autoimmunity. (Source, Source, Source

In addition, altitude can trigger gut issues for some people. If you frequently run at altitude, hypoxic stress (stress related to lower oxygen availability in the body) may also contribute to gut issues. (Source

Underlying imbalances in your gastrointestinal system can drive chronic daily gut issues exacerbated by exercise. Common chronic gut issues include:

  • Small intestinal bacterial overgrowth (SIBO) is an overgrowth of microbes in the small intestine. It may be triggered by poor dietary choices, excessive antibiotic use, and stress.
  • Imbalances in the large intestinal microbiome include excess inflammatory bacteria (or even microscopic parasites) and too few beneficial bacteria. This imbalance is referred to as “dysbiosis.”
  • Yeast overgrowth: An overgrowth of yeast in the intestine can occur in people who have been on many antibiotics or have chronically consumed a high-sugar diet. 
  • Acid reflux: Acid reflux can be caused by too little stomach acid, contrary to what we’ve been told! Acid reflux may also be triggered by specific food sensitivities. 

Finally, overconsuming sports nutrition products high in simple sugars can also trigger gut distress. This is one reason why I use Metabolic Efficiency Training in my nutrition practice to help athletes improve their metabolic efficiency during exercise so they can use sports nutrition products wisely, without overconsuming them.

A metabolic efficiency test is a type of sub-maximal exercise and nutrition test (not the same as a VO2 max test) that depicts how the body uses internal stores of fat and carbohydrates during exercise.

The data from your test can be used to determine what nutrition strategies will best help your health and performance, how you should exercise, and your unique nutrient requirements during training without having to depend on calorie ranges from research. A potential outcome of using a Metabolic Efficiency Training plan is decreased (or completely resolved) gut distress during exercise.

Subsequent analysis by a professional trained in Metabolic Efficiency Training™, which I provide through my Metabolic Efficiency Test Analysis service, can help you determine the exercise and nutrition strategies that will help you optimize your health and athletic performance.

6 Tips to Address Runner’s Stomach and Improve Your Gut Health

People often want a one-stop-shop solution to their gut issues. While it would be nice if there was a simple, single answer to gut issues, I rarely find this to be the case. I’ve spent years recovering from my own gut issues and have worked with dozens of clients with gut issues, so I know this firsthand! 

While you’re certainly welcome to try one-off solutions like psyllium fiber or cutting gluten out of your diet, I have repeatedly found that a comprehensive approach that includes testing, an evidence-based gut supplement protocol based on test results, dietary adjustments, and lifestyle changes produces the best and longest-lasting results when it comes to resolving gut issues. 

1. Identify the Underlying Cause (or Causes) of Your Gut Issues

Is it food sensitivities, such as gluten or dairy sensitivity? Are you dealing with small intestinal bacterial overgrowth? Do you have an imbalance between the beneficial and inflammatory microbes in your gut? A nutritionist trained in the management of gut disorders can help you navigate testing and elimination diets to determine the root cause(s) of your gut issues. In my nutrition practice, I use functional stool testing (the Genova GI Effects test) and strategic nutrition strategies to help clients determine the root causes of their gut issues and help them develop a nutrition, supplement, and lifestyle plan for improving gut health. Please note: I do not recommend doing direct-to-consumer stool tests; I have concerns about these tests’ legitimacy and their recommendations. Doing a stool test with a qualified healthcare provider is always best. 

2. Eat a Minimally Processed Diet Consisting Primarily of Whole Foods

A minimally-processed diet rich in whole foods is supportive of gut health and overall health. A minimally processed, whole-food diet includes high-quality protein, vegetables, fruits, starchy tubers, nuts, seeds, whole grains, legumes, and organic dairy products. A nutritionist can help you personalize your dietary template to meet your unique nutritional needs and preferences. 

3. Optimize Your Sleep

Research shows that poor-quality sleep is a driver of gut issues. In my clients, I can attest that sleep issues correlate strongly with gut issues. If you need help improving your sleep, I have a lot of experience helping my clients with this. (Source

4. Hydrate Properly

Dehydration, both in daily life and especially during runs or other endurance activities, can drive gut issues. Hydration needs vary widely from person to person, but a good baseline rule of thumb is to hydrate to the point that your urine is a pale straw color. (Source

5. Manage Your Stress

We’ve all experienced stress at one time or another that triggered gut issues. The loose, urgent stools many endurance athletes experience on race-day mornings are a good example! Research shows that stress can contribute to a variety of gut issues, including IBS. Stress also negatively affects the balance of microbes in your gut microbiome. Finding ways to manage your stress daily is vital for controlling gut issues. (Source, Source

6. Time Your Nutrition Properly Around Exercise Sessions

Ideally, eating a full meal at least one hour before vigorous exercise is best. Before your exercise session, limiting high-fiber foods, such as leafy greens and cruciferous vegetables, may also help minimize gastrointestinal distress. In addition, be mindful of your caffeine intake before running; for some athletes, caffeine intake triggers or exacerbates loose stools while running or engaging in endurance activities. 

The Bottom Line on Runner’s Stomach

Addressing your gut issues with the help of a qualified professional can not only help you enjoy your sport more but also help you optimize your whole-body health and feel your best in daily life. 

If you are tired of taking a piecemeal DIY approach to your gut issues and want personalized one-on-one guidance, I can help! Schedule a complimentary discovery call to learn how I can help you. 

The content provided on this nutrition blog is intended for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read on this blog.

The information and recommendations presented here are based on general nutrition principles and may not be suitable for everyone. Individual dietary needs and health concerns vary, and what works for one person may not be appropriate for another.

I make every effort to provide accurate and up-to-date information, but the field of nutrition is constantly evolving, and new research may impact dietary recommendations. Therefore, I cannot guarantee the accuracy or completeness of the information presented on this blog.

If you have specific dietary or health concerns, please consult a qualified nutritionist or another healthcare professional for personalized guidance.

Leave a Reply

Your email address will not be published. Required fields are marked *

Lindsay Christensen Dietitian Nutritionist Colorado

Hi, I'm Lindsay

I help mountain athletes improve their performance through a holistic and inclusive approach to nutrition.

Sign up for updates

Recent posts

    Never miss a post!

    Sign up for updates that come right to your inbox.

    Copyright - 2024 Alpine Fuel Nutrition

    Website & Brand by Declet Designs 💛