What causes your stomach problems while running?

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Nausea. Cramps. Gas. Bloating. Diarrhea. Runners are often left guessing at the causes of their upset stomach, which can lead to a rabbit hole of nutritional deficiencies, undernourishment and underperformance. Knowing and weighing the possibilities can help identify the cause without complicating matters. Here are some common culprits of stomach issues on the trails.

Here’s why your stomach hurts when you run.

#1) Eating too close to shopping

When we run, blood is diverted from our digestive system, making it harder to digest the food in our system. What and when you eat before a run can contribute to stomach upset. Consider removing the foods you eat one to three hours before your run and keeping it low in fat and fiber and prioritizing simple carbs.

RELATED: 5 gut training tips for people with shitty guts

#2) Supplements

Do you take a magnesium supplement for those leg cramps at night? Maybe you have a new multivitamin to help fill in some nutritional gaps in your diet? Supplements can add unknowns to the nutritional equation and have unintended consequences when taken in too much or in the wrong form. The supplement industry is not well regulated by the FDA, which makes them susceptible to added ingredients that are not listed on the label. Always be careful and research your supplements before taking anything new.

#3) Too much fiber

Yes, there are too many! Although the body can adapt, sometimes eating double or triple the amount of fiber your body needs daily can cause significant gas, bloating, and diarrhea. It’s especially important to pay attention to this one if you’ve switched to a more plant-based diet or are deliberately trying to increase your daily fiber intake. The daily recommendations for fiber intake for women are 28 grams and men are 38 grams.

RELATED: Hacks to keep your gastrointestinal tract on track

why stomach ache nausea during trail runs

#4) Hydration status

Both underhydration and overconsumption of caffeine can cause stomach upset or disaster. What you hydrate with and how much you hydrate can make a difference in your gut symptoms. Too little fluid intake can cause irregular bowel function, while things like too much caffeine can overstimulate the bowel. Finding the right balance for you is important for managing gastrointestinal symptoms. To start, consume at least half your body weight in fluid ounces plus 16 to 20 ounces for every hour of exercise you do each day, and if you’re sensitive, limit caffeine intake before running.

#5) Food Sensitivity

Too often, this is where runners first turn when trying to figure out their stomach issues and end up unnecessarily cutting out benign foods and important nutrients from their diet. First gluten, then dairy, and before you know it, you’ve cut out a whole host of foods. Many will not be able to identify their eating problem and may end up struggling to eat enough to support their training. Although food allergies and sensitivities can be a real cause of stomach problems, they should be considered only a possibility and not a panacea. If you want to try to pinpoint which food or foods are causing trouble, an organized elimination diet (supervised by a professional to ensure proper fuel and nutrient levels) that eliminates possible culprits one at a time is the way to go. follow !

RELATED: 5 nutritional truths for trail runners

Do you have a question for our RDN? Send your trail-running-nutrition dilemmas to [email protected]

Kylee Van Horn is fired Sports dietitian and competitive trail runner.

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