15 Tips to Help You Avoid Stomach Cramps When Running

There is nothing worse than a rumbling stomach while you are out on a run. Whether you feel side stitches (side cramps) or you feel the need to rush to the nearest porta-potty, stomach issues can really "cramp" your style. Learn how to avoid stomach cramps when running with these 15 tips.

illustration of woman stretching on track with text
Illustration by Jessica Olah, Verywell

Warm Up

A cramp in your side (side stitch) is—just like it sounds—a severe pain in your side body. It typically occurs right below the rib cage. It is not actually related to your stomach (unlike the rest of the issues listed below). While the exact cause of side stitches is unknown, some theories suggest that it could be related to blood flow to the liver, spasms in the diaphragm, or stretching of the ligaments.

To prevent them, remember to warm up properly. This gives your body time to accommodate to the faster breathing as well as to adjust to the stretching of your ligaments.

If you experience a side stitch, try slowing your pace, taking deep breaths, and stopping to stretch for a few minutes.

Hydrate

Do you skip drinking fluids during a run because you worry they will cause sloshing and cramping? It is time to adjust your strategy. This can lead to dehydration, which actually exacerbates stomach issues.

When you are exercising at an intense level, your body diverts blood away from the stomach in order to supply your muscles with much needed oxygenated blood. This means that digestion can be negatively affected, though most people can still tolerate proper fuel choices.

However, if you couple this reduced blood flow with dehydration, it is a recipe for digestive disaster. Your blood volume decreases, which means even less blood flows through the digestive system to help process fuel. This can lead to cramping, vomiting, and diarrhea.

By the time you hit this point, it is very difficult to correct. Instead, aim to stay hydrated from the start. Drink adequate fluids in the days leading up to your training session or race, and remember to drink when you are thirsty throughout your run. 

If you struggle to pay attention to thirst signals or often forget to drink, set a periodic alarm on your watch to remind you.

Practice Fueling

When you train for a long-distance race, you put in hours of running each week to gradually build your muscular and cardiorespiratory endurance. However, people often forget that just like training your legs for those long runs, you also need to train your gut.

Often, newer athletes skip fueling during training but attempt to use a sports drink or gel during their first long race. The result? Stomach cramps, thanks to a belly that has never practiced processing fuel under such circumstances.

Luckily, the fix for this is easy. Simply practice your fueling strategy during training. This will help “teach” your stomach how to process fuel under conditions of decreased digestive blood flow along with the jostling motion of running. 

Since sports nutrition is so individualized, you will also quickly learn what your body tolerates best—whether that is gels, blocks, sports drinks, bars, or any of the other products on the market.

Do Not Over-Fuel

It can be tricky to nail down the correct amount of fuel to take in during a long run. But one thing is certain: trying to replace every calorie you burn is a recipe for disaster.

Instead, aim to take in around 30-60 grams of carbohydrates (about 120-240 calories) per hour on runs lasting more than one hour and 15 minutes. For those doing long-course triathlon and ultra-marathons, you might bump that range up to 30-90 grams of carbohydrates per hour.

As you start experimenting with fueling, start at the lower end of this range. If you feel like you need more energy, you can gradually work your way up to the higher end of the range on subsequent runs and see how your stomach tolerates this.

Check Ingredients

A few decades ago, there were very few sports nutrition products on the market. Gatorade or flat Coca-Cola were basically the runner’s go-to options. Walk into any running store today and you will see a massive amount of fueling products with different nutrition breakdowns.

The problem with the influx of fueling products for runners is that some have ingredients which may cause stomach cramps in certain athletes.

For example, some gels on the market now contain protein as well as carbohydrates. While protein is key for recovery, it can cause gastrointestinal upset if used during a run due to its ability to slow down digestion.

For those participating in events like a half or full marathon, this kind of protein is unnecessary and increases the risk of cramping. The best choice is a high-carbohydrate fuel choice during the run, and then a protein-rich snack for recovery.

That said, ultra-endurance athletes may find some choices that contain a little protein (or fat) useful. These can help with hunger, and protein may also help prevent muscular breakdown. The important difference to note is that ultra-athletes usually run at a slower pace (but over a much longer period of time) than other athletes, so they may have better blood flow through the digestive tract. This offers a bit more flexibility with food choices, which is important during long periods of time. 12 hours of gel could get old very quickly!

Avoid Sugar-Free Foods

Sugar-free foods are a less common cause of stomach cramps when running, but if you are a die-hard gum chewer, listen up. Most sugar-free gums contain sugar alcohols to create a sweet flavor without sugar. You can spot these on the label.

Common Sugar Alcohols

  • Xylitol (most common in gums)
  • Erythritol
  • Sorbitol
  • Mannitol
  • Maltitol

When sugar alcohols reach the digestive tract, they can cause an osmotic effect, pulling water in. During a Netflix binge on the couch, your body may be able to handle limited amounts of these sugar alcohols. Most people can chew a few sticks of gum without any issues.

However, when you couple this osmotic effect with the jostling that happens during a run, these sugar alcohols may cause cramping and diarrhea. It is best to skip the gum altogether, but if you need it during your run, stick with regular sugar-based gum.

In addition, if you eat a lot of sugar-free products as part of your daily diet, it is worthwhile to cut down on these the night before and the morning of a long run. For example, sugar-free cakes, ice creams, and cookies typically have sugar alcohols in them as well.

Minimize Fiber

Fiber is key to digestive health on an everyday basis, helping to bulk up stool and prevent constipation. However, before a run, the last thing you want is a belly full of fiber that can cause cramping and have you rushing to find a bathroom mid-race.

Different people can tolerate different amounts of fiber in a pre-exercise meal. And some people with regular routines may use a moderate fiber meal to help them use the bathroom a few hours before the race.

For example, if you have a bowl of oatmeal every morning and you know that it will help empty your bowels before the race, then do what works for you! But if you deal with stomach cramps or diarrhea during training, take a look at that morning meal and consider cutting down on the fiber. High-fiber ingredients include:

  • Berries
  • Bran
  • Whole grain breads and cereals
  • Beans and lentils
  • Chia seeds and flax seed
  • Peas
  • Broccoli
  • Leafy greens

Minimize Fat

Fat is a satiating nutrient, in that it slows down digestion and helps us feel full longer. While this is great for everyday health, it is not ideal before a training session. You do not want to start running with a belly that is still feeling full and risk cramping. Low-fat, low-fiber breakfast ideas include:

  • Cereal with milk and a banana
  • Toaster waffle topped with peaches
  • Bagel with a small amount of cream cheese
  • Rice with a poached egg
  • Sandwich with a small amount of peanut butter, banana, and honey

The exception to this tip is if you are a fat-adapted athlete who is practicing the keto diet. In that case, you should follow your normal routine, as foods outside of that could cause stomach cramping. For most athletes, however, a standard moderate carbohydrate diet will lead to the best performance.

Know Your Lactose Tolerance

Lactose is sugar that is found in dairy products. Some people lack enough of the digestive enzyme known as lactase to properly break down this sugar. This is what is commonly known as lactose intolerance. If you have this condition, eating certain amounts of dairy can cause stomach cramping and diarrhea.

Interestingly, you can develop lactose intolerance later in life, even if you previously were able to tolerate dairy. Lactase production decreases over time for certain people based on genetic factors. For others, a gastrointestinal infection or inflammatory bowel disease may cause secondary lactose intolerance.

If you are experiencing stomach cramps when running, try taking a closer look at the ingredients in your pre-run meal. Is there a lot of dairy in your meal? If so, nix the dairy for a few weeks and see if you notice any improvements.

If the cramps disappear when you cut dairy, you may have lactose intolerance or a dairy sensitivity, and it is worth discussing with your doctor. If there is no improvement, dairy likely was not the issue.

Assess New Fueling Products

If you are experimenting with different fueling products to find what works best for you during training, odds are that you encounter a product that does not agree with your body.

For example, solid products like energy bars generally increase the sensation of stomach fullness, so athletes with sensitive stomachs may want to avoid these. Your body may not react well to other fuel choices for no particular reason (other than that sports nutrition is very individualized).

Try keeping a log for your long runs, noting your fuel choice, how much you consumed, and any cramping or other gastrointestinal symptoms that you experienced. This will help you rule out certain foods and beverages that perhaps do not settle quite right in your stomach.

Mix Powdered Drinks Properly

Sports drinks are designed to have a particular concentration of carbohydrates in them—ideally, this is around five to eight percent. Most prepared commercial drinks fall nicely within this range. Adding powdered drink mix to the proper amount of water per the instructions will also generally fall within this range.

However, doubling up on the powder, or even adding just a little extra, is not a good idea. By doing this, you create an overly-concentrated drink, and your digestive system has a far more difficult time processing it. This causes your stomach to empty more slowly which increases the risk of stomach cramps.

Stick with the correct powder-to-water ratio for the best gastrointestinal outcomes.

Digest Before Running

Most experts recommend eating a meal about one to four hours prior to running, though this is very individualized. Some runners have an iron stomach that allows them to eat a burger merely thirty minutes before a jog, while others might need two hours to process a small sandwich and some fruit.

If you often experience stomach cramps when running, try eating about three to four hours prior to your training session or event. Allowing more time between eating and running gives you more flexibility for the type and amount of food you can eat, as your body has ample time to digest.

Avoid NSAIDs

While your runner friends may joke about their need for “Vitamin I” (slang for ibuprofen), the overuse of these pills is no laughing matter.

NSAIDs (Non-Steroidal Anti-Inflammatory Drugs) include medications like ibuprofen and naproxen. While some athletes might take these medications prior to or during a run to stave off any muscle soreness, this practice actually increases the risk of stomach upset and cramping.

In addition, overusing NSAIDs on long runs has been shown to increase the risk of hyponatremia (diluting of blood sodium levels), the risk for kidney damage, and could impair muscle recovery. It is wise to avoid these medications before or during a run unless a doctor has advised you to take them.

Cut the Caffeine

Your morning cup coffee is not only good for waking you up, but research has shown that it improves performance for endurance athletes as well. Sounds like a win-win, right?

However, if you have ruled out the other causes of stomach cramps, it might be worthwhile to cut the caffeine and see if this helps. For some people, caffeine intake can cause stomach upset. This can become exacerbated with the nerves and motion that accompany a long run.

Rule Out Medical Conditions

In some cases, stomach cramps could indicate a food sensitivity or intolerance, irritable bowel syndrome, celiac disease, or another digestive complication. It is best to consult with a healthcare professional.

If you find that nothing seems to work to relieve your stomach cramps when running—especially if they are quite painful—visit a doctor to rule out anything serious.

A Word From Verywell

While it is true that most runners' cramps are related to nutrition, hydration, and training intensity, it is always a good idea to visit your doctor if any kind of pain persists. In some cases, the pain could be related to another health condition.

It is a good idea to keep a record of when you experience the pain, where on your body you feel the pain, what you have eaten that day, and what kind of physical activities you have completed. This can be helpful to share with your doctor as well to troubleshoot any issues.

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Article Sources

  • Deng Y, Misselwitz B, Dai N, Fox M. Lactose Intolerance in Adults: Biological Mechanism and Dietary Management. Nutrients. 2015;7(9):8020-35. DOI: 10.3390/nu7095380

  • de Oliveira EP, Burini RC. Carbohydrate-Dependent, Exercise-Induced Gastrointestinal Distress. Nutrients. 2014;6(10):4191-9. DOI: 10.3390/nu6104191

  • de Oliveira EP, Burini RC. Food-Dependent, Exercise-Induced Gastrointestinal Distress. J Int Soc Sports Nutr. 2011;8:12. DOI: 10.1186/1550-2783-8-12

  • Lipman GS, Shea K, Christensen M, et al. Ibuprofen Versus Placebo Effect on Acute Kidney Injury in Ultramarathons: A Randomised Controlled Trial. Emerg Med J 2017;34:637-642. DOI: 10.1136/emermed-2016-206353

  • ter Steege RW, Kolkman JJ. Review Article: The Pathophysiology and Management of Gastrointestinal Symptoms During Physical Exercise, and the Role of Splanchnic Blood Flow. Alimentary Pharmacology & Therapeutics. 2012 Mar;35(5):516-28. DOI: 10.1111/j.1365-2036.2011.04980.x