Running is a high-impact sport, which means that not only are our muscles and joints absorbing the load, but our organs are also being bounced around. Makes sense that this constant motion could lead to digestive issues for many runners.
Often we talk about this in relation to runners’ trots or less pleasantly named runners’ diarrhea.
But the truth is you don’t have to have a full-blown bathroom situation to have some pretty uncomfortable feelings.
There are a number of potential causes and solutions to stomach pains while running that apply whether you’re a new or experienced runner. It can happen to us all, so let’s try to prevent them or at least manage the symptoms from a pain below your rib cage to right in the gut.
What is Runner’s Stomach?
When gastrointestinal (GI) distress occurs during a run or other periods of exercise, it is referred to as “runner’s stomach.” This condition causes cramping, bloating, nausea, diarrhea, vomiting, and pain, in addition to other GI distress symptoms. Other names for these symptoms include runner’s trots, runner’s belly, or runner’s diarrhea.
The name ‘runner’s stomach’ probably came from the sheer number of long-distance runners who experience digestive-related symptoms. In fact, it is estimated to affect between 30 and 90% of distance runners, with younger people reporting it more frequently, according to a study published in Sports Med in 2014. These symptoms can affect both sexes equally.
Running is the most studied form of exercise that can cause these digestive symptoms, though it is not the only one. According to some studies, team sports, intense anaerobic exercise, and sprinting can all result in GI problems. These relationships have, however, only recently been the subject of small, experimental studies.
There are commonalities among the causes of runner’s stomach despite the fact that exercise-induced GI symptoms are highly individualized and can range from being merely annoying to impairing performance.
Cause Of Stomach Cramps While Running
It’s important to know there’s a difference between a side stitch while running and a stomach cramp. We’re focused on the gut here and the major reasons your stomach might hurt during a run.
Effects of Exercise on the Body
When you engage in physical activity like running, your body diverts blood flow away from the digestive system to supply the muscles with oxygen. This redirection of blood flow can slow down digestion, leading to the build-up of gas and stomach discomfort.
Plus, the repetitive impact of running can jostle the contents of your stomach and intestines, further exacerbating the discomfort.
Nerves
If you’re nervous about a new long run, a particular workout or race day it’s much more likely you’ll have stomach distress.
As your anxiety level rises, the body starts pumping out more cortisol (stress hormone). A hormone that’s already going to increase during the run, but which can have the effect of increasing stomach acid.
Full Stomach
I talk a lot about fueling prior to your runs, but a stomach that is overloaded isn’t going to feel great, either.
Blood flow is being diverted from your digestive tract to your muscle to ensure you have the energy you need to keep running. But that means food is not being broken down efficiently, and your stomach eventually feels overworked leading to abdominal cramps.
Dehydration
It’s not just your muscles that need water to keep functioning. Your digestive system is going to slow down, and eventually, that’s going to lead to stomach cramps. This is because dehydration can slow down digestion and exacerbate the risk of developing runner’s stomach.
Particularly if you are using energy gels (as you should) to fuel your runs. You are increasing the chance of discomfort by not hydrating well.
Make sure to drink enough fluids throughout the day, especially before and after your run. It’s also important to sip water during your run if it’s longer or performed in hot weather.
Lack of a Warm Up
If you’ve read anything else I’ve written, you aren’t surprised to see this on the list.
A dynamic warm up has been shown to prevent injuries, lubricate joints and make the overall effort feel easier. The harder the run is on your body, the shallower your breathing will be, which then leads to cramping.
Too Much Sugar
Sports drinks are a great tool for helping us to stay on top of electrolytes and prevent other kinds of muscle cramps and fatigue. BUT there is a lot of data to show that too much is going to lead to stomach issues.
Sports drinks are designed to increase hydration. Sucking down more means the body is holding more water for your muscles which can cause a feeling of bloating and then you add in a bunch of gels and it’s a recipe for runner’s gut.
30-60 grams of sugar per hour of exercise is what’s usually recommended. If you have a lot of stomach issues it can help to vary the source. Meaning sipping a drink like Tailwind, eating ClifBloks and dates…so you vary the type of sugar during the run.
Checkout my fueling ideas for sensitive stomachs >>
Poor Form
Another contributing factor to runner’s stomach is poor form and posture during exercise. Incorrect technique can put unnecessary stress on the stomach and abdominal muscles, leading to discomfort and even cramping.
Make sure that you maintain proper running form, with your chest lifted, shoulders relaxed, and core engaged. This alignment can help reduce the strain on your abdominal area and minimize the risk of developing runner’s stomach.
How to Prevent Stomach Cramps While Running
Great now we know why our body might throw off this unpleasant signal that something is amiss during our run. If it’s happening to you more than once in awhile it never hurts to get medical advice.
But here are some things that can help:
Choose the Right Foods
Choosing the right foods before your run can make a significant difference in preventing stomach discomfort. Opt for easily digestible carbohydrates like whole grain toast with nut butter, oatmeal with fruit, or a smoothie with protein powder.
Eating a balanced meal that includes a combination of carbohydrates, protein, and a small amount of healthy fats can provide your body with the necessary fuel to sustain your workout.
Avoid high-fat and high-fiber foods in your pre-workout meal, as these can slow down digestion and potentially lead to stomach discomfort. Listen to your body and experiment with different meal ideas to find what works best for you.
Food Timing
If you’re eating a full meal then wait 90 minutes to 2 hours before running. This gives your body enough time to break things down and doesn’t ask your stomach to continue working with less blood flow.
Most people will do fine with a small snack prior to a run or even a small breakfast of 100-200 calories that contains simple carbs. Like a slice of sourdough bread and a tablespoon of nut butter.
Keep a Food Log
Start keeping a quick log of what you eat and drink before a run. Also a great idea to note what you eat the night before a long run, as that can play a role.
It could be that specific foods are aggravating your stomach and that shows up during the run.
Milk is an extremely common issue, which makes sense when visualizing that hot milk curdles!
You might also find that you’re eating a little more fiber close to the run than you thought or that you don’t do as well with a lot of fat pre-run. It works great for many of us doing easy long runs, but that doesn’t mean it’s best for you.
BONUS: Taking a probiotic has helped a lot of our athletes resolve issues with the gut while running. It works to improve the health of your gut, which is going to lessen issues.
- Previnex is my personal recommendation based on studies and what it includes. I’ve been using it for years.
- Previnex discount code: RTTF15 is good for 15% of your first order
Stay Hydrated
In addition to fueling, proper hydration is key to preventing runner’s stomach during your workouts. Drink enough water throughout the day leading up to your run to ensure you’re adequately hydrated.
During your run, it’s essential to sip fluids regularly to maintain hydration levels. If you are running for longer durations or in hot weather, consider incorporating electrolyte-rich drinks for replenishing lost minerals.
Hydration doesn’t stop after your run. It’s important to continue hydrating post-workout to aid in recovery and replenish any fluids lost during exercise. Water, coconut water, or sports drinks can all be good options for rehydration.
Remember that everyone’s hydration needs are different, so pay attention to your body’s cues and adjust your fluid intake accordingly. Thirst is not always a reliable indicator of hydration status, so it’s important to drink fluids even before you feel thirsty.
Sip, Don’t Guzzle Electrolytes
Staying hydrated all day long is key. The body is water and it needs it for all of your organs to function at their best, plus a dehydrated muscle is more likely to be overworked and tada…cramp.
But during your run it’s also important to make sure that you sip rather than guzzle.
Avoid Caffeine
Coffee or other forms of caffeine can stimulate the digestive tract. I mean a lot of you know this because it makes you…well go!
Obviously during the run that activation along with the acidity can lead to uncomfortable stomach aches and pains.
Reduce Your Effort
If the cramps are coming on consistently on easy runs then it’s often a good sign you’re still running too hard for your current fitness level.
Remember that easy runs are designed to build your aerobic base, helping to increase your endurance and overall fitness. They are not days to be focused on your watch. Checkout these tips for running in zone 2.
Stop with the NSAIDs
I’ve actually done an entire article on the dangers of taking pain relievers prior to running. But for our purpose here what you need to know is this could be the cause of your side cramps or stitches!
A study of ultra runners found that those who were taking NSAIDS in advance of pain, “just to be safe”, ended up feeling worse during the run and were more likely to deal with stomach upset.
Practice Better Breathing
If a cramp comes on in the middle of a run, try slowing down to a walk. Then start taking some deep belly breaths.
We want to get as much oxygen in to the body and to all of the muscles as possible. Plus, that action deep breathing tells the body it’s ok to relax and we want relaxation ASAP.
Probiotics
You may experience less digestive distress while engaging in endurance exercises if your gut is healthy and you have regular bowel movements. Probiotic supplements can help your gut become stronger and reduce the frequency of bathroom breaks during exercise.
A 2014 study found that taking probiotic supplements for 4 weeks increased runners’ endurance and digestion when exercising in hot weather. A similar 2019 study found that probiotics reduced the gastrointestinal symptoms experienced by marathon runners.
When to See a Doctor
If you frequently experience runner’s stomach, you might be suffering from a condition unrelated to running. Irritable bowel syndrome (IBS) and celiac disease have symptoms that are comparable to runner’s belly, but they are caused by different things and activities. If you experience any of the following signs, you should consult your doctor:
- Diarrhea and cramping episodes that occur more frequently than once per week
- Chronic constipation
- Nausea, gas, and bloating, irrespective of running
- Bowel movements that are often runny
- Blood in your stool
Your doctor will discuss your symptoms with you to determine whether they are a result of running or a different diagnosis.
Hopefully these tips help you prevent future stomach cramps while running!
Looking for more tips to resolve stomach issues?
- Tips to avoid runners diarrhea
- Tips to help with bloating
- Avoid Side Stitch While Running
- Sensitive Stomach Fuel ideas
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