You're two miles into a run, feeling great, and then it hits: a sharp, stabbing pain just below your ribs that makes you want to double over. If you've been running for any length of time, you've almost certainly dealt with a cramp.
A running cramp in the abdomin, sometimes called a “stitch” or "side stitch", is technically called exercise-related transient abdominal pain, or "ETAP". It's extremely common, completely harmless, but very annoying in the moment. Thankfully, there are a few things you can do to make it more likely it go away and maybe even stop it from coming back.
Why Do Stomach Cramps or Stitches Happen?
Unfortunately, nobody really knows for certain. Researchers have been studying this for decades and there still isn't one definitive, agreed upon explanation. But there are three leading theories, and understanding them helps you figure out what's going on in your own body.
1. Peritoneal irritation
Your abdominal organs are wrapped in a membrane called the peritoneum. When you run, the repetitive jostling can cause friction between the layers of this membrane, especially if your stomach is full. That friction triggers pain, commonly on the side, just under your ribs. This is currently the most widely supported theory in the research.
2. Ligament strain
Your stomach, spleen, and liver are connected to your diaphragm by ligaments. When you run, the up-and-down motion of these organs pulls on those ligaments with every stride. The heavier your stomach contents, the more they pull.
3. Diaphragm stress
Your diaphragm is working hard when you run, contracting and relaxing with every breath. When you increase your effort faster than your breathing can keep up, or when you're breathing shallowly, the diaphragm can cramp. Think of it like a calf cramp, but in the muscle that controls your breathing.
So these are the leading theories, but in reality, your stitch probably involves a combination of these factors. What we do know is that certain things make stitches more likely, and that's where the practical advice comes in.
What Makes a Stomach Cramp or Stitch More Likely?
A few common triggers come up again and again:
Eating or drinking too close to your run. A full stomach increases the weight pulling on those ligaments and presses against the peritoneum, increasing friction. Sugary or carbonated drinks are particularly provocative.
Shallow breathing. If you're only breathing into the top of your chest, your diaphragm isn't moving through its full range. This makes it more prone to cramping under effort.
Going out too fast. Sound familiar? Starting harder than your body is ready for puts sudden demand on your diaphragm and core. Your breathing rate spikes before you've had time to settle into a rhythm.
Lower fitness levels or returning from a break. Stitches are more common in newer runners and in anyone coming back from time off. As your fitness improves, they tend to become less frequent.
Weak core muscles. Research has shown that runners with stronger trunk muscles and a larger transversus abdominis (the deep core muscle that wraps around your midsection) experience less stitch pain. Your core plays a bigger role in stabilizing those internal organs than you might think.
How to Get Rid of a Stitch Mid-Run
When a stitch strikes, it can feel pretty debilitating. Here are some techniques that might help ease the symptoms:
Slow your pace and focus on deep belly breaths
Inhale fully through your nose, letting your belly expand. Exhale slowly and completely through your mouth. It relaxes the diaphragm and gives it space to recover.
Lightly press into the spot
Place your hand where you feel the stitch and apply gentle pressure. As you exhale, push a little deeper. This can help release tension in the area.
Stretch it out
Raise the arm on the side of the stitch overhead, then lean gently away from the pain. Hold for 20 to 30 seconds. This stretches the muscles and ligaments around the affected area.
Change your breathing-to-stride pattern
If you notice you're always exhaling as the foot on the stitch side hits the ground, try switching it up. Exhale as the opposite foot lands. This changes which side absorbs the impact and can break the cycle.
If none of these work, it's okay to walk for a bit. A stitch will usually ease off once you reduce the intensity. That's the "transient" part of the name.
How to Reduce the Chance of Stitches Happening
Reducing the likelihood of pesky stomach cramps or stitches is where you can really make a difference. Most of these are small adjustments that add up over time for the better.
Time your food and drink
We'd recommend leaving at least one to two hours between a substantial meal and your run. If you need something closer to your run, keep it light and easy to digest (a banana, a small handful of pretzels). Avoid carbonated beverages before and during your run.
Warm up properly
A good warm-up gradually increases your breathing rate and blood flow rather than shocking your system into action. Dynamic movements that involve trunk rotation are especially helpful for preparing the tissues around your diaphragm. If you're following a Runna plan, your warm-up guidance is built into your session.
Practice belly breathing
This is worth doing outside of your runs too. Lie on your back, place a hand on your stomach, and breathe so that your hand rises and falls with each breath. The more natural this pattern becomes, the less likely you are to default to shallow chest breathing when you pick up the pace. Check out more tips for breathing tips while running here.
Build your core strength
A consistent strength routine that targets your deep core muscles pays dividends here. Exercises like planks and dead bugs strengthen the transversus abdominis, which helps stabilize your organs during the repetitive impact of running. If you're doing Runna's strength sessions, you're already working on this.
Progress gradually
Ramping up your mileage or intensity too quickly is one of the fastest ways to invite a stitch back in. This is true for training in general, and it applies here too. Your body needs time to adapt. This gradual progress is carefully considered in your personal Runna plan.
When to Pay Attention
A stitch that goes away during or shortly after your run is nothing to worry about. But if you're experiencing persistent or severe abdominal pain that doesn't resolve with rest, or pain that comes with other symptoms like nausea, fever, or referred pain to your shoulder tip, it's worth checking in with a medical professional. Those symptoms can occasionally indicate something beyond a standard stitch.
The Bottom Line
Stitches are one of those annoying parts of running that almost everyone deals with at some point. They're not a sign that something is wrong with you, and they tend to become less frequent as your fitness develops and you learn what your body does and doesn't tolerate before a run.
Focus on your breathing, respect your pre-run nutrition timing, and keep building that core strength. And if one catches you mid-run? Slow down, breathe deep, and press into it. You'll be back up to pace before you know it.