How to Prevent Side Stitches When Running

What is a side stitch?

A side stitch is that sharp, cramping or stabbing pain you feel along the side of your belly during exercise, most often just under the ribs. Runners get it a lot, but swimmers and horse riders do too. The medical name is exercise-related transient abdominal pain, usually shortened to ETAP.

The good news is that it is almost always harmless and short-lived. It tends to ease off once you slow down or stop. It is annoying and it can cut a run short, but on its own it is not a sign that something is seriously wrong.

What causes side stitches?

Nobody has pinned down a single cause, but a few theories keep coming up. Most likely it is a mix of these rather than just one.

• The diaphragm. One long-held idea is that the diaphragm, the big breathing muscle under your lungs, cramps or gets short of blood when you work hard. Shallow, rushed breathing may make this worse.
• Irritation of the abdominal lining. A more recent theory points to the peritoneum, the thin lining around your gut. The inner and outer layers may rub and become irritated, especially if your stomach is full and pulling on it.
• Posture. Runners who slouch or round forward seem to get more stitches. A collapsed, hunched position cramps the trunk and can tug on the structures involved.

What ties these together is that a full stomach, weak trunk muscles and sloppy form all crop up again and again. That is handy, because all three are things you can work on.

How to prevent side stitches

Mind what and when you eat

A big meal sitting in your stomach is one of the most common triggers. Leave roughly two hours after a full meal before you run, and keep pre-run snacks small and simple. Sugary drinks and fruit juices are a frequent culprit too, so go easy on those in the hour before you head out. Plain water is the safer choice.

Warm up properly

Starting cold and going straight into a fast pace gives your body no time to settle. A few minutes of easy walking or gentle jogging lets your breathing and your trunk muscles ease into the work. Building from easy to harder, rather than blasting off from the line, is one of the simplest ways to dodge a stitch.

Build core strength

A stronger, more stable trunk holds you upright and takes pressure off the muscles and lining involved in stitches. Planks, dead bugs, bird dogs and side planks are all good general core moves. You do not need a gym. Two or three short sessions a week add up over time.

This is where a structured plan helps. Edge builds general core, strength and mobility work into every plan, which supports better posture and trunk stability over the weeks and months. It will not target stitches specifically, but a stronger, more stable middle is one of the better long-term defences.

Watch your breathing rhythm

Quick, shallow, panicky breathing seems to feed stitches. Aim for slower, deeper breaths that fill the belly rather than just the chest. Some runners like to tie their breathing to their steps, breathing in for three steps and out for two, so the out-breath does not always land on the same foot. Find a rhythm that feels calm and repeatable.

Improve your posture

Run tall. Think about lifting through the chest, keeping your shoulders relaxed and not collapsing forward as you tire. Good posture keeps the trunk open and gives the breathing muscles room to work. It is one of the quieter wins, and it pairs naturally with the core work above.

Build up gradually

Stitches love a sudden jump in pace or distance. Easing into your training and adding load slowly gives your body time to cope. Edge's easy-pace guidance and progress tracking help you build at a sensible rate, so you are less likely to overreach on any single run.

If a stitch strikes: step by step

1. Slow down. Drop to a gentle jog or a walk. Easing the effort is the fastest way to take the edge off.
2. Breathe out hard. Take a deep breath in, then exhale forcefully as the foot on the painful side hits the ground. Repeat for a few strides.
3. Press the spot. Push gently into the sore area with your fingers, or bend forward slightly, to relieve the pull.
4. Stretch it out. Reach the arm on the affected side up and over your head to open up that flank.
5. Ease back in. Once the pain fades, pick the pace back up slowly rather than charging straight back to full speed.

Your prevention checklist

• Leave about two hours after a big meal before running.
• Skip sugary drinks and juices close to your run. Sip plain water instead.
• Warm up with a few minutes of easy walking or jogging.
• Build general core strength two or three times a week.
• Breathe slowly and deeply, and vary which foot the out-breath lands on.
• Run tall with relaxed shoulders and an open chest.
• Add pace and distance gradually rather than in big jumps.

When to see a doctor

A normal side stitch fades quickly once you slow down and it does not come back at rest. See a doctor if the pain is severe, does not settle, keeps returning, or feels different from a usual stitch. Pain on the lower right, pain that spreads, or pain that comes with feeling unwell, breathlessness or chest tightness needs proper medical attention. Edge builds general fitness, not medical care, so if something feels off, get it checked.

Frequently asked questions

Why do I always get a stitch on the same side?

Stitches often show up on the right because the liver sits there and is fairly heavy. The exact reason is not fully settled, but for many runners one side is simply more prone than the other.

Does drinking water cause stitches?

Plain water in small sips is generally fine and helps you stay hydrated. The bigger culprits are large volumes of fluid right before a run and sugary drinks or juices, which seem more likely to trigger a stitch.

Will stitches go away as I get fitter?

Often, yes. Many runners find stitches become less frequent as their core gets stronger, their breathing steadies and their posture improves. Building gradually and training consistently tends to help over time.

Can core training really help with stitches?

A stronger, more stable trunk supports better posture and takes strain off the muscles involved, which many runners find reduces stitches. Edge builds general core, strength and mobility into your plan, though it does not treat stitches specifically.

When should I worry about a stitch?

If the pain is severe, lasts at rest, keeps coming back, or comes with symptoms like breathlessness, chest tightness or feeling generally unwell, stop and see a doctor. A normal stitch eases quickly once you slow down.