🏃‍♀️ Our Guide to the old side stitch

One minute you’re cruising through your run — the next, you’re forced to slow down with a sharp pain under your ribs.

Recently, this came up a little closer to home.

My daughter has been training for our local school cross country and is now off to interschools — which means extra training sessions, even on the weekends (she’s 7!).

Part of me really admires the effort from both the teachers and the kids doing this extra training. Another part of me thinks… she’s only 7!
(That’s probably a separate opinion piece — so I’ll park that for now.)

Last weekend, she went straight from a friend’s sugar-fuelled pool party into a run — and ended up with a stitch. Now she’s worried it’s going to happen every time she runs.

So — I thought I'd break down what’s actually going on, and what she (and you) can do about it.

That’s the dreaded “stitch”, or if you want to get geeky about it- exercise-related transient abdominal pain (ETAP).
It’s common, frustrating, and can affect runners of all levels — from beginners to experienced athletes.

The good news? While it can feel intense, it’s usually harmless — and in many cases, preventable.

🔍 What Causes a Stitch?

There’s no single cause of a stitch, but research points to a few key contributing factors:

  • Diaphragm strain
    Your diaphragm is working hard when you run. If breathing becomes inefficient or demand increases quickly, it can become irritated — leading to pain under the ribs.

  • Ligament tension from internal organs
    Your liver and stomach are supported by ligaments. Repetitive running — especially after eating — can place stress on these structures, triggering pain.

  • Irritation of the abdominal lining (parietal peritoneum)
    One of the leading theories suggests the lining of your abdominal cavity becomes irritated with repetitive movement. This is closely linked to the nerves involved in breathing, which may explain the sharp, localised pain.

  • Posture and movement patterns
    Excessive torso rotation, slouched posture, or poor breathing mechanics can all increase stress through the trunk.

💡 Key point: There’s no single cause — stitches are likely due to a combination of diaphragm load, abdominal tension, and movement mechanics.

📍 Most stitches occur on the right-hand side, which may relate to the position of the liver.

⚡ Who Gets a Stitch?

Anyone can experience a stitch, but it’s more common if you:

  • Are new to running or returning after a break

  • Eat or drink too close to your run

  • Start runs at a high intensity

  • Intense hill running (that's just a theory)

  • Have shallow breathing habits

  • Have reduced core strength or control

🛡️ How to Prevent a Stitch

A few simple changes can make a big difference:

1️⃣ Mind Your Meals

  • Avoid heavy meals 1–3 hours before running

  • Keep pre-run snacks light

  • Avoid large fluid intake right before running

2️⃣ Start Easy & Warm Up

  • Begin your run at an easy pace for 5–10 minutes

  • Include a short dynamic warm-up to prepare your body and breathing

3️⃣ Breathe Better

  • Focus on deep belly (diaphragmatic) breathing

  • Avoid shallow chest breathing

  • Try syncing your breath with your stride
    (e.g. exhale as your right foot lands if you get right-sided stitches)

4️⃣ Strengthen Your Core

  • Target deep abdominal muscles and obliques

  • Improve postural control to reduce unnecessary torso movement

5️⃣ Improve Running Technique

  • Avoid excessive torso rotation

  • Build intensity gradually

  • Don’t “sprint out of the gates” — let your body settle into rhythm

🏃‍♂️ What to Do If a Stitch Hits

If you feel a stitch coming on:

  • Slow down or walk

  • Bend slightly forward and exhale fully

  • Apply gentle pressure to the painful area

  • Stretch by lifting your arm overhead and leaning away from the pain

Most stitches will settle quickly once the load is reduced.

💭 Myth vs Reality

Myth:“A stitch is just a breathing problem.”
Reality: Breathing plays a role, but stitches are likely caused by a combination of diaphragm load, abdominal tension, posture, and movement mechanics.

💡 Key Takeaway

Stitches are common, but they’re not random.

By improving your pre-run habits, breathing, and running technique, you should be able to significantly reduce your chances of getting one — and keep your runs more comfortable and consistent.- 

Give these strategies a go on your next run — and see what difference it makes.

We'll see if these strategies work next week after the interschools!

( p.s Don't worry- I won't be getting her do the core work outs at 7 years old!)

📚 References

  • Morton, A.R. (2004). Exercise-related transient abdominal pain (‘stitch’) in athletes. Sports Medicine, 34(10): 715–730.

  • Springer, J., & Game, J. (2016). Diaphragmatic contribution to ETAP in runners. Journal of Sports Sciences, 34(14): 1345–1352.

  • Wessel, J. et al. (2010). Factors influencing ETAP incidence in adolescent athletes. Pediatric Exercise Science, 22(3): 401–409.

  • Allen, K., & White, P. (2011). Prevention of exercise-related abdominal pain. British Journal of Sports Medicine, 45: 234–238.

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🏃‍♂️ Calf Injuries in Runners