We run through cold and rain, heat and haze, with blisters and black toenails, headaches and knee aches. But a side stitch? That sharp, stabbing pain that hits below the ribs can stop us in our tracks. Although the exact cause of side stitches has yet to be proven, theories abound. Sports medicine doctor Jordan Metzl says the most likely cause is a diaphragm spasm.

The diaphragm, a sheet of muscle that extends across the bottom of
 the ribcage, plays an important role in breathing. Just like your leg muscles, your diaphragm can fatigue and cramp when put under too much stress. That’s why side stitches tend to strike beginner runners or those stepping up pace or distance. The good news is that there are a variety of effective strategies – ones that I put to the test with the runners I coach – that can help prevent this common problem.

1. Shore up your core

Performing just 10 minutes of core-strengthening exercises, like planks and donkey kicks, three times a week (or practising yoga or pilates on a regular basis) can strengthen weak diaphragm muscles, making them more resilient to fatigue and less likely to cramp. Bonus: a stronger core will also help you run more efficiently and reduce your overall vulnerability to injury.

2. Fuel wisely

What and when you eat before a run may contribute to side stitches. If your body is still digesting food, there will be less blood flowing to the diaphragm, which can induce spasms. Foods that are high in fat and fibre take longer to digest, and should be avoided one to two hours before you run. Studies have also found that fruit juices and beverages that are high in sugar can contribute to stitches. Consider keeping a log of the foods and drinks you consume pre-run and when you experience a stitch so you can recognise triggers.

3. Warm-up

Going from standing to a full sprint may save you time on the watch,
 but it can create irregular, rapid-fire breathing patterns, which can leave you bending over in pain. Invest in two to three minutes of brisk walking, and then gradually work into an easy running effort before launching into your planned workout pace.

4. Increase your breath

If breathing is too shallow, it doesn’t provide adequate oxygen to muscles, including the diaphragm. Inhaling and exhaling fully and deeply can help reduce the occurrence of side stitches. Research shows that breathing ‘faster’ – as in, inhale for two steps, exhale for one step – increases depth of breath.

5. Needle match

Despite your best efforts, a side stitch hits. Now what?

a) Slow your pace to a jog
 (or even walk).

b) Exhale as the foot on the opposite side of the stitch strikes the ground.

c) Keep your exhales in sync with that opposite side until the pain subsides.

d) Gradually pick up the pace
 as the pain recedes. Keep your focus on breathing as you continue your run, so the stitch doesn’t return.

Why it works

When you exhale, you use your diaphragm muscles. When this happens in unison with your foot striking the ground, the impact forces travel up the body and into your core and cause the working muscle to spasm, creating a stitch. When you change the side of the landing forces to the opposite side, the tension releases.

READ MORE ON: injury-prevention side stitch