You are out on your run, your pace is good, and suddenly, a sharp pain pierces your side, takes your breath away, and forces you to slow down or even stop. A side stitch affects nearly 7 in 10 runners at least once a year, from beginners to experienced athletes. The good news is that it is never dangerous, and above all, there are practical ways to prevent it, including one factor that is too often overlooked: your nutrition strategy before and during exercise.
In this guide, we explain what a side stitch really is, why it occurs, how to make it go away during a run, and above all, how to prevent it over the long term.
What is a side stitch?
A side stitch, also known as exercise-related transient abdominal pain (ETAP), is a sudden, sharp pain most often felt under the ribs, on the right or left side, sometimes around the stomach or extending up to the collarbones.
It particularly affects endurance sports involving repeated impact: running, but also cycling, swimming, and horseback riding. It generally disappears within a few minutes once the effort is stopped or slowed down.
Good to know: a side stitch is harmless. It poses no danger, even though it can sometimes be intense enough to disrupt a workout or race. However, it should not be confused with chest pain or breathing difficulties, which require medical advice.
Why do you get a side stitch when running? The main causes
The exact mechanism behind a side stitch has not yet been fully explained by science, but several triggering factors have now been clearly identified.
Irritation of the peritoneum
The strongest hypothesis today is that during exercise, the quantity and viscosity of the fluid that lubricates the peritoneum (the membrane surrounding the abdominal organs) change. The repetitive movements of running then create friction between the two layers of this membrane, causing painful irritation.
Poorly controlled breathing
Breathing too shallowly, too quickly, or out of sync with your stride places excessive strain on the diaphragm, which is itself a muscle. Like any muscle lacking oxygen, it can contract painfully, much like a cramp.
A poorly managed pre-exercise meal
This is one of the most well-documented causes, yet one of the most overlooked in usual advice. Eating a heavy meal rich in fat or fiber within 2 hours before exercise places demands on the digestive system at a time when the body should be prioritizing blood flow to the muscles. With the digestive tract still full, it is more prone to pulling sensations during running movements.
A drink that is too concentrated or improperly dosed
A sports drink that is too sugary, too concentrated, or consumed in too large a quantity at once slows gastric emptying and increases the risk of digestive discomfort, including a side stitch. This is something we will discuss in detail below, as it is often the missing link in prevention.
Starting too fast
Starting too fast, without giving your body time to adapt to the effort, increases the strain on the diaphragm and abdominal muscles before they are "warmed up". This is an additional risk factor.
The underestimated role of nutrition in preventing side stitches
Most advice found online focuses on breathing and warm-ups. That is useful, but incomplete: what you eat and drink before and during exercise has a direct, measurable impact on your digestive comfort and therefore on the risk of developing a side stitch.
Before exercise: prepare an easy-to-digest meal
- Choose a meal low in fat and fiber 2 to 3 hours before your outing.
- Opt for simple, easily digestible carbohydrates (banana, energy compote, rolled oats, energy cake...).
- Avoid new or unusual foods just before a race.
During exercise: pay attention to the concentration of your intake
A sports drink that is too concentrated in sugars slows gastric emptying and can cause digestive discomfort, including a side stitch. That is why dosage matters just as much as ingredient quality:
- Aim for an isotonic drink (which is close to the natural concentration of blood) that promotes fast and comfortable absorption.
- Split your intake into several small, regular sips rather than consuming a large amount all at once.
- Always test your energy products during training before using them in a race. This is the principle of gut training, which gradually trains your digestive system to absorb fuel while moving.
Products that are 100% natural, with no artificial flavors or preservatives, are generally better tolerated during exercise. The body more easily recognizes ingredients such as rice syrup or fruit than a long list of additives, which limits the risk of digestive overload.
How can you relieve a side stitch during exercise?
If the pain nevertheless occurs during a run, here are the most effective things to do:
- Slow down or walk for a few moments: there is no need to stop completely, but reducing the intensity relieves pressure on the diaphragm
- Breathe deeply and slowly, expanding your belly as you inhale and contracting your abdominal muscles as you exhale
- Lean your torso away from the painful side while raising the arm on the painful side to stretch the affected area
- Exhale forcefully while leaning forward, with your hands on your knees, if the pain is more intense
- Modify your breathing cycle: favor an odd rhythm (for example, 3 steps inhaling and 2 exhaling) so you do not always land on the same foot at the same point in the breathing cycle. This may limit repeated irritation on one side of the peritoneum
How to prevent side stitches for good: the checklist
| Factor | Good practice |
|---|---|
| Pre-exercise meal | Light, low in fat and fiber, 2–3 hours beforehand |
| Sports drink | Isotonic, in small portions |
| Hydration | Regularly, in small sips, never a large amount at once |
| Breathing | Deep, abdominal, odd-numbered cycle |
| Warm-up | Gradual, with no sprinting in the first few minutes |
| Strength training | Regular core exercises to strengthen the abdominal muscles |
| New products | Always tested during training before a race (gut training) |
Is a side stitch dangerous?
No. A side stitch is a benign phenomenon, even if it can sometimes be sharp and unpleasant. It poses no health risk and generally disappears within a few minutes. The only precaution is not to confuse it with chest pain, tightness, or unusual shortness of breath, which do require medical advice.
Making side stitches a thing of the past
A side stitch is not inevitable: by working on your breathing, adopting a gradual warm-up, and above all taking care with your nutrition strategy before and during exercise, you considerably reduce the risk of experiencing one. Nutrition is often the easiest factor to adjust and the one that produces results fastest. By choosing natural products that are properly dosed and tested in advance, you give yourself the best chance of running without interruption.
Frequently asked questions about side stitches
Does a side stitch only affect beginners?
No. Although it is more common among young runners and those returning to activity, experienced runners can also be affected, particularly during efforts at an intensity close to their threshold.
Should I stop running if I get a side stitch?
Not necessarily. Slowing your pace and adjusting your breathing is often enough to make it disappear without stopping the effort completely. If the pain is too intense, walking for a few moments is recommended.
Can drinking during exercise cause a side stitch?
Drinking is not inherently the cause; the amount and concentration are what matter. A properly dosed isotonic drink, taken in small, regular sips, actually limits the risk rather than increasing it.
Can a side stitch be prevented 100%?
There is no absolute guarantee, as the exact cause has not yet been scientifically determined. But by combining controlled breathing, a gradual warm-up, and an appropriate nutrition strategy, most runners significantly reduce how often it occurs.
