When a sharp ache strikes the side of your torso during a run, you are experiencing a common phenomenon known as a side stitch. Up to 70% of runners report this pain, and it is a primary reason many people slow down or stop their workout entirely. While this discomfort is not usually serious, understanding its formal name and characteristics is the first step toward managing this irritating issue.
Defining Exercise-Related Transient Abdominal Pain
The formal medical term for a side stitch is Exercise-Related Transient Abdominal Pain (ETAP). The term “transient” means the pain is temporary, occurring only during physical activity. ETAP is characterized by localized discomfort ranging from a mild ache or cramping sensation to a sharp, stabbing pain.
The pain is most frequently felt along the lateral aspect of the mid-abdomen, often directly under the lower edge of the rib cage. The sensation is typically reported on the right side, which provides an important clue to the underlying causes.
Understanding the Primary Causes of Side Stitches
The exact reason ETAP occurs is still debated, but the most widely accepted theory focuses on irritation of the parietal peritoneum. This is the thin membrane lining the abdominal cavity, which becomes inflamed when jostled during running. The jarring, repetitive motion of running exacerbates this friction and subsequent irritation.
Another leading theory involves stress on the ligaments connecting internal organs, particularly the liver, to the diaphragm. Since the liver is the largest organ and is situated on the right side, repetitive foot strikes may cause a downward tugging force that strains these supportive ligaments. This strain is compounded when the diaphragm moves upward during exhalation, creating a pinching effect.
A third hypothesis points to a temporary cramp or spasm of the diaphragm muscle itself, often linked to shallow, rapid breathing. This shallow chest breathing fails to fully engage the diaphragm, leading to early fatigue and reduced blood flow in the muscle. This lack of full engagement can cause the diaphragm to cramp, resulting in the sharp pain felt under the ribs.
Immediate Relief Techniques During a Run
When a stitch strikes mid-run, slow your pace down to a walk or stop entirely to regain control of your breath. The most effective immediate relief technique is to focus on deep, controlled, abdominal breathing. Try a forceful exhale through pursed lips when the foot opposite the side of the pain strikes the ground.
You can also apply manual pressure to the painful area. Place two or three fingers firmly onto the spot, pressing inward and upward while simultaneously taking a deep breath in and exhaling slowly. A targeted stretch can also help by extending the torso away from the pain. If the stitch is on the right side, raise your right arm over your head and gently lean toward the left, holding this position for 20 to 30 seconds.
Adjustments for Long-Term Prevention
Nutrition and Timing
One effective way to prevent ETAP is to be mindful of nutrition and hydration timing before a run. Avoiding large meals for at least two to four hours before exercise allows the stomach to empty, reducing pressure on the parietal peritoneum. If a snack is necessary, limit it to a small, easily digestible carbohydrate 30 to 60 minutes before your workout.
Breathing Technique
Deliberate breathing is a powerful preventive tool, specifically by adopting an odd-numbered breath-to-stride ratio (e.g., inhaling for three steps and exhaling for two steps). This non-symmetrical pattern ensures that the exhalation phase alternates between the right and left foot strikes. This technique prevents the diaphragm from being repeatedly stressed on the same side, especially the right side where the liver is located.
Core Strength
Strengthening the deep core muscles, including the transverse abdominis and obliques, is beneficial as it improves trunk stability. A stronger core resists the rotational and vertical forces of running, which minimizes the jarring motion on internal organs and ligaments. Incorporating a dynamic warm-up that includes gentle torso twists and side bends prepares the core musculature for repetitive forces.