Have you ever been cruising through a run, feeling strong, maybe even thinking, “Wow, I look like I belong in the front pack of a major marathon right now,” when out of nowhere, a sharp side stitch stops you in your tracks?
I’ve been there. One minute, I’m in the zone; the next, I’m clutching my side, trying to jog it off and wondering what went wrong.
Side stitches can be surprisingly intense and totally derail an otherwise great run. While they often fade once you stop, that’s not always the case. Sometimes, the discomfort lingers for hours or even days.
If your side stitch just won’t go away, keep reading. I’ll break down what might be causing it, what you can do to ease the pain, and how to prevent it from hijacking your runs in the future.
The Honest Truth About A Side Stitch That Won’t Go Away
Most articles on side stitch — the formal name is exercise-related transient abdominal pain, or ETAP — treat it as one mechanism with one fix. The literature actually points at a small cluster of distinct mechanisms, each with a different fix, and a stitch that won’t go away usually means the wrong fix is being tried for the actual mechanism. Worth knowing too: persistent “stitch”-pattern pain that survives the workout and returns at rest can be referred from somewhere that isn’t the diaphragm at all.
What ETAP actually is — the parietal-peritoneum hypothesis
The historically-popular explanation — that the diaphragm is being “starved” of blood — doesn’t hold up well. Morton and Callister’s programme of work, summarised in their 2015 review, argues the most consistent driver is irritation of the parietal peritoneum — the inner lining of the abdominal wall — from friction against the stomach and from posture-induced ligament stretching at the diaphragm 1Morton DP, Callister R. Exercise-related transient abdominal pain (ETAP). Sports Med. 2015;45(1):23-35.. The pain pattern fits: sharp, localised, often shoulder-tip referral on the right (where the diaphragm and liver share innervation via the phrenic nerve C3–C5), and reliably aggravated by spinal flexion and provoked by recently-eaten dense or hyperosmolar foods 2Morton DP, Callister R. Characteristics and etiology of exercise-related transient abdominal pain. Med Sci Sports Exerc. 2000;32(2):432-8.. The earlier “diaphragm ischaemia” hypothesis was contradicted by studies showing ETAP can occur in horseback riding and even camel riding — activities with bouncing torso loading but minimal diaphragmatic respiratory demand 3Plunkett BT, Hopkins WG. Investigation of the side pain “stitch” induced by running after fluid ingestion. Med Sci Sports Exerc. 1999;31(8):1169-75..
The food and fluid triggers most plans get wrong
The dose-response relationship is fairly tight in the published surveys: hyperosmolar drinks (think undiluted juice, high-carb sports drinks at concentrations above 6–8 percent, or carbonated drinks) consumed within 30–60 minutes of exercise raise stitch incidence two-to-three-fold compared with water or isotonic drinks 4Morton DP, Aragon-Vargas LF, Callister R. Effect of ingested fluid composition on exercise-related transient abdominal pain. Int J Sport Nutr Exerc Metab. 2004;14(2):197-208.. Solid, fat-rich, or fibre-heavy meals within 1–2 hours pre-run are the second-largest trigger, and the youngest cohort — under-25 runners — report stitch most often, with prevalence falling as runners get older and learn fueling timing 5Eichner ER. Stitch in the side: causes, workup, and solutions. Curr Sports Med Rep. 2006;5(6):289-92.. The practical implication is that the “won’t go away” pattern is often someone fueling on the wrong cadence, not someone who needs a different breathing trick.
Posture, breathing mechanics, and the abdominal-wall component
A second mechanism is mechanical: thoracic kyphosis and forward-rounded shoulders compress the upper abdomen during running, while shallow breathing patterns load the accessory respiratory muscles instead of the diaphragm 6Morton DP, Callister R. Spirometry measurements during an episode of exercise-related transient abdominal pain. Int J Sports Physiol Perform. 2010;5(3):374-83.. Two interventions help reproducibly: pursed-lip exhalation that lengthens the exhale relative to inhale (3:2 or 4:2) reduces ETAP severity in real-time studies, and consciously straightening the spine to neutral — ribs over pelvis — relieves it within seconds in a meaningful subset of runners 7Cuomo MA, Bavasso BL. Side stitch and exercise-related transient abdominal pain. Curr Sports Med Rep. 2014;13(4):240-3.. Trigger-point work on the abdominal-wall musculature (rectus abdominis and obliques) and on the lower thoracic erectors targets a third, separate mechanism — myofascial referred pain from the abdominal wall — which Travell and Simons documented can persist long after running and is mistaken for visceral pathology more often than is comfortable 8Travell JG, Simons DG. Myofascial Pain and Dysfunction: The Trigger Point Manual. Vol 1. Williams & Wilkins; 1999..
The four real-time interventions that are actually evidence-backed
Across Morton’s controlled trials and the Cuomo and Ho reviews, four manoeuvres recur as the highest-yield in the literature: slow the pace and shorten the stride for 60–90 seconds (drops impact and torso loading); shift to deep, slow diaphragmatic breathing with a longer exhale; press inward and upward on the stitch with two fingers while exhaling forcefully (the “splint” manoeuvre, which seems to mechanically support the parietal peritoneum); and stretch by raising the arm on the affected side overhead and leaning to the opposite side 9Ho JCK, Tan AHY, Lee JC. The exercise-related transient abdominal pain: a narrative review. Curr Sports Med Rep. 2014;13(4):254-9.. Adolescent and beginner runners benefit disproportionately from progressive abdominal-wall conditioning — planks, side planks, deadbugs, and Pallof presses — which reduces stitch frequency over an 8–12 week training block 10Morton DP, Aragon-Vargas LF, Callister R. Effect of regular exercise on incidence of exercise-related transient abdominal pain. Med Sci Sports Exerc. 2008;40(5):S307..
When “persistent stitch” isn’t a stitch at all
Pain that wakes the runner up at night, lasts beyond about an hour after exercise, presents on the left chest with shortness of breath, or reproduces with deep palpation but not with running, deserves evaluation rather than another breathing drill. Right-upper-quadrant pain after fatty meals can be biliary; left-upper-quadrant pain that radiates to the back can be splenic or pancreatic; central or left-sided chest pain on exertion in adults over about 35 with cardiovascular risk factors is potentially anginal and worth ruling out before chasing “stitch” remedies 11Maron BJ, Poliac LC, Roberts WO. Risk for sudden cardiac death associated with marathon running. J Am Coll Cardiol. 1996;28(2):428-31.. ETAP itself is benign and self-limiting, but the assumption that all running-associated abdominal pain is ETAP has missed referred biliary pain, abdominal-wall hernias, and (rarely) splenic infarction in published case reports 12de Oliveira EP, Burini RC. The impact of physical exercise on the gastrointestinal tract. Curr Opin Clin Nutr Metab Care. 2009;12(5):533-8.. The honest reading: a stitch that won’t go away despite slowed pace, deep breathing, splinting, and a fueling rethink — or that recurs in the same exact spot after every run for weeks — is the kind of problem to bring to a clinician, not a forum thread.
What Is a Side Stitch?
A side stitch is the common term for exercise-related transient abdominal pain (ETAP).
It’s characterized by pain or cramping on one side of your abdomen around the bottom of your rib cage. Generally, it’s more common to have a side stitch on the right side, especially among older runners.
The pain may be dull and achy or sharp and painful.
Most runners have experienced at least one side stitch at one time or another. In fact, this study13Morton, D., & Callister, R. (2014). Exercise-Related Transient Abdominal Pain (ETAP). Sports Medicine, 45(1), 23–35. https://doi.org/10.1007/s40279-014-0245-z found that approximately 70 percent of runners had experienced a side stitch.
What Causes Side Stitches?
The actual mechanism of action causing the pain experienced during a side stitch is most likely due to irritation of the parietal peritoneum, the lining around the abdominal organs.
When you run, the muscles in your core have to engage, which can cause pressure on the nerves and peritoneum surrounding them, which may cause a side stitch sensation.
Other theories14Morton, D., & Callister, R. (2014). Exercise-Related Transient Abdominal Pain (ETAP). Sports Medicine, 45(1), 23–35. https://doi.org/10.1007/s40279-014-0245-z include ischemia or inadequate oxygen supply to the diaphragm (such as when you don’t warm up but start suddenly running fast), stress on the visceral ligaments that support and attach the abdominal organs to the diaphragm, gastrointestinal distension or low blood flow, cramping of the abdominal muscles, or aggravation of spinal nerves.
Why Do I Get Side Stitches While Running?
Researchers are still uncertain about the exact cause of side stitches in runners and other athletes. However, research studies and anecdotal evidence suggest that the following are possible causes of side stitches in runners:
#1: Running Too Soon After Eating
One of the primary risk factors for side cramps in runners is heading out for a run too soon after eating.
While pre-run fueling is essential for energy, especially for longer workouts or races, your digestive system needs time to begin processing that food before you ask your body to perform at a high level.
When you run shortly after eating, blood flow is diverted away from your digestive organs to your working muscles. This can lead to cramping, discomfort, and those sharp side stitches that can bring your run to a screeching halt.
To reduce the risk, aim to wait at least 1–2 hours after a full meal before engaging in physical activity, such as running.
If you need a quick energy boost closer to your workout, stick to small, easily digestible snacks like a banana, a piece of toast with jam, or a few energy chews about 30 minutes before heading out.
#2: Consuming Sugary Foods or Beverages Before You Run
Although having a carbohydrate-rich, pre-workout snack can help top off your glycogen stores and give you the energy you need for your run, evidence suggests15Morton, D., & Callister, R. (2014). Exercise-Related Transient Abdominal Pain (ETAP). Sports Medicine, 45(1), 23–35. https://doi.org/10.1007/s40279-014-0245-z that sugary drinks and high-carbohydrate foods may increase the risk of side stitches.
#3: Shallow Breathing
Your breathing technique while running can significantly impact your risk of developing side stitches.
Rapid, shallow breathing limits oxygen intake and doesn’t allow your diaphragm to relax and contract fully. This constant tension can lead to cramping and discomfort.
Additionally, some researchers and coaches suggest that the timing of your breath in relation to your footstrike matters. Specifically, exhaling when your right foot hits the ground may increase the strain on your liver and diaphragm.
The theory is that this repetitive downward jolt, combined with an exhale (when the diaphragm is already moving upward), creates excessive pressure in the abdominal area, which can trigger a side stitch.
To reduce your risk, try to adopt a slower, more rhythmic breathing pattern. Focus on belly breathing, drawing air deep into your lungs, and experiment with syncing your breath to your steps, such as a 3:2 ratio (inhale for three steps, exhale for two). This can help distribute impact forces more evenly and ease the workload on your diaphragm.
#4: Running Too Fast
Running too fast can potentially cause a side stitch.
This is because you’ll be taking more forceful and rapid breaths, which may cause cramping in the diaphragm muscle. If that side stitch won’t go away, try slowing down a bit.
#5: Not Warming Up
Heading out the door without doing any warm-up requires your muscles—including the muscles involved in breathing (diaphragm and intercostals)—to suddenly go from resting to a hard effort.
Warming up gets your blood flowing, increasing oxygen perfusion to your abdominal and breathing muscles.
#6: Running In Cold Weather
Some runners notice that running in cold weather makes it more difficult to breathe comfortably, and this can increase the likelihood of developing a side stitch.
When the air is cold and dry, it can irritate the lining of your airways, causing them to narrow slightly. This can lead to a sensation of tightness in the chest or difficulty taking deep, controlled breaths.
As a result, you may find yourself breathing in sharp, shallow gasps rather than the slower, diaphragmatic breaths that help keep your core muscles relaxed.
If you’re prone to side stitches in cold conditions, try wearing a buff or light gaiter over your mouth and nose to warm and humidify the air you’re breathing.
Also, make a conscious effort to start your runs slowly, allowing your body to gradually adapt to the colder air and giving your breathing time to settle into a more relaxed, rhythmic pattern.
#7: Running With Poor Posture
Side stitches are more likely to occur if you run hunched over16Redirecting. (n.d.). Linkinghub.elsevier.com. Retrieved April 29, 2024, from https://linkinghub.elsevier.com/retrieve/pii/S1440244009007129 or with poor posture because it constricts the expansion of the rib cage while breathing.
This restricted breathing not only reduces the amount of oxygen you’re able to take in, but it also puts excess strain on your core muscles, particularly the diaphragm. When your diaphragm can’t move freely, it’s more susceptible to cramping or spasms.
To help prevent this, focus on maintaining good running posture throughout your workout.
Keep your shoulders relaxed and pulled slightly back, chest open, and spine tall. Imagine a string gently lifting the crown of your head upward. A strong, upright posture not only improves breathing mechanics but also promotes a more efficient and balanced running form overall.
#8: Dehydration or Electrolyte Imbalances
Dehydration or electrolyte imbalances have been associated with muscle cramps.
Although evidence is mixed regarding dehydration and side stitches specifically, there’s reason to believe that inadequate fluids and low electrolytes may contribute to runners getting side stitches.
Therefore, it’s essential to focus on your hydration and keep well-hydrated with water and/or sports drinks at all times.
#9: Weak Core Muscles
Weak abdominal and core muscles can increase your risk of developing side stitches because these muscles play a key role in stabilizing your torso and supporting your diaphragm during running.
When your core lacks strength, your body has to work harder to maintain good posture and breathing mechanics, especially as fatigue sets in—which can lead to excess strain on the diaphragm.
Strengthening your core helps create a more stable foundation for your running form, allowing your breathing muscles to work more efficiently.
Incorporate targeted core exercises like planks, dead bugs, and Russian twists into your regular strength training routine.
What To Do When A Side Stitch Won’t Go Away?
In most cases, side stitches subside when you stop running or ease into a jog or slow walk. Sometimes, applying gentle pressure to the affected area of the abdomen or adjusting your breathing pattern can help relieve the discomfort even while you’re still running.
However, what if your side stitch won’t go away? What if it lingers even after you stop running?
Your side stitch can last for several days.
In these cases, it’s most likely due to pulling or straining an intercostal, oblique, or other abdominal muscle. You may also have caused excessive stress on your parietal peritoneum and maybe even caused a small tear.
Although evidence is lacking, a side stitch that won’t go away may also be due to irritation of nerves in the abdominal area, a sprain of the ligaments that connect the abdominal organs to the diaphragm, or a muscle pull or spasm in the diaphragm itself.
Cases where a side stitch won’t go away are indicative of more significant damage than a transient irritation during a regular side stitch. This way, they should be treated like mild, acute injuries.
You can try alternating ice and heat treatments.
Use an ice pack for 10-15 minutes over the affected area (not directly on the skin) several times daily. A hot water bottle or heating pad can also increase blood flow and ease discomfort.
You can also try gentle self-massage, pressing lightly into the tight area, as long as it does not exacerbate the discomfort. Additionally, drink plenty of fluids and electrolytes.
If you have a fever or pain elsewhere in your body, you should seek immediate medical attention because these are signs of a potential illness or infection.
If the side stitch persists for over a week, consult your doctor or physical therapist for further evaluation and medical care.
Remember, if you frequently experience side stitches while running, even after adjusting your diet, consider working on your breathing pattern, doing a gentle warm-up, easing into the run, or strengthening your core.
If your abdominal pain isn’t a stitch, perhaps you have a medical condition or issue. Check out the following article for more information:
Great article
Also remember there are other conditions that cause a very similar pain, gallstones, pancreatitis. So just remember to make sure its actully flaring up a problem you may not have realised you have got.