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Race Fueling

Why Do I Get a Stomach Ache After Swimming?

Why you get stomach ache after swimming - and what you can do to feel better, fast.

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Ah yes, the problem of stomach ache after swimming. You’re not alone, my friend, and the first step toward avoiding gas and stomach aches after swimming is to ask for help, so you’re on the right track.

Excessive or repetitive air swallowing (also known as aerophagia) produces unfavorable GI symptoms, like bloating, stomach ache, belching, abdominal distension, and flatulence. When swimming, your body is placed into a horizontal position and swallowing too much air (big gulps), not fully exhaling underwater prior to taking the next breath, and mouth-only breathing (not using the nose).  Rapid/short breathing patterns may trap gas in the stomach, increasing the risk of post-swim stomachaches. 

In addition to aerophagia, gastrointestinal reflux disease, or GERD for short, is another potential culprit for GI-related discomfort with swimming.  As the most common GI-related clinical diagnosis, GERD can cause heartburn, chest pain, burping, nausea, bloating, and abdominal discomfort.  GERD tends to be worse in horizontal positions or when bending (think during turns).  While moderate physical activity can help improve reflux symptoms, excessive exercise may trigger them.  So, be aware when training for that Ironman!

How to reduce gas and stomach ache after swimming:

1. Control your breathing when swimming to avoid taking big gasps of air. Aim for more frequent breathing (e.g., every other stroke), and make sure to forcefully exhale underwater before taking your next breath. Create controlled, rhythmic, and calm breathing patterns before trying to increase your speed or effort in the water.  

2. Avoid gas or reflux-promoting fare before you swim, like greasy foods, caffeine, high- fiber foods (e.g., beans, broccoli, apples, asparagus, cauliflower, cabbage, fructose), which slow bowel motility.  For those who are sensitive, steer clear of lactose-containing foods like cheese, yogurt, and milk.  Individuals with GERD should also avoid acidic or reflux-promoting foods.  In addition to the aforementioned greasy foods and caffeine, these include citrus fruits, spicy foods, chocolate, and mints.  A low FODMAP (Fermentable Oligo- Di- Monosaccharides and Polyols) diet may help decrease symptoms of abdominal pain and bloating in some, as well.

3. Cut out gum chewing and carbonated beverages (e.g., soda, carbonated water, etc.) on the days that you swim.  Carbonated beverages contain carbon dioxide gas.  Chewing gum (or sucking on hard candies) leads to excess air swallowing, and gum often contains sugar alcohols, which leads to the next item on the list.

4. Avoid artificial sweeteners, such as sorbitol, xylitol, and mannitol.  Because they are not digested in the small intestine, these can increase the risk of gas and bloating.

5. Eat slowly before you swim, as fast eating may cause air to enter the stomach.

6. Keep a food diary of commonly consumed foods 4-12 hours prior that trigger excessive gas before swim workouts so that you can avoid them in future workouts/races.  This may also help identify underlying intolerances.  Start by eliminating one food at a time in order to identify triggers, while avoiding nutritional deficiencies.  

7. Avoid drinking from a straw, which includes using a straw-based hydration system when cycling. Each sip from the straw draws air into your mouth (from the upper part of the straw), which is then swallowed and increases the risk for gas/bloating.

8. Avoid large meals before swimming. Smaller meals clear the digestive system more quickly and don’t trigger as much stomach acid release, decreasing bloating and reflux symptoms.   Exercise soon after eating may increase the extent of acid reflux.  If you need a boost, try eating a small snack of around 100-200 calories in the 30- 60 minutes before swimming. Start paying attention to how much time your body needs to digest food before shifting into a horizontal position.

9. Wear loose-fitting clothes after swimming. Tight clothing around the waist and abdomen can increase stomach pressure, mechanically leading to increased gas pain or reflux.  There’s no getting around tight swimsuits, but, if you can, slip into something more comfortable once back on dry land. 

If you still experience pain, bloating, gas, or stomach aches after swimming, consult a medical professional for further evaluation.  Bloating and stomach pain are common symptoms of functional gastrointestinal disorders such as irritable bowel syndrome, and can potentially be symptoms of more serious diseases.  Chances are high that bloating and stomach pain with swimming is harmless and can be contained with these tweaks.  But, medications can assist with the management any underlying disorders (including GERD) when indicated, and registered sports dietitians are invaluable in identifying nutritional triggers and timing.  So, be sure to reach out if symptoms are frequent, seemingly mysterious, or recalcitrant to simple fixes! 

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