Why Does My Stomach Hurt After Swimming?

Water Contamination Can Cause Digestive Distress

One possible reason for stomach pain and other gastrointestinal (GI) symptoms is recreational water illness, which is caused by exposure to microbes or chemicals found in the water where people swim, notes the Centers for Disease Control and Prevention (CDC). Illnesses contracted this way can affect the GI and respiratory systems, skin, ears, and eyes. Diarrheal illness is the most common result of infections contracted from recreational waters. You can become ill from swallowing contaminated water, from breathing in its mist, or from skin contact.

The chemicals used to treat swimming pool water, such as chlorine, can also make you sick via skin contact or ingestion of treated water, or inhalation of fumes. Chlorine poisoning can produce symptoms that include severe stomach pain and vomiting, among an array of symptoms in other parts of the body, according to MedlinePlus. Chlorine poisoning requires immediate medical attention. Call 911, or Poison Control at 800-222-1222. There is also an automated service called WebPoisonControl, available nationwide via its website or a smartphone app.

Recreational water illnesses are best prevented by avoiding contact with contaminated water. Practicing good personal hygiene will also help protect you while preventing the spread of illnesses to others. Don’t go swimming while you have GI-related illness — some microbes can live in water for up to seven days, even in water that’s been chemically treated to reduce such contaminants.

Swallowing Air Can Lead to Discomfort

Improper breathing techniques can make a swimmer gulp air, notes U.S. Masters Swimming, a nonprofit membership organization for adult swimmers. This phenomenon, called aerophagia, can result in belching, bloating, gas, and abdominal pain after swimming, according to Cleveland Clinic. Swallowing air traps it in the gastrointestinal tract. If large quantities of air are ingested, the symptoms can be quite painful.

Swimmers are prone to aerophagia when they take big gulps of air or exhale too fast or too forcefully, leading them to inhale too much on the next breath. To counteract this problem, practice controlled, regular breathing during your swim:

• Sip air as you inhale, rather than taking in big breaths.
• Exhale in a slow, controlled manner, with your face in the water.
• Practice correct technique and timing for each stroke, so that your mouth is as far as possible from the water on each inhale.
• Use bilateral breathing to breathe from both sides and avoid waves in your face — this is crucial when you’re in a busy pool or in open water.

Overuse Can Cause Abdominal Muscle Strain

Abdominal muscle strain due to an overuse injury is another cause of stomach pain after swimming, according to Strength Lab LDN, a personal training studio with locations in London. Overuse injuries are common in swimming, because it consists of repetitive movements that engage the same muscles over and over.

There’s more of a risk of injury if your inner core muscles (the deep abdominal and back muscles that stabilize the spine) are weak, says the Canadian Academy of Manual and Musculoskeletal Physiotherapists (CAMPT). This might be the case if you’re new to swimming or returning after a lengthy absence.

According to research, symptoms of abdominal strain include:

• Pain and swelling of the muscle
• Reduced muscle movement or stiffness
• Skin bruising or discoloration

If you experience this kind of stomach pain after swimming, you should rest to allow your strained muscles to recover. Apply cold packs soon after the injury to reduce inflammation, and consider using a compression bandage or garment to lessen bruising and aid in muscle recovery. Once the inflammation subsides, a heating pad or other warm compress can be helpful, says the Cleveland Clinic. Heat therapy increases blood flow and relaxes stiff muscles, helping ease pain.

If you have significant pain, bruising, or a visible bulge when you contract the muscle, you may need imaging. An ultrasound, CT, or an MRI can help your doctor determine the extent of the injury and formulate a treatment plan. Physical therapy or surgery may be warranted if the injury is more severe.

If a weak core has contributed to a muscle injury, you can work on strengthening your abs and core once you recover. A strong core will make you less prone to swimming-related injury, the Mayo Clinic says. Your core helps you stabilize your body position in the water while adding power to your movements, according to Evolve Physical Therapy, a practice with locations in Oregon. This contributes to improved technique and a more efficient stroke, in addition to injury prevention.

When to See a Doctor

Mild or infrequent stomach pain after swimming can usually be relieved by changing your habits, or with time, rest, and at-home treatments. However, if your stomach or abdominal pain is severe and persistent, or it’s getting worse instead of better, you need to see a doctor.

If you’re experiencing symptoms you suspect are related to chemical exposure (including chlorine), seek emergency medical attention, advises MedlinePlus.

GI symptoms related to a potential waterborne infection may require medical attention, says Mount Sinai hospital in New York City. These include abdominal pain that doesn’t improve within 48 hours or gets worse; an inability to keep liquids down; diarrhea that lasts for five days or more; and fever. Muscle overuse injuries that are more severe also require a doctor’s visit, according to research.