In winter or on a rainy day, an indoor pool can be just the way to get moving and to get your heart pumping. However, common chemicals in pool water that can get more concentrated indoors may make it harder on your lungs.
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“The main concern with indoor pools is the chlorine, which is used as a disinfecting agent,” says pulmonologist Rachel Taliercio, DO. “While it’s important to keep harmful bacteria under control, it can be potentially irritating.”
Swimming in indoor pools can expose you to higher levels of chlorine in the air and increase your risk for lung-related problems, but the benefits of exercise often will outweigh the risks. It’s important to consider the overall health of your lungs and the amount of exposure. If you have any signs of discomfort like coughing, wheezing or feeling like your throat burns, stop and take a break.
Overall, competitive swimmers are at greater risk than recreational swimmers since they spend a lot more time in pools than the average person.
What’s chlorine got to do with it?
Chlorine is the most common disinfectant used in indoor and outdoor swimming pools, and a certain level is required to kill any dangerous bacteria in the water.
In outdoor pools, the chlorine dissipates quickly, but indoor pools keep it more contained. This chlorine concentration can be a problem.
“If an indoor pool isn’t regulated well, swimmers can begin to see symptoms of tracheobronchitis, such as coughing or maybe some wheezing,” she says. “There might be some burning in your throat.”
A bigger issue is chloramine, a mixture of chlorine and ammonia that can cause a strong chlorine smell in pools because it can worsen existing allergies. In pools, it’s mainly found hovering a few inches above the water’s surface where swimmers draw their breaths. Chloramines limit the movement of fresh air over the water’s surface, according to the Centers for Disease Control and Prevention (CDC).
Potential problems associated with indoor pools
Airway hyperresponsiveness, which can be seen in asthma, occurs when the bronchial tubes in the lungs spasm abnormally and can lead to coughing and tightness in the chest.
If you’re a competitive swimmer, it could be easy to confuse these symptoms with the effects of strenuous training. One study reported that after monitoring a group of competitive swimmers, exposure to chlorine from an indoor pool caused changes in their airway mucosa. The study focused on whether or not the airway mucosa metabolism can assess risk of any diseases like sports results or acute and chronic diseases. If you train in an indoor pool and experience these symptoms regularly, consult your doctor.
Research also suggests that taking infants and toddlers, whose lungs aren’t mature yet, to indoor pools could potentially lead to a higher incidence of allergies and/or asthma.
“The answer isn’t clear cut,” says Dr. Talierico. “We also have evidence that indoor pools don’t cause any problems with young children. I wouldn’t advise parents who hear about these higher chances of developing asthma to stop putting their kids in recreational swimming programs. There’s too much overall health benefit kids get from swimming.”
How to get relief
If you find you aren’t comfortably breathing while swimming indoors, get out of the pool and leave the pool area. In many cases, simply getting out of the pool will offer relief.
If an overwhelming smell of chlorine around an indoor pool is causing symptoms or discomfort, consider finding another pool. You may also want to consider a saltwater pool or one with another type of disinfectant, such as bromine.
“Most importantly, when you’re in an indoor pool, make sure the area is well-ventilated,” says Dr. Talierico. “I also recommend that you shower afterward to get the pool water off your body.”