Dyspnea, or shortness of breath, can be aggravated by endurance sports such as swimming. Dyspnea after swimming often stems from allergic reactions to chlorine exposure in swimming pools or muscle fatigue from strenuous exercise. Occasionally, this condition can be life-threatening and requires medical intervention. If this condition persists for more than an hour or so, seek medical help.
Inspiratory Muscle Fatigue
Exercise-induced inspiratory muscle fatigue, or IMF, is a condition caused by weakness of the diaphragm and chest muscles that fill the lungs with air, which can result in acute respiratory failure. A study in the May 2011 issue of the Journal of Strength and Conditioning Research assessed the effects of swimming distances on the magnitude of IMF. The researchers recruited 10 trained swimmers to complete 100, 200 and 400 m time trials and measured their maximal lung capacity before and after each event. The study found a correlation between the distance swam and the swimmers' total lung capacity, where fatigue was higher after the longer distances. After the longer distances were completed, swimmers experienced an increase in perceived dyspnea.
Chlorine Exposure
Chlorine used as a disinfectant for pool water is a known lung irritant that causes dyspnea, inflammation of the lungs and decreased oxygen levels in the pulmonary tissues. An article published in the April 2006 issue of Pediatric Emergency Care described the case of a 9-year-old girl who went to the hospital with shortness of breath about 12 hours after exposure to chlorine from pool purification tablets. The attending physicians gave the girl oxygen and prescribed the use of a bronchodilator to open her airways. After four months, the patient suffered from mild airway obstruction, but shortly thereafter she made a full recovery.
Bronchiolitis
An article in the March 2004 issue of Respiratory Care documented a case of a 23-year-old previously healthy man who came to the hospital with a cough and sore throat shortly after swimming in a fitness center pool. Almost two days later, he developed dyspnea and a worsening cough. Physicians ordered a chest X-ray and discovered nodular opacities, or clear spots within the lungs, which were consistent with bronchiolitis, an inflammation of the airways. The patient was treated with corticosteroids to alleviate the inflammation of the airways and he fully recovered five months later.
Breathing Techniques
A study in the July 2009 issue of the Journal of Strength and Conditioning Research evaluated the effects of breathing techniques on the prevalence of IMF in 10 competitive collegiate swimmers. The participants were instructed to follow one of two breathing techniques: one breath for every stroke, or one breath for every four strokes. The researchers measured the inspiratory flow rates at rest and immediately after the physical challenges. The study found that lung capacity decreased by 21 percent after the four stroke regime, but only by 11 percent after the one stroke regime. The study concluded that IMF is increased when breathing frequency is decreased.
References
- "Journal of Strength and Conditioning Research"; Influence of Different Breathing Frequencies on the Severity of Inspiratory Muscle Fatigue Induced by High-Intensity Front Crawl Swimming; D. Jakovljevic, et al.; July 2009
- "Respiratory Care"; Acute Inhalation Injury with Evidence of Diffuse Bronchiolitis Following Chlorine Gas Exposure at a Swimming Pool; T. Parimon, et al.; March 2004
- "Pediatric Emergency Care"; Chlorine-Related Inhalation Injury from a Swimming Pool Disinfectant in a 9-Year-Old Girl; R. Vohra, et al.; April 2006
- "Journal of Strength and Conditioning Research"; Exercise-Induced Inspiratory Muscle Fatigue during Swimming: The Effect of Race Distance; S. Brown, et al.; May 2011
