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Perhaps the demon to rival swimmer’s shoulder around the pool deck is asthma. Asthma can present an onslaught of debilitating symptoms, but is often used as a catchall diagnosis (much like swimmer’s shoulder) to describe a vast range of conditions. Rhinitis and various allergies carry similar symptoms, but our main focus in this post will be on asthma itself. Although greats such as Mark Spitz, Tom Dolan, Kurt Grote and Amy Van Dyken (among others) have successfully battled asthma to thrive on the Olympic stage, asthma has gotten the best of many swimmers and driven them out of the sport prematurely.

A link between asthma and competitive swimming is consistent in literature, but hardly unanimous. However, there is no consensus on the threshold at which chlorine exposure via recreational swimming can trigger an increased risk of asthmatic symptoms. Ferrari (2011) found that recreational swimmers at indoor chlorinated pools had a higher rate of developing symptoms than a non-swimmer control group, but asthmatic non-swimmers exhibited a higher frequency of symptoms as compared to asthmatic non-swimmers. However, Font-Ribera (2011) had a massive sample of 5,738 kids with longitudinal information from age six months through age 10 and found no increase in risk of asthmatic symptoms based on recreational swimming pool attendance. Data instead found an increase in lung function and a reduction of asthmatic symptoms.

Here’s a glance at some of the research linking competitive swimming to asthma:

  • Bougault (2012) found that long-term, intense swim training in indoor chlorinated pools resulted in airway changes similar to non-swimmers with mild asthma, but with higher mucin expression. Increases in mucin expression were independent of airway hyperresponsiveness. Although changes occurred as a result of long term training, the study did not reach the issue of their permanence.
  • In a sample of elite swimmers, Moreira (2011) found similar levels of vascular permeability (a form of airway damage) in the swimmers compared to non-swimmers, but vascular permeability was not dependent on airway hyperresponsiveness or inflammation.
  • Stadelman (2011) found high levels of bronchial responsiveness in elite swimmers. 83% presented with respiratory symptoms and 65% had positive provocation test.
  • Helenius (2002) conducted a five year prospective study on a group of highly trained swimmers. Of the swimmers who still swimming at both the beginning and end of study, there was a 31% asthma rate during the pretest and 44% rate five years later. Asthma reversed in swimmers who retired during the study period and returned for post-testing.

As noted previously, the data linking competitive aquatics to asthma is hardly unanimous. Sidiropoulou (2009) found that water polo players had LOWER rates of exercise induced asthma than football (aka, soccer) and basketball players of similar age. More recently, NM (2012) found no evidence of increased eiosinophilic airway inflammation in aquatic athletes compared to non-aquatic athletes.

Despite the evidence linking asthma to competitive swimming, many of us know swimmers who have all the symptoms but somehow pass the battery of tests administered in the medical clinic, especially when swimmers (or any aerobic athletes for that matter) are graded against general population norms. Being told “there’s nothing wrong you” when symptoms persist can be equally as vexing as a positive test for asthma. In a sample of Brazilian male competitive swimmers age 6-14, 32.7% showed spirometric alterations. However, in the same sample, 31.2% of those with symptoms received no treatment (Fiks 2009). These athletes often enter a frustrating cycle in which treatments, medications, and other interventions don’t work, leaving them frustrated and possibly quitting.

What can you do with Asthma?

Now, I’m a coach…not a medical doctor. Asthma is a serious medical condition that is sometimes treated by powerful steroidal medications. Always tread with caution in this area. That said, because there are definite links between asthma and several topics squarely in the coaching scope-of-practice (posture, breathing patterns, psychology, environment), coaches can do several things to become part of a solution, especially when a solution appears elusive. There’s no definite evidence of causation, but there are tangible signs of correlation that we would be remiss to ignore. Fortunately, these areas all involve aspects of health and performance that we should address as coaches anyway. It’s a true chicken-or-the-egg scenario…is the classic swimmer’s posture an antecedent to the pulmonary symptoms, or is it a byproduct of the pulmonary symptoms? Does mental stress predispose one to asthmatic symptoms or does asthma cause psychological distress?

The literature has found definite links between the musculoskeletal and pulmonary/respiratory. To the extent the musculoskeletal is affected by other systems, we may identify additional linkages as well. Lunardi (2011) found that patients with asthma (both mild and severe cases) had a more forward head position, rounded shoulders, lower chest wall expansion (i.e. uncentered ribcage), decreased shoulder internal rotation, and decreased thoracic spine flexibility compared to non-asthmatic patients. Further, lower thoracic, cervical, and shoulder pain was significantly higher in asthmatics than non-asthmatics. Chaves (2010) found altered cervicocranial position and hyoid (translation: altered head and neck position) in young patients with asthma.

All of the above characteristics and symptoms are hallmarks of common imbalances in swimmers, but also of faulty breathing patterns, which we have covered thoroughly here in recent months. We may hypothesize that the more functional your breathing patterns are, the more of a buffer you might have against respiratory stress. Psychology is also related to both breathing patterns and asthma: Ritz (2011) found that after a period of induced psychosocial stress, asthma sufferers exhibited expiratory lengthening and greater tidal volume variability compared to non-asthmatics.

Environment is another variable to be considered, but there is scant evidence that alternatives to chlorine such as saltwater or bromine would be an improvement. The issue simply has not been studied with the same depth as with chlorine. Since coaches have to fight for lane space in many places, getting pools to redo their entire filtration system to accommodate more intense training is a stretch, though subjectively I think we’d all take the outdoor aquatic paradise of Palo Alto or Irvine compared to a six lane, five foot deep chlorine bathtub enclosed by a protective bubble half the year.

Summary onAsthma and Swimming

Consider all factors to improve respiration proactively in healthy swimmers and to aid those struggling with asthmatic symptoms. Although breathing it is not a common part of the athletic screening process, the links between asthma with posture, breathing, and psychology are reasons that breathing patterns should be addressed in all athletes, if for no other reason than to rule out possible contributing factors. Coaches can’t treat asthma, but we can address related areas that can improve both health and performance. In terms of environment, evidence on the role of chlorine is mixed, but suggests it can exacerbate symptoms at the competitive level. Research on the effects of salt water and bromine pools remains scant and would be helpful to gain more answers on how to improve respiratory and pulmonary health in swimmers.


  1. Bougault V, Loubaki L, Joubert P, Turmel J, Couture C, Laviolette M, Chakir J, Boulet LP. J Allergy Clin Immunol. Airway remodeling and inflammation in competitive swimmers training in indoor chlorinated swimming pools. 2012 Feb;129(2):351-358.e1. Epub 2011 Dec 22.
  2. Ferrari M, Schenk K, Mantovani W, Papadopoulou C, Posenato C, Ferrari P, Poli A, Tardivo S. Attendance at chlorinated indoor pools and risk of asthma in adult recreational swimmers. J Sci Med Sport. 2011 May;14(3):184-9. Epub 2011 Jan 22.
  3. Font-Ribera L, Villanueva CM, Nieuwenhuijsen MJ, Zock JP, Kogevinas M, Henderson. Swimming pool attendance, asthma, allergies, and lung function in the Avon Longitudinal Study of Parents and Children cohort. J.Am J Respir Crit Care Med. 2011 Mar 1;183(5):582-8. Epub 2010 Oct 1.
  4. Stadelmann K, Stensrud T, Carlsen KH. Respiratory symptoms and bronchial responsiveness in competitive swimmers. Med Sci Sports Exerc. 2011 Mar;43(3):375-81.
  5. Moreira A, Palmares C, Lopes C, Delgado L. Airway vascular damage in elite swimmers. Respir Med. 2011 Nov;105(11):1761-5. Epub 2011 Jun 12.
  6. Helenius I, Rytilä P, Sarna S, Lumme A, Helenius M, Remes V, et al. Effect of continuing or finishing high-level sports on airway inflammation, bronchial hyperresponsiveness, and asthma: a 5-year prospective follow-up study of 42 highly trained swimmers. J Allergy Clin Immunol. 2002;109:962-8.
  7. Päivinen MK, Keskinen KL, Tikkanen HO. Swimming and asthma: factors underlying respiratory symptoms in competitive swimmers. Clin Respir J. 2010 Apr;4(2):97-103.
  8. Lunardi AC, Marques da Silva CC, Rodrigues Mendes FA, Marques AP, Stelmach R, Fernandes Carvalho CR Musculoskeletal dysfunction and pain in adults with asthma. J Asthma. 2011 Feb;48(1):105-10. Epub 2010 Dec 29.
  9. Chaves TC, de Andrade e Silva TS, Monteiro SA, Watanabe PC, Oliveira AS, Grossi DB. Craniocervical posture and hyoid bone position in children with mild and moderate asthma and mouth breathing. Int J Pediatr Otorhinolaryngol. 2010 Sep;74(9):1021-7. Epub 2010 Jun 20.
  10. Ritz T, Simon E, Trueba AF. Stress-induced respiratory pattern changes in asthma.Psychosom Med. 2011 Jul-Aug;73(6):514-21. Epub 2011 Jun 28.
  11. Fiks IN, Santos LC, Antunes T, Gonçalves RC, Carvalho CR, Carvalho CR . Incidence of asthma symptoms and decreased pulmonary function in young amateur swimmers. J Bras Pneumol. 2009 Mar;35(3):206-12.
  12. Sidiropoulou MP, Kokaridas DG, Giagazoglou PF, Karadonas MI, Fotiadou EG. Incidence of Exercise Induced Asthma in Adolescent Athletes Under Different Training and Environmental Conditions. J Strength Cond Res. 2011 Sep 9. [Epub ahead of print]

By Allan Phillips. Allan and his wife Katherine are heavily involved in the strength and conditioning community, for more information refer to Pike Athletics.

Dr. John Mullen, DPT, CSCS world-renowned physical therapist and strength coach.
  1. February 7, 2012

    Further Reading about the connection between asthmas, chlorine, and swimming pools

    Potential alternative means for sanitation

  2. February 7, 2012

    Has there been anything connected with pool air temp? The HS pool my team trains at keeps the air pretty warm (although if you ask my low body fat athletes, the air is always cold) and on its warmest (and what feels heavier) days we have pretty intense coughing issues (change in season times/temps in particular).

    We hosted a meet there this past November where the facility staff turned off the heat (for the air) and with 250+ swimmers and another 50 people on deck for 4 hours it was easier than any night where we had 75-100 kids spread out over the same period of time.

  3. February 8, 2012

    @coacherik…As far as I know, the formal evidence linking warm pool air (or any ambient air for that matter) to asthma is tenuous. There is plenty of anecdotal evidence, and many experts reason that the increased oxygen demands at temperature extremes may trigger attacks, but they haven’t yet found the exact mechanism. Part of what makes it tough from a research perspective is parsing out the number of interrelated factors. For example, hot air is a better incubating environment for many pollutants…if an attack occurs, is it via the pollutants or is it via the hot air? I’d say that hot air is definitely recognized as a risk factor by the medical community, but whether there is a direct causal relationship is unclear in the research.

  4. February 12, 2012

    Looking at some of the detailed articles on breathing muscles that you all have posted here, I wonder if all the investigation into chlorine is missing the boat. Swimming, different from any terrestrial sport, and indeed, different from even water polo, places restrictions on the rate of respiration. Those restrictions can be mitigated by stroke rate, but even then, we have a fairly narrow band of stroke rates that are associated with effective swimming.

    Also, one could hypothesize that the role of the abdominal muscles in maintaining effective body position in the water affects, perhaps restricts proper breathing.

    I would be interested in your thoughts.


  5. February 12, 2012

    @ Robert, great thought. Restricted respiratory rhythm in combination could potentially be a contributor.

    Also, the partial pressure of the different lobes of the lungs is different in swimming due to the horizontal position, making another different stress of the respiratory system.

    These stresses in combination of chlorine levels could accelerate or contribute to respiratory problems in swimmers.

    Good thoughts!

    • February 13, 2012

      Gents – thanks to both of you for your consideration — and it surely is difficult to think of the types of experimental design and/or analytical equipment required to do this. I would imagine something along the lines of determining causes of something like carpal tunnel might be similar.

      Anyhow, thanks again for considering my question and thanks for the informative articles.


  6. February 13, 2012

    @Robert…good observations. Dr. John hit some key points in response. I think all the non-chemical factors that you referenced can certainly play a role in respiratory problems and deserve further study, especially because there has been so little to date. Swimming does require a unique combination of respiration and stabilization, where sacrificing respiration can become a stabilization strategy. I’d simply add that the world of formal research values that which can be neatly quantified, and something like chlorine level is more conducive to measurement than factors like breathing mechanics or balance in the water.

  7. November 21, 2012

    Another great post. About a year after I had started swimming in high school I started to cough and wheez more during workouts, I figured it was my annual cough but it lasted much longer. Eventually I went to my doctor and he diagnosed me with exercise induced asthma (i had never been diagnosed with it before nor had i had the symptoms) After I got medication for it my preformance improved significantly, so my theory is swimming has something to do with it for some people.

  8. April 4, 2015

    I´m not sure about posting this comment because I suggest a specific antihistamine drug (CLORFENIRAMINE) that worked really good in me; it was so good to me that after some days after two weeks of using I suspended and was unnecesary anymore. This is my story: My symptoms step by step after leaving the pool were: coughing, continuous coughing, sputum, shortness of breath, sputum containing some blood, difficult breathing and drowning sense. Aftermths last swimming practice I felt scary. I turned to a physician; he asked me to attend the swimming practice as usual and later practiced in me a pulmonary endoscopy. He saw inside bleeding and suggested me to end up swimming practices. It was a bad new, it was like taking away a big part (the fun one) of me because I love swimming. About a year after during a meeting with an aged retired physician friend of mine I talked about it and he suggested me that drug (Clorfeniramine). I took after any swimming practice one tablet just after leaving the pool (before shower and dressing up) and and the after effects disappeared and after a bit more than two weeks it was unnecesary anymore. I hope this might be helpful to someone. Thanks.

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