Is water-based exercise an effective and safe type of exercise for adults with asthma?

Asthma is a common condition in which inflammation and narrowing of the air conducting tubes may cause intermittent symptoms, possibly limiting activities of daily life. Some adults believe that exercise could trigger an asthma attack. However, research has shown the opposite—that adults who exercise may have less chance of having an asthma attack, and taking exercise in water may be more beneficial than taking exercise on land. In this review, we aimed to evaluate the effect and safety of water-based exercise for adults with asthma.

We found a total of three studies involving 136 participants with an average age between 33 and 36 years with well-controlled asthma. They underwent water-based exercise from 40 to 60 minutes three to five times a week; the programme lasted 10 to 24 weeks in two studies, and one day only in one study.

We considered data reported on quality of life, asthma general symptoms or asthma exacerbations, measure of lung function (FEV1, forced expiratory volume of the lung in the first second of air expired) and adverse events. The quality of evidence is very low because of issues with selection of participants, small number of participants, differences in exercise duration and intensity and differences in levels of asthma. Often surrogate endpoints were measured instead of patient-important outcomes.

To sum up, more studies are needed to find out the effect and safety of water-based exercise for adults with asthma. The quality of evidence is very low because of issues with selection of participants, differences in exercise duration and intensity and differences in levels of asthma; surrogate endpoints were measured instead of patient-important outcomes.

This plain language summary is current as of 13 May 2014.

Authors' conclusions: 

The small number of participants in the three included studies, the clinical and methodological heterogeneity observed and the high risk of bias assessed mean that we are unable to assess the place of water-based exercise in asthma. Randomised controlled trials are needed to assess the efficacy and safety of water-based exercise for adults with asthma. For future research, we suggest greater methodological rigour (participant selection, blinding of outcome assessors, reporting of all outcomes analysed and registering of the study protocol).

Read the full abstract...
Background: 

Asthma is a common condition characterised by airway inflammation and airway narrowing, which can result in intermittent symptoms of wheezing, coughing and chest tightness, possibly limiting activities of daily life. Water-based exercise is believed to offer benefits for people with asthma through pollen-free air, humidity and effects of exercise on physical function.

Objectives: 

To evaluate the effectiveness and safety of water-based exercise for adults with asthma.

Search strategy: 

We searched the Cochrane Airways Group Specialised Register of Trials (CAGR), the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Allied and Complementary Medicine Database (AMED), PsycINFO, the Latin American and Caribbean Health Science Information Database (LILACS), the Physiotherapy Evidence Database (PEDro), the System for Information on Grey Literature in Europe (SIGLE) and Google Scholar on 13 May 2014. We handsearched ongoing clinical trial registers and meeting abstracts of the American Thoracic Society (ATS), the European Respiratory Society (ERS) and the British Thoracic Society (BTS).

Selection criteria: 

We included all randomised controlled trials (RCTs) of adults with asthma comparing a water-based exercise group versus one or more of the following groups: usual care, land-based exercise, non-exercise.

Data collection and analysis: 

Two review authors (AJG, VS) independently extracted data from the primary studies using a standard form developed for this purpose, which includes methods, participants, interventions and outcomes. We contacted trial authors to request additional data. Data were input by one review author and were double-checked by a second review author.

Main results: 

In this systematic review, we provide a narrative synthesis of available evidence from three small studies including 136 adult participants. The studies were at high risk of bias. No meta-analysis was possible because of methodological and interventional heterogeneity between included studies. The primary outcomes of quality of life and exacerbations leading to use of steroids were not reported by these studies. For exacerbations leading to health centre/hospital visits, uncertainty was wide because a very small number of events was reported (in a single study). Secondary outcomes symptoms, lung function, changes in medication and adverse effects, where available, described for each included study. The overall quality of the studies was very low, and no clear differences were noted between water-based exercise and comparator treatments. Therefore, we remain very uncertain about the effects of water-based exercise for adults with asthma.