Background: Physical training programmes have been designed for asthmatic subjects with the aim of improving physical fitness, neuromuscular coordination and self-confidence. Habitual physical activity increases physical fitness and lowers ventilation during mild and moderate exercise thereby reducing the likelihood of provoking exercise induced asthma. Exercise training may also reduce the perception of breathlessness through a number of mechanisms including strengthening respiratory muscles. Subjectively, many asthmatics report that they are symptomatically better when fit, but results from trials have varied and have been difficult to compare because of different designs and training protocols.
Objectives: The purpose of this review was to assess evidence for the efficacy and effectiveness of physical training in asthma.
Search strategy: We searched the Cochrane Airways Group Specialised Register, SportDiscus and the Science Citation Index up to May 2005.
Selection criteria: Randomised trials in asthmatic subjects undertaking physical training. Subjects had to be eight years and older. Physical training had to be undertaken for at least 20 to 30 minutes, two to three times a week, over a minimum of four weeks.
Data collection and analysis: Eligibility for inclusion and quality of trials were assessed independently by two reviewers.
Main results: Thirteen studies (455 participants) were included in this review. Physical training had no effect on resting lung function or the number of days of wheeze. The results of this review have shown that lung function and wheeze is not worsened by physical training in patients with asthma. Physical training improved cardiopulmonary fitness as measured by an increase in maximum oxygen uptake of 5.4 ml/kg/min (95% confidence interval 4.2 to 6.6) and maximum expiratory ventilation 6.0 L/min (95% confidence interval 1.5 to 10.4). There were no data concerning quality of life measurements.
Authors' conclusions: In people with asthma, physical training can improve cardiopulmonary fitness without changing lung function. It is not known whether improved fitness is translated into improved quality of life. It is comforting to know that physical training does not have an adverse effect on lung function and wheeze in patients with asthma. Therefore, there is no reason why patients with asthma should not participate in regular physical activity.