A large amount of parents of children with exercise-related asthmatic complaints have doubts about the beneficial effects of exercise in asthmatic children. Approximately forty to ninety percent of children with asthma suffer from exercise-related shortness of breath.
Despite asthma medication which can prevent exercise-induced bronchoconstriction (EIB), exercise-related symptoms often lead to avoidance of exercise. Conversely, exercise can improve physical fitness and it is often thought that exercise is beneficial for your lung function. A significant need exists for a complete overview of the effects of exercise training in this patient group.
Published online in the BJSM, a recent systematic review detected 29 studies which investigated the effects of exercise programs in children with asthma compared to asthmatic children who did not receive exercise programs. Despite the moderate quality of the studies, several conclusions can be made regarding important asthma outcomes.
Although it is common among asthma patients to think that exercise can improve their ‘lung function’, researchers hardly found any evidence for improvement in lung function parameters by training. On the other hand, EIB could slightly be improved by training. These exercise-related symptoms are thought to be caused by the increased volume of inhaled dry and cold air during training, which can cause airway bronchoconstriction and obstruction via several pathways.
Researchers measured the degree of EIB as the decrease in lung function after a submaximal exercise test such as cycling on an ergometer. The decrease in lung function after an exercise test was slightly smaller in children which completed an exercise training program, which implies that regular exercise training could be beneficial for exercise-related asthma symptoms.
A limited amount of studies also measured asthma-related outcome measures such as quality of life, school absenteeism, and symptom scores. Although evidence is scarce, most of the asthma-related outcomes were improved after training. In addition, asthmatic children were able to improve their cardiorespiratory fitness to the same extent as non-asthmatic children.
Most improvements of cardiorespiratory fitness were seen in studies with an exercise program with a minimum duration of three months, with at least two 60-minute training sessions per week, and a training intensity set at the personalised ventilatory threshold (which correspondents to approximately 80 percent of maximum heart rate).
It can be concluded that, if asthmatic children consequently use their prescribed medication, exercise training has overall beneficial effects in asthmatic children. Physical exercise can be considered safe and therefore should be recommended in children with asthma.
For more information on how to manage asthma and other respiratory problems turn to chapter 50, Respiratory symptoms during exercise, in Clinical Sports Medicine.
Maartje Willeboordse is a PhD student at the Paediatric Pulmonology Department of the Academic Hospital in Maastricht. She studied the biology of human performance and her research focuses on the relationship between paediatric asthma and obesity and the role of lifestyle factors such as weight reduction and exercise.