Exercise effects in adults with asthma

Asthma is a common chronic disease, affecting over 339 million people worldwide. People with asthma present with episodes of symptoms such as shortness of breath, wheezing, coughing, and chest tightness, which can be triggered by a variety of factors. However not all asthma is the same. The severity, frequency, duration, and symptoms vary, making asthma a complex heterogeneous disease, with many triggers of symptoms. Exercise is one such trigger that induces asthma symptoms, however, despite this exercise remains important for people with asthma and can usually be performed safely in this population. Indeed, people with asthma are recommended to engage in regular physical activity. Despite this, low levels of physical activity are still being reported in those living with asthma, particularly in those with severe disease. This unnecessary avoidance of physical activity and exercise results in negative health consequences including poorer respiratory functioning, increased disease severity, and healthcare use, decreased physical and mental health, and decreased quality of life. This chapter discusses the available evidence in relation to the benefits of regular exercise training in asthma. Several physiological and psychological benefits are reported including improved asthma control, fewer asthma symptoms and exacerbations, reduced medication and healthcare use including reduced emergency department visits, improved health status, and decreased symptoms of anxiety and depression. Although there is a paucity of evidence regarding the mechanisms responsible for the beneficial effects of exercise training in asthma, a number of mechanisms have been proposed which will also be explored. Finally, based on the currently available evidence clinical practice recommendations for exercise prescribers are provided using the FITT (frequency, intensity, time, and type) principles for exercise prescription, as well important safety considerations that should be taken into account. However, more research is required to determine optimal exercise prescription principles within the asthma population.