By The Cochrane Library (2012)
People with asthma may show less tolerance to exercise due to worsening asthma symptoms during exercise or other reasons such as deconditioning, as a consequence of inactivity. Some may also restrict activities as per medical advice or family influence and this might result in reduced physical fitness. Physical training programs aim to improve physical fitness, neuromuscular coordination and self confidence. Subjectively, many people with asthma 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. Also, as exercise can induce asthma, the safety of exercise programmes need to be considered