Whether the mechanism is respiratory heat loss1 or increased osmolarity due to respiratory water loss,2exercise is a potent stimulus for provoking asthma symptoms in children. For this reason children with asthma may avoid exercise which may in turn be detrimental to their physical and social conditioning. On this background the efficacy of exercise training in children with asthma has generated continued interest over the years. The use of exercise training programmes in the clinical management of children with asthma is at best controversial. While a number of studies have reported an improvement in lung function, aerobic capacity/conditioning, psychosocial behaviour, and a reduced incidence and severity of exercise induced bronchoconstriction,3-11the findings in these studies have been variable and have not addressed the clinical efficacy of such programmes. The quality of the studies has varied and assessing the efficacy of such programmes depends on which outcomes are assessed and how these outcomes are measured.

It is widely recognised that suitable training regimens increase exercise tolerance and capacity in healthy individuals, with greater improvements usually being seen in the more sedentary subjects.12 This is generally due to a greater capacity for improvement in non-trained individuals. Improvements in exercise capacity are usually accompanied by a number of physiological adaptations including increased oxygen uptake (V˙o ₂), reduced ventilatory requirements, reduced cardiac frequency, and a reduction in lactic acid production at any …