Pulmonary function and respiratory response during exercise in children

Abstract

This short review discusses the development of respiratory function and pulmonary ventilation during exercise in children. Children have a lower lung capacity than adults because of their smaller chest and relatively narrow airways. Respiratory muscle strength (RMS), which is evaluated by maximal expiratory (PEmax) and maximal inspiratory (PImax) mouth pressure, is also lower in children than adults. RMS tends to be higher among children who exercise, in particular, in those who swim. Minute pulmonary ventilation during exercise is lower in children, whereas respiratory frequency and tidal volume to vital capacity are higher, suggesting that exercising children have lower ventilatory efficiency and higher ventilatory effort than adults. Thus, expiratory flow limitation (expFL) caused by mechanical constraints, observed in adult females with small chest walls and in endurance athletes with high ventilatory demands, is also observed in most children. Although expFL limits hyperventilation and leads to exercise-induced arterial hypoxemia (EIAH) in adults, only a third of children show EIAH. Physically trained children with high maximal oxygen uptake tend to have a greater expFL, which could be one of the mechanisms responsible for EIAH.

Keywords

• children
• respiratory muscle
• ventilation
• exercise