E ffects of exercise and eucapnic hyperventilation on bronchial clearance in man

Environ. Exercise Physiol. 43(l): 46-50, 1977.-The effects of exercise and eucapnic hyperventilation on bronchial clearance were assessed in 10 healthy nonsmoking adults. A ggmTc-albumin aerosol was inhaled as a bolus in late inspiration under controlled conditions to produce deposition primarily in large airways. Lung retention of radioactivity was quantified using a gamma camera and subsequent computer analysis. Compared with quiet breathing (control), exercise signifi-cantly speeded clearance (P < 0.05). Resting eucapnic hyper-ventilation at levels similar to those achieved during exercise produced less speeding. Compared to control conditions these changes may be brought about by a) mechanical effect of increased lung movement, and b) effects on the autonomic nervous system, mediated via the parasympathetic pathway producing stimulation of airway mucus glands and/or sympa