Maximal exercise does not increase ventilation heterogeneity in healthy trained adults

The effect of exercise on ventilation heterogeneity has not been investigated. We hypothesized that a maximal exercise bout would increase ventilation heterogeneity. We also hypothesized that increased ventilation heterogeneity would be associated with exercise-induced arterial hypoxemia (EIAH). Healthy trained adult males were prospectively assessed for ventilation heterogeneity using lung clearance index (LCI), S_cond, and S_acin at baseline, postexercise and at recovery, using the multiple breath nitrogen washout technique. The maximal exercise bout consisted of a maximal, incremental cardiopulmonary exercise test at 25 watt increments. Eighteen subjects were recruited with mean ± SD age of 35 ± 9 years. There were no significant changes in LCI, S_cond, or S_acin following exercise or at recovery. While there was an overall reduction in SpO₂ with exercise (99.3 ± 1 to 93.7 ± 3%, P < 0.0001), the reduction in SpO₂ was not associated with changes in LCI, S_cond or S_acin. Ventilation heterogeneity is not increased following a maximal exercise bout in healthy trained adults. Furthermore, EIAH is not associated with changes in ventilation heterogeneity in healthy trained adults.