Changes in lung function during an extreme mountain ultramarathon

This study aimed to assess the effects of an extreme mountain ultramarathon (MUM, 330km, 24000 D+) on lung function. Twenty-nine experienced male ultramarathon runners performed longitudinally [before (pre), during (mid), and immediately after (post) a MUM] a battery of pulmonary function tests. The tests included measurements of forced vital capacity, forced expiratory volume in 1s, peak flow, inspiratory capacity, and maximum voluntary ventilation in 12s (MVV12). A significant reduction in the running speed was observed (-43.0% between pre-mid and mid-post; P<0.001). Expiratory function declined significantly at mid (P<0.05) and at post (P<0.05). A similar trend was observed for inspiratory function (P<0.05). MVV12 declined at mid (P<0.05) and further decreased at post (P<0.05). Furthermore, there are significant negative correlations between performance time and MVV12 pre-race (R=-0.54, P=0.02) as well as changes in MVV12 between pre- and post-race (R=-0.53, P=0.009). It is concluded that during an extreme MUM, a continuous decline in pulmonary function was observed, likely attributable to the high levels of ventilation required during this MUM in a harsh mountainous environment.