ALTERATIONS IN PULMONARY-FUNCTION CONSEQUENT TO COMPETITIVE MARATHON RUNNING

  • 1 January 1979
    • journal article
    • research article
    • Vol. 11  (3) , 244-249
Abstract
To investigate the mechanisms underlying the significant reductions in vital capacity after marathon racing, spirometric, maximum expiratory flow-volume (MEFV), DLCO [CO diffusing capacity] and residual volume (RV) measurements were made on 13 runners (11 males and 2 females) 1-2 wk prior to the marathon, immediately after finishing the race and the next day. An average 0.48 l (8.6%) reduction in post-race forced vital capacity (FVC) was accompanied by an equivalent increase in RV. Total lung capacity did not change, and the reduction in FVC was a result of an expiratory rather than an inspiratory limitation. Post-race FEV1 [forced expiratory volume in 1 s] and FEF200-1200 [forced expiratory fraction 200-1200 s] remained unchanged while FEV1-2, FEF1 and FEF2 were reduced 19.7, 26.7 and 23.3%, respectively. Mean DLCO was unchanged. Pulmonary function on the following day was similar to that on the control day. Apparently after the race expiratory flow was unaffected at high lung volumes, but was decreased at low lung volumes (within the effort-independent portion of the MEFV curve). Apparently small airway closure occurs at an increased lung volume, which would result in a decreased FVC and an increased RV.