Does lung function limit performance in a 24-hour ultramarathon?

Respir Physiol. 1989 Nov;78(2):253-63. doi: 10.1016/0034-5687(89)90057-1.


Based on observations of impaired lung function after marathon and ultramarathon running, it was hypothesized that the decline in running speed during a 24-h ultramarathon may be explained, in part, by ventilatory muscle fatigue. To test this hypothesis, ten competitors in the 1988 TAC/USA National 24-h Championship performed a battery of pulmonary function tests every 3 h during the race. The tests included measurement of inspiratory capacity, peak flow, forced vital capacity, forced expiratory volume in 1 sec, maximum voluntary ventilation for 12 sec (MVV12), and maximal respiratory pressures. Running speed was averaged over 3-h periods. MVV12 was significantly decreased (17%), but only after 24 h of running. All other ventilatory measures tended to decrease over time but the changes were not significant. However, after correcting for between-subject differences in running speed, the variance in MVV12 accounted for 39% (P less than 0.0001) of the variance in running speed. It was concluded that the decrease in ventilatory muscle endurance may constrain running speed in extremely prolonged running events.

MeSH terms

  • Adult
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pulmonary Ventilation / physiology
  • Respiration / physiology*
  • Respiratory Function Tests
  • Respiratory Muscles / physiology*
  • Running*
  • Time Factors