Respiratory function changes in a wilderness multisport endurance competition: a prospective case study.

OBJECTIVE

To document serially and in detail the changes in respiratory function during competition in a typical wilderness multisport endurance athlete.

METHODS

Prospective observational case study over two years during a 105 km wilderness multisport endurance competition consisting of cross country skiing, cross country running, cycling, and whitewater canoeing. Nedocromil prophylaxis was used during the second year of the study only. FEV1, FVC, flow volume loops, and oxygen saturation were measured serially during the race.

RESULTS

Baseline spirometry and histamine bronchial provocation tests were normal. SaO2% decreased to a minimum of 92%. Decreases in both FEV1 (up to 25%) and FVC (up to 22%) were observed at race finish in both years. Although FEV1/FVC ratios only decreased marginally, the pattern of change in maximum expiratory flow rates was most consistent with evolving airflow obstruction. The changes were not prevented by nedocromil. The subject did not develop symptomatic wheezing or abnormal breathlessness and finished the event without incident.

CONCLUSIONS

Ultra endurance multisport competition may induce substantial changes in respiratory function. These appear to be attributable to evolving airflow obstruction.