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Updated: Sep 30, 2026
Conducting Maximal and Submaximal Endurance Exercise Testing to Measure Physiological and Biological Responses to Acute Exercise in Humans
Published on: October 17, 2018
Respiratory function changes in a wilderness multisport endurance competition: a prospective case study
Ian R Rogers1, Dale Speedy, David Hillman
1Department of Emergency Medicine, Sir Charles Gairdner Hospital, Perth, Australia. ian.rogers@health.wa.gov.au
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.
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