Lung function and oxygen saturation after participation in Norseman Xtreme Triathlon

Objectives To examine evidence of exercise-induced bronchoconstriction (EIB) defined as >= 10% reduction in forced expiratory volume in one second (FEV1) and exercise-induced arterial hypoxemia (EIAH) defined as >= 4% reduction in oxygen saturation (SpO(2)) from before to after participation in the Norseman Xtreme Triathlon. Secondarily, to assess whether changes in FEV1 and SpO(2) are related to respiratory symptoms, training volume, and race time. Methods In this quasi-experimental non-controlled study, we included 63 triathletes (50 male/13 female) aged 40.3 (+/- 9.0) years (mean +/- SD). Fifty-seven (46 male/11 female) measured lung function and 54 (44 male/10 female) measured SpO(2) before the race, 8-10 minutes after the race (post-test 1) and the day after the race (post-test 2). Respiratory symptoms and training volume were recorded with modified AQUA questionnaire. ANOVA for repeated measures was used to detect differences in lung function and SpO(2). Statistical significance was accepted at 0.05 level. Results Twenty-six participants (46%) presented with EIB at post-test 1 and 16 (28%) at post-test 2. Lung function variables were significantly reduced from baseline to post-test 1 and 2. Thirty-five participants (65%) showed evidence of mild to moderate EIAH. No significant correlations were observed except a weak correlation between maximal reduction in FEV1 and respiratory symptoms (r = 0.35, P = .016). Conclusion Our results demonstrated that 46% of the participants presented with EIB and 65% showed evidence of EIAH after the Norseman Xtreme Triathlon. Changes in FEV1 and SpO(2) were not correlated to weekly training hours or race time. We observed a weak correlation between maximal reduction in FEV1 and respiratory symptoms.