Effect Of Exercise-specific Mask On Respiratory Function In Athletes With And Without Exercise Induced Bronchoconstriction

Abstract

PURPOSE: Heavy ventilation is a known factor in exercise induced bronchoconstriction (EIB), leading to airway hyperresponsiveness in endurance athletes over time. How an exercise-specific mask designed for heavy ventilation affects EIB status and overall respiratory function following intense exercise is not well studied. Thus, we aimed to determine the effect of an exercise-specific facemask on airway function post-exercise in athletes with and without EIB at a normal indoor temperature. METHODS: Male (n=13) and female (n=7) athletes underwent two separate graded exercise tests to fatigue on a treadmill at 20 °C (20-40 % RH) while wearing an exercise-specific mask in one test (M) and unmasked (UM) in the other. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow (PEF), forced expiratory flow at 25-75% (FEF25-75), and forced expiratory flow at 50% (FEF50) were measured pre and at 3,6,10,15, 20, & 30 min post-exercise. Participants with a >10% reduction in FEV1 post-exercise (EIB+), those with an FEV1 reduction not meeting the threshold for EIB+ (EIB suspect), and participants without EIB (EIB-) were compared. RESULTS: Overall (n = 20) percentage of baseline post-exercise was improved (p>0.05) in the M condition compared to the UM condition for FEV1 (92.8 vs 92.1), FVC (91.4 vs 90.6), PEF (93.3 vs 87.2), FEF25-75 (93.5 vs 88.3) and FEF50 (93.3 vs 87.7). When EIB+ (n=3) and EIB- (n=12) subjects were compared, the magnitude of the difference in the M condition was smaller than that of the UM condition for all spirometry measures except for PEF. The magnitude of these differences between EIB+ and EIB- in the UM condition was reduced the most in the M condition for FEF50 (26.6% UM vs 11.0% M) and FEF25-75 (30.0% UM vs 20.4% M). The face mask reduced the absolute drop in FEV1 post-exercise in 67% of EIB+ subjects, 40% of EIB suspect subjects, and 42% of EIB- subjects. CONCLUSIONS: Wearing an exercise-specific mask attenuates reductions in respiratory function post-exercise in EIB+ participants. However, EIB suspect and EIB- athletes may also benefit from wearing a mask designed for heavy ventilation exercise. To fully understand the protective benefits of a mask in high ventilation athletes, provocation tests with post-exercise spirometry in both M and UM conditions should be performed.