Exercise-induced arterial hypoxemia in female masters athletes

The purpose of the study was to characterize exercise induced arterial hypoxemia (EIAH) in female masters athletes (FMA). We hypothesized that FMA would experience EIAH during treadmill running. Eight FMA (48-57 years) completed pulmonary function testing and an incremental exercise test until exhaustion (V̇O₂max⁡ = 45.7 ± 6.5, range:35-54 ml/kg/min). On a separate day, the participants were instrumented with a radial arterial catheter and an esophageal temperature probe. Participants performed three to four constant load exercise tests at 60-70 %, 75 %, 90 %, 95 %, and 100 % of maximal oxygen uptake while sampling arterial blood and recording esophageal temperature. We found that FMA decrease their partial pressure of oxygen (86.0 ± 7.6, range:73-108 mmHg), arterial saturation (96.2 ± 1.2, range:93-98 %), and widen their alveolar to arterial oxygen difference (23.2 ± 8.8, range:5-42 mmHg) during all exercise intensities however, with variability in terms of severity and pattern. Our findings suggest that FMA experience EIAH however aerobic fitness appears unrelated to occurrence or severity (r = 0.13, p = 0.756).