Abstract
INTRODUCTION: Due to the mandatory use of a mask, and the authorization to do outdoor sports in Catalonia, we aimed to assess the physiological impact of the hypercapnia hypoxia generated by the masks during aerobic sports practice. METHODS: Eight subjects (2 women, 6 men) were assessed at baseline with and without a mask, and immediately after a 21-flex test performed following the Ruffier protocol with a mask. Measures of HR (heart rate), concentration of O(2) and CO(2) inside the mask and SatO(2) were assessed. The test was carried out in ambient air in squares in the city of Barcelona. RESULTS: A decrease in O(2) was recorded, and when comparing the, baseline 20.9%, baseline mask 18.3%, post-exercise 17.8% (p < 0.001). An increase in CO(2) in the three preconditions (464, 14162, 17 000 ppm; p < 0.001). Basal saturation O(2) was 97.6 ± 1.5% and post exercise 92.1 ± 4.12% (p 0.02). CONCLUSIONS: The use of masks in athletes causes hypoxic and hypercapnic breathing as evidenced by increased effort during exercise. The use of masks during a short exercise with an intensity around 6–8 METS, decreases O(2) by 3.7% and increases the CO(2) concentration by 20%.