Impact of wearing a surgical and cloth mask during cycle exercise.

We sought to determine the impact of wearing cloth or surgical masks on the cardiopulmonary responses to moderate-intensity exercise. Twelve subjects ( = 5 females) completed three, 8-min cycling trials while breathing through a non-rebreathing valve (laboratory control), cloth, or surgical mask. Heart rate (HR), oxyhemoglobin saturation (SpO), breathing frequency, mouth pressure, partial pressure of end-tidal carbon dioxide (PCO) and oxygen (PO), dyspnea were measured throughout exercise. A subset of  = 6 subjects completed an additional exercise bout without a mask (ecological control). There were no differences in breathing frequency, HR or SpO across conditions (all  > 0.05). Compared with the laboratory control (4.7 ± 0.9 cmHO [mean ± SD]), mouth pressure swings were smaller with the surgical mask (0.9 ± 0.7;  < 0.0001), but similar with the cloth mask (3.6 ± 4.8 cmHO;  = 0.66). Wearing a cloth mask decreased PO (-3.5 ± 3.7 mm Hg) and increased PCO (+2.0 ± 1.3 mm Hg) relative to the ecological control (both  < 0.05). There were no differences in end-tidal gases between mask conditions and laboratory control (both  > 0.05). Dyspnea was similar between the control conditions and the surgical mask ( > 0.05) but was greater with the cloth mask compared with laboratory (+0.9 ± 1.2) and ecological (+1.5 ± 1.3) control conditions (both  < 0.05). Wearing a mask during short-term moderate-intensity exercise may increase dyspnea but has minimal impact on the cardiopulmonary response. Wearing surgical or cloth masks during exercise has no impact on breathing frequency, tidal volume, oxygenation, and heart rate However, there are some changes in inspired and expired gas fractions that are physiologically irrelevant. In young healthy individuals, wearing surgical or cloth masks during submaximal exercise has few physiological consequences.