To minimize transmission of SARS-CoV-2, the novel coronavirus responsible for COVID-19, the Center for Disease Control and World Health Organization recommend wearing facemasks in public. Some have expressed concern that these may affect the cardiopulmonary system by increasing the work of breathing (Wb), altering pulmonary gas exchange and increasing dyspnea, especially during physical activity. These concerns have been derived largely from studies evaluating devices intentionally designed to severely affect respiratory mechanics and gas exchange. We review the literature on the effects of various facemasks and respirators on the respiratory system during physical activity using data from several models: cloth face coverings and surgical masks, N95 respirators, industrial respirators and applied high resistive or high deadspace respiratory loads. Overall, the available data suggest that although dyspnea may be increased and alter perceived effort with activity, the effects on Wb, blood gases and other physiological parameters imposed by facemasks during physical activity are small, often too small to be detected, even during very heavy exercise. There is no current evidence to support sex-based or age-based differences in the physiological responses to exercise while wearing a facemask. While the available data suggest that negative effects of using cloth or surgical facemasks during physical activity in healthy individuals are negligible and unlikely to impact exercise tolerance significantly, for some individuals with severe cardiopulmonary disease, any added resistance and/or minor changes in blood gases may evoke considerably more dyspnea and, thus, affect exercise capacity.
Face Masks and the Cardiorespiratory Response to Physical Activity in Health and Disease