ABSTRACT
BACKGROUND: During the COVID-19 pandemic, studies of the physiological effects of masking during exercise have been rare. METHODS: Twelve healthcare workers performed a cardiopulmonary exercise test while wearing a surgical mask, an N95 mask, or no mask. Variables were collected at rest, warm-up, anaerobic threshold, and maximal exercise. RESULTS: From rest to maximal exercise, both the surgical and N95 masks decreased inspiratory flow, minute ventilation, and prolonged inspiratory time compared to the no mask condition. Oxygen uptake (VO2) and oxygen pulse (VO2/HR) decreased at rest, warm-up, and maximal exercise in both the surgical and N95 mask conditions (vs. no mask). At the anaerobic threshold, the surgical mask also led to a reduction of oxygen uptake and oxygen pulse compared to no mask. The maximal oxygen uptake (VO2% predicted) also decreased in both the surgical and N95 mask conditions. In addition, the severity of dyspnea increased, and exercise time decreased for both surgical and N95 masks. Compared to no mask, wearing an N95 mask led to lower breathing frequency and lower ventilation efficacy (assessed by VE/VCO2 and VE/VO2) from rest to maximal exercise (all p < 0.05 for trend). Wearing an N95 also led to retention of carbon dioxide (p < 0.05 for trend). CONCLUSIONS: Wearing a surgical mask leads to a somewhat negative impact on cardiopulmonary function, and this effect is more serious with an N95 mask. Attention should be paid to exercise while wearing surgical or N95 masks.