Effect of Masks on Cardiopulmonary Exercise Test and Lower Limb Muscle Performance for Evaluating the Safety of Wearing Surgical Masks During Aerobic Exercise in Normal Subjects: Study Protocol for A Randomized Cross-Over Trial
Abstract Background: Face masks are an important mitigation strategy against respiratory virus contact and community transmission. Sometimes, people must wear surgical mask at rest or during exercise to minimize the risk of cross-infection, but it is unclear whether wearing a surgical mask during exercise can impact cardiopulmonary health. Thus, we designed this study using the cardiopulmonary exercise test (CPET) with simultaneous surface electromyography (EMG) to objectively evaluate the impact of mask-wearing on ventilation, exercise intolerance, and aerobic functional capacity.Methods: Healthy young subjects without professional sports experience will be recruited in this randomized cross-over clinical study. The recruited subjects will be randomly allocated into two groups: Group 1 will first receive an intervention protocol (CPET wearing surgical mask) followed by 2-7days of washout. This will be followed by a control protocol (CPET without wearing surgical mask). Group 2 will receive the opposite sequence of interventions. The surface EMG data will be simultaneously collected. The primary outcome is the maximum oxygen uptake (VO2max) between the two CPETs (with or without a mask). The secondary outcomes are peak oxygen consumption (VO2), volume of carbon dioxide released (VCO2), tidal volume (VT), and EMG parameters including root mean square (RMS), and median frequency (MF). An ANOVA with a two-stage crossover will be used. Three factors will be considered for the experimental effect: the type of intervention (wearing masks or not wearing masks), the experimental periods (period I and period II), and individual differences in subjects. The paired t-test will be used to compare the differences of CPET parameters and surface EMG values between subjects with and without a mask. Discussion: This study offers insight on the use of surgical mask during aerobic exercise by CPET in the normal subjects. The data expand on the use of CPET with surface EMG for insight into the pathophysiological relationship between cardiopulmonary function and muscular motor performance.Trial registration: Chinese Clinical Trial Registry, ID: ChiCTR2000033449. Data of registration: June 1, 2020.