Impact of Mask Wearing on Post-Exercise Hemodynamics

As the guidelines regarding COVID-19 regressed, many fitness centers established regulations requiring mask-wearing during exercise. Data suggest that the impact of a mask during exercise has minimal effects on exercise hemodynamics. The post-exercise period has been described as a window of opportunity to lower blood pressure, a phenomenon called post-exercise hypotension. The impact of wearing a mask on post-exercise hemodynamics is unknown. PURPOSE: The purpose of this study was to examine the impact of mask-wearing during exercise on post-exercise hemodynamics. METHODS: Nine total participants aged 18-30 yr were recruited for this experimental cross-over study. This within-subject design involved six randomized conditions; control no mask, no exercise (CON-NE), control-surgical mask, no exercise (CON-SUR), control-exercise, no mask (CON-E), exercise surgical mask (EXS-SUR), exercise N95 mask (EXS-N95), and exercise cloth mask (EXS-CL). The exercise protocol was a HIIT 4 x 4 on a cycle ergometer. Participants exercised at 85% of VO2max for four minutes, followed by a three-minute rest period, repeated four times. Measurements of cardiac output (Q), stroke volume (SV), heart rate (HR), systemic vascular resistance (SVR), and brachial blood pressure (BP) were measured pre-exercise for 20-min, during exercise, and postexercise for 60-min. RESULTS: Exercising at high intensity with the surgical, cloth, and N95 masks showed no statistically significant differences in HR, systolic BP, diastolic BP, SV, SVR, and RPE during exercise when compared to the CON-E condition (all p \u3e 0.05). Post-exercise data revealed no statistical differences in systolic BP or diastolic BP compared to the CON-E condition (both p \u3e 0.05). HR was significantly lower (roughly 4-5 ± 1.8 bpm p \u3c 0.01) in the CON-E group compared to all exercise mask-wearing groups following exercise. Additionally, SV (p\u3c0.001) and Q (p=0.002) were significantly lower in the EXS-N95 group compared to the other exercise groups. CONCLUSION: This study is consistent with current literature in suggesting that mask-wearing during exercise, even at high intensity, has no effect physiologically during exercise and on post-exercise hemodynamics. The impact of wearing a mask during exercise may alter the mechanisms of post-exercise hypotension