FIGURE 2. Mean exertion level over time. Notes: Interrupted y-axis to improve visualization of data. Fitted linear mixed effect model showed: average exertion level was significantly different among some respirators and over time (p < 0.0001). DB had significantly different exertion level from PAPR at 6 hr (adjusted p = 0.0256) and marginally at 8 hr (adjusted p = 0.0510). N95 had marginally different exertion level from PAPR at 6 hr and 8 hr (adjusted p = 0.0510). N95+V+MM and N95+V did not have significantly different exertion level (adjusted p > 0.5). N95 + MM and N95 did not have significantly different exertion level (adjusted p > 0.5).
