Body plethysmography and CPET (Modules 1–2)
CM
The increased breathing resistance due to the different filter materials of the face masks was confirmed by the testing on the Sheffield head according to EN 149. Body plethysmographic examinations showed increases in total airway resistance (Rtot), specific airway resistance, work of breathing and respiratory power, and slight decreases in FVC and FEVEngeroff and co-authorsPrevious studies investigated the potential effects of masks using different exercise protocols and outcomesDuring increased physical exercise, the human organism reacts with physiological adaptation (e.g., increased minute ventilation, heart rate), which can be measured precisely using CPET. In our study, the increase in minute ventilation was smaller wearing a mask compared to NM at each load level. This can be explained by the increased breathing resistance and an alteration in the breathing pattern due to the specific type of maskThe CPET examination findings regarding the improved breathing efficiency can be verified with the help of ergometric and workplace studies (modules 3 and 4) where the mask was worn under everyday use conditions. In these examinations a longer respiratory cycle time depending on the mask type (SM < CM < FFP2) was shown.In addition, our data reveal further results concerning the effects of wearing a mask on breathing efficiency. Firstly, subjects with greater FVC and FEVSecondarily, based on the positive association between FVC, FEV