What conclusions can be drawn from the study as it pertains to wearing a face mask?
Zemke: As part of our studies, the test subjects underwent exercise stress tests, and we could show that wearing a face mask did not impair their performance and exercise capacity.
Freiwald: Face masks should be replaced more frequently. In some instances, it may also make sense to conduct additional physical performance tests with persons with health impairments due to chronic obstructive pulmonary diseases or smoking, for example. Additionally, research into the type of face mask might be important since higher filtration efficiency means increased breathing resistance.
Zemke: Competitive sports use special respiratory training devices to improve lung strength and increase breathing resistance. This might also be an interesting aspect when it comes to wearing face masks. Thanks to increased breathing resistance, wearing a face mask might also train and improve the function of the respiratory muscles.
The hypothesis is that wearing an FFP2/N95 mask may increase carbon dioxide rebreathing since we re-breathe the air we normally breathe out. Does your research uncover any insights into this aspect?
Zemke: Yes, it does. The ratio of exhaled CO2 and inhaled O2 did not change with wearing a mask, which suggests there is no significant rebreathing taking place. However, our study noted an increase in end-tidal CO2, which was also measured in other studies. The residual air volume in a person’s lungs only increases an insignificant amount when he/she wears a mask. It is minor compared to the tidal volume (the volume of air inhaled in a single, normal breath), which means there is no physiologically relevant carbon dioxide (CO2) rebreathing when you wear a face mask. Other studies that measured CO2 concentration in the blood reached the same conclusion as our study.
How can we make wearing an FFP2/N95 mask more comfortable from a sports scientist’s perspective?
Zemke: Wearing a face mask takes some getting used to. Education alone might already change the mindset of some people and encourage them to tolerate wearing a face mask and not perceive it as a nuisance.
Freiwald: We must also remember that facial masks serve another vital role: it signals to those around us that a virus is circulating and that we should keep our distance to prevent infection. Once mask mandates are lifted, we lack a visual cue that everyone understands.