FFP2, N95, and KN95 masks: Does wearing them affect endurance and athletic performance?

Does wearing a mask diminish athletic performance? Do we fatigue faster while wearing a face mask during exercise? Our subjective perception might suggest that a mask or face covering restricts us. A study by the University of Wuppertal explored the physiological effects of wearing KN95 or FFP2 (European Union standard) face masks.

In this MEDICA.de interview, Professor Jürgen Freiwald and Janis Zemke talk about the actual effects of FFP2/N95 mask wearing.

Mr. Zemke, what prompted this study?

Janis Zemke: While I studied sports science, the practical courses prompted me to delve into the physiological impact of wearing a face mask. Wearing a mask didn’t put any great limits on me, but I noticed many people feel very restricted by it. Hence, I teamed up with Professor Freiwald and developed a study on this research topic.

Professor Jürgen Freiwald: The study intended to provide insights into the effects of wearing masks on respiratory, cardiac, and metabolic parameters and the impact of masks on endurance performance.

How does the study monitor the effects of FFP2/N95 mask wearing?

Zemke: We asked twelve male test subjects to submit to performance tests using a cycle ergometer once with and once without wearing a mask in a randomized sequence at a weekly interval. In each case, we used spiroergometry (cardiopulmonary exercise testing) to collect respiratory, metabolic, and cardiac data.

In hindsight, where you surprised by some aspects?

Freiwald: Some findings did indeed surprise us. We asked the study participants about their personal take and opinion on the issue. We were surprised to learn that the subjective perception and the objective parameters differed significantly. Although the subjects alleged a reduction in their performance, the performance measurements did not confirm this assumption. We were in for another surprise during our research of the subject. The Occupational Health and Safety Administration suggests wearing a face mask no longer than 75 minutes, at which point it should be replaced. As far as I know, schools don’t know about this guideline.

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.