key: cord-0884799-qsv6m7ta
authors: Eberhart, M.; Orthaber, S.; Kerbl, R.
title: Effects of wearing face masks under moderate physical effort
date: 2021-03-20
journal: nan
DOI: 10.1101/2021.03.18.21253539
sha: 8a548eefa6d9925f97068af81db9ef26cd4a522c
doc_id: 884799
cord_uid: qsv6m7ta

Due to the COVID-19 pandemic, face masks have become part of daily life and work. Only few studies have investigated potential negative effects of this measure. It was aim of this study to evaluate whether face masks may affect oygen saturation and heart reate under moderate physical effort. Ten healthy volunteers were asked to climb up four floors (96 steps) with and without a face mask. Oxygen saturation and heart rate were recorded before and after this procedure. Physical activity lead to a slight decrease of oxygen saturation of 3.0% (+/- 3.1) without and 3.7% (+/- 3.8) with face masks (p= 0.28). Heart rate increased by 31.0 (+/- 18.7) and 33.3 (+/- 15.9) beats per minute (p= 0.39). Desaturation was more pronounced in individuals > 40 years, however was uncritical in all cases. This study shows that in healthy adults the use of face masks does not significantly affect oxygen supply nor cause additional cardiac load.

Due to the COVID-19 pandemic, face masks or medical masks are recently recommended by international institutions (1, 2) . In several countries, the wearing of face masks is regulated by law for certain sectors of public life (3) . Especially medical staff members and other health professionals are obliged to routinely wear face masks during work hours. Thus far, only few studies have investigated potential negative effects of this measure, although complaints of staff members about headache, fatigue, respiratory and other problems are frequent.

It was aim of this study to evaluate whether face masks may affect oygen saturation and heart reate under moderate physical effort.

After approval by the local ethics committee (EK 33-108 ex 20/21), ten healthy volunteers (6 female, 4 male) were recruited to participate in this comparative study. Five subjects were younger than 30 years (mean 27±0.7), five older than 45 years (55.2±5.4). All subjects were in good health, non-smokers and used to wear masks during their daily work hours.

The participants were asked to climb up four floors (96 steps) in the same speed they would choose under routine conditions, once with (FM) and once without a face mask (NOFM). The order of the two runs was randomized and an interval of 5 minutes was scheduled in between.

For FM runs, standard surgical face masks were used (CE norm DIN EN 14683). Oxygen saturation and heart rate were recorded immediately before and 10 seconds after physical activity by use of a pulse oximetric finger sensor (PULOX PO-200). Furthermore, the time spent for climbing the four floors was recorded.

Statistical analyses were done using Excel© (Microsoft Office, Excel 2013). For numerical data the t test was used. Statistical significance was set at p < 0.05. Table 1 shows mean values of oxygen saturation and heart rate before and after physical activity for FM and NOFM runs, respectively. The mean time spent for climbing up the 4 floors was 65 (± 5) seconds for FM runs and 65 (± 6) for NOFM runs. Physical activity lead to a slight decrease of oxygen saturation of 3.7% (± 3.8) for FM and 3.0% (± 3.1) for NOFM runs (p= 0.28). Heart rate increased by 33.3 (± 18.7) and 31.0 (± 15.9) beats per minute, respectively (p= 0.39).

. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) 

Our study demonstrates that in healthy adults face masks do not negatively affect oxygen supply and cardiac function under conditions of moderate physical activity. These findings are in line with previous studies that report no significant drop in oxygen saturation and, in particular, no potentially harmless alterations (4) (5) (6) (7) (8) . Our recordings demonstrate that moderate physical activity (climbing up 96 steps) leads to a moderate decrease of oxygen saturation, similarly with and without face mask.

Beder et al. found that a postoperative SpO 2 decrease was more pronounced in surgeons over the age of 35 when compared to younger colleagues (7) . In our study, the older age group also showed a higher drop of SpO 2 when using a mask, the difference was however not statistically significant.

Wearing a face mask did not significantly influence the HR in our study, neither in rest nor after moderate physical activity. Roberg et al. report a slightly higher HR for subjects walking on a treadmill and wearing face masks (5) . In contrast, Butz did not note any compensatory increase of HR through face mask use (6). Dattel et al. similarly found no influence upon HR (8) . In addition, these authors also recorded end-tidal CO 2 values (etCO 2 ), which proved to remain in the normal range in flight instructors wearing face masks for 90 minutes (8) . . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted March 20, 2021. ; https://doi.org/10.1101/2021.03.18.21253539 doi: medRxiv preprint

The sample size of our study was relatively low (n=10). The results were however quite consistent in all volunteers and lead to the conclusion that surgical masks do not negatively affect oxygen supply and cardiac function during moderate physical activity.

Our results suggest that complaints reported as a consequence of wearing a face mask are not due to hypoxemia or cardiac load. In contrast, surgical masks appear to be safe for healthy adults even under conditions of moderate physical activity.

. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) SpO 2 oxygen saturation in % (± SD), HR = heart rate in 1/min (± SD), Walking time in seconds (± SD)

. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted March 20, 2021. ; https://doi.org/10.1101/2021.03.18.21253539 doi: medRxiv preprint

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