Effects of Face Mask Use on Objective and Subjective Measures of Thermoregulation During Exercise in the Heat

Abstract

Background: While increased face mask use has helped reduce COVID-19 transmission, there have been concerns about its influence on thermoregulation during exercise in the heat, but consistent, evidence-based recommendations are lacking. Hypothesis: No physiological differences would exist during low-to-moderate exercise intensity in the heat between trials with and without face masks, but perceptual sensations could vary. Study Design: Crossover study. Level of Evidence: Level 2. Methods: Twelve physically active participants (8 male, 4 female; age = 24 ± 3 years) completed 4 face mask trials and 1 control trial (no mask) in the heat (32.3°C ± 0.04°C; 54.4% ± 0.7% relative humidity [RH]). The protocol was 60 minutes of walking and jogging between 35% and 60% of relative VO2max. Rectal temperature (Trec), heart rate (HR), temperature and humidity inside and outside of the face mask (Tmicro_in, Tmicro_out, RHmicro_in, RHmicro_out) and perceptual variables (rating of perceived exertion (RPE), thermal sensation, thirst sensation, fatigue level, and overall breathing discomfort) were monitored throughout all trials. Results: Mean Trec and HR increased at 30- and 60-minute time points compared with 0-minute time points, but no difference existed between face mask trials and control trials ( P > 0.05). Mean Tmicro_in, RHmicro_in, and humidity difference inside and outside of the face mask (ΔRHmicro) were significantly different between face mask trials ( P < 0.05). There was no significant difference in perceptual variables between face mask trials and control trials ( P > 0.05), except overall breathing discomfort ( P < 0.01). Higher RHmicro_in, RPE, and thermal sensation significantly predicted higher overall breathing discomfort ( r2 = 0.418; P < 0.01). Conclusion: Face mask use during 60 minutes of low-to-moderate exercise intensity in the heat did not significantly affect Trec or HR. Although face mask use may affect overall breathing discomfort due to the changes in the face mask microenvironment, face mask use itself did not cause an increase in whole body thermal stress. Clinical Relevance: Face mask use is feasible and safe during exercise in the heat, at low-to-moderate exercise intensities, for physically active, healthy individuals.

Effects of Wearing a Mask During Exercise on Physiological and Psychological Outcomes in Healthy Individuals: A Systematic Review and Meta-Analysis

“…The RPE was significantly higher in those wearing surgical masks (SMD 0.36, 95% CI 0.21–0.52; p < 0.01; I 2 = 30%), while no effect was observed in those with FFP2/N95 respirators ( p = 0.06) or cloth masks ( p = 0.21), as shown in Fig. 5 a. Additionally, 14 studies reported on dyspnea [ 12 , 25 , 37 – 39 , 43 , 48 , 50 , 52 – 56 , 60 ], five reported on fatigue level [ 3 , 18 , 40 , 41 , 47 ], and six reported on thermal sensation [ 3 , 18 , 40 , 47 , 56 , 57 ]. This meta-analysis establishes that wearing face masks during exercise results in significantly higher dyspnea (SMD 0.72), fatigue level (MD 1.34), and thermal sensation (SMD 0.67) in participants (Fig.…”

“…Overall, 22 studies used a progressive exercise test [ 3 , 12 , 14 , 18 , 24 , 26 , 30 , 35 , 36 , 39 , 41 , 43 – 45 , 48 , 50 , 51 , 53 – 55 , 59 , 60 ], while 19 employed the steady-state constant exercise test [ 13 , 15 , 25 , 29 , 31 , 34 , 37 , 38 , 40 , 42 , 46 , 47 , 49 , 52 , 56 – 58 , 61 , 62 ], and two used interval exercise tests [ 28 , 32 ]. Moreover, one study used a resistance exercise test [ 33 ], and one used a sit-to-stand test [ 27 ].…”

Facial mask acute effects on affective/psychological and exercise performance responses during exercise: A meta-analytical review

“…Each domain was rated as "low risk of bias," "high risk of bias," and "some concerns" for the reported outcomes, and the overall risk of bias judgment: low risk of bias-all domains showed a low risk of prejudice; some concerns: in at least one domain for this outcome but not being at high risk of bias for any domain, and high risk of bias-when in at least one domain for this outcome or have some concerns for multiple domains in some way that substantially reduces confidence in the result. 2021;Rojo-Tirado et al, 2021;Ryu and Jong-Geun, 2021;Slimani et al, 2021;Tornero-Aguilera et al, 2021;Yoshihara et al, 2021;Zhang et al, 2021;Cabanillas-Barea et al, 2022;Jesus et al, 2022;Ng et al, 2022;Rosa et al, 2022;Steinhilber et al, 2022) met all the eligibility criteria and were included in the review. Two additional studies (Shaw et al, 2020;Otsuka et al, 2022) were found from other sources (e.g., references from included studies, and publications founded in other reviews).…”

“…All studies presented a control condition (i.e., no face mask wearing). The samples were composed mostly by healthy (Zimmerman et al, 1991; Roberge (Fikenzer et al, 2020;Shaw et al, 2020;Wong et al, 2020;Ade et al, 2021;Epstein et al, 2021;Kampert et al, 2021;Yoshihara et al, 2021), healthy trained (Rojo-Tirado et al, 2021;Ng et al, 2022) resistance-trained (Rosa et al, 2022), and healthy sedentary (Otsuka et al, 2022) adults; athletes (Dantas et al, 2021;Egger et al, 2021;Tornero-Aguilera et al, 2021) and amateur soccer players (Modena et al, 2021). The sample size varied from six (Otsuka et al, 2022) Among the types of exercise, the participants performed on cycle ergometer (n = 14) (Zimmerman et al, 1991;Fikenzer et al, 2020;Lässing et al, 2020;Shaw et al, 2020;Ade et al, 2021;Doherty et al, 2021;Egger et al, 2021;Epstein et al, 2021;Mapelli et al, 2021;Zhang et al, 2021;Jesus et al, 2022;Ng et al, 2022;Otsuka et al, 2022;Steinhilber et al, 2022), walking in treadmill (n = 13) (Roberge et al, 2010;Roberge et al, 2012a;Roberge et al, 2012b;Chen et al, 2016;Kim et al, 2016;Wong et al, 2020;Bar-On et al, 2021;…”

“… Rojo-Tirado et al, 2021;Ryu and Jong-Geun, 2021;Yoshihara et al, 2021;Cabanillas-Barea et al, 2022;Rosa et al, 2022), and FFP2/N95 + EV (n = 5)(Roberge et al, 2010;Roberge et al, 2012a;Chen et al, 2016;Kim et al, 2016;Steinhilber et al, 2022). The effects of face mask wearing during exercise on affective/psychological parameters were assessed by some studies (n = 33)(Roberge et al, 2010;Roberge et al, 2012a;Roberge et al, 2012b;Chen et al, 2016;Kim et al, 2016;Person et al, 2018;Fikenzer et al, 2020;Lässing et al, 2020;Morris et al, 2020;Shaw et al, 2020;Wong et al, 2020;Ade et al, 2021;Bar- On et al, 2021;Dantas et al, 2021;Doherty et al, 2021;Driver et al, 2021;Egger et al, 2021;Epstein et al, 2021;Fukushi et al, 2021;Kampert et al, 2021;Mapelli et al, 2021;Modena et al, 2021;Reychler et al, 2021; Rojo-Tirado et al, 2021;Slimani et al, 2021;Tornero-Aguilera et al, 2021;Yoshihara et al, 2021;Zhang et al, 2021;Cabanillas-Barea et al, 2022;Ng et al, 2022;…”