Effect of Surgical Mask use on Peak Physical Performance During Exercise Treadmill Testing-A Real World, Crossover Study

Abstract

Background: Mask wearing is an essential strategy to combat the spread of SARS-CoV-2. Some individuals may wear masks during physical activity to reduce disease transmission. This study aimed to investigate the real-world effect of wearing a surgical face mask on physiological parameters at peak exercise in healthy individuals.Methods: In this crossover design study, participants underwent maximal treadmill electrocardiogram exercise tests using the Bruce protocol on two separate occasions, once with a standard 3-ply surgical face mask and once without. Heart rate, oxygen saturation, blood pressure, rate pressure product, metabolic equivalents (METS) and total exercise time were measured. Subjective rate of perceived exertion was also assessed using the modified Borg Scale.Results: 50 adults (mean age = 31.7 ± 6.5 years; 27 males) completed both treadmill tests. Mask wearing resulted in a significant reduction in peak METS by 1.5 units, maximum speed by 0.5 km/h, exercise time by 68.4 s with a significantly lower peak heart rate by 4.4 bpm, and lower percentage of age-predicted maximum heart rate by 2.5% (p < 0.001 for all parameters). During each corresponding stage of the Bruce protocol, the average modified Borg score was found to be significantly higher in subjects exercising with mask after adjusting for age, gender and body mass index (p < 0.03).Conclusion: In a cohort of healthy individuals, wearing of a surgical face mask during maximal treadmill exercise lead to reduced physical performance and increased rate of perceived exertion. Individuals exercising with surgical masks need to be mindful of these limitations while undergoing physical training in order to differentiate these physiological responses from symptoms of early respiratory illness.

Added Breathing Resistance during Exercise Impairs Pulmonary Ventilation and Exaggerates Exercise-Induced Hypoxemia Leading to Impaired Aerobic Exercise Performance

“…The most intriguing observation was that breathing resistance causes a marked degree of hypoventilation linearly with increased breathing resistance at a given metabolic demand throughout the mild, moderate, and vigorous exercise stages supporting previous findings [8][9][10]. Conversely, others reported little or no significant changes in exercising V E [2,17].…”

“…Further, such impaired perceptions were positively related to a level of added breathing resistance in agreement with previous findings [2,3,7,9,18,19] and likely adversely affected exercise tolerance shown as a significantly elevated perceived exertion and breathing discomfort at all stages of exercise. Some of the present results must be interpreted with caution, as breathing resistance in this study was implemented via airflow leakage-controlled resistor, but not in the form of mask wearing commonly utilized in other studies [3,[6][7][8][9][10][11][12][13][14] and experienced in daily life while the resistance materials were taken from commercially available respirators. However, it should also be noted that FFP-class masks in Europe and/or others in the U.S.…”

“…For example, studies examining mask wearing during mild to moderate exercise (e.g., 2.7-5.6 km/h) showed no significant physiological impact on heart rate, breathing frequency, and oxygen saturation with slightly increased subjective discomfort, and thermal burden when tested with young, healthy individuals [3][4][5][6]. Other investigators showed that mask wearing during vigorous exercise impairs cardiopulmonary function and physical performance with increased subjective exertion as a function of breathing resistance [7][8][9][10], while others reported no significant difference in either physiological or performance variables [11][12][13].…”

“…Interestingly, two most recent studies [8,11] that examined the impact of mask wearing on physiological parameters during maximal effort exercise have demonstrated completely opposite results. Dalakoti et al [8] tested wearing the surgical mask during maximal treadmill exercise and showed significantly reduced exercise performance (e.g., reduced exercise time, peak METs, and maximum speed) compared with the unmasked condition.…”

“…Interestingly, two most recent studies [8,11] that examined the impact of mask wearing on physiological parameters during maximal effort exercise have demonstrated completely opposite results. Dalakoti et al [8] tested wearing the surgical mask during maximal treadmill exercise and showed significantly reduced exercise performance (e.g., reduced exercise time, peak METs, and maximum speed) compared with the unmasked condition. On the other hand, Epstein et al [11] tested wearing surgical masks and N95 respirator during maximal cycle exercise and indicated no differences in exercise performance between control (e.g., unmasked condition) and masked conditions, together with no meaningful changes in physiological parameters such as respiratory rate and oxygen saturation.…”