Effects of locally made double – layered cloth face masks on exercise performance and cardiopulmonary parameters during physical activity in healthy adults

Abstract

Background: Due to the COVID–19 pandemic, cloth facemasks are used worldwide as a major prevention method against the spread of the disease, keeping dust away from the respiratory tract and avoiding acquiring other respiratory illnesses. The effects of the Ugandan–made cloth masks on the cardiorespiratory function have not been studied in Uganda and other Low–Income Countries. The aim of this study was to determine the effect of locally fabricated cloth masks on the cardiorespiratory response to exercise. Methods: In a quasi–experimental crossover study, 30 healthy adults (18–45 years old) underwent two maximal cardiopulmonary exercise tests (CPETs) on a treadmill following the Bruce protocol first without a mask (NM) and then with a cloth face mask (M). Exercise time (ET), heart rate (HR), blood oxygen saturation (SPO2) were measured. Descriptive data and medical history were collected pre–trial. Approval was obtained from School of Biomedical sciences IRB (Ref. SBS–2021–100/2, 2022–04–03). Informed consent was obtained before participation. Data were analyzed using Stata v.15, normality assessed with the Shapiro–Wilk test, and a paired t–test compared means between masked and unmasked conditions. Results: In a study involving 30 participants, 70% of whom were males with an average age of 24.7 years and an average BMI of 21.8, various physiological parameters were measured. The participants initially had average systolic blood pressure (SBP) of 117.5 mmHg, diastolic blood pressure (DBP) of 75.5 mmHg, and oxygen saturation (SpO2) of 97.7%. Wearing a mask resulted in slight decreases in SBP to 111±11 (p–value = 0.0005; 95% CI = 0.12–1.16), DBP to 69.8±9 (p–value = 0.0002; 95% CI = 0.15–1.19), and SpO2 to 96.6±2 (p–value = 0.03; 95% CI = 0.04–1.08). There was a negligible change in maximal oxygen consumption (VO2max) from 37.4±8 to 37.5±6 (p–value = 0.967; 95% CI = 0.51–0.5). During exercise or recovery, there was an increase in heart rate (HR) from 72±10 to 178±4 (p–value = 0.0002) and in SBP/DBP from 151±20/86±20 (p–value = 0.011/0.097), respectively. However, there were no significant differences observed between the unmasked and masked groups in HR at recovery (p–value = 0.51) and SBP/DBP at recovery (p–value = 0.196/0.179). Conclusion: Wearing a Ugandan made double layered cloth face mask during vigorous exercise on a graded treadmill incremental exertion test had no discernible detrimental effect on pulse rate, maximum oxygen consumption and exercise performance among adults with normal cardiorespiratory function. Hence, they can wear masks during errands, especially for strenuous activities like gym workouts or labour in a pandemic.