Acute Effects Of Using Mask During Exercise On Physiological Indices

Wearing a mask during exercise may impede breathing, cause dyspnea, exacerbate perceptual feel, discomfort accompanied by sympathetic stress response. PURPOSE: Investigate the use of cloth mask (CM) on time-to-exhaustion (TTE), physiological indices, OMNI Rate of Perceived Exertion (RPE) and Ratings of Mask Discomfort (RMD) on lactate threshold (LT) and peak exercise. METHODS: Sixteen healthy males (age: 30.6 ± 8.4 years; height: 1.72 ± 0.04 m; weight: 67.0 ± 5.8 kg; body mass index (BMI): 22.6 ± 1.9 kg·m-2, body fat percentage: 16.0 ± 4.7 %; maximal oxygen consumption (VO2max): 44.2 ± 4.8 mL·min·kg-1)) volunteered and were randomly assigned to either CM or no mask (NM) with a cross over design and a 7-day washout period. Body composition was measured using Bioimpedance Analysis machine. Participants underwent a discontinuous incremental running treadmill protocol. RESULTS: ANOVA repeated measures (df, 1, 8) indicated significant differences between overall variables and groups (F = 10.75, p = 0.001); between groups for oxygen uptake (VO2) (NM: 32.02 ± 8.78 vs CM: 26.92 ± 7.34 mL·kg-1·min-1, p = 0.00); Overall mask discomfort (OMD) (NM: 1.96 ± 1.74 vs CM: 4.02 ± 2.11, p = 0.00); Breathing resistance (BR) (NM: 1.69 ± 1.69 vs 4.36 ± 2.18, p = 0.00); hotness, warmness, stuffiness (HWS) (NM: 1.64 ± 3.46 vs CM: 3.46 ± 2.14, p = 0.00); Odor (NM: 0.20 ± 0.59 vs CM: 0.42 ± 0.94, p = 0.00). Significant differences were found at peak exercise between conditions for TTE (NM: 122.00 ± 13.23 vs CM: 106.00 ± 17.65 min, p = 0.00), VO2max (NM: 44.17 ± 4.84 vs CM: 31.73 ± 9.00 mL·kg-1·min-1, p = 0.00); heart rate (NM: 185.75 ± 10.75 vs CM: 178.63 ± 1.98 beats·min-1, p = 0.00); minute ventilation (NM: 86.03 ± 12.66 vs CM: 55.77 ± 13.30 L·min-1, p = 0.00), lactate (NM: 7.44 ± 1.01 vs CM: 6.04 ± 1.98 mmol·L-1, p = 0.001) and respiratory rate (NM: 52.67 ± 9.43 vs CM: 48.00 ± 8.79 breaths·min-1, p = 0.005). CONCLUSION: Amidst significant changes in physiological indices associated with mask during exercise, there were higher perceptual discomforts though generally tolerable by healthy active population from light exercise intensity to LT. CM during exercise at high intensity levels are generally not advisable as almost all indices were significantly different and may potentially cause adverse physiological or physical response.