Impact of the COVID-19 pandemic: Effects of High Intensity Exercise on Physiological Indicators of Recovery Period by Wearing Face Masks of Elite Athletes

Abstract

Abstract Background Athletes need to maintain the necessary physical conditioning for sports performance with wearing face masks to reduce the risk of virus transmission during training and competition during the COVID-19 situation. The quantitative and physiological (i.e., heart rate, PRE, lactate) effects of face masks on exercise capacity needs to be reported. The purpose of this study was to evaluate elite athletes’ sports performance and body composition during the COVID-19 in 2020, and to quantify in detail the effect of KF94 on changes in lactic acid during recovery after high-intensity aerobic exercise. Methods The 13 athletes who participated in December 2019 and December 2020 were surveyed and matched by age, gender, and sports categories to evaluate their body composition and sports performance (lower limb strength test, anaerobic power test). In addition, a crossover design was used to examine the effects of using a disposable KF94 face mask during exercise. Results The 2020 group (16.29 ± 3.25 kg) was lower in the leg muscle mass than the 2019 group (16.72 ± 3.24 kg). The right knee extensor strength (p = 0.005) and power (p = 0.003) were lower in the 2020 group’s isokinetic muscle function than in the 2019 group. In the Wingate anaerobic test, peak power (p = 0.001) and average power (p = 0.006) of the 2020 group were also lower than those of the 2019 group. Resting state blood lactate level were 1.35 ± 0.14mM/L without a mask, 2.50 ± 0.49mM/L with an KF94 mask (p < 0.001). Also, the lactic acid concentration at 20 minutes of recovery after maximum exercise was 5.98 ± 1.53mM/L without a mask, 7.61 ± 1.85mM/L with an KF94 mask (p < 0.001). However, there was no statistical differences in blood lactate concentrations immediately after exercise (p = 0.407), at 5 (p = 0.671) and 10 minutes (p = 0.313) of recovery. The rate of lactic acid removal in the post-exercise recovery period were 53.56 ± 6.77 (%) without a mask, 45.5 ± 9.9 (%) with a KF94 mask (p < 0.001). The maximum laps of shuttle run tests were 101.5 ± 22.5 laps without a mask, 94.2 ± 20.2 laps with a KF94 mask (p < 0.001). However, changes in maximum heart rate and post-exercise recovery heart rate showed no statistical difference regardless of the mask (p = 0.118). Conclusions The main results of the study show that anaerobic peak power, average power, and extensor muscles of the lower-limb were significantly lower than before the COVID-19 situation by wearing masks in training and normal daily living, and the KF94 mask-wearing group had lower performance in high-intensity aerobic exercise and recovery rate than non-mask group.