Effects of COVID-19 on diaphragm thickness and physical performance of athletes

Abstract Introduction Studies suggest that diaphragm thickness (DT) is associated with inspiratory muscle strength and consequently, better ventilatory and mechanical efficiency. On the other hand, infectious diseases such as COVID-19 may impact the structure and function of the respiratory system. Objective Assess the association between DT and the physical performance (PP) of athletes and the effects of COVID-19 infection on these parameters. Methods This is a cross-sectional study of 63 athletes of both sexes from different sport modalities (women: 16.67 ± 5.03 years, 52.09 ± 14.01 kg, 155.90 ± 13.86 cm; men: 23.44 ± 9.65 years, 72.24 ± 14.18 kg, 174.84 ± 6.84 cm), submitted to DT assessment using ultrasound, followed by the PP(Yo-Yo) test) to determine maximum oxygen intake (VO2max). Pearson’s correlation was used to determine the association between VO2max and DT, and the Student’s t-test for differences between athletes with a positive and negative diagnosis for COVID-19. The significance level was set at 5%. Results There was no association between DT and PP (r = 0.30 and p = 0.22) or between athletes unaffected and affected by COVID-19 in relation to DT (57.00 ± 0.26 vs 52.00 ± 0.25%; p = 0.91) and PP (43.88 ± 2.29 vs 38.34 ± 13.61 ml/kg/min; p = 0.69). Conclusion DT was not associated with maximum oxygen intake in athletes. In addition, athletes infected by COVID-19 exhibited no differences in VO2max or DT when compared to nonaffected individuals.