Fig. 4.

Long-term exercise increased the levels of the four circulating miRNAs and enhanced the inhibitory effects on SARS-CoV-2 replication. a Absolute quantification of the expression of the four serum miRNAs in individual serum samples from healthy volunteers with or without 8 weeks of continuous integrative physical exercise (control vs exercise) using qRT-PCR. b, c Cytometric analysis (b, left), fluorescence images (b, right) and western blot (c) of GFP-S protein-overexpressing HEK293T cells after treatment with serum exosomes collected from healthy people with or without 8 weeks of continuous integrative physical exercise (control vs exercise). d Efficacy of exosomes collected from the control and exercise groups in inhibiting the replication of SARS-CoV-2. Data are shown as means ± SEMs. Statistical significance was assessed using the two-tailed unpaired Student’s t-test. **P < 0.01; ***P < 0.001