Zhang, X., Li, X., Sun, Z., He, Y., Xu, W., Campbell, H., Dunlop, M., Timofeeva, M. & Theodoratou, E. 2020, 'Physical activity and COVID-19: an observational and Mendelian randomisation study', Journal of Global Health, 10(2), article no: 020514. https://doi.org/10.7189/jogh-10-020514