Constantinou, Demitri, et al. “‘I’m Doing It for myself’: Using a Smartphone-Based Exercise Service During the COVID-19 Lockdown in the Faculty of Health Sciences, University of the Witwatersrand, South Africa”. South African Journal of Sports Medicine, vol. 33, no. 1, Apr. 2021, pp. 1-6, doi:10.17159/2078-516X/2021/v33i1a9053.