Published on in Vol 8, No 8 (2020): August
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/17699, first published
.
1 School of Physical Education and Sport Training, Shanghai University of Sport, Shanghai, China
2 Shanghai Research Center for Physical Fitness and Health of Children and Adolescents, Shanghai University of Sport, Shanghai, China