Department of Sport Science, University of Seoul, Seoul, Korea (Drs H. J. Kim and Jae and Mr J. Y. Kim); Department of Physiotherapy, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, India (Dr Babu); Department of Thoracic and Cardiovascular Surgery, Seoul National University Children's Hospital, Seoul, Korea (Drs Kwak and W.-H. Kim); JW LEE Center for Global Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea (Drs Kwak and W.-H. Kim); and Division of Urban Social Health, Graduate School of Urban Public Health, University of Seoul, Seoul, Korea (Dr Jae).

Correspondence: Sae Young Jae, PhD, Department of Sport Science and Division of Urban Social Health, Graduate School of Urban Public Health, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, South Korea ([email protected]).

All authors have read and approved the manuscript.

The authors declare no conflicts of interest.