[1] Hungarian Sch Sport Federat, Budapest, Hungary
[2] Leibniz Inst Prevent Res & Epidemiol BIPS, Bremen, Germany
[3] Univ Wollongong, Sch Math & Appl Stat, Wollongong, NSW, Australia
[4] Univ Ljubljana, Inst Biostat & Med Informat, Fac Med, Ljubljana, Slovenia
[5] Univ Ljubljana, Ljubljana, Slovenia
[6] Portuguese Inst Sport & Youth, Lisbon, Portugal
[7] Univ Wollongong, Early Start & Illawarra Hlth & Med Res Inst, Wollongong, NSW, Australia