Protocol
The adolescents were recruited during a regular medical visit, and they were assessed over two days with a one-week interval. On the first day, the adolescents performed muscle strength assessment tests, completed the HRQoL questionnaire, and received a triaxial accelerometer to wear on their waist for seven days. On the second visit, the adolescents returned the accelerometer and performed a maximal cardiopulmonary exercise test (CPET). This study was conducted between August 2018 and March 2019. Blinded assessors to the group allocation performed all the assessments.