Inclusion Criteria:  Written informed consent/assent ASD diagnosis according to the DSM-IV/5 Proficient knowledge of Dutch  Exclusion Criteria:  A physical disability hampering the administration of the standardized tests (e.g. unable to sit on a bicycle/perform a motor skill test in standing position) Participants with an intellectual disability (defined as an intelligence quotient < 70) Participants with severe medical problems (e.g. severe metabolic disorders, oncological disease, diabetes), because of safety reasons Wave 1 participants only: the use of antipsychotics, because of safety reasons in the context of performing a maximal exercise test Participation in another clinical trial In case of pregnancy