Low levels of physical activity (PA) in adolescents with Autism Spectrum Disorder (ASD) increase the risk for both physical and mental health problems during adolescence and subsequent adulthood. To enable the identification of adolescents with ASD at risk for developing an inactive lifestyle and to inform the future design of high-quality, evidence-based and ASD-specific PA interventions and programs, several gaps of the current literature need to be addressed.~To date, no PA and cardiorespiratory fitness (CRF) tests have been validated in adolescents with ASD, causing an inability to accurately assess and interpret these two important health markers.~There is a lack of knowledge regarding PA correlates in this population, resulting in difficulties to identify adolescents with ASD at risk of developing an inactive lifestyle.~It is still unknown why adolescents with ASD are predominantly inactive and qualitative research of the perspectives of adolescents with ASD towards PA participation in order to understand their PA behavior is scant.~Therefore, the aims of this project with regard to adolescents with ASD are:~To examine the concurrent validity of two self-report PA instruments and the concurrent validity and test-retest reliability of a submaximal CRF test.~To determine potential complex and multiple (interactions between) correlates of PA, using a comprehensive assessment protocol.~To explore the perspectives of adolescents with ASD concerning the barriers and facilitators of PA participation.
The purpose of this study is to increase knowledge and insights with regard to physical activity behavior in adolescents with Autism Spectrum Disorder.