Parental and familial factors related to participation in a home-based physical activity intervention in children with obesity or Prader-Willi syndrome

•Parental social and demographics factors relate to participation in a home-based physical activity program with their child.•Parental hours of employment may limit time available to participate in a physical activity program with their child.•Future interventions should consider strategies to increase family cohesion as a vehicle to attain greater compliance.•The role of familial factors and social determinants of health in children's physical activity needs further examination.