Abstract
The International Classification of Functioning, Disability, and Health (ICF) offers a comprehensive bio-psycho-social model for evaluating the multifaceted needs of individuals with disabilities. While its adoption in healthcare settings is widespread, its utilization within the domain of physical activity interventions, particularly for adolescents with intellectual disabilities (IDs), remains insufficiently explored. This study rigorously examines the efficacy of a 6-month ICF-based Adaptive Physical Activity (APA) intervention on the development of fundamental motor skills (FMSs), improvements in physical fitness (PF), and enhancements in quality of life (QoL) among adolescents with ID. A total of thirty-eight adolescents were randomly allocated into either an intervention group (IG), which participated in the tailored APA program, or a control group (CG), which received standard physical education. The findings demonstrated statistically significant improvements in the IG's test of gross motor development (TGMD) total, locomotor, object control, and QOL scores relative to the CG (p < 0.001, η² = 0.330, 0.249, 0.224, and 0.439, respectively). Furthermore, substantial gains were observed in PF measures, including upper and lower limb strength as well as cardiorespiratory fitness (p < 0.001, η² = 0.254, 0.351, 0.176). Strong positive correlations were noted between FMS, PF, and QoL (r = 0.34-0.71, p < 0.05). This study underscores the importance of tailoring physical activity programs for adolescents with ID, offering insights into the relationships between FMS, PF, and QoL, and guidance for future interventions aimed at improving health outcomes in this population.