Factors influencing the health-related physical fitness of Chinese children and adolescents with intellectual disabilities

Objectives To explore individual-level and family-level factors related to the core components of health-related physical fitness (HRPF) in children and adolescents with intellectual disabilities (IDs).Methods 112 participants aged 6–18 years from a Chinese special school were included. HRPF indicators (cardiopulmonary fitness, muscular strength and endurance, flexibility, and body composition) were measured using the Eurofit physical fitness test battery. Sociodemographic information was collected via a parent-reported questionnaire. Hierarchical regression models were used for data analysis.Results Adolescents with IDs outperformed children in cardiopulmonary fitness and muscular strength but had lower flexibility (all p < 0.05). Girls with IDs had lower scores for cardiopulmonary fitness and muscular strength but higher flexibility than those boys (all p < 0.05). Participants with profound IDs performed worse in most fitness indicators than those with mild to severe IDs (all p < 0.05). Participants from higher-income families had higher body mass index but lower flexibility than those from lower-income families; while parental education levels were significantly correlated with flexibility (all p < 0.05).Conclusions Age, gender, and ID severity were significantly correlated with the HRPF. Family-level factors showed limited but significant associations. Targeted interventions addressing these multidimensional influences are needed.