Physical fitness of adolescents with intellectual and developmental disabilities in special support schools: Insights from Japan's 2023 national survey.

BACKGROUND

Adolescents with intellectual and developmental disabilities (IDD) often demonstrate lower physical fitness than their typically developing (TD) peers. Physical fitness is influenced by factors such as body size, physical activity, ethnicity, and environmental conditions; however, large-scale studies in Asian populations remain limited.

OBJECTIVE

This study aimed to assess physical fitness in Japanese adolescents with IDD, accounting for height, weight, and physical activity levels.

METHODS

Data were obtained from Japan's 2023 National Survey on Physical Fitness, Athletic Ability, and Exercise Habits. Participants included 2,216 adolescents with IDD attending special support schools and 921,297 TD students. Variables included height, weight, total weekly physical activity time, and eight physical fitness tests: handgrip strength, sit-ups, sit-and-reach test, repetitive side jump, 20-m shuttle run, 50-m run, standing long jump, and handball throw. After propensity score matching by sex, Mann-Whitney U tests and ordinal logistic regression analyses were performed.

RESULTS

After adjusting for height, weight, and physical activity level, adolescents with IDD showed consistently lower performance across all test items than their TD peers, regardless of sex (effect sizes r = 0.35-0.74). Longer total weekly physical activity time was positively associated with better comprehensive evaluations. The IDD group had approximately twice the prevalence of obesity and significantly less weekly physical activity time.

CONCLUSIONS

Japanese adolescents with IDD demonstrate lower physical fitness, higher obesity rates, and reduced physical activity than TD peers. Targeted interventions, including increased physical activity, are needed to improve health and functional outcomes in this population.