Examination of the relationship between body composition and physical fitness parameters in Turkish children: The TUBON project

The purpose of this study was to examine the relationships between body composition, physical fitness, and motor coordination parameters in Turkish children. This thesis evaluated the associations between body composition (BC) indicators and components of physical fitness and motor coordination using data obtained from the TÜBİTAK-SBAG Project No. 120S408. The study sample consisted of 6,310 children (3,253 boys and 3,057 girls) from various regions of Türkiye. Age-group distribution included 911 children aged 6–7.99 years, 1,228 children aged 8–9.99 years, 2,875 children aged 10–14.99 years, and 1,296 children aged 15–17.99 years. BC variables were assessed using anthropometric measurements (triceps and medial calf skinfold thickness, waist/hip circumference) and bioelectrical impedance analysis (BIA). Motor coordination was evaluated using the Kiphard–Schilling Body Coordination Test (KTK), and physical fitness was assessed through push-up, curl-up, standing long jump, flamingo balance, and handgrip strength tests. The findings revealed significant relationships between BC components and both motor coordination and physical fitness parameters. Increased fat-free mass was associated with better strength, power, and balance performance, whereas higher body fat percentage negatively affected several physical fitness outcomes. Children with greater muscle mass demonstrated superior handgrip strength, standing long jump performance, and hopping tasks. KTK scores were also shown to be related to BC indicators. These results highlight the biological basis of musculoskeletal development and motor skill performance during childhood and emphasize that physical fitness cannot be evaluated independently of body composition. In conclusion, this study provides important insights into the growth, developmental characteristics, and motor competence profiles of Turkish children. The results offer valuable reference information for sports scientists, educators, pediatricians, and coaches, underscoring the need to incorporate body composition assessments into evaluations of children's physical fitness. Future studies are recommended to develop age-specific prediction models, use longitudinal designs, and further examine method comparisons in special populations.