Multidimensional Profiling of Physical Fitness and Behaviors among Rural Chinese Adolescents Aged 6-13: A Small-Sample Cross-Sectional Study

Purpose: To characterize the physical fitness and behavioral profiles of school-aged children in rural China and to examine associations between lifestyle factors and somatic as well as physiological health indicators. Methods: In a cross-sectional study, we conveniently sampled 26 students aged 6-13 years (16 boys, 10 girls) from Fucheng Subdistrict, Luoding, Guangdong. Multidimensional assessments covered four domains: body morphology, physiological function, physical fitness, and lifestyle behaviors. Data were analyzed and visualized in Python 3.12.3. Pearson correlations were used to construct a correlation matrix and a significance-annotated heat map (two-tailed; P<0.05 were considered statistically significant, P<0.01 were considered statistically highly significant). Results: Overall developmental status approximated age-matched norms, and no cases of overweight or obesity were identified. The Physical Activity Questionnaire for Older Children (PAQ-C) score averaged 2.65 ± 0.61; approximately 77% did not meet the recommended activity threshold. Non-learning screen time averaged 2.81 ± 0.64 hours/day, exceeding health guidance. Correlation analyses showed that physical activity level was positively associated with skeletal muscle percentage and negatively associated with weight, BMI, body-fat percentage, and systolic blood pressure; conversely, screen exposure time was positively associated with weight, BMI, and systolic blood pressure, and negatively associated with physical activity. Radar plots indicated relatively better flexibility but marked weaknesses in balance and physical activity dimensions. Conclusions: Rural adolescents face a clustering risk characterized by high screen time and low activity. Community and school interventions should adopt a dual strategy of "moving more and sitting less", strengthening support for physical activity and managing screen time across school and family settings to jointly improve physical fitness and health in school-aged children.