Abstract: Objective To evaluate the effects of physical exercise on liver function and size in adolescents. Methods A total of 361 adolescent subjects from Jining,Shandong Province were selected and divided into low, moderate, and high-intensity exercise groups according to the frequency of moderate intensity exercise. Physical examination tests were conducted including morphological indicators, blood biochemical indicator measurements, liver size and the presence of non-alcoholic fatty liver disease. Independent sample t-tests and variance analysis were performed using SPSS 26.0, and correlation analysis was conducted using Spearman correlation analysis and multivariate linear regression analysis. Results Compared with the moderate and low-intensity exercise groups, the high-intensity exercise group had significantly lower diastolic blood pressure, homeostatic model assessment of insulin resistance (HOMA-IR), and triglycerides (TG), as well as significantly higher height, maximum oblique diameter of the right liver lobe, and direct bilirubin (DBIL). Correlation analysis showed that as exercise intensity increased, aspartate aminotransferase/alanine aminotransferase, DBIL, and the maximum oblique diameter of the right liver lobe increased significantly (P＜0.05). The results of the cumulative effect of exercise type and intensity indicate that exercise type does not influence the effect of exercise intensity on liver function and size. Conclusions Regular exercise in adolescents can not only shape body, but also improve glucose and lipid metabolism and enhance liver function.

Key words: exercise, adolescents, liver function, the maximum oblique diameter of the right liver lobe