Changes in physical fitness and body composition according to the physical activities of Korean adolescents

This study comparatively analyzed obesity, lean balance, and physical fitness related to growth and development in female middle school students to investigate the importance of regular physical activity on body composition and physical fitness in adolescence. The subjects were 31 elementary school students in grades 5–6 in Seoul, consisting of 16 students in the regularly active group and 15 students in the inactive group. Body composition and physical fitness factors were measured. Height, weight, body mass index (BMI), fat mass, and fat-free mass were measured using Inbody 3.0. Physical fitness factors such as muscle strength (grip strength), muscle endurance (situps), flexibility (body flexion), agility (side stepping), and lean balance (balancing with eyes closed), were measured as described herein. The results of comparing the two groups’ obesity-related body composition, the weight (P<0.001), body fat mass (P<0.001), BMI (P<0.002), and % body fat (P<0.033) were significantly higher in the inactive group compared to the physically active group. Comparison of lean balance was there was a significant difference in muscle mass between the left and right Arm (P<0.001), left and right leg (P<0.002) in the inactive group. comparing physical fitness between groups was trunk flexion (P<0.001) and side stepping (P<0.001) were higher in the physically active than the inactive group. This study found significant differences in weight, body fat, BMI, flexibility, and side stepping between the physically active and inactive groups, which may negatively affect health indicators related to adolescents’ growth, development, and obesity. Therefore, attempts to promote physical activity in growing adolescents are crucial.