Relationship Between Body Composition And Physical Activity And Physical Fitness In Adolescence

Purpose:Obesity and the lack of physical activity in youth are the major reason of the decline on physical fitness.This study takes the decline of adolescents'physical fitness as an entry point,trying to analyze the influence of body composition and physical activity on physical fitness.Methods:The sample consist of total 702 subjects(349 male,353female)were selected from middle school.Body composition,physical activity,physical fitness will be test.The body composition test were using inbody(Inbody230,South Korea);physical activity was used PAQ-A to obtain subjective physical activity data;physical fitness including accordance national fitness test standard.Indicators:grip,50m run,standing long jump,cardiopulmonary,flexion,vertical jump,5×5meters shulttrun.Linear regression was used to analyze the effects of age and gender on body composition,physical activity,and physical fitness;One Way ANOVA was used to test the differences between different body reorganizations and different levels of physically active physical fitness;multiple linear regression was used to analyze the influence of body composition and physical activity on physical fitness.the regression model can be included in the regression model if the independent variable satisfies I error less than 0.05 and R~2 is than 0.05.Results:There are significant differences in physical fitness(p<0.001),and body composition,keletal muscle and Fat%(p<0.001),BMI and physical activity did not differ between genders.(2)From age view,physical fitness increased with age;BMI and skeletal muscle also increased;Fat%was among girls for the rise,the drop for boys;(3)In the weight group,The NWNO group was the best in terms,which was significantly greater than NWO(p<0.05).(4)Boys 11-year-old 50-meter running,16-year-old grip strength,50-meter running,standing long jump,5x5 meter reentry run under different physical strength,girls 11-year-old grip strength,5×5 meter reentry run,12 years old and 14 Aged endurance,16-year-old girls 5×5meters back to run,different physical activity intensity between the significant difference,high-intensity group was significantly higher than the low-intensity physical fitness(p<0.05).(5)There was a positive correlation between age,sex,skeletal muscle and physical fitness(p<0.001).Skeletal muscle had a positive effect on physical fitness.The higher the skeletal muscle content,the better the physical quality;age,gender,Fat%and 50 meters.Running,standing long jump and endurance had a negative effect(p<0.001).The higher Fat%,the worse physical fitness.There was no significant correlation between age,gender,and BMI on physical fitness;age,gender,and PA were positively related to physical fitness(p<0.001).The greater physical activity,the better physical fitness.(5)BMI and Fat%have a significant correlation R=0.617,which does not satisfy the condition of multiple linear regression independent variables,when performing multiple linear analysis,BMI/Fat%is established separately from other independent variables,and the results indicate that the age is increasing.At the same time,the larger the skeletal muscles,the higher the physical activity score,and the lower the BMI/Fat%,the better the physical condition.Conclusions:(1)There was no significant difference in physical activity among adolescents in terms of gender and age;(2)There was a significant difference between normal body weight and normal body weight;(3)Large-intensity physical activity had the greatest effect on physical fitness;(4)Skeletal muscle has a positive effect on physical fitness,and Fat%has a negative relationship with physical fitness.(5)Sex has an effect on physical fitness.At the same time as older people participate in more physical activities,increase the content of skeletal muscle in the body,and reduce the percentage of body fat,the better the physical condition.