Objective To explore the relationship between obesity and the various parameters of physical fitness and provide the basis of physical fitness management for people.Methods A total of 725 male college students recruited from a University in Yangzhou.Height,weight,waist circumference and physical fitness of the subjects were measured.According to Obesity criteria (BMI and/or WC) ,the college students were divided into the following 4 groups(BMI obesity group(BOG),WC obesity group(WOG),BMI and WC obesity group(BWOG) and normal group(NG)).Logistic regression analysis was used to explore the relationship between obesity and physical fitness.Results (1) Significantly,1500m (P<0.01) of BWOG,BOG and WOG,push-ups (P<0.01) and standing time on one foot with closed eyes (P<0.01) of BOG and WOG and whole body reaction time(P<0.01) of BOG were lower than that of NG.(2) Vital capacity of BWOG and WOG (P<0.01),and grip strength (P<0.01) and back strength of BWOG and BOG (P<0.05) were higher than that of NG.(3) Multiple logistic regression showed that the odds ratios of WOG(βBOG=-1.002,OR=0.367,95%CI=0.191-0.702,P<0.01) and BOG(βWOG=-1.785,OR=0.169,95%CI=0.038-0.772,P<0.05) for low 1500m subjects were higher,of BWOG(βBWOG=1.776,OR=5.901,95%CI=1.298-26.828,P<0.05) and BOG(βWOG=1.681,OR=5.365,95%CI=1.667~24.670,P<0.05) for high vital capacity subjects were higher, of BOG for subjects of low Push-ups(βBOG=-0.658,OR=0.518,95%CI=0.280-0.960,P<0.05) and whole body reaction time(βBOG=-0.902,OR=0.405,95%CI=0.213-0.775,P=0.005) were higher,of WOG for high back strength(βWOG=-1.583,OR=0.207,95%CI=0.045-0.946,P<0.05) were higher while of BWOG and BOG for high grip strength subjects (βBWOG=1.786,OR=5.974,95%CI=1.315-27.155,P<0.05;βBOG=0.712,OR=2.036,95%CI=1.088-3.806,P<0.05) were higher,as compared to the NG.Conclusions ubjects of BWOG,BOG and WOG show reduced cardiorespiratory,BOG and WOG show lower upper arm muscular endurance and balance.The subjects of BOG show lower agility,BWOG and WOG show increased muscular strength and vital capacity while the subjects of BWOG have higher vital capacity,upper arm muscular and back strength.

Objective: To investigate the causal relationship between junior high school students aggressive behavior, physical exercise and academic performance, so as to provide a reference basis for the development of scientific exercise programs. Methods: A longitudinal followup study was conducted on 502 junior high school students over a 12month period from June 2021 to June 2022 using the Buss-Perry Aggressive Questionnaire (BPAQ), Physical Activity Questionnaire for Adolescents (PAQ-A), and test scores as the measurement tools (T1:June 2021, T2:December 2021, T3:June 2022), and a crosslagged model was constructed to measure the relationship between aggression, physical activity and academic performance. Results: At T1, physical exercise had a positive effect on academic performance at T2 (β=0.22) and a negative effect on aggressive behavior at T2 (β=-0.13), aggressive behavior negatively affected academic performance at T2 (β=-0.23), and academic performance had a negative effect on aggressive behavior at T2 (β=-0.09). Physical exercise at T2 had a negative effect on aggressive behavior at T3 (β=-0.05) and a positive effect on academic performance at T3 (β=0.19). Aggressive behavior at T2 negatively influenced academic performance at T3 (β=-0.08). Academic performance at T2 negatively influenced aggressive behavior at T3 (β=-0.06) (P<0.05). The results of crosslagged modeling of junior high school students aggressive behavior, physical exercise and academic performance showed that the model was well fitted (χ2/df=8.80, CFI=0.96, NFI=0.95, RFI=0.87, IFI=0.96, TLI=0.88, RMSEA=0.12). The results of multigroup structural equation modeling showed that the differences between the models and the baseline model (CFI=0.95, TLI=0.86, RMSEA=0.10, 90%CI=0.08-0.11, P<0.01) were not statistically significant in terms of gender (△CFI<0.05, P>0.05). Conclusions Physical exercise negatively predictes aggressive behavior and positively predictes academic performance, and academic performance and aggressive behavior negatively affect each other. A scientific exercise program should be developed to reduce aggression and effectively improve adolescents academic performance.