Objective To investigate the associations between physical health status,refraction and ocular biometrics in school-age children,and further clarify the relation of eyes'refractive status to physical growth and development,so as to provide scientific evidences for myopia prevention and con-trol.Methods A total of 1718 children(977 boys and 741 girls)aged 8-12 years were enrolled in this study.They were collected uncorrected visual acuity,refraction and ocular biometrics,including spherical equivalent,cylindrical equivalent,axial length(AL),corneal refraction(K1,K2)and anteri-or chamber depth(ACD),as well as the AL/CR ratio and spherical equivalent refraction(SER).Moreover,their height,weight and physical fitness level were measured,including speed,strength,flexibility,agility and aerobic endurance.Then all data were analyzed using the Pearson correlation,One-way ANOVA and multiple linear regression model.Results The overall prevalence of myopia was 43.83%,which was higher in girls than in boys(46.96%vs.41.45%).Moreover,the height and weight of school-age children were negatively correlated with SER(P<0.01),but positively correlated with AL,ACD and AL/CR(P<0.01).After controlling the age and gender variables in the multiple linear regression model,it was found that for 10-cm increase in height,SER decreased by 0.013 D(P<0.01),AL extended by 0.022 mm(P<0.01),and ACD increased by 0.002 mm(P<0.05).In addi-tion,for 10-kg increase in the body weight,the AL would be 0.009 mm longer(P<0.05)and ACD 0.002 mm deeper(P<0.05).Moreover,the speed,strength and agility were negatively correlated with SER(P<0.01,P<0.05),but positively correlated with AL,ACD and AL/CR(P<0.01,P<0.05).The maximal oxygen uptake level was positively correlated with SER(P<0.01),and negatively correlated with AL,ACD and AL/CR(P<0.01,P<0.05).After controlling the age and gender variables in the multiple linear regression model,it was found that the children with worse speed quality had shorter AL(-0.043 D,P<0.05).Meanwhile,the better agility was accompanied by the lower SER(-0.003 D,P<0.01),longer AL(+0.002 mm,P<0.05),lighter ACD(+4.812e-4 mm,P<0.05),and higher AL/CR(+2.446e-4,P<0.05).Conclusion With variables of age and gender controlled,the height,weight,and the speed and agility quality are highly associated with eyes'refractive status among chil-dren aged 8-12 years old.It is suggested that the human body may have a coordination mechanism to regulate the development of the body stature,physical fitness and ocular biometrics in the early child-hood,which should be considered in their myopia prevention and control.

Objective To investigate the associations between physical health status,refraction and ocular biometrics in school-age children,and further clarify the relation of eyes'refractive status to physical growth and development,so as to provide scientific evidences for myopia prevention and con-trol.Methods A total of 1718 children(977 boys and 741 girls)aged 8-12 years were enrolled in this study.They were collected uncorrected visual acuity,refraction and ocular biometrics,including spherical equivalent,cylindrical equivalent,axial length(AL),corneal refraction(K1,K2)and anteri-or chamber depth(ACD),as well as the AL/CR ratio and spherical equivalent refraction(SER).Moreover,their height,weight and physical fitness level were measured,including speed,strength,flexibility,agility and aerobic endurance.Then all data were analyzed using the Pearson correlation,One-way ANOVA and multiple linear regression model.Results The overall prevalence of myopia was 43.83%,which was higher in girls than in boys(46.96%vs.41.45%).Moreover,the height and weight of school-age children were negatively correlated with SER(P<0.01),but positively correlated with AL,ACD and AL/CR(P<0.01).After controlling the age and gender variables in the multiple linear regression model,it was found that for 10-cm increase in height,SER decreased by 0.013 D(P<0.01),AL extended by 0.022 mm(P<0.01),and ACD increased by 0.002 mm(P<0.05).In addi-tion,for 10-kg increase in the body weight,the AL would be 0.009 mm longer(P<0.05)and ACD 0.002 mm deeper(P<0.05).Moreover,the speed,strength and agility were negatively correlated with SER(P<0.01,P<0.05),but positively correlated with AL,ACD and AL/CR(P<0.01,P<0.05).The maximal oxygen uptake level was positively correlated with SER(P<0.01),and negatively correlated with AL,ACD and AL/CR(P<0.01,P<0.05).After controlling the age and gender variables in the multiple linear regression model,it was found that the children with worse speed quality had shorter AL(-0.043 D,P<0.05).Meanwhile,the better agility was accompanied by the lower SER(-0.003 D,P<0.01),longer AL(+0.002 mm,P<0.05),lighter ACD(+4.812e-4 mm,P<0.05),and higher AL/CR(+2.446e-4,P<0.05).Conclusion With variables of age and gender controlled,the height,weight,and the speed and agility quality are highly associated with eyes'refractive status among chil-dren aged 8-12 years old.It is suggested that the human body may have a coordination mechanism to regulate the development of the body stature,physical fitness and ocular biometrics in the early child-hood,which should be considered in their myopia prevention and control.

Objective: To investigate the effects of after school exercise service (referred to as the "after school ES") on physical health, so as to provide evidence for possible beneficial effect of after school ES. Methods: Students in the fourth grade of primary school were recruited from September 2021 to July 2022 in Changsha City and divided into the control group ( n =220) and the after school ES group ( n =220). The control group only participated in the regular physical education activities of the school. The after school ES group received after school ES for one academic year, 4 times a week, 40-50 minutes per time, for a total of 32 weeks. Body shape indicators such as height, weight and percentage of body fat, as well as physical fitness indicators such as 50 meter running, grip strength and progressive aerobic cardiovascular endurance run (PACER) were measured in September to October 2021 and June to July 2022, respectively. Independent sample t-test, Chi square test and two factors repeated measurement analysis of variance were used for statistical analysis of the data. Results: After one academic year, compared with the control group [(13.52±2.30)kg], muscle mass of primary school students in the after school ES group [(13.76±2.32)kg] significantly increased, while waist to hip ratio [(0.95±0.16)] and percentage of body fat [(20.17±7.43)%] significantly decreased compared to the control group [(1.01±0.21), (22.02±12.34)%]( F=330.70, 6.85, 4.33, P <0.05). The proportion of overweight and obesity in after school ES group decreased significantly from 19.5% to 12.3% ( χ 2=4.35, P <0.05). Compared with the control group, the scores of 50 meter running [(10.00±1.06, 10.21±0.83)s], 1 minute sit up [(33.25±8.24, 30.76±9.34)times], sitting and flexion [(14.53±7.50, 8.59±6.32)cm], 1 minute rope skipping [(125.01±30.50, 115.97±32.09)times], eyes closed and single legged standing [(30.00±34.72, 25.72±23.82)s], selective response time [(635.66±91.72, 652.79±120.42)ms] and VO 2max [(45.31± 1.02 , 43.67±0.85)mL/(kg〖 ·min)] in the after school ES group were significantly improved, with statistical significance ( F= 5.32 , 443.14, 97.23, 814.07, 36.49, 6.11, 396.91, P <0.05). Conclusions After school ES can improve body shape of primary school students, reduce the risk of overweight and obesity and enhance physical fitness. It is recommended that schools should appropriately increase after school ES to promote physical fitness of students.