Abstract Physical activity promotes the physical and mental health of children and adolescents, and a growing body of research has demonstrated the positive effects of physical exercise, including better academic performance. This review presents a retrospective analysis of the existing literature in order to explore the relationship between physical activity patterns and academic performance in children and adolescents. This study analyzes the impact of differences in the duration, frequency, intensity, and type of physical activity on the academic performance of children and adolescents, which provides a basis for improving the quality and effect of such physical activities. High-quality evidence supports the view that long-term, high-frequency, aerobic physical activities of moderate-to-vigorous intensity have a positive impact on children and adolescents’ academic performance. This study provides a reference to help families, schools, and society to scientifically and rationally promote physical activity among children and adolescents.

Objective: To analyze the status of outdoor activities on weekends among children and adolescents of different educational stages in Shanghai and their impact on myopia, so as to provide a basis for formulating more specific prevention and control protocol of myopia. Methods: From September to October 2022, a stratified cluster random sampling method was employed to select 84 schools (27 kindergartens, 21 primary schools, 15 junior high schools and 21 high schools) across Shanghai, enrolling a total of 28 654 children and adolescents aged 4 to 18 for the study. Ophthalmic examinations were conducted to ascertain the prevalence of myopia among children and adolescents. Additionally, a questionnaire survey was administered to collect data on outdoor activity duration and associated factors. Multivariate Logistic regression analysis was utilized to investigate the associated factors of outdoor activity levels on weekends. Results: The overall myopia detection rate among children and adolescents was 58.4%, with a higher rate observed in girls (59.2%) compared to boys (57.6%). The myopia detection rates for children and adolescents with an average daily outdoor activity duration of ≥2 h and <2 h on weekends were 54.6% and 68.8%, and the differences were statistically significant ( χ 2=8.12,460.89, P <0.01). Multivariable Logistic regression analysis revealed that girls ( OR =0.80), those with a myopic parent ( OR =0.68), schools from urban districts ( OR =0.72), higher education stages (primary school: OR =0.65, junior high school: OR =0.24, high school: OR =0.14) and spending≥2 h/d on homework during weekends ( OR =0.57) among children and adolescents were less likely to engage in outdoor activities for ≥2 h on weekends ( P <0.01). After incorporating gender, parental myopia status, educational stage, school location, average daily duration on weekends for spending on homework, electronic product usage and outdoor activities as dependent variables in a multivariate Logistic regression analysis, the results showed that children and adolescents with an average outdoor activity duration for ≥2 h on weekends had a lower risk of myopia ( OR =0.86, P < 0.01). Conclusions The level of outdoor activity among children and adolescents on weekends needs to be improved. Outdoor activities on weekends is an associated factor for myopia among children and adolescents. Particularly, girls, those with myopic parents, schools from urban districts, and spending long hours on homework during weekends among children and adolescents require increased attention.

Objective: To investigate the refractive progression and associated factors of children of different ages and refractive status, and to provide guidance on myopia prevention and control program formulation and work practice. Methods: A total of 20 kindergartens, primary schools, and secondary schools in 2 districts of Shanghai were selected based on the existing cohort, and baseline data in 2015 and one year follow up data in 2016 were collected from 1 510 children aged 4 to 14, including cycloplegic spherical equivalent refraction (SER), axial length (AL), and corneal curvature. The distribution and progression of SER and AL in children of different ages and refractive status were analyzed, and the influencing factors of SER progression (ΔSER) were explored using multiple linear regression. Results: ΔSER remained relatively stable at age 4 and 5 (average -0.08 to -0.07 D/year), and SER drifted significantly towards myopia (average -0.50 to -0.31 D/year) in all groups older than 6 years, dropping back to -0.44 to -0.33 D/year after age 11; Elongation of AL (ΔAL) was 0.27 to 0.35 mm/year in 4 to 10 years group, and decreased to 0.15 to 0.22 mm/year in 11 to 14 years group. The ΔSER and ΔAL were greatest in the new onset myopes [(-0.90± 0.05 )D, (0.51±0.02)mm], followed by the low myopia group [(-0.68±0.04)D, (0.36±0.02)mm], then followed by the moderate to high myopia group[(-0.49±0.06)D，(0.23±0.03)mm] and the lowest in the hyperopia group[(-0.21±0.02)D, ( 0.26 ±0.01)mm], with a statistically significant difference among these groups ( P <0.05). Age ( β =-0.07), baseline SER ( β = 0.05 ) and ΔAL ( β =-0.78) were independent influencing factors for refractive progression in the 4 to 10 years old group, while ΔAL( β =-1.55) was the only independent influencing factor in the 11 to 14 years old group ( P <0.05). Conclusion The elongation of AL in preschoolers is mostly physiologically and should be prevented from growing beyond the physiological range by increasing outdoor activities. The primary students, as well as students with pre myopia or low myopia are the priority groups for dynamic monitoring and intervention in myopia prevention and control.

Objective: To investigate the visual acuity and correction conditions of children and adolescents in Shanghai, so as to provide a scientific basis for developing intervention measures to prevent myopia and protect vision among children and adolescents. Methods: From October to December 2022, a stratified cluster random sampling survey was conducted, involving 47 034 students from 16 municipal districts in Shanghai, covering kindergartens (≥5 years), primary schools, middle schools, general high schools and vocational high schools. According to the Guidelines for Screening Refractive Errors in Primary and Secondary School Students, the Standard Logarithmic Visual acuity Chart was used to examine naked vision and corrected vision of students, and general information was collected. The distribution and severity of visual impairment in different age groups were analyzed, and χ 2 tests and multivariate Logistic regression were used to explore factors associated with visual impairment. Results: The detection rate of visual impairment among children and adolescents was 76.2%, with a higher rate among females (78.8%) than males ( 73.8 %), higher among Han ethic students ( 76.2 %) than minority students (71.2%), and higher among urban students (76.7%) than suburban students (75.8%), all with statistically significant differences ( χ 2=162.6, 10.4, 5.5, P <0.05). The rate of visual impairment initially decreased and then increased with age, reaching its lowest at age 7 (53.8%) and peaking at age 17 (89.6%) ( χ 2 trend = 3 467.0 , P <0.05). Severe visual impairment accounted for the majority, at 56.6%, and there was a positive correlation between the severity of visual impairment and age among children and adolescents ( r =0.45, P <0.05). Multivariate Logistic regression showed that age, BMI, gender, ethnicity and urban suburban status were associated with visual impairment ( OR =1.18, 1.01, 1.38 , 0.79, 0.88, P <0.05). Among those with moderate to severe visual impairment, the rate of spectacle lens usage was 62.8%, yet only 44.8 % of those who used spectacle lens had fully corrected visual acuity. Females (64.9%) had higher spectacle lens usage rates than males (60.6%), and general high school students had the highest spectacle lens usage (83.9%), and there were statistically significant differences in gender and academic stages ( χ 2=57.7, 4 592.8, P <0.05). Conclusions The rate of spectacle lens usage among students with moderate to severe visual impairment is relatively low, and even after using spectacle lens, some students still do not achieve adequate corrected visual acuity. Efforts should focus on enhancing public awareness of eye health and refractive correction and improving the accessibility of related health services.