Background: In an aging and digital society, Internet use is significantly associated with residents’ physical exercise. This study aimed to explore the association between Internet use and physical exercise among Chinese middle-aged and older adults in two respects: Internet use and the purpose of Internet use. Methods: The data used in this study were obtained from the 2018 China Health and Retirement Longitudinal Study (CHARLS) conducted by Peking University. The logit model and the ordered probit model were used to analyze the association between Internet use and physical exercise, and the substitution variable method was used to examine the robustness of the results. Results: (1) Internet use and the frequency of Internet use significantly increased the probability and frequency of middle-aged and older adults’ participation in physical exercise (p < 0.001). (2) “Watching news”, “chatting” and “watching videos” via the Internet were positively associated with physical exercise, while “playing games” had no impact. (3) Internet use had a greater impact on physical exercise participation among middle-aged adults and those living in urban areas than among older adults and those living in rural areas. Conclusions: This study suggests that Internet use among middle-aged and older adults is positively associated with their participation in physical exercise; the government should try to increase the popularity of Internet use to encourage their participation in physical exercise.

Increasing medical expenditure is viewed as one of the critical challenges in the context of population ageing. Physical activity (PA), as a primary prevention strategy for promoting health, is considered as an effective way to curb the excessive growth in medical expenditure. This study aimed to analyze the association between PA and the household out-of-pocket medical expenditure (HOPME) among Chinese urban adults aged 45 and over, and to explore the mediating role of spousal health behaviour. This study analyzed a nationally longitudinal survey: 2014–2018 China Family Panel Studies (CFPS). Fixed effects regression model was applied to estimate the association between PA and annual HOPME. Sobel model was utilized to test the mediating effect. (1) PA was negatively associated with the annual HOPME among urban resident aged 45 and over in China. Exercising 1–5 times per week and maintaining the duration of each exercise session at 31–60 min were effective in reducing annual HOPME. (2) Spousal PA played a significant mediating role in the relationship between respondent's PA and annual HOPME. (3) The negative association between the respondent's PA and HOPME were found among women and those aged between 45 and 65, so was the mediating effect of spouse's PA. Individual PA not only directly reduces HOPME but also indirectly contributes to this reduction by enhancing the PA levels of their spouses. To capitalize on these benefits, more actions should be taken to increase the availability of PA facilities, enhance the public awareness of PA's benefits, and encourage residents to consistently engage in regular PA.

Aims: To make time series analysis on the 29-year (1985−2014) trends in height among Han Students Aged 7-18 in China and predict their future height from the perspective of interdisciplinary studies of demography and physical education. Methods: The data were from the findings of seven cross-sectional surveys from the Chinese National Survey on Students’ Constitution and Health (CNSSCH). The mean, standard error, variance analysis, trend test, F test, T test, development growth and growth rate were used to make a descriptive analysis of height trends. The ARIMA model in the time series analysis was applied to predict the height development of Han students in 2024. Results: The height of students aged 7-18 substantially increased from 1985 to2014. The mean of the height of boys increased by 3.99 cm, 8.01 cm, 8.31 cm, 8.63 cm, 9.81 cm, 11.62 cm, 10.38 cm, 9.22 cm, 7.50 cm, 5.59 cm, 4.51 cm, and 3.79 cm, respectively. The mean of the height of girls increased by 6.66 cm, 7.36 cm, 8.00 cm, 8.84 cm, 9.60 cm, 8.66 cm, 5.57 cm, 4.65 cm, 3.95 cm, 3.32 cm, 2.87 cm and 3.32 cm, respectively. The increasing disparity of the sex differential in the mean height was also observed. From 1985 to 2014, the mean of height difference between boys and girls aged 7-18 had been increased constantly. Their mean height differences were 3.27 cm, 4.03 cm, 4.64 cm, and 5.13 cm, respectively in 1985, 1995, 2005, and 2014. A narrowing of the urban−rural differential in the mean height was observed. In 1985, on average, urban boys aged 7-18 were 4.18cm higher than rural boys in the same age group. And the height differences between urban and rural boys in the same age group were 3.58 cm, 3.18 cm and 2.41 cm, respectively in 1995, 2005 and 2014. According to comparison results, the mean height of urban girls was greater than that of rural girls, and the height difference between urban and rural girls had been constantly narrowed as well. The results of 4 comparisons showed that the height differences between urban and rural girls were 3.68 cm, 3.12 cm, 2.62 cm, and 1.98 cm, respectively. Conclusions: There was a general increase in the height of Chinese Han students aged 7-18 in the past 29 years and difference between sex, rural-urban and age have been observed. In 2024, the height of students will continue to grow.