Family socioeconomic status and moderate to vigorous physical activity among Chinese adults: the chain mediating roles of exercise environment and exercise motivation.

Family socioeconomic status was positively associated with moderate to vigorous physical activity among Chinese adults aged 20-59 years.

• Sample size was 55,804 adults aged 20-59 years from the 2020 National Fitness Survey.
• The correlation between family SES and MVPA was r = 0.053, p < 0.01.
• Multiple linear regression and chain-mediation modeling were performed using SPSS 30.0.
• The association was examined after accounting for mediating variables including exercise environment and exercise motivation.

Exercise environment independently mediated the relationship between family socioeconomic status and MVPA, accounting for the largest share of the total effect.

• The independent mediation effect size of exercise environment was 0.439 (95% CI = 0.387 ~ 0.494).
• This independent mediation pathway accounted for 48.67% of the total effect.
• This was the largest of the three identified mediation pathways.

Exercise motivation independently mediated the relationship between family socioeconomic status and MVPA.

• The independent mediation effect size of exercise motivation was 0.168 (95% CI = 0.141 ~ 0.195).
• This independent mediation pathway accounted for 18.63% of the total effect.
• This was the second largest of the three identified mediation pathways.

Exercise environment and exercise motivation jointly formed a chain-mediation pathway linking family socioeconomic status to MVPA.

• The chain-mediation effect size of exercise environment and exercise motivation together was 0.170 (95% CI = 0.128 ~ 0.151).
• This chain-mediation pathway accounted for 15.52% of the total effect.
• The pathway proceeds from family SES through exercise environment and then through exercise motivation to MVPA.

The direct effect of family socioeconomic status on MVPA varied across age subgroups.

• Ages 20-29: β = 0.090, 95% CI = 1.139 ~ 1.726, p < 0.01.
• Ages 30-39: β = 0.076, 95% CI = 0.854 ~ 1.311, p < 0.01.
• Ages 40-49: β = 0.059, 95% CI = 0.731 ~ 1.282, p < 0.01.
• Ages 50-59: β = 0.081, 95% CI = 1.410 ~ 2.101, p < 0.01.
• Significant interaction effects were observed across age subgroups, with the youngest (20-29) and oldest (50-59) groups showing the strongest direct effects.

The direct effect of family socioeconomic status on MVPA differed significantly between males and females.

• Males: β = 0.089, 95% CI = 1.315 ~ 1.709, p < 0.01.
• Females: β = 0.014, 95% CI = 0.033 ~ 0.430, p < 0.05.
• The effect was substantially stronger in males than in females.
• Significant interaction effects by sex were observed.

The direct effect of family socioeconomic status on MVPA was present in both urban and rural subgroups, with significant interaction effects.

• Urban residents: β = 0.038, 95% CI = 0.469 ~ 0.814, p < 0.01.
• Rural residents: β = 0.043, 95% CI = 0.592 ~ 1.160, p < 0.01.
• Significant interaction effects were observed across urban-rural subgroups.
• The effect was slightly stronger in rural than urban residents based on beta coefficients.