Physical Inactivity in China: Findings from 645 903 Adults in Consecutive Nationally Representative Surveys During 2010 to 2018

Background: Physical inactivity is an essential health-related behaviour and a significant risk factor for chronic non-communicable diseases. Temporal trends in physical inactivity in Chinese adults are unclear. Method: Four nationally representative cross-sectional surveys were conducted in 31 provinces in China between 2010 and 2018. Using a multi-stage, stratified, cluster-randomized sampling method, 669 919 Chinese adults were selected to participate in the surveys, and 645 903 adults were included in the analyses. Domain-specific (work-, transport-, and recreation-) moderate- to vigorous-intensity physical activity (MVPA) was measured using the Global Physical Activity Questionnaire. Physical activity  was defined as not doing at least 150 minutes of moderate-intensity, 75 minutes of vigorous-intensity PA per week, or any equivalent combination of the two. Temporal changes in physical inactivity and no domain-specific PA were analyzed using linear regression methods. All analysis was accounted for the complex sampling design. Findings: From 2010 to 2018, the prevalence of physical inactivity among Chinese adults increased from 17·9% (95%CI, 16·3-19·5) to 22·3% (95%CI, 20·9-23·8) (Ptrend <0·0001). The increasing trends were more pronounced in rural adults aged 18-34 years (17·9% to 26·7%), less educated (16·8% to 21·2%), and those engaged in agriculture related-work (13·6% to 19·2%) (all Ptrend <0·0001). The prevalence of no work-related PA increased from 20·4% (95%CI, 18·5-22·2) to 33·2% (95%CI, 31·3-35·1), while no recreation-related PA prevalence decreased from 83·1% (95%CI, 81·0-85·1) to 78·9% (95%CI, 76·6-79·4) (all Ptrend <0·0001). An increase was observed in trends associated with mean minutes per week of recreation-related MVPA; however, a decrease was observed in work-related MVPA. Interpretation: In China, more than one-fifth of adults failed to achieve the recommendation of adequate PA. The current trend in physical inactivity is rising. We found divergent trends in the no domain-specific physical activity , highlighting the need for developing more targeted physical activity promotion strategies to improve population health. Funding: The National Key R&D Program of China (grant number: 2018YFC1311702, 2018YFC1311076), Chinese central government. Declaration of Interest: The authors have no competing interests to declare. Ethical Approval: All CCDRFS surveys were approved by the National Health and Family Planning Commission of China (former Ministry of Health) and Ethical Committee of National Centre for Chronic and NonCommunicable Disease Control and Prevention, Chinese Centre for Disease Control and Prevention (No.201010, No.201307, No.201519-A, No.201819). Every participant provided written informed consent.