About the Authors

Xiaoxia Peng

Contributed equally to this work with: Xiaoxia Peng, Shige Song

Affiliation School of Public Health and Family Medicine, Capital Medical University, Beijing, China

Shige Song

Contributed equally to this work with: Xiaoxia Peng, Shige Song

Affiliation Institute of Sociology, Chinese Academy of Social Sciences, Beijing, China

Sheena Sullivan

Affiliation School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, Australia

Jingjun Qiu

Affiliation School of Public Health and Family Medicine, Capital Medical University, Beijing, China

Wei Wang

wei6014@yahoo.com

Affiliations School of Public Health and Family Medicine, Capital Medical University, Beijing, China, School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, Australia, Graduate School, Chinese Academy of Sciences, Beijing, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: XP S. Song WW. Analyzed the data: XP. Contributed reagents/materials/analysis tools: S. Song. Wrote the paper: XP. Participated in the preparation and revision of the manuscript: S. Sullivan WW. Contributed to administrative and technical support: JQ. Responsible for planning, acquisition of data, and obtaining funding for this study: WW.