Physical activity and constipation in Hong Kong adolescents

PLoS One. 2014 Feb 28;9(2):e90193. doi: 10.1371/journal.pone.0090193. eCollection 2014.


Objective: To examine the association of constipation with exercise, non-exercise physical activity, and sedentary behaviours in Hong Kong adolescents.

Methods: In 2006-2007, 42 secondary schools were randomly selected to participate in the Hong Kong Student Obesity Surveillance (HKSOS) project. A total of 33692 Form 1-7 students (44.9% boys; mean age 14.8, SD 1.9 years) completed an anonymous questionnaire on lifestyle behaviours. Constipation was defined as a frequency of evacuation of less than once every two days. Exercise (moderate-to-vigorous levels) and non-exercise physical activity (NEPA) were each considered insufficient when less than 1 hour per day, and sedentary behaviours were considered excessive when over 4 hours per day. Logistic regression was used to calculate adjusted odds ratio (AOR) for constipation in relation to exercise, NEPA, and sedentary behaviours, adjusting for potential confounders.

Results: Constipation was identified in 15.6% (95% CI 15.2% - 16.0%) of adolescents overall, 14.0% in those with sufficient exercise and 19.6% in those without. Constipation was associated with insufficient exercise (AOR 1.26, 95% CI 1.16 - 1.36), insufficient NEPA 1.21 (1.10 - 1.33) and excessive sedentary behaviours (1.25, 1.17 - 1.34). Compared with having none of the above 3 inactive behaviours, increasing AORs of constipation were observed for having 1 (AOR 1.23), 2 (AOR 1.57) and 3 (AOR 1.88) inactive behaviours (p for trend <0.001).

Conclusions: Constipation was associated with insufficient physical activity and excessive sedentary behaviours among Chinese adolescents with a dose-response relation. If the association is causal, constipation could be prevented by promotion of physical activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adolescent Behavior*
  • Constipation / epidemiology*
  • Female
  • Health Behavior
  • Hong Kong / epidemiology
  • Humans
  • Logistic Models
  • Male
  • Motor Activity / physiology*
  • Odds Ratio
  • Risk Factors
  • Schools
  • Sedentary Behavior*
  • Surveys and Questionnaires

Grants and funding

This work was supported by the Strategic Research Theme in Public Health of the University Research Committee, University of Hong Kong. There is no grant number, and the URL is: The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.