title: The International Prevalence Study on Physical Activity: results from 20 countries.
abstract: BACKGROUND
  Physical activity (PA) is one of the most important factors for improving population health, but no standardised systems exist for international surveillance. The International Physical Activity Questionnaire (IPAQ) was developed for international surveillance. The purpose of this study was a comparative international study of population physical activity prevalence across 20 countries.
  
  
  METHODS
  Between 2002-2004, a standardised protocol using IPAQ was used to assess PA participation in 20 countries [total N = 52,746, aged 18-65 years]. The median survey response rate was 61%. Physical activity levels were categorised as "low", "moderate" and "high". Age-adjusted prevalence estimates are presented by sex.
  
  
  RESULTS
  The prevalence of "high PA" varied from 21-63%; in eight countries high PA was reported for over half of the adult population. The prevalence of "low PA" varied from 9% to 43%. Males more frequently reported high PA than females in 17 of 20 countries. The prevalence of low PA ranged from 7-41% among males, and 6-49% among females. Gender differences were noted, especially for younger adults, with males more active than females in most countries. Markedly lower physical activity prevalence (10% difference) with increasing age was noted in 11 of 19 countries for males, but only in three countries for women. The ways populations accumulated PA differed, with some reporting mostly vigorous intensity activities and others mostly walking.
  
  
  CONCLUSIONS
  This study demonstrated the feasibility of international PA surveillance, and showed that IPAQ is an acceptable surveillance instrument, at least within countries. If assessment methods are used consistently over time, trend data will inform countries about the success of their efforts to promote physical activity.
authors.affiliation: Centre for Physical Activity and Health, School of Public Health, University of Sydney, Sydney, Australia. adrianb@health.usyd.edu.au.
authors.forename: Adrian
authors.initials: A
authors.lastname: Bauman
authors.forename: Fiona
authors.initials: F
authors.lastname: Bull
authors.forename: Tien
authors.initials: T
authors.lastname: Chey
authors.forename: Cora L
authors.initials: CL
authors.lastname: Craig
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Ainsworth
authors.forename: James F
authors.initials: JF
authors.lastname: Sallis
authors.forename: Heather R
authors.initials: HR
authors.lastname: Bowles
authors.forename: Maria
authors.initials: M
authors.lastname: Hagstromer
authors.forename: Michael
authors.initials: M
authors.lastname: Sjostrom
authors.forename: Michael
authors.initials: M
authors.lastname: Pratt