Who, when, and how much? Epidemiology of walking in a middle-income country.

BACKGROUND: Physical inactivity is one of the leading causes of morbidity and mortality worldwide. Walking, an inexpensive and accessible activity, is protective against unhealthy outcomes. Little data on walking practices are available outside developed countries. This study estimated the prevalence and correlates of compliance with physical activity recommendations through leisure-time and all-domain (combined leisure time, commuting, and work-related) walking in individuals aged > or =20 years in a southern Brazilian city.

METHODS: Data from two population-based surveys carried out in 2002 and 2003 in Pelotas, Rio Grande do Sul, were compared and analyzed in 2004. Multistage sampling procedures were undertaken in both surveys. Compliance with physical activity recommendations was defined as > or =150 minutes/week of walking during the previous week, although other cut-off points were estimated. The International Physical Activity Questionnaire was used in both studies.

RESULTS: Samples comprised 3182 (2002 study) and 3100 (2003 study) individuals. Nonresponse rates were 5.6% and 3.5%, respectively. Both prevalence and correlates of leisure-time and all-domains walking were markedly different. Compliance with physical activity guidelines (> or =150 minutes/week) through walking was 40.6% (all domains) and 15.0% (leisure time). Poor and uneducated participants had a lower likelihood of walking than higher-income and more educated people, particularly in leisure time. Walkers were also more likely to practice other vigorous and moderate-intensity activities.

CONCLUSIONS: Although the results derive from a single Brazilian city, they are likely to be relevant to similar environments/locales in middle-income countries, where the obesity epidemic is rapidly increasing. Due to the low levels of walking detected, particularly during leisure time, healthcare professionals are encouraged to recommend walking to their patients.