Background and Purpose
Physical activity is an important determinant of overall health by preventing diseases and promoting health. Major advances in continuous monitoring of indicators of physical activity and sedentary behavior were achieved in Brazil in recent years through the consolidation of the Surveillance of Risk and Protective Factors for Chronic Diseases Telephone Survey (Vigitel). Previous data from Vigitel (2006-2009) showed unfavorable physical activity and sedentary behavior trends and persistency of inequities against vulnerable groups (children, elderly, women and less educated people). These have led to many national public policies seeking to promote physical activity and reduce sedentary behavior.

Objectives
To analyze time trends in physical activity levels and sedentary behavior in Brazilian adults from 2009 to 2012.

Methods
We used data from Vigitel, a cross-sectional telephone-based study of adults (18 or older) living in households with a fixed telephone line in all 26 Brazilian capitals and the Federal District. We estimated trends from 2009 to 2012 for four indicators: (I) active in leisure time (weekly practice of at least 150 minutes of moderate physical activity or 75 minutes of vigorous physical activity during leisure time), (II) active in transportation to work or school (usual roundtrip of at least 30 minutes to work or school using bicycle or walking), (III) physically inactive (absence of any physical activity in leisure time in the last three months; of physical exertion at work; of commuting to work or school by walking or cycling and of performing heavy house cleaning), (IV) time watching television of three or more hours a day (proxy of sedentary behavior). The prevalence of indicators was presented by sex, age and education level of the study population for the year 2012. Poisson regression models were used to determine significant variation in the indicator between 2009 and 2012, having the year as the independent variable. We considered changes significant when regression coefficients for the variable 'year of survey' were statistically different from zero for a p-value of less than 0.05.

Results
Between 2009 and 2012, we identified an increase in the proportion of actives in leisure time (men: 39.0 to 41.5%; women: 22.1 to 26.5%) (p<0.01) and a reduction in the proportion of actives at transportation (men: 17.6 to 13.8%, women: 16.5 to 14.5%) (p<0.001). Also, the prevalence of physical inactivity in both sexes remained unchanged (~15%), while the proportion of men who watch three or more hours of TV daily increased (22.4 to 26.5%)  (p <0.001). In 2012, leisure-time physical activity was higher in men, directly associated with education and inversely associated with age. Active transportation decreased only after 55 years of age and was inversely associated with education. Watching TV for more than 3h/day was more prevalent in the youngest (18-24 y) and in the oldest (= 55 y) and inversely associated with education. Physical inactivity increased only after 55 years of age.

Conclusions
The time-trend analysis reveals a worrying scenario: stagnation in high levels of physical inactivity, reduction of active transportation and increase of TV watching among men. Also, similarly to what had been previously observed, inequities against vulnerable groups persist in all outcomes, even in leisure-time physical activity (the only indicator with positive trends in the studied period). This scenario might indicate low short-term effectiveness of the increasing governmental efforts to promote physical activity in the country, although specific evaluation studies are still needed.

Implications for Practice and Policy
Improvements in surveillance systems have provided valuable information on population levels of physical activity and sedentary behavior in Brazil. The current unfavorable context concerning physical activity requires cross-sector policies and comprehensive evaluation of interventions. Also, programs and policies with evidence of suitability and cost-effectiveness in developing countries should be prioritized, such as the consolidation of physical activity at school and the expansion of Open Streets programs for active recreation.

Support / Funding Source
Agency of the São Paulo Research Foundation (Fapesp).