Time trends of physical activity for leisure and transportation in the Brazilian adult population: results from Vigitel, 2010-2019

This time-series study examined a 10-year historical series of the physical activity prevalence for leisure and transportation in the Brazilian adult population. Information from 512,969 adults interviewed from the Vigitel between 2010 and 2019 was analyzed. Individuals who reported practicing at least 150 minutes/week of moderate-intensity physical activity or at least 75 minutes/ week of vigorous-intensity physical activity were considered active during leisure time. Individuals who reported walking or cycling to/from work, course, or school at least 30 minutes/day, equivalent to at least 150 minutes/week of moderate-intensity physical activity, were considered active during transportation. The prevalence of physical activity for leisure and transportation was calculated annually and stratified by sex, age group, schooling, and race/ skin color. The segmented regression model was applied to analyze the time series. Annual percent change and average annual percent change were calculated. Over time, the prevalence of physical activity for leisure increased, and the prevalence of physical activity for transportation decreased. The highest prevalence of physical activity for


Background
The benefits of physical activity are widely recognized for mental and physical health in all age groups 1,2 . The regular practice of physical activity improves physical fitness, bodyweight control, and sleep quality and reduces the risk of cardiovascular diseases, high blood pressure, and type II diabetes 1 . Although these messages are highlighted in every health and well-being guideline 2 , physical activity levels are still insufficient worldwide 3,4 . Besides this pandemic of physical inactivity, the prevalence of obesity is expected to continue rising in the following years 5 , with serious implications for the global burden of chronic diseases. Note that the prolonged quarantine imposed by the COVID-19 pandemic had a negative impact on the physical activity level around the world, contributing to a worse quality of life, and that physical activity has proven to be beneficial in clinical conditions frequently associated with severe COVID-19 6 . Many countries are currently struggling to attenuate the negative impacts of these diseases, spending large amounts of public funds to keep complex health systems instead of investing in simple and inexpensive actions to promote physical activity 7,8,9 . This scenario places physical activity at the center of the public health program 10 , with a growing need for evidence on the effectiveness of different strategies to increase its levels. Thus, the scientific literature has shifted from emphasizing indicators and outcomes of physical activity to a more recent focus on context determinants, public policies, and global monitoring 11,12 . However, comprehending all aspects that affect physical activity as a lifestyle behavior is a complex task. Many personal and environmental factors, including age, sex, urban characteristics, safety, income, and others, play a role in people's decision to engage in health practices as part of their daily lives 13 . Similarly, economic and cultural aspects of different communities and regions can impact the perception of barriers encountered by population groups to perform physical activity 13,14 . Nevertheless, most research is conducted in high-income countries 15 .
Brazil has achieved some advances with surveillance programs and specific interventions targeting physical activity in different domains. In recent decades, behavior change programs have focused on physical activity for leisure, with educational and counseling actions associated with infrastructure investments and qualification of human resources 16,17 . Nonetheless, information about the process and impacts of these programs across regional areas and vulnerable groups is scarce 18,19 . These programs have given less attention to physical activity for transportation, with limited actions to promote active commuting for schools or local changes in urban structure and facilities to enable walking and bicycling 17 . The unequal distribution of these initiatives and the shortage of supportive urban environments in many countries of Latin America make sustaining these approaches in the long term more challenging 15, 20 .
Among these countries, Brazil stands out for monitoring physical activity behavior since 2006, with the Risk and Protective Factors Surveillance System for Chronic Noncomunicable Diseases Through Telephone Interview (Vigitel, in the Portuguese-language acronym) 21 . The Vigitel survey holds people sociodemographic and health information from all capitals and the Federal District, enabling a longitudinal analysis of physical activity among the Brazilian population 22 . An annual scientific report gathering all these data provides a unique opportunity to guide public health decision-making and tailor physical activity promotion strategies according to regional contexts and population profiles.
Despite the successful implementation of physical activity promotion strategies in Brazil, the implementation of actions is still rising, and more research is necessary to identify the circumstances and the differences among groups for the effective and sustainable adoption of an active lifestyle. Therefore, to better understand the physical activity pattern at the national level in different groups and guide policymakers to develop strategies to promote public health, this study aimed to analyze a historical series of the physical activity prevalence for leisure and transportation in the Brazilian population according to sex, age group, schooling, and race/skin color, by a 10-year temporal trend from 2010 to 2019. We have also investigated the difference in the overall prevalence of physical activity in both domains in the Brazilian state capitals and Federal District comparing the rates of the initial and final years of the historical series.

Methods
This time-series study analyzed data from the Brazilian adult population (≥ 18 years) from the Vigitel between 2010 and 2019. The Vigitel is a population-based study, started in 2006, whose objective is to monitor, by a telephone survey, the frequency and distribution of the main determinants of chronic diseases. For that purpose, each year, the system obtains probabilistic samples of adult individuals residing in households with at least one landline phone registered in each of the Brazilian state capitals and Federal District 23,24 .
The Vigitel sample size calculation defined a minimum sample of approximately 2,000 adults per city/year to estimate the frequency of any risk factor in this population, using a 95% confidence interval (95%CI) and a maximum error of two percentage points. For specific estimates, according to sex, a maximum error of three percentage points was expected, assuming similar proportions of women and men in the sample.
Briefly, the Vigitel sampling procedure is conducted in two stages. In the first stage, 5,000 probabilistic samples of telephone lines in each city are drawn. The Vigitel obtains the lists of telephone lines from the landline phone companies operating in the cities. Commercial and non-operational lines are excluded. This draw takes place systematically and stratified by region of the city or according to the prefix of the phone lines (area code). Then, the phone line samples are drawn again and organized into replicas of 200 lines. Each replica reproduces the same distribution ratio as the original record. The second stage involves identifying active residential lines in parallel with randomly selecting a resident aged 18 or over living in the respective household to answer the questionnaire 23 . More details of the sampling procedure can be seen in a previous publication and the annual report of the Brazilian Ministry of Health 23,24 .
The outcomes considered in this time-series study were the practice of physical activity for leisure and transportation. The block of questions corresponding to the physical activity practice was validated by Monteiro et al. 25 and remained unchanged over the analyzed period.
Physical activity for leisure was assessed using the following questions: "In the last three months, have you practiced any type of physical exercise or sport? (yes/no)", "Do you exercise at least once a week? (yes/no)", "How many days a week do you usually practice physical exercise or sport? (1-2; 3-4; 5-6 days/week; every day including Saturday and Sunday)", "On the day you practice exercise or sport, how long does this activity last? (< 10; 10-19; 20-29; 30-39; 40-49; 50-59; ≥ 60 minutes)" 24 . Individuals who reported practicing at least 150 minutes/week of moderate-intensity physical activity or at least 75 minutes/week of vigorous-intensity physical activity were considered active during leisure time 26 .
Concerning physical activity for transportation, the following questions were asked: "Do you go to or return from work walking or cycling?" (yes, the entire journey; yes, part of the journey; no)", "How much time do you spend to go to and return from this journey (on foot or by bicycle)? (< 10; 10-19; 20-29; 30-39; 40-49; 50-59; ≥ 60 minutes)", "Currently, are you attending a course/school or taking someone to a course/school? (yes/no)", "Do you go to or return from school walking or cycling? (yes, the entire journey; yes, part of the journey; no)", "How much time do you spend to go to and return from this journey (on foot or by bicycle)? (< 10; 10-19; 20-29; 30-39; 40-49; 50-59; ≥ 60 minutes)" 24 . Individuals who reported walking or cycling to/from work, course, or school at least 30 minutes/day, equivalent to at least 150 minutes/week of moderate-intensity physical activity, were considered active during transportation 26 .
The prevalence of active individuals in leisure and transportation was calculated annually from 2010 to 2019 for the total level and stratified by sex (male/female), age group (18-34/35-59/≥ 60 years), schooling in years (0-8/9-11/≥ 12), and self-perceived race/skin color (white/non-white). The prevalence was also estimated for the state capitals and Federal District for the initial and final years of the time series and the prevalence difference between these years (change) was calculated.

Data analysis
The annual prevalence of physical activity for leisure and transportation was calculated for the total sample and according to sex, age group, schooling, and self-perceived race/skin color. The complex sample design and the sample-weighting factor were considered in all these analyses. The differences between groups were evaluated using a 95%CI. A segmental regression model was used to analyze the physical activity prevalence time series 27 . This statistical modeling technique, also called joinpoint regression or regression with inflection points, explains the relationship between two variables by using regression lines. It also assumes a linear trend between these points and has the same assumptions of the linear regression, except for homoscedasticity and no autocorrelation. This analysis allows incorporating such conditions when they are violated in an adjustment using a weighted regression model.
In this study, the annual prevalence rates of physical activity were considered as dependent variables (Y) and years of the study period as independent variables (X). The segmented regression model allowed to categorize the prevalence trends as stationary, increasing, or decreasing and to detect points of change in the trends. This statistical approach assumes that the change in rates is constant over each time partition defined by the transition points but varies among different time partitions. This model also provides annual percent change (APC), average annual percent change (AAPC), and their respective 95%CI. Significant changes (increase or decrease) in variables were indicated when regression coefficients were significantly different from zero (p < 0.05).
Lastly, the chi-square test (χ²) was used to verify differences in the prevalence of physical activity for leisure and transportation between 2010 and 2019 for all state capitals and the Federal District. We used Stata, version 16.0 (https://www.stata.com); Python, version 3.7.10 (http://www.python. org); and R (http://www.r-project.org). The significance level adopted was 5%.

Results
From 2010 to 2019, the Vigitel interviewed 512,969 individuals. Participants were mostly women (53.9%); aged 35-59 years (42.7%); reported 9-11 years of schooling (37.5%), and declared having nonwhite skin color (55.6%). The annual prevalence rates of physical activity for leisure and transportation between 2010 and 2019 to total sample and by sex, age group, schooling, and race/skin color were calculated. Figure 1 shows a 10-year temporal trend (2010-2019) of physical activity for leisure and transportation according to sex, age group, schooling, and race/skin color. During the entire study period, prevalence of physical activity for leisure was significantly higher among men compared with women, individuals aged 18-34 years compared with the other age groups, and those with ≥ 12 years of schooling compared with other groups. The prevalence between white and non-white individuals showed no significant difference, except for the years 2010 and 2011, when the prevalence was significantly higher among white individuals. Concerning physical activity for transportation, we observed a significantly lower prevalence among those aged ≥ 60 years compared with younger groups and a significantly higher prevalence among non-white individuals compared with white individuals in all analyzed years. No significant difference was found between the sexes, age groups 18-34 and 35-59 years, and individuals with 0-8 and 9-11 years of schooling over the entire study period. Prevalence rates were significantly lower among those with ≥ 12 years of schooling compared with the other groups in the years 2010, 2014, 2017, and 2018. Table 1 shows the time trend analysis of physical activity for leisure. All variables showed a trend with only one inflection point over the study period. The total sample showed a significant increasing trend   Note: values refer to prevalence (blue, orange, and green lines) and 95% confidence interval (gray lines).
Cad. Saúde Pública 2022; 38(10):e00057222 Table 1 Segmented temporal analysis of physical activity for leisure. had a significant increasing trend during the whole period, with AAPC ranging from 0.45% for the age group ≥ 60 years to 1.11% for non-white individuals.
In the time trend analysis of physical activity for transportation, we found only one inflection point over the study period in all investigated variables ( Table 2)   Considering the Brazilian state capitals and Federal District, all cities, except for the Federal District and Porto Alegre, showed a statistically significant increase in the prevalence of physical activity for leisure between 2010 and 2019. The significant increase ranged from 5.5% in Recife to 18.7% in Rio Branco. Regarding physical activity for transportation, 17 out of 27 cities showed a significant reduction in prevalence between 2010 and 2019. The significant reduction ranged from 3% in Natal to 8.6% in Rio Branco (Table 3).

Discussion
This nationally representative study conducted with the Brazilian adult population showed opposite trends when analyzing the prevalence of physical activity for leisure and transportation over a 10-year period. We found that the prevalence of physical activity for leisure increased and the prevalence of physical activity for transportation decreased. The highest prevalence of physical activity for leisure occurred among males, young individuals (18-34 years), and those with high education (≥ 12 years), whereas older adults (≥ 60 years), those with high education (≥ 12 years), and white people presented the lowest prevalence of physical activity for transportation over the last decade. Consid-  ering the World Health Organization (WHO) action plan on physical activity that aims to support all people being more physically active and improving health 26 , our findings are quite relevant due to revealing inequalities in the physical activity levels in Brazil and identifying subgroups on which the public policies should be focused. The lower prevalence of physical activity for leisure observed in women, older individuals, and among those with lower schooling has been well documented in the literature 28,29,30,31,32,33,34 . Regarding race/skin color, some studies have described an association between white race/skin color and higher physical activity levels for leisure 29,35 , but little is known about the nature of this disparity. Most evidence attributes it to social class issues, such as unaffordable facilities, unavailable childcare, high crime rates, and fear for personal safety 28,34,35 . A prior study designed to examine the differences in physical activity for leisure by race/ethnicity and education in a nationally representative cohort of 9,261 community-dwelling adults in the United States showed that education was far more impor-Cad. Saúde Pública 2022; 38(10):e00057222 tant than race/ethnicity as a determinant of physical activity for leisure 29 . A more recent study, also conducted in the United States, demonstrated that white adults had a higher prevalence of physical activity than black adults, considering achieving 10 minutes of moderate activity and 10 minutes of vigorous activity in the past month. Nevertheless, individual poverty and neighborhood poverty were associated with decreased physical activity rates among both white and black participants 36 . Findings from the National Health and Nutrition Examination Survey (NHANES 2007(NHANES -2016, also demonstrated that among adolescents and young adults (12-29 years), younger age, white race, and higher income were associated with a higher level of physical activity for leisure 37 .
As far as we know, in Brazil, only two studies investigated the relationship between physical activity for leisure and race/skin color and they found a higher prevalence of physical activity for leisure among white adults 30,38 . In this study, the prevalence of physical activity for leisure was higher in white adults solely in the years 2010-2011, showing no difference in the years from 2012 to 2019. A possible explanation for the lack of difference observed since 2012 is the implementation of the Health Academy Program in Brazil, by the Ministry of Health, in 2011 39 . Preliminary results from one center of the Health Academy Program in Belo Horizonte showed that most participants of this program were non-white individuals (56.4%) 40 .
The main objective of the Health Academy Program is to promote health for all the population by implementing gym centers throughout Brazil, with infrastructure, equipment, and professional staff 41 . This program includes physical activity classes in rehabilitated public open spaces in lowincome neighborhoods, health screening and counseling, and many other community-building activities in place-based settings (parks and plazas) 39 . A prior study investigated the impact of the Health Academy Program in 80 cities in the Pernambuco state, assessing 2,370 individuals in 2011, 3,824 individuals in 2012, and 3,835 individuals in 2013. The authors reported that the odds of reaching 150 minutes/week of physical activity for leisure was 5.06 (95%CI: 3.34; 7.67) for current participants (≤ 6 months) and 10.35 (95%CI: 6.93; 15.47) for current participants (> 6 months) compared with individuals that never participated 42 . A recent scoping review, including 24 studies published between 2008 and 2020, concluded that the Health Academy Program increases the amount of physical activity for leisure 39 . These findings are in line with our results, which showed an increase in the prevalence of physical activity for leisure from 2010 to 2015 in the Brazilian adult population, irrespective of sex, schooling, and race/skin color. The national coverage of this program can also justify the increase in the prevalence of physical activity for leisure in most Brazilian state capitals.
Regarding the physical activity for transportation, shifts from sedentary transport to active transport (walking and cycling) are a potential source of physical activity and enable its accumulation in daily life, rather than requiring intentional exercise 43 . In this study, the prevalence of adults that reached the recommended level of 150 minutes of moderate activity during the week accrued from active transport was low compared with studies from other countries 43,44 , varying from 11.9% to 17.9%, and it decreased over the 10-year period (AAPC = -0.32). In fact, the prevalence of physical activity for transportation decreased from 2010 to 2013 (APC = -1.80) and increased slightly from 2014 to 2019 (APC = 0.46). However, the increase was insufficient to offset the decrease at the beginning of the decade.
The use of public transportation in Brazil is associated with lower income 45,46 , which hinders access to individual means of transportation more efficient than collective modes 47 . From 2001 to 2012, the increase in the average income of the Brazilian population was accompanied by a rise of 138.6% in the fleet of motor vehicles, with a remarkable increase of 14.6% in the year 2012 48 , which may have contributed substantially to reducing physical activity for transportation as observed in this study. A study conducted on a large sample of Swedish adults reported that vehicle ownership mediated a significant proportion of the association between walkability parameters (e.g., residential density and land use mix) and walking for transportation 49 . Note that the inflection point observed between 2013 and 2014 happened at the same time as the deep economic Brazilian recession that started in the second trimester of 2014 and severely compromised the workers' income 50 , which may have contributed to an increase in active transport in this period. Regarding the increase in the prevalence of physical activity for transportation in the period from 2014 to 2019, note that the bike lanes in Brazilian capitals increased by 133% from 2014 to 2018, which is as an effective government strategy to improve cycling for transport and leisure 51 .
Cad. Saúde Pública 2022; 38(10):e00057222 The higher prevalence of physical activity for transportation in adults with lower education (< 12 years of schooling) and non-white race/skin color observed in all years studied reinforces the association between active transport and lower socioeconomic status. In Brazil, these individual characteristics are associated with informal work, unemployment, and lower average earnings per hour 52 . When considering solely the race/skin color, 70% of the people who live below the poverty line and 69% of the people who live in houses with some sort of inadequacy are black or mixed race 53 . A prior study developed in Curitiba (Brazil) has shown that adults living in areas with higher income showed a 44% lower likelihood of walking for transportation when compared with residents of lower-income areas 54 .
The inverse relationship between socioeconomic status and physical activity for transportation has been described elsewhere, mainly in low-and middle-income countries 45,46,54 , where occupational, household, and transport domains are the most common types of physical activity. A prior study designed to provide data about the frequency and distribution of active transportation to work in Brazil showed that around one-third of the adult population travels on foot or by bike to work and the frequency of active transportation decreased with increased income and schooling in both sexes and was higher among younger adults 45 . According to Rydin et al. 55 , the higher prevalence of physical activity for transportation in low-and middle-income countries might be due to the budgetary constraint of the poorest families, the spatial segregation existing in the metropolises, and the precariousness of public transport, rather than a practice guided by the health benefits. By contrast, in high-income countries, physical activity for leisure is the main contributor to the total physical activity level 13 .
This study has some limitations. The Vigitel sample included only the households with landlines, which could potentially introduce some selection bias. However, post-stratification weights were used to minimize possible sociodemographic differences and the absence of universal coverage of the telephone landline network 56 . Also, physical activity measures were obtained by self-report, which could lead to an under or overestimation of the prevalence. To minimize this bias, the Vigitel planning included information quality control with the management of each survey measure. Studies evaluating the physical activity indicators' validity and reliability have shown that they seem reproducible and sufficiently accurate 25,57 .
As for strengths, we highlight the use of data from a population-based survey including all Brazilian capitals and the Federal District, with a large sample in a 10-year historical series. Also, we analyzed the trends of physical activity for leisure and transportation according to important sociodemographic characteristics of the sample, such as sex, age group, schooling, and race/skin color. The study results may contribute to monitoring risk factors for chronic diseases and subside the policymakers to implementing public policies to promote physical activity and improve active mobility in cities.
To comprehend other aspects associated with the variation in the prevalence of physical activity for leisure and transportation in the Brazilian adult population, future studies should address environmental factors, such as climate and urban characteristics, including safety, structure, and facilities that enable walking and cycling.

Conclusions
During the 10-year study period, the prevalence of physical activity for leisure increased and the prevalence of physical activity for transportation decreased. Regarding the different sociodemographic groups, women, individuals aged ≥ 35 years, and those with lower education (< 12 years) showed a lower prevalence of physical activity for leisure, whereas older adults (≥ 60 years), those with high education (≥ 12 years), and white people demonstrated a lower prevalence of physical activity for transportation. Considering the Brazilian state capitals and Federal District, the prevalence of physical activity for leisure increased in most cities, whereas the prevalence of physical activity for transportation decreased in 17 out of 27 cities. To increase the overall physical activity level of the population, policymakers should propose synergic strategies that encourage and facilitate physical activity for leisure and transportation, also considering the differences among sex, age group, schooling, and race/skin color.  La prevalencia de la actividad física para el ocio y el transporte se calculó anualmente y se estratificó por sexo, grupo de edad, escolaridad y color de piel/ raza. Se aplicó un modelo de regresión segmentada para analizar la serie temporal. Se calcularon las variaciones porcentuales anuales y las variaciones porcentuales medias anuales. Con el paso del tiempo, la prevalencia de la actividad física para el ocio tuvo un aumento y una reducción para el transporte. La mayor prevalencia de actividad física para el ocio se observó entre hombres, jóvenes y personas con educación secundaria. Los ancianos, las personas con educación secundaria y los blancos tuvieron una prevalencia más baja en el transporte activo. Los formuladores de políticas deben proponer estrategias de fomento a la actividad física para el ocio en mujeres, personas ≥ 35 años y personas con baja escolaridad (< 12 años), y la actividad física para el transporte entre los ancianos (≥ 60 años), aquellos con educación secundaria (≥ 12 años) y personas blancas.