Abstracts

INTRODUCTION

The regular practice of physical activity (PA) has been recommended for people all ages due to its beneficial effects on health¹1 . World Health Organization. Global recommendations on physical activity for health. Geneva: WHO; 2010.. Such effects are also observed in both physical²2 . Strong WB, Malina RM, Blimkie CJ, Daniels SR, Dishman RK, Gutin B, et al. Evidence based physical activity for school-age youth. J Pediatr 2005; 146(6): 732-7. and mental health³3 . Biddle SJ, Asare M. Physical activity and mental health in children and adolescents: a review of reviews. Br J Sports Med 2011; 45(11): 886-95. of children and adolescents. Despite that, a great proportion of young people have low levels of PA⁴4 . Hallal PC, Andersen LB, Bull FC, Guthold R, Haskell W, Ekelund U; Lancet Physical Activity Series Working Group. Global physical activity levels: surveillance progress, pitfalls, and prospects. Lancet 2012; 380(9838): 247-57.. Evidence suggest that the physically active behavior in adolescence tends to be continued in adulthood⁵5 . Friedman HS, Martin LR, Tucker JS, Criqui MH, Kern ML, Reynolds CA. Stability of Physical Activity across the Lifespan. J Health Psychol 2008; 13(8): 1092-104..

In this sense, the understanding of the factors which influence PA among adolescents is important in order to develop intervention strategies which maintain or attenuate the declines observed at this age⁶6 . Marshall SJ, Biddle SJ, Gorely T, Cameron N, Murdey I. Relationships between media use, body fatness and physical activity in children and youth: a meta-analysis. Int J Obes Relat Metab Disord 2004; 28(10): 1238-46.. Several studies have been trying to understand the correlates and determinants of PA among adolescents, in order to increase the effectiveness of programs and interventions on the promotion of PA among teenagers⁷7 . Bauman AE, Reis RS, Sallis JF, Wells JC, Loos RJ, Martin BW; Lancet Physical Activity Series Working Group. Correlates of physical activity: why are some people physically active and others not? The Lancet 2012; 380(9838): 258-71..

Practicing PA demands spaces and specific facilities, therefore the study of the natural and built up environments' characteristics is important in the understanding of how much those are able to stimulate or inhibit PA⁸8 . Hino AAF, Reis RS, Florindo AA. Ambiente construído e atividade física: Uma breve revisão dos métodos de avaliação. Rev Bras Cineantropom Desempenho Hum 2010; 12(5): 387-94. ^{, 9}9 . Sallis JF, Cervero RB, Ascher W, Henderson KA, Kraft MK, Kerr J. An ecological approach to creating active living communities. Annu Rev Public Health 2006; 27: 297-322.. In fact, there is an increasing number of studies assessing the relations between environment and youngsters' PA¹⁰10 . Ding D, Gebel K. Built environment, physical activity, and obesity: what have we learned from reviewing the literature? Health Place 2012; 18(1): 100-5.. Among teenagers, it is believed that the influence of the social and built up environments is also important¹¹11 . Ding D, Sallis JF, Kerr J, Lee S, Rosenberg DE Neighborhood environment and physical activity among youth: A review. Am J Prev Med 2011; 41(4): 442-55. ^{, 12}12 . Davison KK, Lawson CT. Do attributes in the physical environment influence children's physical activity? A review of the literature. Int J Behav Nutr Phys Act 2006; 3: 19., once they are subjected to social standards or rules (parents' authorization or friends' invitations, for example) which may interfere on their access to a number of locations, including places intended for PA practicing. For example, adolescents who live in more insecure regions, in terms of crime incidence, and with higher social disorder¹³13 . Molnar BE, Gortmaker SL, Bull FC, Buka SL. Unsafe to Play? Neighborhood Disorder and Lack of Safety Predict Reduced Physical Activity Among Urban Children and Adolescents. Am J Health Promot. 2004; 18(5): 378-86. or the ones living far from parks and recreational facilities¹⁴14 . Cohen DA, Ashwood JS, Scott MM, Overton A, Evenson KR, Staten LK et al. Public Parks and Physical Activity Among Adolescent Girls. Pediatics 2006; 118(5): e1381-9. are less active than teenagers who live in safer places and close to parks. However, there is basically no evidence of this relation in countries of low or medium incomes. In Brazil, two large studies carried out in capitals do not present a direct relation between safety perception and PA practice. Nevertheless, the same studies show that observing people their own age practicing PA in the neighborhood and noticing the existence of places they like near their home (♂ OR = 1.96; 95%CI 1.40 - 2.78 and ♀ OR = 1.33; 95%CI 1.10 - 1.74)¹⁵15 . de Farias Júnior JC, Lopes Ada S, Mota J, Santos MP, Ribeiro JC, Hallal PC. Perception of the social and built environment and physical activity among Northeastern Brazil adolescents. Prev Med 2011; 52(2): 114-9. and the presence of people their own age (♀ OR = 1.8; IC95% 1.3 - 2.4) are associated to PA practice¹⁶16 . Reis RS, Hino AA, Florindo AA, Añez CR, Domingues MR. Association between physical activity in parks and perceived environment: a study with adolescents. J Phys Act Health 2009; 6(4): 503-9..

However, in addition to being limited and few studies, the results available up until now show inconsistency as to their findings. Thus, given the need for broadening the knowledge on PA correlates among Brazilian adolescents and the neraly inexistence of studies on which environmental characteristics are related to PA in this age group, this study aims at analyzing the association between the characteristics perceived in the neighborhood environment and the practice of PA among high school students in the city of Curitiba (PR).

METHODS

This study is characterized as a school-based cross-sectional survey. The data were collected between March and May 2006, in Curitiba (PR), as a part of the project "Determinantes da atividade física e obesidade em escolares do ensino médio da rede pública da cidade de Curitiba (PR), Brasil" ("Determinants of physical activity and obesity among high school students from public schools in Curitiba (PR), Brazil").

According to the Secretaria Estadual de Educação do Paraná, in 2006 (year when the data were collected), there was a municipal population of 42,563 student adolescents in public schools, studying during daytime. In order to estimate the size of the sample, there were considered a sampling error of three percentage points, a estimated prevalence for PA practice at recommended levels of¹1 . World Health Organization. Global recommendations on physical activity for health. Geneva: WHO; 2010. 50%, a design effects of 1.5, a confidence interval of 95% and an additional 10% for eventual losses and refusals. Based on these criteria, we reached a minimum sample of 1,609 adolescents. The final sample consisted of 1,611 high school students. The sample size, calculated a posteriori, allows the detection of associations of higher chance at 1.15 with minimum power of 87% for an alpha value of 5%. For this, the G*Power software, version 3.1.3, was used. In order to obtain a representative sample, we used a process of cluster proportional selection in two stages. In the first one, it was established the proportion of students according to the number of enrollments in each one of the nine administrative regions of Curitiba. Schools were selected randomly (n = 14) so that the number of students would meet the desired proportion for each region. In the second stage, the proportion of students in each one of the three high school grades in the regions was determined. School classes, with enough students to meet the desired number of students per grade, were randomly selected (n = 62) within the participant schools.

For the collection of the data, a questionnaire previously developed and validated for the evaluation of the perceived environment among American adolescents¹⁷17 . Rosenberg D. Neighborhood Environment Walkability Scale for Youth (NEWS-Y): reliability and relationship with physical activity. Preventive Medicine 2009; 49(213): 8.; however, it was translated and adapted into Portuguese and it presented adequate reliability values. For the present study, the Portuguese version was used in a group of teenagers in order to test the clarity and understanding of the items¹⁸18 . Farias Júnior JC. Development and validation of a questionnaire measuring factors associated with physical activity in adolescents. Rev Bras Saude Mater Infant 2011; 11(3): 301-12.. Its use was carried out inside the classroom, during Physical Education class, and guided by interviewers who were trained for such.

In order to assess the overall PA, we used the question adopted by the Youth Risk Behavior Surveillance System¹⁹19 . Centers for Disease Control and Prevention. Physical activity levels of high school students - United States, 2010. MMWR Morb Mortal Wkly Rep 2011; 60(23): 773-7.. This measure has already been used in Brazilian studies²⁰20 . Farias Júnior JC, Siqueira FV, Nahas MV, Barros MVG. Prevalence and associated factors to insufficient level physical activity and in youth from two city of Brazil: last seven days or typical week. Rev Bras Ativ Fís Saúde 2011; 25(4): 619-29. and it presents acceptable elevated reproducibility values (Interclass Correlation R = 0.87; 95%CI 0.81 - 0.91) and concurrent validity²¹21 . Nahas MV, Barros MVG, Florindo AA, Farias Júnior JC, Hallal PC, Konrad L et al. Reprodutibilidade e validade do questionário saude na boa para avaliar atividade física e habitos alimentares em escolares do ensino médio. Rev Bras Ativ Fís Saúde 2007; 12(3): 10-8.. The teenagers who reported practicing PA five or more days a week for at least 60 minutes were classified as active, corresponding to the most recent PA recommendations among youngsters¹1 . World Health Organization. Global recommendations on physical activity for health. Geneva: WHO; 2010.. Once the perceived environment variables may present several forms of association for different PA levels²²22 . Gordon-Larsen P, McMurray RG, Popkin BM. Determinants of adolescent physical activity and inactivity patterns. Pediatrics 2000; 105(6): E83., a question was used in order to identify the adolescents who take up any PA for at least 20 minutes at least once a week. This question has also been used in surveys of national coverage with American teenagers²³23 . Lowry R, Lee SM, Fulton JE, Kann L. Healthy People 2010 Objectives for Physical Activity, Physical Education, and Television Viewing Among Adolescents: National Trends From the Youth Risk Behavior Surveillance System, 1999-2007. J Phys Act Health 2009; 6 Suppl 1: S36-45..

The perception of the neighborhood environment was assessed by tem questions on the characteristics of the neighborhood in which the teenager lives, based on the items of the module of perceived environment assessment¹⁷17 . Rosenberg D. Neighborhood Environment Walkability Scale for Youth (NEWS-Y): reliability and relationship with physical activity. Preventive Medicine 2009; 49(213): 8.. The processes of translation, clarity and reliability were previously performed in a pilot study with Portuguese adolescents²⁴24 . Santos MP, Page AS, Cooper AR, Ribeiro JC, Mota J. Perceptions of the built environment in relation to physical activity in Portuguese adolescents. Health Place 2009; 15(2): 548-52.. For this study, the translated version was used in a group of teenagers in order to assess its clarity and understanding, and there was no need for further adaptations. The questions used were: "there are many places I like", "Most streets have sidewalks", "there are biking tracks or walking trails", "taking a walk or playing is safe in my neighborhood", "it is easy to see people walking", "there is so much traffic it is difficult to take a walk", "there are too many crimes", "I always see people my age playing or exercising", "There are a lot of interesting things to be seen when I take a walk", "the streets are well lit at night". The response options consisted of four categories ("I strongly disagree", "I disagree", "I agree" and "I strongly agree").

Two strategies were adopted for the analysis. First, the association between each question on the environment and the study's outcomes (PA) were analyzed and, for such, the answers were grouped in "I agree" (including the options "I agree" and "I strongly agree") and "I disagree" ("I disagree" and "I strongly disagree"). Then, the overall perception on the characteristics of the neighborhood were analyzed considering all questions, having assigned values between 1 (I strongly disagree) and 4 (I strongly agree), with a final score varying from 10 (minimum) to 40 (maximum) points. In order for the highest score to represent the best environmental perception, the questions "there is so much traffic it is difficult to take a walk" and "there are too many crimes" had their scores inverted. The final result was named "Overall perception of the neighborhood environment", which was categorized: "very bad", "bad", "good" and "very good".

The variables gender, age, weight, height, mother and father school education and the number of cars in the house were self-reported and used as potential confounding variables. Weight and height were used in order to calculate the body mass index (BMI). For this classification, we used the cutoff point derived from the Brazilian population²⁵25 . Conde WL, Monteiro CA. Body mass index cutoff points for evaluation of nutritional status in Brazilian children and adolescents. J Pediatr (Rio J). 2006; 82(4): 266-72. to define the classes "average weight" (low and normal weight) and "excess of weight" (overweight and/or obesity). The highest parental school education (father or mother) was used considering the highest of the three categories: complete elementary school (parents with no school education or complete elementary education, at best), complete high school education (parents who finished high school or who have incomplete college education) and complete college education (parents who, at least, finished their college education). The number of cars in the house was grouped into four categories (none; one; two; and three or more cars).

For the description of the participants in the study, the distribution of absolute and relative frequencies was used, comparing both gender using the χ² test for proportions. Potential confounding variables were identified according to the criteria suggested in literature: 1) to be associated with the dependent variable within the "exposure" levels; 2) to be associated to the exposure and 3) not to be an "effect" of the "exposure" (independent variable)²⁶26 . Rothman KJ, Greenlan S, Lash TL. "Validade em estudos epidemiológicos". In Epidemiologia Moderna. ArtMed: Porto Alegre; 2011. p. 887.. Similar studies have identified, yet, that the factors associated to PA differ significantly between genders¹⁵15 . de Farias Júnior JC, Lopes Ada S, Mota J, Santos MP, Ribeiro JC, Hallal PC. Perception of the social and built environment and physical activity among Northeastern Brazil adolescents. Prev Med 2011; 52(2): 114-9., therefore it was chosen to conduct the stratifies analyses according to the gender.

The relation between the variables of perceived neighborhood environment and the practice of PA was analyzed according to two outcomes (to exercise at least 20 minutes a day/week and to fulfill the recommendation of 60 minutes of PA at least Five days/week) through binary logistic regressions stratified by gender. The raw model was obtained through the analysis of neighborhood environmental factors with PA (for both outcomes); then, for the adjusted model, the relation between each environmental variable and the PA was analyzed, considering the confounding variables, specifically for outcomes and strata (gender). Finally, besides the confounding variables, all factors of neighborhood environment perception statistically related to PA were inserted in a third model of analysis. Such analyses were carried out by the statistical softwares SPSS 17.0 and STATA 9.2 and the significance level was kept at 5%. Considering it is a cluster sample, the correction for the design effect was performed through the "svy" command for the analysis of data from complex samples.

The research was approved by the Research Ethics Committee of the Pontifícia Universidade Católica do Paraná (CEP-PUCPR, No. 1076/2006) and the protocols followed the recommendations by the National System of Research Ethics.

RESULTS

The characteristics of the studied sample are presented in Table 1. Most part of the sample consisted of girls (59.7%), with largest proportion of teenagers, in both gender, it is in a similar and concentrated age range between 15 and 17 years of age (84.0%). Largely, adolescents reported that the highest parental school education was complete high school level and that they possess at least one family car. Also, most participants reported that, in their neighborhood, there are places they like (64.9%), There are sidewalks (63.4%) and biking tracks (56.2%) and safety is perceived as positive (52.9%). The "overall neighborhood environment perception" as "very good" was more frequent among boys (34.0% considered it to be "very good") when compared to girls (23.1%). Finally, most part of the participants (82.9%) take part in some PA (at least 20 minutes in one day/week), though only 14% of them classify within the recommendation for PA practice with benefits to health (60 minutes at least five days/week). In general, the proportion of active boys was higher than the one of girls for both PA outcomes (91.2 versus 82.9%; 21.9 versus 9.4%, respectively).

In Table 2, the analyses of the raw and adjusted associations between the perceived environment variables and the PA for boys and girls are presented, following the 20-minute PA criterion. Among girls, the only neighborhood environment variable which remained in the final model, after the adjustment of the remaining variables, was "there are interesting things in my neighborhood" (OR = 1.77; 95%CI 1.05 - 2.96). Among boys, the variables "There are places I like in my neighborhood" (OR = 2.18; 95%CI 1.33 - 3.58) and "I see people my age practicing PA" (OR = 1.95; 95%CI 1.13 - 3.37) remained associated to PA in the final model. The "overall neighborhood environment perception" remained associated to PA for both girls (OR = 1.92; 95%CI 1.15 - 3.22) and boys (OR = 3.13; 95%CI 1.97 - 4.97)

In Table 3 we presented the results of the association between PA practice at recommended levels and the neighborhood environment perception, according to gender. Among girls, there were no associations for any of the environmental variables, while among boys only the variable "I see people my age practicing PA" remained associated to the final model (OR = 1.68; 95%CI 1.15 - 2.45). No associations to the indicator "overall neighborhood perception" were observed for either gender.

DISCUSSION

This was one of the first studies to identify the environmental correlates among adolescents in Brazil and one of the few in Latin America. The probabilistic sampling allowed inferring to the population of public schools of the city and had enough power to detect relatively small effects. Still, the analyses were stratified between boys and girls, enabling gender-specific applications. Besides that, the confounding variables were properly tested and applied according to the normative criteria, not limited only to what has been suggested in the literature. At last, two distinct cutoff points were used, allowing the identification of variables which may contribute so that teenagers do "some/any" physical activity and achieve the recommended activity levels, making this study more applicable into reality.

However, some limitations ought to be considered for the interpretation of this study's results. Its cross-sectional design does not allow identifying the sense of the observed associations, and therefore, the adolescents may have presented better perception of their environment as a result of the increased levels of PA. The PA practice was assesses by a widely used overall measure with adequate psychometric properties²⁷27 . Lee KS, Loprinzi PD, Trost SG.. Determinants of physical activity in Singaporean adolescents. Int J Behav Med 2010; 17(4): 279-86., though it does not detail the domain (leisure or transportation) in which it is performed, neither its intensity, characteristics which are related in different ways to the environment⁷7 . Bauman AE, Reis RS, Sallis JF, Wells JC, Loos RJ, Martin BW; Lancet Physical Activity Series Working Group. Correlates of physical activity: why are some people physically active and others not? The Lancet 2012; 380(9838): 258-71.. In addition to that, the instrument used in order to assess the environmental characteristics perception was originally developed for adults and, although it has been translated, adapted, tested and previously applied to¹⁷17 . Rosenberg D. Neighborhood Environment Walkability Scale for Youth (NEWS-Y): reliability and relationship with physical activity. Preventive Medicine 2009; 49(213): 8., it may not allow the assessment of important environmental characteristics for teenagers. Despite the sample's size and design, only students from the public educational system were assessed, making it impossible to broaden the result data over all population. Also, the possible effects of negative confounding were not taken into consideration in the adjusted model.

The present study showed that the perception on neighborhood environment is different between genders, being more positive among boys rather than among girls. The neighborhood environment perception had higher association to PA practice (at least 20 minutes of PA one day/wee) when compared to the recommended PA practice (60 minutes of PA at least five days/week). Also, greater amounts of environment perception variables were associated to higher PA practice among boys when compared to girls.

In general, PA practice among girls seems not to relate to isolated environmental characteristics²⁸28 . Reis RS, Hallal PC, Parra DC, Ribeiro IC, Brownson RC, Pratt M et al. Promoting physical activity through community-wide policies and planning: findings from curitiba, Brazil. J Phys Act Health 2010; 7(2): 137-45.. In this study, only one out of the ten questions ("there are interesting things to see") on the environment was associated to the practice of a PA among girls, which is corroborated by a study conducted in Portugal with teenagers of the same age range²⁴24 . Santos MP, Page AS, Cooper AR, Ribeiro JC, Mota J. Perceptions of the built environment in relation to physical activity in Portuguese adolescents. Health Place 2009; 15(2): 548-52.. However, the measure of the overall neighborhood environment perception was more strongly associated to PA practice in lower volumes, once no association to the practice PA at recommended levels were observed. This result was not observed was not observed as well in another study conducted in Brazil (João Pessoa), in which girls who reported having interesting things to see, places they liked and to see other adolescents practicing physical activities presented higher probability of recommended PA²⁰20 . Farias Júnior JC, Siqueira FV, Nahas MV, Barros MVG. Prevalence and associated factors to insufficient level physical activity and in youth from two city of Brazil: last seven days or typical week. Rev Bras Ativ Fís Saúde 2011; 25(4): 619-29.. Local characteristics may contribute to this inconsistency of the findings. For example, Curitiba presents elevated residential density, amount of squares and green areas and structures for PA, resulting in higher availability of places for this practice²⁹29 . Santos MS, Hino AA, Reis RS, Rodriguez-Añez CR. Prevalence of barriers for physical activity in adolescents. Rev Bras Epidemiol 2010; 13(1): 94-104., which diminishes the variability of the exposure variable. On the other hand, studies carried out in the same population group showed that the environmental barriers are the least reported ones²⁹29 . Santos MS, Hino AA, Reis RS, Rodriguez-Añez CR. Prevalence of barriers for physical activity in adolescents. Rev Bras Epidemiol 2010; 13(1): 94-104. and they did not associate with PA³⁰30 . Prins RG, Oenema A, van der Horst K, Brug J. Objective and perceived availability of physical activity opportunities: differences in associations with physical activity behavior among urban adolescents. Int J Behav Nutr Phys Act 2009; 6: 70., among girls. Therefore, at least among girls, the environment may be considered a factor against the their relationship with PA when compared to individual and psychological variables³⁰30 . Prins RG, Oenema A, van der Horst K, Brug J. Objective and perceived availability of physical activity opportunities: differences in associations with physical activity behavior among urban adolescents. Int J Behav Nutr Phys Act 2009; 6: 70..

Among boys, "places they like", "seeing people their same age" and the overall measure of environment perception were associated to the practice of a PA. In a review study, when analyzed the relation of environment perception measures and the self-reported PA, 29% of all comparisons were significant and, although none of the environment variables have been strongly related to PA, important factors, such as Access to recreational equipments and the presence of sidewalks and biking tracks, are somehow associated¹⁰10 . Ding D, Gebel K. Built environment, physical activity, and obesity: what have we learned from reviewing the literature? Health Place 2012; 18(1): 100-5..

When we analyze the recommended levels of PA practice among boys, the only variable which did not present significant association was "seeing people their own age", also associated among teenagers from João Pessoa²⁰20 . Farias Júnior JC, Siqueira FV, Nahas MV, Barros MVG. Prevalence and associated factors to insufficient level physical activity and in youth from two city of Brazil: last seven days or typical week. Rev Bras Ativ Fís Saúde 2011; 25(4): 619-29.. This result reinforces the importance of having partners, for boys, in the places they practice PA, evidencing greater influence of the social environmental characteristics in relation to the physical relations in the practice of PA. In a study performed in Rotterdam (Netherlands), on the other hand, when assessing moderate levels of PA, it was found an association between the perception of parks and squares and the practice of strolling or biking as a PA during leisure time, and also between the perception of public sports spaces and the practice of these activities at least three times a week³¹31 . Pizarro AN, Santos MP, Ribeiro JC, Mota J. Physical activity and active transport are predicted by adolescents - different built environment perceptions. J Public Health 2012: 20(1): 5-10..

Curiously, safety, traffic and criminality did not represent significant association for both gender and PA criteria, similar to what was observed in Portugal²⁴24 . Santos MP, Page AS, Cooper AR, Ribeiro JC, Mota J. Perceptions of the built environment in relation to physical activity in Portuguese adolescents. Health Place 2009; 15(2): 548-52.. Pizarro found that a possible explanation for the non-association between PA as na active means of transportations and the safety of the neighborhood is the fact that teenagers do not have another option, considering the irrelevant perception of safety in this context³²32 . Slater SJ, Ewing R, Powell LM, Chaloupka FJ, Johnston LD, O'Malley PM. The association between community physical activity settings and youth physical activity, obesity, and body mass index. J Adolesc Health 2010; 47(5): 496-503.. However, there are differences between the results of studies carried out in different countries³²32 . Slater SJ, Ewing R, Powell LM, Chaloupka FJ, Johnston LD, O'Malley PM. The association between community physical activity settings and youth physical activity, obesity, and body mass index. J Adolesc Health 2010; 47(5): 496-503. ^{, 33}33 . Mak KK, Ho SY, Lo WS, McManus AM, Lam TH. Prevalence of exercise and non-exercise physical activity in Chinese adolescents. Int J Behav Nutr Phys Act 2011; 8: 3., which may be explained by contextual aspects, such as the difference in criminality rates between high, medium and low income countries, or even methodological matters (for example, the low quality of safety measures).

CONCLUSION

A great proportion of adolescents do not meet the recommendation for PA practice. It is also concluded that the environment characteristics are related specially to the practice of some kind of PA and are less consistent when regarding recommended levels. Therefore, it is possible that the environment perceived aspects may be important in the practice of a PA, which is better than practicing no PA at all³⁴34 . Reis RS, Kelly CM, Parra DC, Barros M, Gomes G, Malta D et al. Developing a research agenda for promoting physical activity in Brazil through environmental and policy change. Rev Panam Salud Publica 2012; 32(2): 93-100.. Both the social environment characteristics and the physical environment are positively associated to the practice of a PA in general, though in a more inconsistent way between gender and in a more relevant way for boys when compared to girls.

These findings confirm that the perception of some environment factors may be important for teenagers' PA practicing, and it should be considered when analyzing the connections between urban planning and health in populations of various age range. Tools and strategies have been suggested in order to include evidence on this relation for the implementation of policies and changes within the urban environment³⁵. Such information must be employed in urban planning involving systems of public transportation, parks, squares and biking tracks, making these locations rather attractive as meeting points for adolescents in PA practice.

REFERENCES

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