Open-access Apoyo social de la familia y amigos para la actividad física de adolescentes: análisis con modelos de ecuaciones estructurales

Cad Saude Publica csp Cadernos de Saúde Pública Cad. Saúde Pública 0102-311X 1678-4464 Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz El apoyo social es un importante predictor para el mantenimiento de la actividad física en la adolescencia, por ello, el enfoque socioecológico valora el impacto de la interacción entre individuos, o grupos con recursos disponibles en el entorno social, con el fin de adoptar un estilo de vida activo. Por lo tanto, este estudio analiza el apoyo social de las relaciones de familia y amigos para la práctica de actividad física de adolescentes. Utilizando la Teoría Ecológica Social, aplicamos modelos de ecuaciones, desde una perspectiva observacional con diseño transversal, en la que participaron 2.710 brasileños adolescentes, de 14 a 18 años de edad. Fue posible identificar que cuanto mayor era el apoyo social de los amigos (β = 0,30; RMSEA = 0,065; CFI = 0,953; TLI = 0,922; SRMR = 0,048), al igual que el apoyo social de la familia, mayor era la actividad física de los adolescentes (β = 0,27; RMSEA = 0,015; CFI = 0,997; TLI = 0,995; SRMR = 0,013). Sin embargo, el respaldo de ambas fuentes en el mismo modelo de análisis no indicó valores de ajuste adecuados. Los resultados sugieren que los adolescentes que percibieron un apoyo social de los miembros de la familia o amigos tienen niveles mejores de actividad física. Este resultado confirma que el apoyo social es un importante promotor de la práctica de actividad física. Introduction The World Health Organization (WHO) 1 found that physical inactivity is the fourth leading risk factor for death worldwide, second only to high blood pressure, tobacco use, and high blood glucose. Adolescence is considered a decisive period for adopting adequate physical activity behaviors, as these benefit bone health, prevent chronic noncommunicable diseases 2,3,4, and are considered a determining factor in active behavior throughout life 5. The literature shows that social support is an important predictor for the maintenance of physical activity in adolescence 6,7,8,9. As a facilitator to physical activity, this construct substantiates theoretical models such as social cognitive, behavior modification, social learning, and social ecological theories 10. Theoretical models studies on health promotion allows us to understand lifestyle behaviors, such as physical activity. Among these models, the social-ecological approach values the impact of individuals or groups interaction with available resources in the social environment for adopting an active lifestyle 9,11,12,13. Personal attributes within the social environment and the creation of an interpersonal network are key references for developing positive and negative habits related to physical activity during adolescence 9,14. Thus, we may understand social support as a complex and multidimensional construct that helps comprehending how different relationships either positively or negatively influence the way individuals deal with possible adversities during their development 15. Family setting is considered an important source of support for the practice of physical activity during adolescence 8,9,11,16 for facilitating active behavior by different mechanisms - encouraging situations that favor physical activity, proposing different practice strategies, and providing instrumental support and company during the physical activity 17,18. Another important source of social support are friends; as adolescents spend a considerable amount of time with their colleagues, with whom they coexist in common settings such as school and clubs 19,20, they may also be considered relevant shapers of active behaviors. Regardless of the presence of social support from family and friends, promoting the practice of physical activity among adolescents is an important matter. Yet, few studies employed methods of analysis that enable the evaluation of a complex mechanism, such as the social support construct, by decomposing effects. Active behavior development processes within a context may vary according to individual personal attributes and perceived social environment (family and friends) 11,12,21. Understanding the perceived social support from family and friends for the practice of physical activity among different adolescent populations is necessary to provide subsidies, promote, and increase physical activity levels within this age group. Previous studies on this topic begin by direct relationship analyses; accordingly, structural equation modeling allows us to test mediation models under a theoretical construction using observational data. Considering that, this study aims to analyze the relationship between social support from family and friends and the practice of physical activity in adolescents from a region in Southern Brazil. Methods An observational cross-sectional study was conducted with 24,353 adolescents aged between 14 and 18 years, enrolled in 67 public high schools in Greater Florianópolis, Santa Catarina State, Brazil. Using random, cluster, and proportional methods, sampling was calculated according to the number of adolescents enrolled in the public school system. Based on the proportion distribution formula proposed by Luiz & Magnanini 22, we adopted a 3% sample error, 95% confidence interval, 50% prevalence, and 2.0 design effect, resulting in a required sample of 2,048 students. With the approval of the Human Research Ethics Committee of the Santa Catarina State University (UDESC; permit n. 501.582), the schools and classes that would compose the sample were randomly selected. Due to the type of clustering, 25 public schools were systematically selected and proportionally distributed among the 13 municipalities that compose the Greater Florianopolis by region and population density. In total, 19 schools were randomly selected and six automatically recruited for being the only ones within their municipality. Then, 126 classes were selected with proportional distribution per grade and study shift (morning, afternoon, etc.). All students were invited to participate in the study upon presentation of the signed free and informed consent form, resulting in a final sample of 2,710 adolescents. A short version of the International Physical Activity Questionnaire (IPAQ) was used to verify adolescent’s physical activity level. The instrument was proposed by the International Consensus Group on Physical Activity Measurement, founded by the WHO, with representatives in 25 countries, including Brazil 23. It addresses questions on how much time did participants spend on vigorous and moderate physical activities and walks during the last seven days. Adolescents were classified into “meeting the recommendations” and “not meeting the recommendations”, according to WHO recommendation of 60 minutes of daily moderate and vigorous physical activity 1. Social support for the practice of physical activity was measured using the Social Support for Exercise Behaviors survey instrument - created by a group coordinated by James F. Sallis 24 and validated for Brazilian adolescents by Reis & Sallis 25. It comprises two scales: perceived support from family and perceived support from friends, both composed of 13 statements regarding support for the practice of physical activity. In this survey, adolescents must assign a score to each statement on an ordinal scale (0 = never; 1 = almost never; 2 = sometimes; 3 = frequent; 4 = very frequent). The final score is the sum of each scale assigned scores. Our study sample was characterized using descriptive statistics, with means, standard deviations, and frequency distributions. The Spearman’s correlation was used to verify collinearity between social support from family and friends. All analyses were performed using the IBM SPSS statistics 20.0 software (https://www.ibm.com). A structural equation modeling analysis was conducted to evaluate direct associations between social support from family and friends and the practice of physical activity in adolescents. Parameters were estimated by the Asymptotically Distribution Free (ADF) method using the Stata 13 software (http://www.stata.com). Adjustment evaluation was performed using the following parameters: root mean square error of approximation (RMSEA) - where values below 0.08 indicate adequate adjustment; goodness of fit index (GFI); Tucker-Lewis Index (TLI), where values must be equal to or greater than 0.90 to indicate adequate-fitting model 26; and a standardized root mean square residual (SRMR) below 0.05 27. Initially, a confirmatory factor analysis was conducted to analyze family social support and friends social support. After confirmation, both constructs were treated as latent variables with three plots including indicators with common characteristics: the first included indicators related to emotional support, the second to informational support, and the third to tangible 28,29. Then, the measurement model was analyzed to verify whether the latent variables (social support from family and social support from friends) were correlated. After that, the structural model was initially developed including three constructs: physical activity, perceived social support from family, and perceived social support from friends. Physical activity was treated as an indicator, based on WHO classification of physical activity (whether or not meeting the recommendations), and perceived social support from family and friends as latent variables. Different models were created including a single source of social support within each. We adopted this strategy because the measurement model showed that, when jointly analyzed, the two social support scales failed in adequately fitting quality indicators. The gender indicator was also included in all models for demonstrating powerful interactive effects on adolescents’ physical activity, as different physical activity levels between girls and boys are widely reported in the literature 30. Results The sample comprised 2,710 adolescents, among which 57.9% were female and mean age was 16.90 (SD = 1.02) years. Regarding physical activity classification, 57.8% of the adolescents did not meet WHO recommendations for weekly physical activity. As for perceived social support, the mean was relatively low for family support, 12.15 (SD = 10.52) points, and for friends support, 14.55 (SD = 11.51), on a scale ranging from 0 to 52. Polychoric correlation tested the internal consistency between the items of each scale on perceived social support. According to data presented in Table 1, all items were correlated (p > 0.05), confirming the instrument good internal consistency. Table 1 Correlation between indicators of the instrument for social support from family and friends. Family social support items SF1 SF2 SF3 SF4 SF5 SF6 SF7 SF8 SF9 SF10 SF11 SF12 SF13 SF1 1.00 SF2 0.71 1.00 SF3 0.46 0.54 1.00 SF4 0.51 0.57 0.73 1.00 SF5 0.65 0.64 0.55 0.61 1.00 SF6 0.47 0.53 0.56 0.63 0.54 1.00 SF7 0.27 0.27 0.38 0.34 0.39 0.31 1.00 SF8 0.20 0.14 0.20 0.14 0.32 0.14 0.62 1.00 SF9 0.41 0.39 0.43 0.51 0.55 0.44 0.40 0.40 1.00 SF10 0.46 0.50 0.37 0.48 0.53 0.50 0.21 0.14 0.52 1.00 SF11 0.47 0.45 0.53 0.60 0.65 0.53 0.41 0.29 0.61 0.58 1.00 SF12 0.46 0.45 0.50 0.55 0.60 0.51 0.42 0.31 0.54 0.53 0.66 1.00 SF13 0.51 0.54 0.47 0.54 0.60 0.59 0.35 0.24 0.50 0.53 0.60 0.68 1.00 Friends social support items SA1 SA2 SA3 SA4 SA5 SA6 SA7 SA8 SA9 SA10 SA11 SA12 SA13 SA1 1.00 SA2 0.75 1.00 SA3 0.51 0.61 1.00 SA4 0.53 0.62 0.75 1.00 SA5 0.61 0.64 0.65 0.70 1.00 SA6 0.47 0.56 0.62 0.67 0.61 1.00 SA7 0.31 0.36 0.43 0.41 0.49 0.32 1.00 SA8 0.26 0.27 0.36 0.34 0.40 0.25 0.66 1.00 SA9 0.37 0.38 0.42 0.44 0.54 0.34 0.55 0.61 1.00 SA10 0.41 0.50 0.47 0.55 0.55 0.52 0.33 0.30 0.52 1.00 SA11 0.48 0.50 0.54 0.60 0.65 0.54 0.49 0.42 0.59 0.62 1.00 SA12 0.44 0.50 0.59 0.61 0.60 0.56 0.49 0.44 0.53 0.56 0.68 1.00 SA13 0.48 0.56 0.57 0.63 0.58 0.65 0.38 0.28 0.44 0.53 0.59 0.70 1.00 Note: S + F (item of the instrument Social Support for Exercise Behaviors, for family) + item number; S + A (item of the instrument Social Support for Exercise Behaviors, for friends) + item number. The confirmatory analysis of each social support scale verified adequate adjustment indexes for social support from family (RMSEA = 0.032; TLI = 0.908; CFI = 0.941; SRMR = 0.029) and friends (RMSEA = 0.036; TLI = 0.909; CFI = 0.939; SRMR = 0.045) (Figure 1). Figure 1 Confirmatory factor analysis of Social Support for Exercise Behaviors for family and friends scales. Note: S + F (item of the instrument Social Support for Exercise Behaviors, for family) + item number; S + A (item of the instrument Social Support for Exercise Behaviors, for friends) + item number. As for measurement model between perceived social support from family and perceived social support from friends, we found no adequate adjustment values (RMSEA = 0.172; CFT = 0.768; TLI = 0.565; SRMR = 0.068) (Figure 2). Figure 2 Measurement model between perceived social support from family and perceived social support from friends. SSA: parcel item of the instrument Social Support for Exercise Behaviors, for friends; SSF: parcel item of the instrument Social Support for Exercise Behaviors, for family. By including perceived social support from family and friends and physical activity in the structural equations modeling analysis and considering gender as an indicator of physical activity we found inadequate adjustment indexes, indicating that the general model was not confirmed (RMSEA = 0.159; CFT = 0.513; TLI = 0.318; SRMR = 0.236) (Figure 3). Figure 3 Final model for analysis between physical activity and perceived social support from family and friends. SSA: parcel item of the instrument Social Support for Exercise Behaviors, for friends; SSF: parcel item of the instrument Social Support for Exercise Behaviors, for family. We found adequate adjustment values in the model for physical activity and perceived family social support (Figure 4). These results indicate a direct relationship between social support and physical activity classification (β = 0.27; p < 0.001), as well as gender (β = 0.12; p < 0.001). The model reached a considerably high explanatory value (r2 = 0.88) and adequate adjustment indicators (RMSEA = 0.015; CFI = 0.997; TLI = 0.995; SRMR = 0.013). Figure 4 Analysis model between physical activity and family social support. SSF: parcel item of the instrument Social Support for Exercise Behaviors, for family. The model with perceived social support from friends, physical activity, and gender, presented in Figure 5, show adequate adjustment index values (RMSEA = 0.065; CFI = 0.953; TLI = 0.922; SRMR = 0.048), confirming the relationship between social support (β = 0.20; p < 0.001) and gender (β = 0.085; p < 0.001) with physical activity. The model had a strong explanatory power (r2 = 0.88). Figure 5 Analysis model between physical activity and friends social support. SSA: parcel item of the instrument Social Support for Exercise Behaviors, for friends. Discussion Our main results indicate that, when subjected to a structural model, the perceived social support from family and friends influence adolescents’ physical activity, reinforcing the ecological approach to studies on health-related behaviors by the premise that different social settings foster different types of behaviors. Our data confirm that physical activity practiced by adolescents tend to be influenced by their social environments 6,11,12,21. The constructs of social support from family and friends presented adequate values in the confirmatory factor analysis. All items composing the instrument evaluate the same construct: the perceived social support for each scale, family and friends. Such construct is supported by the unifactorial structure test of the scale applied to adolescents, since items correlations were statistically significant among each other, as well as scales total score 26,31. The confirmatory analysis of Social Support for Exercise Behaviors items helped validating the instrument for Brazilian adolescents 2, showing an adequate reliability and internal consistency for this population. In this study, adolescents with a higher perceived social support from family presented higher levels of physical activity, corroborating results reported in the literature, which indicates that family social support plays an important role in active behavior during adolescence 7,8. This may be explained by the fact that families, especially parents, teach skills and defend beliefs that help adolescents shape important attitudes and behaviors towards physical activity 32. Family setting is considered the most conducive structure to healthy development changes during adolescence 11. Although adolescence experiences vary according to the contexts, the family promotes transformations in behavioral patterns 33 and adolescents who perceive their support for practicing physical activity end up by adopting healthy habits and becoming physically active. Another relevant finding in this study was that the high perceived social support from friends was directly related to higher levels of physical activity, corroborating other studies on this subject 9,17,34. A review performed by Mendonça et al. 8 found friends to be the most consistent source of social support in the association between overall physical activity and social support. Friends influence in the practice of physical activity may result from social norms, imposed by themselves, to suit the group 19. That occurs because adolescents adopt behaviors based on those of friends within their social environment, as friendship networks are built according to shared interests, attitudes, and behaviors 12,19,34. We found a peculiarity regarding the employed structural models, whereby analyses on social support from family and friends, when in the same structural model, failed in presenting acceptable adjustment indexes. This may be technically justified by the fact that the measurement model (the previous step) between the two scales showed inadequate adjustment indicators values; if indicators are inadequate in the measurement model, the structural model will follow the same trend 27. These results theoretically indicate that adolescents who perceive receiving support for practicing physical activity from at least one of the sources tend to present better physical activity levels. Another important factor is the way through which support is provided. Family members tend to encourage their children to practice physical activity through different means, such as providing transportation and equipment; in turn, friends tend to offer greater social support by inviting colleagues to practice physical activities 8, which may lead to a disparity in the overall individual models. We found considerably low averages of perceived social support from family and friends among adolescents, as well as a low factorial load of the direct relationship between social support from both family and friends and physical activity. Meta-analysis studies on this subject 6,7 found positive effects (although relatively modest) on the association between social support and physical activity among adolescents. Their results suggest that support from family and friends influences physical activity; however, the low associations suggest that social support explains part of the variation in activity-related behavior in adolescents 6. Our study has some limitations. Physical activity, for example, was measured in a general manner (sum of moderate and vigorous physical activity), possibly underestimating activity levels. Physical activity was also evaluated using a subjective method and, even though the employed instrument has acceptable measurement properties to monitor habitual physical activity levels in adolescents older than 14 years 23, self-reporting evaluation imply a potential bias regarding subjectivity. Even so, questionnaires were deemed the best choice for the logistics of evaluating large sample sizes and are widely used in epidemiological studies. Our study strength is using an analysis. model that estimates the strength of all hypostatized relationships in a theoretical scheme, besides using the confirmatory analysis to verify whether the items that comprise the instrument really evaluate the same construct - social support. Only individual models with social support from family or friends had adequate adjustment indexes, possibly indicating that social support and its effects on adolescents are inherent to social environments. Conclusion Considering the investigated factors, we identified that social support from family or friends was associated with the practice of physical activity among adolescents from a region in Southern Brazil, as they presented better physical activity levels when they perceived support from at least one of these sources. Thus, the data indicate that the construct is an important promoter of physical activity and should be considered in intervention programs focused on promoting better physical activity levels in this age group. Our results are important to better understand adolescents’ active behavior, which, although individual, is also influenced by context characteristics and social relationships. Understanding the determinants of physical activity is essential to support new strategies to reduce sedentary behavior. Supporting or promoting social environment for the development of healthy habits and lifestyles has been a prevention strategy adopted in different public health areas. Thus, physical activity promotion programs should develop strategies focused not only on the individual, but also in increasing the support from social networks involving this group. Acknowledgments To Brazilian Graduate Studies Coordinating Board (CAPES) for the financial support. To Dr. Juliana Silva, who contributed to the research design and development. References 1 1. World Health Organization. Global status report on noncommunicable diseases. Geneva: World Health Organization; 2014. World Health Organization Global status report on noncommunicable diseases 2014 Geneva World Health Organization 2 2. Ho FKW, Louvie LHT, Chow CB, Wong WH, Ip P. Activity improves mental health through resilience in Hong Kong Chinese adolescents. BMC Pediatr 2015; 15:48-57. Ho FKW Louvie LHT Chow CB Wong WH Ip P Activity improves mental health through resilience in Hong Kong Chinese adolescents BMC Pediatr 2015 15 48 57 3 3. Marques A, Calmeiro L, Loureiro N, Frasquilho D, Matos MG. Health complaints among adolescents: associations with more screen-based behaviours and less physical activity. J Adolesc 2015; 44:150-7. Marques A Calmeiro L Loureiro N Frasquilho D Matos MG Health complaints among adolescents associations with more screen-based behaviours and less physical activity J Adolesc 2015 44 150 157 4 4. Kapcakova J, Vaselska ZD, Geckova AM, Djk JP, Rejonoveld S. Is being a boy and feeling fat a barrier for physical activity? The association between body image, gender and physical activity among adolescents. Int J Environ Res Public Health 2014; 11:1167-76. Kapcakova J Vaselska ZD Geckova AM Djk JP Rejonoveld S Is being a boy and feeling fat a barrier for physical activity The association between body image, gender and physical activity among adolescents Int J Environ Res Public Health 2014 11 1167 1176 5 5. Bélanger M, Sabiston CM, Barnett TA, O'Loughlin E, Ward S, Contreras G, et al. Number of years of participation in some, but not all, types of physical activity during adolescence predicts level of physical activity in adulthood: results from a 13-year study. Int J Behav Nut Phys Act 2015; 12:76. Bélanger M Sabiston CM Barnett TA O'Loughlin E Ward S Contreras G Number of years of participation in some, but not all, types of physical activity during adolescence predicts level of physical activity in adulthood: results from a 13-year study. Int J Behav Nut Phys Act 2015 12:76 12:76 6 6. Laird Y, Fawkner S, Kelly P, Mcnamee L, Niven A. The role of social support on physical activity behaviour in adolescent girls: a systematic review and meta-analysis. Int J Behav Nut Phys Act 2016; 13:79. Laird Y Fawkner S Kelly P Mcnamee L Niven A The role of social support on physical activity behaviour in adolescent girls a systematic review and meta-analysis Int J Behav Nut Phys Act 2016 13 79 79 7 7. Yao CA, Rhodes RE. Parental correlates in child and adolescente physical activity: a meta-analysis. Int J Behav Nut Phys Act 2015; 12:10. Yao CA Rhodes RE Parental correlates in child and adolescente physical activity a meta-analysis Int J Behav Nut Phys Act 2015 12 10 10 8 8. Mendonça G, Cheng LA, Mélo EN, Farias Junior JC. Physical activity and social support in adolescent: a systematic review. Health Educ Res 2014; 29:822-39. Mendonça G Cheng LA Mélo EN Farias JC Junior Physical activity and social support in adolescent: a systematic review. Health Educ Res 2014 29 822 839 9 9. Silva P, Lott R, Mota J, Welk G. Direct and indirect effects of social support on youth physical activity behavior. Pedriatr Exerc Sci 2014; 26:86-94. Silva P Lott R Mota J Welk G Direct and indirect effects of social support on youth physical activity behavior Pedriatr Exerc Sci 2014 26 86 94 10 10. Elder JP, Ayala GX, Harris S. Teories and intervention approaches to health-behavior change in primary care. Am J Prev Med 1990; 17:275-84. Elder JP Ayala GX Harris S Teories and intervention approaches to health-behavior change in primary care Am J Prev Med 1990 17 275 284 11 11. Belanger-Gravel A, Gauvin L, Fagarge F, Lafete M. Correlates and moderators of physical activity in parent-twee dyads: a socio-ecological perspective. Public Health 2015; 129:1218-23. Belanger-Gravel A Gauvin L Fagarge F Lafete M Correlates and moderators of physical activity in parent-twee dyads a socio-ecological perspective Public Health 2015 129 1218 1223 12 12. Simpkins SD, Schaefer DR, Prince CD, Vest AE. Adolescent friendships, BMI, and physical activity: untangling selection and influence through longitudinal social network analysis. J Res Adolesc 2012; 23:537-49. Simpkins SD Schaefer DR Prince CD Vest AE Adolescent friendships, BMI, and physical activity untangling selection and influence through longitudinal social network analysis J Res Adolesc 2012 23 537 549 13 13. Reimers AK, Jekauc D, Mess F, Mewes N, Woll A. Validity and reliability of a self-report instrument to assess social support and physical environmental correlates of physical activity in adolescents. BMC Public Health 2012; 12:705. Reimers AK Jekauc D Mess F Mewes N Woll A Validity and reliability of a self-report instrument to assess social support and physical environmental correlates of physical activity in adolescents BMC Public Health 2012 12 705 705 14 14. Yunes MAM, Juliano MC. A bioecologia do desenvolvimento humano e suas interfaces com educação ambiental. Cadernos de Educação 2010; 37:347-79. Yunes MAM Juliano MC A bioecologia do desenvolvimento humano e suas interfaces com educação ambiental Cadernos de Educação 2010 37 347 379 15 15. Marôco JP, Campos JADB, Vinagre MG, Pais-Ribeiro JL. Adaptação transcultural Brasil-Portugal da escala de satisfação com o suporte social para estudantes do Ensino Superior. Psicol Reflex Crít 2014; 27:247-56. Marôco JP Campos JADB Vinagre MG Pais-Ribeiro JL Adaptação transcultural Brasil-Portugal da escala de satisfação com o suporte social para estudantes do Ensino Superior Psicol Reflex Crít 2014 27 247 256 16 16. Spurr S, Bally J, Trinder K. Predictors of physical activity in positive deviant adolescentes. J Pediatr Nurs 2016; 31:311-8. Spurr S Bally J Trinder K Predictors of physical activity in positive deviant adolescentes J Pediatr Nurs 2016 31 311 318 17 17. Cheng LA, Mendonça G, Farias Junior JC. Physical activity in adolescents: analysis of social influence of parents and friends. J Pediatr (Rio J.) 2014; 90:35-41. Cheng LA Mendonça G Farias JC Junior Physical activity in adolescents: analysis of social influence of parents and friends. J Pediatr (Rio J.) 2014 90 35 41 18 18. Beets M, Cardinal B, Aldeman B. Parental social support and the physical activity-related behaviors of youth: a review. Health Educ Behav 2010; 37:621-64. Beets M Cardinal B Aldeman B Parental social support and the physical activity-related behaviors of youth a review Health Educ Behav 2010 37 621 664 19 19. Sawaka KJ, McCormack GR, Nettel-Agurre A, Hawe P, Doylw-Baker PK. Friendship networks and physical activity and sedentary behavior among youth: a systematized review. Int J Behav Nutr Phys Act 2013; 10:130. Sawaka KJ McCormack GR Nettel-Agurre A Hawe P Doylw-Baker PK Friendship networks and physical activity and sedentary behavior among youth a systematized review Int J Behav Nutr Phys Act 2013 10 130 130 20 20. Fritzgerald A, Fritzgerald N, Aherne C. Do peer matter? A review of peer and/or friends' influence on physical activity among American adolescents. J Adolesc 2012; 53:941-58. Fritzgerald A Fritzgerald N Aherne C Do peer matter A review of peer and/or friends' influence on physical activity among American adolescents J Adolesc 2012 53 941 958 21 21. Daviso KK, Nishi A, Kranz S, Wyckoff L, May JJ, Earle-Richadson GB, et al. Association among social capital, parenting for active lifestyle, and youth physical in rural families living in upstate New York. Soc Sci Med 2012; 75:1488-96. Daviso KK Nishi A Kranz S Wyckoff L May JJ Earle-Richadson GB Association among social capital, parenting for active lifestyle, and youth physical in rural families living in upstate New York Soc Sci Med 2012 75 1488 1496 22 22. Luiz RR, Magnanini MMF. A lógica da determinação do tamanho da amostra em investigações epidemiológicas. Cad Saúde Colet (Rio J.) 2000; 8:9-28. Luiz RR Magnanini MMF A lógica da determinação do tamanho da amostra em investigações epidemiológicas Cad Saúde Colet (Rio J.) 2000 8 9 28 23 23. Guedes DP, Lopes CC, Guedes JERP. Reprodutibilidade e validade do Questionário Internacional de Atividade Física em adolescentes. Rev Bras Med Esporte 2005; 11:151-8. Guedes DP Lopes CC Guedes JERP Reprodutibilidade e validade do Questionário Internacional de Atividade Física em adolescentes Rev Bras Med Esporte 2005 11 151 158 24 24. Sallis JF, Grossman RM, Pinkis RB, Patterson TL, Nader PR. The development of scales to measure social support for diet and exercise behaviors. Prev Med 1987; 16:825-36. Sallis JF Grossman RM Pinkis RB Patterson TL Nader PR The development of scales to measure social support for diet and exercise behaviors Prev Med 1987 16 825 836 25 25. Reis RS, Sallis JF. Validade e reprodutibilidade da versão brasileira da Escala de Suporte Social para o Exercício em Adolescentes. Rev Bras Ciênc Mov 2005; 13:7-15. Reis RS Sallis JF Validade e reprodutibilidade da versão brasileira da Escala de Suporte Social para o Exercício em Adolescentes Rev Bras Ciênc Mov 2005 13 7 15 26 26. Browne MW, Cudeck R. Alternative ways of assessing model fit. In: Bollen KA, Long JS, editors. Testing structural equation models. Newbury Park: Sage; 1993. p. 136-62. Browne MW Cudeck R Bollen KA Long JS Testing structural equation models Alternative ways of assessing model fit 1993 Newbury Park Sage 136 162 27 27. Hair JF, Anderson RE, Tathan RL, Black WC. Análise multivariada de dados. 5ª Ed. Porto Alegre: Bookman; 2005. Hair JF Anderson RE Tathan RL Black WC Análise multivariada de dados. 5ª 2005 Porto Alegre Bookman 28 28. Heaney CA, Israel BA. Social networks and social support. In: Glanz K, Rimer BK, Viswanath K, editors. Health behavior and health education: theory, research and practice. 4th Ed. San Francisco: Jossey-Bass; 2008. p. 189-206. Heaney CA Israel BA Glanz K Rimer BK Viswanath K Health behavior and health education: theory, research and practice. 4th Social networks and social support 2008 San Francisco Jossey-Bass 189 206 29 29. Stroebe W, Stroebe M. The social psychology of social support. In: Higgins ET, Kruglanski Aw, editors. Social psychology: handbook of basic principles. New York: Guilford Press; 1996. p. 597-621. Stroebe W Stroebe M The social psychology of social support. Higgins ET Aw Kruglanski Social psychology: handbook of basic principles. New York Guilford Press 1996 597 621 30 30. Carney J, Veldhuizen S, Kwan M, Hay J, Faught BE. Biological age and sex-related declines in physical activity during adolescence. Med Sci Sport Exerc 2013; 46:730-5. Carney J Veldhuizen S Kwan M Hay J Faught BE Biological age and sex-related declines in physical activity during adolescence Med Sci Sport Exerc 2013 46 730 735 31 31. Hu LT, Bentler PM. Cutoff criteria for fit indexes in covariance structure analysis: conventional criteria versus new alternatives. Struct Equ Modeling 1999; 6:1-55. Hu LT Bentler PM Cutoff criteria for fit indexes in covariance structure analysis conventional criteria versus new alternatives Struct Equ Modeling 1999 6 1 55 32 32. Edwardson CL, Gorely T. Parental influences on different types and intensities of physical activity in youth: a systematic review. Psychol Sport Exerc 2010; 11:522-35. Edwardson CL Gorely T Parental influences on different types and intensities of physical activity in youth a systematic review Psychol Sport Exerc 2010 11 522 535 33 33. Portugal APM, Alberto IMM. Caracterização da comunicação entre progenitores e filhos adolescentes: estudo das variáveis sociodemograficas. Ciênc Saúde Colet 2015; 20:1389-400. Portugal APM Alberto IMM Caracterização da comunicação entre progenitores e filhos adolescentes estudo das variáveis sociodemograficas Ciênc Saúde Colet 2015 20 1389 1400 34 34. Lopes VP, Gabbard C, Rodrigues LP. Effects of psychosocial variables in the similarity and interdependence of physical activity levels among adolescent best friend dyads. J Sports Sci 2016; 34:821-8. Lopes VP Gabbard C Rodrigues LP Effects of psychosocial variables in the similarity and interdependence of physical activity levels among adolescent best friend dyads J Sports Sci 2016 34 821 828
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