Validade e reprodutibilidade da versão brasileira da escala se suporte social para o exercício

Social Support is an important psychosocial mediator of physical activity, particularly in adolescents. However, a valid and reliable instrument to measure this mediator in Brazilian adolescents is not available. The purpose of this study was to evaluate psychometrically a Brazilian-Portuguese version of the Social Support for Exercise Behavior Scale with adolescents. Participants were 540 high-school students (57.5% boys) with ages ranging from 14 to 17 years. A sub-sample of 64 participants was randomly selected to assess one week test-retest reliability by intraclass correlation. Internal consistency reliability was assessed by Cronbach's alpha. Concurrent criterion validity was assessed by Spearman rank-order correlation between the social support scales and minutes per week of moderate to vigorous physical activity (MVPA), minutes of structured activities per week and minutes per week of walking for transport. Cronbach's alpha for subscales ranged from 0.78 to 0.81 and Intraclass coefficients ranged from 0.61 to 0.81. All social support subscales correlated significantly with at least two physical activity measures supporting validity. These social support scales showed adequate reliability and moderate validity with Brazilian adolescents. Objective physical activity measures are needed to evaluate further the validity.