Social support and physical activity in adolescents: a longitudinal study.

The objective of this study was analyze longitudinally the association between types of social support provided by different sources and physical activity and assess the moderation of this relationship by the sex and age of adolescents. This is observational longitudinal study (2014 to 2017), with a yearly data collection involving 330 adolescents (50.6% girls), aged between 10 and 13 years in 2014 (starting year), from João Pessoa, Paraíba state, Brazil. Physical activity was measured by a questionnaire and the time (minutes/week) spent on sports, physical exercise, recreational activities and active displacement was determined. The emotional and instrumental social support provided by the father, mother and friends were positively and significantly associated with time spent on sports, physical exercises, recreational activities, and with active displacement when provided by the mother. Instrumental support provided by friends exhibited a greater magnitude of association with time spent on sports and recreational activities (p≤0.05) when compared to its emotional counterpart. Adolescents who received greater social, emotional and/or instrumental social support from their parents and friends spent more time on sports, physical exercises and recreational activities over the years.