Identificação de padrões de atividade física e comportamentos sedentários em adolescentes, com recurso à avaliação momentânea ecológica

Abstract

Purpose The knowledge of physical activity levels and sedentary behaviour of adolescents is important, so that interventions to promote health have to be in accordance with the target population. Therefore this study aimed to examine the prevalence and clustering of physical activity and sedentary behaviours among urban adolescents. Methods The study comprised a total of 651 adolescents (273 boys and 378 girls) aged 12-14, from 4 public urban schools. Ecological Momentary Assessment was used to measure sedentary behaviours and physical activity, using 15 minutes time intervals. Results On weekdays, studying was the activity on which adolescents spent more time (boys 114.5 min/day, 11.3%; girls 135.4 min/day, 13.1%). Followed by television (TV) (boys 97.8 min/day, 9.6%; girls 59.7 min/day, 5.8%), computer use (boys 42.7 min/day, 4.2%), and talking with friends (girls 31.5 min/day, 3%). On average boys practiced 40.9 min/day (4%) and girls 24 min/day (2.3%) on physical activity. On weekend days, the most consuming leisure time was TV (145.8 min/day, 13.5%) and computer use (136.6 min/day, 12.9%) for the boys, and studying (144.3 min/day, 13.1%) and TV (133.5 min/day, 12.2%) for the girls. Based on these behaviours three meaningful cluster solutions were found both for boys and girls, respectively. For the boys: cluster 1) less actives, spent less time studying, but spent more time watching TV and on the computer (n = 63); cluster 2) devoted more time studying and spent less time on physical activity, watching TV and using computer (n = 126); cluster 3) actives, spent less time watching TV and studying (n = 84). For the girls: cluster 1) actives, less time studying, watching TV and using computer (n = 28); cluster 2) devoted to studies, sociable and non-actives (n = 77); cluster 3) much time watching TV, non-sociable and non-actives (n = 273). Conclusion Girls were less active than boys. Despite having higher levels of physical activity than girls boys also presented higher levels of sedentary behaviours. These data suggest that it is possible to be considered physically active and spend a lot of time in sedentary behaviours. This should be considered in intervention programs aimed to promote active and healthy lifestyles among adolescents.