Variability of Spanish adolescents' physical activity patterns by seasonality, day of the week and demographic factors

In this study, we examined the variability of physical activity (and inactivity) patterns in relation to gender, age, type of school, day of the week, and season of the year among a sample of Spanish adolescents aged 12-16 years. Levels of physical activity engagement, "who" was active/inactive, and "when" they were active/inactive were addressed. A Spanish translation and modification of Cale's Four by One-Day Physical Activity Questionnaire was administered by interviewer to 323 participants to measure estimated energy expenditure. Activity was assessed for two weekdays and two weekend days on two occasions during the autumn and two occasions during the winter. In an effort to better describe adolescents' active/inactive lifestyles, energy expenditures were translated into physical activity categories (i.e. active, moderately active, inactive, and very inactive). Results revealed that mean adolescent total daily energy expenditure was 41.46 kcalkg-1day-1 (s=7.05), which corresponded to the "active" category. Factorial and mixed analyses of variance showed statistically significant differences in energy expenditure by gender, season, day of the week, and type of school (P0.001). Female adolescents spent less daily energy than their male counterparts and, consequently, they were less active overall, even though they were more moderately active than boys. Participants were more active in winter than in autumn, which was largely due to the accumulation of time engaged in more lifestyle activities than differences in strenuous exercise. Adolescents were also less active on weekdays than during weekends. An interaction effect emerged for day of the week and type of school with adolescents attending public (or state) schools presenting higher daily energy expenditures than those from private schools during weekends (P0.01). The results suggest that girls may prefer less vigorous forms of activity. They also indicate that adolescents are investing time in physical activity when they have the freedom to participate or not (i.e. weekends), in particular those from public schools. We suggest that differences in gender, seasonality, and weekends versus weekdays, together with the choice of lifestyle activities, should be considered when designing activity promotion strategies among Spanish adolescents.