Sporty summer and lazy winter? PA of youth from a seasonal perspective.

Objectives:
Many children in Europe are insufficiently active (1), which makes the promotion of children´s physical activity (PA) a critical health promotion
target. However, there are some uncontrollable factors such as amount of daylight, weather conditions, temperatures and precipitation
levels that might influence PA behavior (2). Conditions for moderate to vigorous physical activity (MVPA) seem to be optimal when the
environmental temperature ranges between 20°C and 25°C (3). This study aims to examine if the season is related to the objectively measured
PA of youth of Luxembourg.
Methods:
150 youth (90 females and 60 males) aged from 10–17 (M = 12.37, SD = 2.14) years participated in this longitudinal study, which took place
at two measurement periods, the first between October and December (winter) and the second between May and July (summer). PA
behavior was objectively assessed by wearing an accelerometer (ActiGraph GT3X-BT) for seven consecutive days. Daily time spent in MVPA
was calculated as an indicator of the youth’s PA behavior.
Results:
A repeated measures ANOVA revealed a significant seasonal effect for MVPA per day (F(1, 1136.66) = 9.14, p < .05, partial η² = .06). More
minutes of MVPA per day were accrued in summer (M = 53.24, SD = 21.40) than in winter (M = 49.04, SD = 20.88). Both in winter and in
summer, MVPA per day differed significantly between females and males (winter: t(148) = 5.83, p < .001; summer: t(148) = 4.85, p < .001),
whereby females (winter: M = 41.70, SD = 15.89; summer: M = 46.79, SD = 17.26) showed significantly fewer minutes in MVPA per day
than males (winter: M = 60.05, SD = 22.67; summer: M = 62.91, SD = 23.43). However, there was no significant interaction between season
and gender, F(1, 89.85) = .723, p = .397).
Discussion:
According to the results of this study, youth are less physically active in winter than in summer. Therefore, schools, sports clubs and communities
should offer special PA programs for this season, which are independent from climatic conditions and equally suitable for females
and males. Measuring PA throughout the year enables to monitor the activity behavior more accurate and may help in developing such
programs.