Volume and pattern and seasonal variation of school-day sedentary time: A cross-sectional study in Swedish 2nd and 5th graders

Purpose: Some evidence suggests an association between sedentary behavior and increased cardio-metabolic disease risk. The purposes of this study are to describe volume and pattern of school-day sedentary time, and compare school-day sedentary time across seasons in terms of volume and pattern in Swedish 2nd and 5th graders.

Methods: Volume and pattern of sedentary time (<100 counts per minute) were objectively measured with accelerometer (Actigraph GT3X+) in 75 (boys n=40) 2nd and 88 (boys n=43) 5th graders in three different schools in September 2012 and March and May 2013 (Kidscape II project). The pupils were encouraged to wear the accelerometer at the right hip by means of an elastic band for the whole school-day except during water-based activities. Pupils with three or more school days per week of accelerometer-data will be considered for further analysis. Daily mean and median of volume (total minutes spent sedentary) and number of bouts (prolonged sequences of sedentary time lasting ≥20, ≥10 and ≥5 consecutive minutes) and breaks of sedentary time are calculated for September, March and May respectively. The oneway repeated measures analysis of variance (rANOVA) will be used when comparing seasonal variations of volume of sedentary time and number of bouts and breaks of sedentary time.

Results: We hypothesize that volume and pattern of sedentary time differ between age, gender and seasons. Preliminary results will be presented during the conference.

Conclusions: This study will provide insight in volume and pattern and seasonal variations of school-day sedentary time in Swedish 2nd and 5th graders.