Compensation of Physical Activity and Sedentary Time in Primary School Children

Purpose: There is considerable debate about the possibility of physical activity compensation. This study examined whether increased levels in physical activity and/or sedentary behaviour on one day were predictive of lower levels in these behaviours the following day (compensatory mechanisms) among children.

Methods: Two hundred and forty-eight children (121 boys, 127 girls) aged 8-11 years from nine primary schools in Melbourne, Australia, wore a GT3X+ ActiGraph for seven consecutive days. Time spent in light (LPA) and moderate- to vigorous-intensity (MVPA) physical activity was derived using age-specific cut-points. Sedentary time was defined as 100 counts∙min. Environmental data (temperature, precipitation, daylight hours) were obtained daily and matched to accelerometer wear days. Multilevel analyses (day, child, school) were conducted using generalized mixed models.

Results: On any given day, every additional 10 minutes spent in MVPA was associated with approximately 25 minutes less LPA and 5 minutes less MVPA the following day. Similarly, additional time spent in LPA on any given day was associated with less time in LPA and MVPA the next day. Time spent sedentary was associated with less sedentary time the following day. Adjusting for environmental variables did not change observed ‘compensation effects’.

Conclusion: The results are consistent with the compensation hypothesis, whereby children appear to compensate their physical activity or sedentary time between days, irrespective of environmental weather conditions. Further research, such as examination of potential moderators or experimental studies, are needed to examine what factors may explain apparent compensatory changes in children’s physical activity and sedentary time.