Tuesday, November 18, 2014

An intervention aimed at interrupting sitting time in schoolchildren

Sedentary behaviour, especially prolonged uninterrupted sitting, may be bad for cardiometabolic health. Breaking up sitting time may be more effective for health promotion than reducing total sitting time. However, there are currently no studies available reporting intervention effects on breaking up children's sedentary time. In a study just published online in the journal Pediatric Exercise Science we report on a study in which we examined intervention effect on objectively measured number of breaks in sedentary time, number of sedentary bouts (≥10 mins) and total and average amount of time spent in those sedentary bouts among 10- to 12- year-old Belgian children. The total sample included 354 children aged 10-11 with valid ActiGraph accelerometer data at pre- and post-test. Only few and small intervention effects were found, namely on total time spent in sedentary bouts immediately after school hours and on average time spent in sedentary bouts before school hours  and immediately after school hours in favour of children from intervention schools. Unexpectedly, girls from intervention schools decreased the number of breaks during school hours
and increased the number of sedentary bouts on a weekend day, whereas girls in control schools showed an increase in number of breaks and a decrease in number of bouts. In conclusion, UP4FUN did not have a consistent or substantial effect on breaking up children's sedentary time and these data suggest that more intensive and longer lasting interventions are needed, if interrupting sitting time is to be further pursued.

Sunday, November 16, 2014

Sedentary behaviour and health in children: Evaluating the evidence

There is much to do about sedentary behaviour -too much (prolonged) sitting, for example by means of TV watching, computer and other IT activities, long school or office days et cetera- as a possible risk factor for cardiometabolic health. Scientists have claimed that sedentary time is a risk factor for cardiometabolic health partly or largely independent of physical activity. I.e. even if you do enough exercise, if you sit most of the rest of the day, your cardiometablic health may be at unnecessary risk. Some countries have already proposed recommendations for maximum sedentary time and interventions to reduce or interrupt sedentary time have been developed and are being tested or implemented.
In a commentary just published in the journal Preventive Medicine, with Prof. Mai Chin A Paw as first author, we argue that the evidence for sedentary behaviour as an independent cardiometabolic risk factor for children and adolescents is certainly not yet convincing, and propose research that should be conducted first to see if a stronger case can be build for treating sedentary behaviour as a separate risk factor, before we start using the meagre means for preventative interventions on sedentary behaviour instead of promoting physical activity and healthy eating.