Teenage girls sit or lie down for 19 hours a day, study finds

A STUDY of the sedentary habits of teenage girls has found that they spend an average of almost 19 hours a day either sitting or lying down. This accounts for almost 80 per cent of the 24-hour day.

Some 111 girls aged between 15 and 18 took part in the University of Limerick study, using miniature recording accelerometers, which showed how much time they spent sitting, standing or lying down.

There was little difference between the time spent sitting or lying down during the week (18.8 hours) and at the weekend (18.9 hours).

However, during school hours, the teenagers spent more time in long, unbroken bouts of sitting, lasting more than 20 minutes in duration.

During their spare time outside school hours, the periods spent sitting and lying down were shorter.

Research has found that long uninterrupted bouts of sedentary time can have a negative impact on health and can increase the risk of coronary heart disease and other illnesses.

And even though a person may take the recommended amount of physical exercise, these long bouts of sitting and lying down will still have a negative impact on health.

The University of Limerick researchers noted that school-based interventions to decrease sitting time were lacking, and they encouraged schools to introduce measures that would stop students sitting still for such long periods.

The work was undertaken by PhD students Deirdre Harrington and Kieran Dowd under the supervision of Dr Alan Donnelly, and in collaboration with Dr Alan Bourke from the Department of Electronics and Computer Engineering, and County Limerick Local Sports Partnership.

This research is continuing and a large study is now tracking the behaviour and health of 60 girls, measuring how their sitting time affects blood cholesterol markers and risk factors for diabetes.

Another study is examining sitting behaviour and health in the University of Limerick’s adult staff and older students.