Exercise reduces health impact of sitting - but only in those sitting for less than 8 hours per day
Links between sedentary behaviour, mortality and heart disease are not always well understood.
Increase in any type of activity displaces another activity or sleep.
Higher sitting times (more than six hours) associated with higher mortality risks (all-cause and CVD).
Increased risk mostly seen in those who did not meet physical activity recommendations.
But even the physically active affected if sitting more than 8 hours per day.
Replacing sitting with sleeping (if total sleep > 7 hours) resulted in increased mortality risk.
Participants included nearly 150,000 Australian men and women aged 45 years and older.
Reported how many hours spent sitting, standing, sleeping and engaged in physical activity.