“People who sat for eight hours a day but were physically active had a much lower risk of death than those who sat for fewer hours, but were not physically active,” Professor Brown said.
“This suggests physical activity is important, no matter how long you spend sitting each day.
“Indeed, the risk of death associated with sitting for eight hours a day was eliminated for people who did a minimum of one hour of physical activity per day.
“The greatest risk of death was for people who both sat for long periods of time and were inactive.”
The findings, published in leading medical journal The Lancet, support the recommendation made in the Australian physical activity and sedentary behaviour guidelines.
The guidelines advise all adults to accumulate between 30 and 60 minutes of physical activity per day, with the upper end of this range offsetting the harmful effects of too much sitting.
Only about a quarter of the people included in the study did an hour or more of exercise per day.
The researchers also found that sitting watching television for more than three hours per day was linked to an increased risk of death in all activity groups except the most active.
“We stress this is not because of a causal link between watching TV and an increased risk of death,” Professor Brown said.
“There could be a number of factors which contribute, such as long hours watching TV being a marker of a generally unhealthier lifestyle, or snacking while watching TV.”
Professor Brown’s study forms part of a special report by The Lancet.
The Lancet has issued four major research papers on physical inactivity to coincide with the Rio de Janeiro Olympics – and two of these feature UQ researchers.
Dr Tracy Kolbe Alexander contributed to research on the global economic cost of non-communicable diseases from physical inactivity.
Meanwhile Professor Brown, Dr Kolbe Alexander and a visiting research scholar from Brazil, Gregore Mielke also wrote a published commentary about women’s participation in sport.