A study has shown that people are spending as much as 21 hours a day just sitting…and increasing their risk of serious disease in the process.
According to an Australian study published in the European Heart Journal, people who spend a lot of their time sitting are most likely to have higher levels of blood fats, a key risk factor in obesity, heart disease and diabetes.
Dr Genevieve Healy, a researcher at the University of Queensland (UQ), has been studying sedentary behaviour since 2005 and compiled the data for the study. More than 4700 people over the age of 20 wore a motion detector on the hip for seven days to see how long they sat and how much they took a break from sitting. The least amount of sedentary time for any subject was 1.8 hours a day; the most was 21.2 hours a day. The least number of times anyone got up per day was 14; the most was an average of 179 times a day (you can almost hear the lounge springs groan).
What was telling, though, was the results of lab tests that went along with the monitoring. People who spent the most time sitting were most likely to have higher levels of blood fats, lower levels of “good” cholesterol and higher levels of a blood protein that signals artery inflammation. That held true even among people who spent some time each day exercising, but didn’t move much otherwise. On the other hand, those who did a lot of sitting, but also took a lot of breaks, had smaller waists and reduced amounts of inflammation.
Dr Healy says most of us typically sit for at least half the day, working, going to school and commuting, and then in front of one or more screens at home. “But our research shows that even small changes, as little as standing up for one minute, might help to lower the health risk,” Dr Healy says.
And it is the type of movement that appears to make a difference. Dr Healy is currently involved in further studies to find out more, but she suspects there may be benefits in how the postural muscles in the legs and back contract when standing. If this is the case, switching to a workstation that allows you to sit and stand could help reduce waist circumference and also reduce risk factors linked to obesity, cardiovascular disease and diabetes.
While additional exercise did not lead to improved results in the sample studied, Dr Healy says it’s not an excuse to give up the gym membership just yet. “It’s really important to still do exercise,” she says, adding that it should be done as well as frequent movement at the office – movement which means getting out of the chair, not just exercising in the chair. “If you just try to incorporate some activity throughout the day, and it could be something quite simple, it does add up,” Dr Healy says.
Taking regular breaks also has musculoskeletal benefits, according to bio-mechanist and ergonomist Dr Gary Dennis, who lectures at the School of Human Movement studies at UQ. He says sitting for a long time without moving and having awkward posture are the two biggest risk factors for injury in a work environment. People sitting for long periods can develop “tissue creep”, basically a stretching of the tissues that weakens core stability and increases a person’s risk of injury.
“Not only is getting up and moving around better for your cardiovascular health, you don’t get as many musculoskeletal problems, such as lower back pain,” he says.