Sedentary behavior can cause death, a study warned

How you sit is more important for your health than the total amount of time you’re sitting, a new study claims.

Adults are sedentary for nine to 10 hours of their waking day, which can lead to cardiovascular risks and even death.

Experts say that what matters is the length of time between each burst of activity when someone is mostly sedentary. 

They studied the amount of time people were sitting throughout the day and compared it to their rates of mortality.

The results showed that those who got up and moved every half hour or less were less likely to be at risk of death than those that stayed sedentary for longer.

It is recommended for people who have mainly sedentary jobs to get moving every half hour to help them stay active and promote a healthy heart.

Researchers compared the length of time people are sedentary to their mortality rates. They found that if people briefly moved every 30 minutes, it would help lower their risk of death

Researchers from Columbia University studied 7,985 adults who were over the age of 45.  

The study, published in Annals of Internal Medicine, found that adults who sit for one to two hours at a time without moving have a higher mortality rate than adults who acquire the same amount of sedentary time in shorter lengths.

‘We tend to think of sedentary behavior as just the sheer volume of how much we sit around each day,’ said Dr Keith Diaz, associate research scientist in the Department of Medicine at Columbia University Medical Center and lead author of the study.

‘But previous studies have suggested that sedentary patterns, whether an individual accrues sedentary time through several short stretches or fewer long stretches of time, may have an impact on health.’

The researchers used hip-mounted activity monitors on the participants to objectively measure inactivity during waking time over a period of seven days.

On average, sedentary behavior accounted for 77 percent of the participants’ waking hours, equivalent to more than 12 hours per day. 

Over a median follow-up period of four years, 340 of the participants died. 

Mortality risk was calculated for those with various amounts of total sedentary time and various sedentary patterns. 

So if you have a job or lifestyle where you have to sit for prolonged periods of time, we suggest taking a movement break every half hour.  

Dr Keith Diaz, lead author of the study

Those with the greatest amount of sedentary time, more than 13 hours per day, and who frequently had sedentary bouts of at least 60 to 90 consecutive minutes had a significant increase in death risk.

In contrast, those who had the least total sedentary time and the shortest sedentary bouts had a lower risk of death.

The researchers also found that participants who kept most of their sitting bouts to less than 30 minutes were more likely to be healthy and decrease their chances of death.

‘So if you have a job or lifestyle where you have to sit for prolonged periods of time, we suggest taking a movement break every half hour,’ Dr Diaz said. 

‘This one behavior change could reduce your risk of death, although we don’t yet know precisely how much activity is optimal.’

This is the largest study to look at the impact of the length of sedentary behavior on mortality rates.  

‘This study adds to the growing literature on how dangerous long periods of sitting are for our health, and underscores a growing awareness among clinicians and researchers that sitting really is the new smoking,’ said study co-author Dr Monika Safford, chief of the Division of General Internal Medicine and the John J. Kuiper Professor at Weill Cornell Medicine. 

‘We need creative ways to ensure that we not only cut back on the total amount we sit, but also increase regular interruptions to sitting with bursts of activity.’