New York, Sep 12: Does your job force you to sit for one to two hours at a stretch without moving? Beware, it may raise the risk of dying early than people who sit cumulatively for the same time, but in shorter bouts, a study has warned. The findings showed that people 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 nearly two-fold increase in death risk compared with those who had the least total sedentary time and the shortest sedentary bouts. Conversely, people who kept most of their sitting bouts to less than 30 minutes had the lowest risk 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. This one behaviour change could reduce your risk of death," said lead investigator Keith Diaz, associate research scientist at Columbia University Medical Centre (CUMC). "The 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," added Monika Safford, professor at Weill Cornell Medical Centre. For the study, published in the journal Annals of Internal Medicine, the team used hip-mounted activity monitors to objectively measure inactivity during waking time over a period of seven days in 7,985 adults over age 45. "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," Safford added.