Take a movement break every 30 minutes, say experts.
As well as the total amount of sedentary time, the length of sitting bouts was also an important factor.
Diaz cites a motto by the American Heart Association, which says "Sits less, move more", and notes that such a simple guideline doesn't quite cut it. He is an associate research scientist at Columbia University Medical Center in New York City.
"That risk is reduced if we exercise at least 150 minutes per week, but not entirely eliminated", he concluded. The study has not designed the experiment to prove how sitting time directly causes premature death and this is a limitation of this study.
"The REGARDS study was originally created to examine why blacks (and particularly blacks in the Southern US) have a greater risk for stroke than whites", said Diaz.
Writing in the journal the Annals of Internal Medicine, Diaz and colleagues from seven USA institutions describe how they kitted out almost 8,000 individuals aged 45 or over from across the United States with activity trackers between 2009 and 2013. To measure their movements, the adults were asked to wear accelerometers for one week. Over about 4 years of follow-up, individuals with low total sedentary time showed about the same mortality rates whether bout duration was classified as low ( 10 minutes on average) or high ( 10 minutes).
Overall, during a typical 16-hour waking day, the four groups spent an average of 12.3 hours being sedentary-with the mean "bout" of uninterrupted butt time being 11.4 minutes.
"As we age, and our physical and mental function declines, we become more and more sedentary", wrote Diaz.
Sitting more than 30 minutes at a stretch increases one's chances of dying.
In contrast, those who had the least total sedentary time and the shortest sedentary bouts had a lower risk of death.
He also explained that sitting for long periods can cause blood to pool in the legs and that the combination of blood pooling, decreased blood flow, and turbulent blood flow is believed to be conducive to the development of plaque formation in the blood vessels.
"We have a psychological drive for high-sugar, high-calorie foods", Stephanie Rost, a registered dietician with the Weight Watchers 360 program, said, according to the CNN report.
"Bout duration is a little trickier", said Diaz.
A new study has found that people with desk jobs are nearly twice as likely to die younger, with researchers calling prolonged sitting "the new smoking".
University of Toronto's associate professor of medicine Dr. David Alter added that the recent findings suggested that people should only not avoid #Excessive sedentary time.
This is the largest study to look at the impact of the length of sedentary behavior on mortality rates.
While the study was funded by the US National Institutes of Health and Coca-Cola, neither were involved in the research.
Not surprisingly, those who were more active also tended to be younger, have less body mass, and have fewer health issues (diabetes, hypertension, cardiovascular disease) in general.
"The first time we do this, the positive effects are immediate", she said. "With all studies, we need replication of the findings in different populations to solidify our conclusions concerning the veracity of the findings".
"Just like weight-management strategies, we will need to monitor how much time we spend sitting, moving and undertaking exercise in a much more deliberate way than we have perhaps thought previously", Alter said.
'This one behavior change could reduce your risk of death, although we don't yet know precisely how much activity is optimal'.