Neville Owen of Baker IDI Heart and Diabetes Institute in Australia said key indicators of cancer risk are lower when prolonged sitting is interrupted with brief breaks of 1 or 2 minutes.
"Sitting time is emerging as a strong candidate for being a cancer risk factor in its own right. It seems highly likely that the longer you sit, the higher your risk. This phenomenon isn't dependent on body weight or how much exercise people do," Owen said in a statement. "In our studies, we've measured waist circumference, insulin resistance and inflammation -- indicators of cancer risk common to many physical activity-cancer studies. We found that even breaks as short as 1 minute can lower these biomarkers."
One study found 60 percent of a study subjects' waking day -- 9.3 hours -- was spent sedentary, including meals, commutes and computer/television time, while another 35 percent -- 6.5 hours -- was spent engaged in light activity such as walking to a meeting, Owen said.
Office workers can spend over 75 percent of their working hours sitting, with bouts of 30 minutes or more of unbroken sedentary time common.
The findings were presented at the American Institute for Cancer Research's annual research conference in Washington.