Back in December we shared a video that illustrated how and why the simple act of sitting for hours and hours every single day is a potentially lethal in-activity for all humans. Now a new study finds that leisurely parking one’s derrière in a chair or on the couch for more than 6 hours a day may be particularly harmful to women because it raises our risk of developing several cancers, including invasive breast and ovarian.

According to the American Cancer Society, “While extensive research links physical activity to cancer prevention, few studies have examined the link between sitting time and the risk of specific cancers. Over the past few decades, time spent sitting has increased due to several factors, including technological advancements, like computers and video games, and changes in transportation.”

That’s why this new “sitting and cancer” study, led by Alpa V. Patel, Ph.D., the strategic director of the Cancer Prevention Study-3 for the American Cancer Society, is making a number of people stand up and take note. Dr. Patel is a cancer epidemiologist whose research has focused on the role of the physical activity in cancer prevention and obesity as a risk factor for cancer.

She and her team of investigators compared leisure time sitting to cancer risk among more than 146,000 men and women (69,260 men and 77,462 women) who were cancer-free and enrolled in the American Cancer Society Cancer Prevention Study II Nutrition Cohort. Between 1992 and 2009, 18,555 men and 12,236 women were diagnosed with cancer.

The researchers found that longer leisure-time sitting (6 hours or more a day) was associated with a 10% increased risk of developing any cancer in women, compared to those women who sat for less than 3 hours. And, more specifically, longer sitting time for women was associated with a 65% higher risk for multiple myeloma, a 10% higher risk for invasive breast cancer, and a 43% higher risk for ovarian cancer. These increased risks were determined after adjustments for physical activity, BMI and other factors.

But sitting time, however, was not associated with cancer risk in men. So they say that more research needs to be done “to better understand the differences in associations between men and women.”

The bottom line… get up and move as much and as often as you can.