NEW YORK — Older women spend two-thirds of their day not moving around, generally getting up every half hour for periods of movement, according to a study designed to help researchers understand patterns of sedentary behavior.
About 32 percent of all sedentary time occurred in blocks of at least 30 minutes, while about 12 percent occurred for at least 60 minutes, according to a research letter published Wednesday in the Journal of the American Medical Association.
The study of more than 7,000 women with an average age of 71 is one of the first to quantify how sedentary they are during the day, and future studies will examine what role movement outside of exercise has on health, said Eric Shiroma, lead study author. The researchers will follow the women to see how sitting or standing in place for many hours each day can affect heart disease, cancer and diabetes risk, he said.
"It's too early to know a lot of these answers," Shiroma, a researcher in preventive medicine at Brigham and Women's Hospital in Boston, said Wednesday in a telephone interview. "I would like to be able to describe to people what an active lifestyle should be outside of just physical activity. There's a lot of activity we can do without just going to the gym. It's a far more complex relationship than just your 30 minutes of moderate physical activity a day."
The research released Wednesday included participants in the Women's Health Study who in 2011 joined an additional investigation assessing physical activity using accelerometers. The women were asked to wear the accelerometer for seven days while they were awake.
The study showed that women spent about 66 percent of their waking day in sedentary behavior, totaling about 9.7 hours a day.
Future studies may help better understand if recommendations to move every 30 minutes benefit health and whether exercising for a half an hour a day but not moving for many other hours is healthier than not exercising yet spending waking hours in motion, Shiroma said.
"We need to really look more into what it means to be sedentary and active," he said. "It's not simply the time in the gym. There is the whole rest of the day out there. We need to be able to do that before we can make recommendations."