Women who maintain an active lifestyle are still spending too much of their time sitting, according to new findings by Northwestern researchers.

An NU study monitored the activity levels of 91 women between the ages of 40 and 75 years old for one week using an activPAL activity monitor, which estimates energy expenditure based on a person’s activity level. Although many of the women exceeded the weekly 150 minutes of moderate exercise recommended by the federal government, the women still spent an average of nine hours a day sitting.

Lynette Craft, an author of the study and professor at NU’s Feinberg School of Medicine, said the discovery contrasts with commonly held beliefs about health and exercise.

“I think some people assume, ‘If I’m getting my 30 to 40 minutes of physical activity a day, I’m doing what I need to do for my health,’” Craft said in a news release. “Of course, exercise is very important and is associated with many positive health benefits, but negative health consequences are associated with prolonged sitting.”

The NU study joins a growing body of research suggesting that sedentary behavior is detrimental to overall health.

Last week, Doctors Health Press reported that the average person spends 60 percent of their lives sitting and 30 percent sleeping, leaving only 10 percent for physical activity. The study found that sedentary behavior greatly increases the risk for cardiovascular disease.

Craft said the increasingly desk-bound nature of many office jobs contributes to sedentary lifestyles.

She added that people can make small changes in their days to avoid sitting for extended periods of time.

“Just getting up, moving around, maybe standing up when talking on the phone, walking down the hall instead of sending an email,” Craft said. “We do think they could gain health benefits.”