Older women who spend a lot of time sitting die earlier than their most active peers, new research shows.
A new study of about 93,000 postmenopausal women shows those with the highest amounts of sedentary time—defined as sitting and resting but not sleeping—have increased premature mortality rates.
The association remains even when controlling for physical mobility and function, chronic disease status, demographic factors, and overall fitness—meaning that even habitual exercisers are at risk if they have high amounts of idle time.
Published online in the American Journal of Preventive Medicine, the study shows that women with more than 11 hours of daily sedentary time faced a 12 percent increase in all-cause premature mortality compared with the most energetic group—those with four hours or less of inactivity.
The sedentary group also upped their odds for death due to cardiovascular disease, coronary heart disease, and cancer by 13, 27 and 21 percent, respectively.
“The assumption has been that if you’re fit and physically active, that will protect you, even if you spend a huge amount of time sitting each day,” says Rebecca Seguin, assistant professor of nutritional sciences at Cornell University. “In fact, in doing so you are far less protected from negative health effects of being sedentary than you realize.”
Use it or lose it
Worse still, excess sedentary time tends to make it harder to regain physical strength and function. Women begin to lose muscle mass at age 35, a change that accelerates with menopause.
Regular exercise, especially lifting weights and other muscular strength-building exercises, helps to counteract these declines, but research shows that more everyday movement on top of working out is also important for maintaining health.
“In general, a use it or lose it philosophy applies,” Seguin says. “We have a lot of modern conveniences and technologies that, while making us more efficient, also lead to decreased activity and diminished ability to do things. Women need to find ways to remain active.”
Starting in middle age and even younger, women can adopt small changes that make a big difference.
“If you’re in an office, get up and move around frequently. If you’re retired and have more idle time, find ways to move around inside and outside the house,” Seguin says. “Get up between TV programs, take breaks in computer and reading time, and be conscious of interrupting prolonged sedentary time.”
Though previous research has linked prolonged sedentary time with poor health outcomes, the new study is one of the largest and most ethnically diverse of its type. The women, ages 50 to 79 at the study’s outset as part of the national Women’s Health Initiative Study, were followed over 12 or more years.
The National Heart, Lung and Blood Institute funded the study.
Source: Cornell University