Slowing Down in Older Age

Sedentary behavior in women found to increase with age and body mass index

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) With older age can come retirement and a chance to slow down, and according to research, that slowing down can carry over to physical activity as well.

A recent study found that time spent being sedentary increased as age and body mass index (a measure of height and weight) increased in a group of older women.

The researchers also found that these periods of sedentary behavior primarily occurred in shorter stretches of time (under 30 minutes).

"Add periods of physical activity to your daily routine."

This study was led by Eric J. Shiroma, MEd, MS, of the Harvard School of Public Health. This research team examined patterns of sedentary behavior in older women and evaluated whether such behavior was connected to age, body mass index (a measure of height and weight) and smoking status.

These researchers analyzed data from 7,247 women in the Woman’s Health Study. Study participants were sent an accelerometer (a device that measures motion) and given detailed instructions on how to use it. The women were told to wear the accelerometer during the day for seven days and asked to keep a diary recording which days they wore the monitor.

The average age of study participants was slightly over 71 years. Women wore the accelerometer for an average of close to 15 hours per day for about seven days.

The women were found to be sedentary for about 66 percent of the time that they spent wearing the accelerometer during the seven-day period on average. This translates to about 10 hours per day.

The researchers also looked at whether sedentary behavior occurred in shorter or longer bouts. They defined a bout of sedentary behavior as an uninterrupted stretch of time (minutes) in which the accelerometer recorded less than 100 counts of movement per minute.

These researchers found that most sedentary behavior occurred in shorter bouts. About 5 percent of the total number of sedentary bouts lasted 30 minutes or more.

The researchers also found that after taking into account wear time and smoking status, total sedentary time and the number of sedentary bouts increased as age and body mass index increased.

One limitation of this study, as noted by the study authors, was that their sample was primarily white and of a higher socioeconomic status, so the findings might not apply to different groups of women. They also noted that the accelerometer cannot tell the difference between sitting and standing.

The authors of this study concluded that future studies should focus on confirming the negative health effects of being sedentary so that recommendations can be made on ways to reduce this kind of behavior.

Amber Watson, DC, MS, chiropractor at Total Wellness Austin, and dailyRx Contributing Expert said, "This research shows that as women age, their total daily activity level decreases and body mass index (BMI) increases.They also found that the bouts of sedentary behavior were, on average, smaller increments (less than 30 minutes)."

Dr. Watson continued with, "The average age of women in this study was 71, and the accelerometer used could not distinguish between sitting and standing position."

This study was published on December 17 in JAMA.

Some of the study authors reported potential conflicts of interest with Actigraph, the company that makes the accelerometer that the study participants used.

Review Date: 
December 17, 2013
Last Updated:
December 30, 2013