Exercise Doesn't Affect Time on Your Rear

Physical activity among women does not help them from sitting less

(RxWiki News) Despite the push to get Americans moving, those who do exercise are still sitting too much.

A recently published study shows that regardless of how much women work out, all spend the same amount of time sitting throughout the day.

The results show that public health officials should help sway Americans to spend less time in a chair or on the couch each day, according to the authors.

"Move around throughout the day!"

Even with the recommended exercise time, people who sit for long periods of time are likelier to develop obesity, diabetes, cardiovascular disease, and even some cancer, previous studies have shown.

The study, led by Lynette Craft, PhD, adjunct assistant professor in preventive medicine at Northwestern University, aimed to see if the time spent being active was linked to the time spent not moving among women.

Researchers recruited 91 women between the ages of 40 and 75 from a mammography clinic and gathered information on their height, weight, time spent doing physical activity, medical history and other demographics.

They excluded women who had a history of heart disease, diabetes, cancer, or were pregnant.

For one week, each participant wore a tracking device on their thigh from the time they woke up to the time they went to sleep each day.

The devices counted how long participants spent standing, walking, sitting and doing moderate to vigorous exercise for at least 10 minutes or more.

Afterwards, the women were divided into groups based on how long and how intensely they exercised.

Each participant was grouped as either having sufficient or insufficient moderate to vigorous physical activity.

Researchers found the women averaged 64 hours sitting, 28 hours standing and 11 hours walking and moving that wasn't directly exercise.

There was no significant difference in the time spent sitting, standing and walking between the sufficient and insufficient groups, who exercised 294 minutes and 20 minutes on average per week respectively.

Even among the women who were at or above the recommended 150 minutes of exercise a day, women in the study spent an average of nine hours a day sitting.

"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,'" Dr. Craft said in a press release.

"Of course, exercise is very important and is associated with many positive health benefits, but negative health consequences are associated with prolonged sitting, and this study shows that just because you're physically active doesn't mean you're sitting less."

The authors recommend switching out sitting time with some kind of light activity in addition to exercising the recommended amount of time.

"We all know someone who gets a good workout in every day, but then spends a large portion of their day sitting in front of a computer with few breaks," Dr. Craft said.

"If these people could replace some of the sitting with light activity---just getting up, moving around, maybe standing up when talking on the phone, walking down the hall instead of sending an email---we do think they could gain health benefits."

The authors note they only looked at women in their study and they didn't focus on the reasons why women spent more time sitting.

The study was published October 4 in the International Journal of Behavioral Nutrition and Physical Activity. The authors did not have any competing interests to declare.

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Review Date: 
November 5, 2012