The results of a national US study suggest that women are at greater risk for developing metabolic syndrome than men because they are less likely to do at least 30 minutes of exercise a day. It found that although regular physical activity is linked to better health in both sexes, it appears to make a bigger difference for women.

Metabolic syndrome is a cluster of poor health indicators, such as high blood pressure, high cholesterol, and too much weight around the middle, that increases the risk for chronic diseases such as stroke, heart disease and type 2 diabetes.

Researchers at Oregon State University (OSU) in Corvallis, Oregon, write about their findings in an study published online on 31 March in the journal Preventive Medicine.

Bradley Cardinal, professor of social psychology of physical activity at OSU and Paul Loprinzi, a student in his lab, initially set out to investigate links between physical activity, depression and metabolic syndrome, and found a difference between the sexes.

Loprinzi, who is now assistant professor of exercise science at Bellarmine University, in Louisville, Kentucky, told the media this week:

“The results indicate that regular physical activity participation was associated with positive health outcomes for both men and women; however, there was a greater strength of association for women.”

Loprinzi said 30 minutes of exercise a day reduces a person’s risk for depression, high cholesterol and developing metabolic syndrome.

Cardinal said:

“It’s pretty striking what happens to you if you don’t meet that 30 minutes a day of activity.”

“Women in our sample had better health behavior – they were much less likely to smoke for instance, but the lack of activity still puts them at risk,” he added.

For their study, Loprinzi and Cardinal looked at nationally representative data from 1,146 men and women who took part in the 2005-2006 National Health and Nutrition Examination Survey (NHANES).

To record their daily physical activity, the men and women had been fitted with accelerometers. This is considered to be a more accurate and objective measure of daily exercise than for example self-reports via questionnaires.

The results showed that women on average were getting only about 18 minutes of moderate-to-vigorous exercise per day, whereas men were on average getting 30 minutes.

They showed that just over one in three women had metabolic syndrome, and one in five had symptoms of depression.

Depression is not just about mental health, it is also linked to physical health. Cardinal said there is evidence that depression can put people at higher risk of accumulating abdominal fat and developing insulin resistance, both risk factors for metabolic syndrome.

But doing exercise reduces depression, said Cardinal:

“So the key message here is to get that 30 minutes of exercise every day because it reduces a great deal of risk factors,” he urged.

The study did not look into the reasons why women aren’t getting enough daily physical activity, but the authors said previous studies have pointed to habits that begin quite early in life.

Cardinal said there is evidence that when their children are around the age of 5 or 6, parents tend to let boys play and be outdoors more than girls, out of concern for their safety.

Loprinzi said this behavior extends into adulthood, and also overall confidence could play a part, adding that studies suggest compared to men, women are not so sure they can overcome their barriers to exercise, and for example, often cite child-rearing as a reason they don’t have enough time to exercise.

Loprinzi and Cardinal are about to publish a study that may help women with these difficulties. It shows that you don’t have to do all your 30 minutes in one go, you can do short spurts of activity, that add up to 30 minutes over the day. Even taking the stairs instead of the elevator can make a difference, or walking up and down while talking on the phone.

Written by Catharine Paddock PhD