Adult women need an hour of exercise to prevent body fat--study

Researchers at Brigham and Women’s Hospital and Harvard Medical School, Boston, U.S., revealed that without any restraint in the amount of food, women with normal weight could keep obesity at bay with moderate work-out sessions every day.

Principal researcher, I-Min Lee, Brigham and Women’s Hospital and Harvard Medical School stated, “Once overweight, it may be too late because physical activity-at least, at levels carried out by study participants-was not associated with less weight gain.”

“These data suggest that the 2008 federal recommendation for 150 minutes per week, while clearly sufficient to lower the risks of chronic diseases, is insufficient for weight gain prevention absent caloric restriction,” said the study authors.

Details of the study
The research team began the experiment in 1992 on over 34,000 American women, aged around 54.

The subjects were categorized into three groups on the basis of their weekly physical activity; first group did moderate exercise for 150 minutes; second group performed 150 to 420 minutes of moderate physical activity; and the third group did more than 420 minutes of rigorous activity.

Brisk walking, gardening and relaxed bicycling were considered moderate-levels of physical activity.

During the survey, subjects were also asked to record their physical activity and body weight along with factors like smoking and menopause status.

They were followed for a period of 13 years till 2007.

Findings of the study
Analysis revealed that normal weight women indulging in an hour of moderate physical activity per day were able to maintain their body mass index (BMI) at 25 by the end of the survey.

However, it was also found that groups of women exercising lesser gained 5.7 pounds on an average during the study, while the group exercising the maximum was less likely to gain weight.

It was hence stated that if people exercise actively--running or cycling hard, more benefits could be gained in lesser time.

Lee said, “The weekly total of 420 minutes is nearly triple the 150 minutes of moderate daily exercise currently recommended by U.S. health officials and illustrates the challenge American women face in maintaining a healthy weight.”

However, Lee added, “Women should not let the findings discourage them from exercising, but they may want to make small changes now.”

The study appears online in the Journal of American Medical Association.