Women Should Exercise 60 Minutes a Day
A new study published in the Journal of the American Medical Association says that women need 60 minutes of moderate exercise a day to prevent weight gain as they age if they consume a normal diet.
The findings suggest women need more exercise than the current federal guidelines of 150 minutes a week, or 30 minutes five days a week, of moderate-to-intense activity.
“I don’t want people to throw up their hands and say ‘I can’t do it,’ ” said I. Min Lee, the study’s lead researcher and a doctor and associate professor at Harvard Medical School and Brigham and Women’s Hospital in Boston.
Women at a normal weight who consume a normal diet can beat middle-age weight gain by working out intensely for 30 minutes a day, whether by running, cycling, swimming laps or working out at a gym. Weight gain can also be prevented with 60 minutes of moderate activity, such as walking, a leisurely bike ride or playing catch.
The federal guidelines of 150 minutes a week of moderate-to-intense exercise are designed to prevent disease and obtain other health benefits. However, a 2002 report by the Institute of Medicine suggested 60 minutes a day, or 420 minutes a week, are needed to prevent weight gain.
Dr. Lee said because the basis of IOM’s findings have been questioned, she and other researchers decided to look at the issue within the group of women participating in the federal Women’s Health Study. She also said the goal was to look at women who weren’t dieting and were consuming a normal diet to see what impact physical activity has on weight.
The study looked at 34,079 healthy U.S. women who consumed a usual diet from 1992 to 2007. The women were all age 45 or older at the start, with an average age of 54. They were given a questionnaire about the amount of exercise or activity they engaged in per week at the start of the study and then at three-year intervals. Their activity was tracked for an average of 13 years while weight changes were tracked over a three-year period.
Overall, women gained an average of 5.7 pounds in the study. However, those who were normal weight, with a body-mass index of less than 25, maintained their weight if they exercised for 60 minutes a day. Women who exercised less generally gained weight. Dr. Lee said for overweight or obese women, 60 minutes of exercise a day wasn’t enough to maintain weight, suggesting calories need to be cut.