How much exercise a day prevents weight gain?



Posted on March 23, 2010 at 5:40 PM

Updated Friday, Jan 4 at 10:45 AM

As people age, the pounds tend to pile on. A new study finds out, for women, at least, how much exercise you need to do every day if you want stop that from happening.

Some exercise classes are geared for women over 50.

"I would be willing to do it if it was going to maintain my weight and keep my health," said Jane Davern, exerciser.

"I would do it, I would exercise to maintain my body weight," said Jean Holmes, exerciser.

Dr. I-min Lee, from Brigham and Women's Hospital in Boston, and her colleagues studied more than 34,000 women starting at an average age of 54, following and updating their activity level for 13 years.

Here's what researchers found:

"If you want to prevent your weight gain over time, you need to be physically active at the level of 60 minutes of moderate intensity physical activity, so the equivalent of one hour a day of brisk walking or 30 minutes a day of jogging or running," said Dr. Lee, MBBS, SCD, Brigham and Women's Hospital.

However, the same rule does not apply to all.

"We found that physical activity was effective in controlling weight only among women who started off with a normal BMI. The women who were overweight or obese, physical activity, with the range done in the study, was not sufficient to control their weight," said Lee.

But researchers say don't let that discourage you because exercise has other important benefits.

"While our study shows that this might not be sufficient to maintain normal weight, it clearly is sufficient to reduce the risk of developing many chronic diseases including heart disease, certain types of cancer, Type II diabetes," said Lee.

"I have to watch what I eat and I am trying to lose the weight and exercise, diet and exercise. That's what my goal is," said Debbie Reppucci.

The study appears in this week's Journal of the American Medical Association.