Why You Need An Hour of Exercise Every Day

To prevent weight gain in middle age, women need one hour a day ?of moderate exercise?

Credit: Rennett Stowe

Being active doesn’t mean you have to train for a triathlon — try an hour of brisk walking or 30 minutes of jogging each day

All women know this one. As we age, we begin a war with our weight.

Now, a new study shows that 60 minutes a day of moderately intense physical activity may be the answer for normal-weight middle-aged women to prevent weight gain.

While there’s plenty of research on what to eat in order to shed pounds, the researchers contend there’s been little study into just how much physical activity is needed to prevent weight gain over time.

Physical Activity and Weight Gain in Middle-Age

In a recent study published in the Journal of the American Medical Association, Dr. I-Min Lee and her colleagues from Harvard Medical School followed more than 34,000 women starting at an average age of 54. Dr. Lee tracked the participants’ physical activity level and weight over 13 years. All the women were advised to follow their normal diet and not restrict their calories over time.

Depending on their daily level of activity, the women were classified into three activity groups equivalent to doing:

  • moderately intense exercise for 60 minutes
  • between 30 and 60 minutes
  • less than 30 minutes 

For women at a normal weight who consumed a normal diet, the study found that exercise helped prevent middle-age spread.

”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,” says Dr. Lee.

For overweight or obese women, 60 minutes of exercise wasn’t enough to prevent weight gain over time. On average, these participants gained about 5.7 pounds over the duration of the study. However, the most active women gained the least weight. The indirect message from this finding suggests that in order to maintain weight, overweight or obese women need to cut calories in addition to exercising.

Aim for 30 to 60 Minutes of Exercise Daily

Although needing an hour a day of exercise may dishearten some women, Dr. Lee says, “Let’s not lose sight of the fact that any amount of physical activity, even 150 minutes a week [about 30 minutes a day], is sufficient to lower the risk of developing many chronic diseases.”

Numerous studies have cited this amount in helping to improve cardiovascular health, offer some measure of protection against Alzheimer’s disease, control blood-sugar levels in diabetes and stave off some cancers.

Being active doesn’t mean you have to train for a triathlon, either. Most women in the study did moderate activity such as brisk walking, ballroom dancing, cycling and playing with their grandchildren. Those doing 30 minutes of vigorous activity a day participated in jogging, swimming laps or fast cycling.

It’s not certain, however, if these findings also apply to men as they age, since men tend to be more physically active and have more muscle mass, which more easily helps with weight control.

Originally published in TV Week. For daily updates, subscribe to the free TV Week e-newsletter, or purchase a subscription to the weekly magazine.