Nutrition Frenzy

First federal guidelines set minimum amount of activity adults need

For most adults, that’s 2 hours a week.

How much physical activity you need depends largely on age and level of fitness.

Moderate exercise adds up for sluggish adults. Rake leaves, take a quick walk around the block or suit up for the neighborhood softball game. More fit adults could pack in their week’s requirement in 75 minutes with vigorous exercise, such as jogging, hiking uphill, a bike race or speedy laps in the pool.

It’s OK to start slowly. Someone who’s done no exercising will start seeing benefits with as little as 10 minutes of moderately intense exercise a day, which is an incentive to work up to the recommended amounts, said Rear Adm. Penelope Royall, deputy assistant secretary for disease prevention.

To put science behind the how-much-is-enough debate, HHS gathered an expert panel to review all the data. The panel found that regular physical activity can cut the risk of heart attacks and stroke by at least 20 percent, reduce chances of early death, and help people avoid high blood pressure, type 2 diabetes, colon and breast cancer, fractures from age-weakening bones and depression.

What’s the right kind of exercise? The guidelines advise:

* You don’t have get all the activity at once. A walk for an hour three days a week works as well as, say, a 30-minute exercise class on weekdays or saving most of the activity for a two-hour Saturday bike ride.

* For aerobic activities, go at least 10 minutes at a time to build heart rate enough to count.
You should be able to talk while doing moderate activities but not catch enough breath to sing. With vigorous activities, you can say only a few words without stopping to catch a breath.

* Children’s daily hour should consist of mostly moderate or vigorous aerobic activity, such as skateboarding, bike riding, soccer, simple running.

* Three times a week, children and teens need to include muscle-strengthening activities — sit-ups, tug-of-war — and bone-strengthening activities, such as jumping rope or skipping.

* Adults should do muscle-strengthening activities — push-ups, weight training, carrying heavy loads or heavy gardening — at least two days a week.

* Older adults who are still physically able to follow the guidelines should do so, with an emphasis on activities that maintain or improve balance.

These are minimum goals, the guidelines note. People who do more will see greater benefits.