It's no secret: A healthy diet and regular exercise are essential to good health at any age.

Now Uncle Sam has made it official with new exercise guidelines released this week that set minimum requirements for good health.

For most adults that amounts to just 2 1/2 hours of exercise a week. And you don't have to get all the activity in one shot — a short daily walk works just as well as an exercise class on the weekends. Aerobic activity should last at least 10 minutes, to get your heart rate up. For children and teens, the guidelines call for at least an hour of brisk activity daily.

The Health and Human Services Department's guidelines provide a key benchmark at a time when obesity and diseases associated with it are on the rise.

In Hawai'i, for instance, state Department of Health statistics show 57 percent of adults are either overweight or obese — a major risk factor for diabetes.

In 2007, 30 states had obesity rates of 25 percent or higher, according to the Centers for Disease Control.

Need more motivation? In formulating these guidelines, the government points to statistics that show regular physical activity can cut by 20 percent the risk of heart attacks and strokes. It can help avoid high blood pressure, type 2 diabetes, colon and breast cancers and depression.

Time to get moving, folks.