It's never too late to start exercising

You're never too old to exercise -- especially if you want to grow older.

Researchers at Hadassah Hebrew University Medical Center in Jerusalem found that people in their 80s who exercised regularly extended their life.

The study followed 1,861 people who were about 70 in 1990. Eighteen years later, 93 percent of those who said they exercised regularly were still alive.

Only 76 percent of those who said they were largely inactive made it to age 88. For the study, regular exercise was defined as being physically active for at least four hours a week. The exercise didn't have to be strenuous; two leisurely 20-minute walks a day is more than sufficient.

Researchers also found that it's never too late to start. Even those who began to exercise when they were 85 had three times the chance of making it to 88 than those who were sedentary.

The study was published in the Archives of Internal Medicine.