The good news for seniors is that being "active" can include physical activities such as housework, yard work, child care and just about any activity that requires standing up and moving around.
Researchers from the National Institute on Aging tracked the activity levels of 302 adults over 65 for six years. Instead of relying on participants' abilities to accurately recall their activities, researchers gave the participants a dose of water made of heavier-than-normal isotopes of hydrogen and oxygen, which the body slowly releases as carbon dioxide during physical activity. Throughout the study, researchers measured how much of the heavy oxygen was left inside patients. The lower the level of oxygen, the more active that person had been.
After six years, the researchers split the participants into three groups, according to their level of physical activity. The group with the highest activity levels experienced a 12 percent death rate; the group with mid-range activity levels had an 18 percent death rate; and the least active group had a 25 percent death rate.
Researchers say the study indicates that physical activity has a much greater effect in old age than previously thought. They stress that seniors can benefit from any activity that expends energy, not just traditional exercise.