The more active you are, the more likely you’ll live longer than your inactive peers, according to a report in the Journal of the American Medical Association.

Researchers from the National Institute on Aging in Bethesda, Md. studied a group of 300 men and women between the ages of 70 and 82. Since people often overestimate the amount of exercise they do, the investigators decided to measure activity level more directly by calculating how much carbon dioxide the participants created during the course of their daily routines. (Carbon dioxide is a byproduct of any energy-producing activity in the body.)

To make those measurements, the researchers gave the participants a special kind of water that i s made up of unusual forms of hydrogen and oxygen. By measuring the amount of hydrogen and oxygen in the participants’ urine, the scientists were able to calculate how much carbon dioxide had to have been expended.

When they divided the group into thirds, based on activity level, the NIA researchers found that the most active group had a 12% risk of dying over the course of the six-year study. The middle group had a 17.6% risk of dying during the study and the least active group had a 24.&% risk of dying during the study.

What it Means: This study provides more evidence that physical activity is one of the keys to good health. In this study, the total level of activity included more than what we think of as exercise--going to the gym or taking long walks. Climbing stairs, gardening, doing housework and other activities also seemed to help prolong life.

From the Archive:
01/21/2002 Walk, Don't Run
10/17/2005 Aging Naturally