Exercise after 40 may be the most crucial exercise

We've been taught that exercise at any age is beneficial to good health and longevity, but recent research has zoomed in on a time period in your life when it may the most important of all.

Researchers from the University of Mississippi and the University of California, San Francisco looked at telomere data — those are the caps at the end of DNA strands that are linked to longevity — from 6,500 adults based on a national survey. They found that exercise prevented telomere shrinkage and prolonged life in those ages 40-65.