Don't be concerned if running or exercise will add years to your life, be concerned with adding life to your years.
Books by George Sheehan
This Running Life
Going the Distance: One Man's Journey to the End of His Life
George Sheehan on Running to WinHow to Achieve the Physical, Mental and Spiritual Victories of Running
Personal Best:The Foremost Philosopher of Fitness Shares Techniques and Tactics for Success and Self-Liberation