I’m no fan of exercise. But as I imminently approach 40, I’m feeling and seeing its value more and more. The purpose of fitness is not longevity - it is independence and quality of life. Just assume you’re going to live to age 90 either way. Look around at some 80 year olds. Breathing machines, walkers, bed ridden… how do you want to spend your years? Years! Your body will become a torture prison unless you tend to it. Dying is the least of my concerns.