"It is a shame for a man to grow old without seeing the beauty and strength of which his body is capable." Socrates
Let me let you in on a little secret. Just because the majority of people "breakdown" as they age DOES NOT mean it is normal. You do not all of a sudden just start breaking down, getting aches and pains, get fatter, lose muscle.
It is the accumulation of how you have been eating for years that slows down your metabolism. How you have been living, etc.
It starts with us. It always has and always will. Being a better mother, better father, grandparent, husband, wife, neighbor, human. This is what it is all about. Bettering the world through bettering ourself!