It's called having a healthy diet and exercising regularly. People who eat mainly a Mediterranean diet live longer than people with other less healthy diets. There is already a big difference in people who are unhealthy and uncomfortable in their own body by their 60s and people who regularly practice moderate exercise and eat healthy diets who can live comfortable adventurous lives into their 80s and 90s.

Sometimes the world is cruel and someone does everything the can to be healthy and fit into old age but they are robbed of that experience by tragic events and/or disease. Life's not fair.