On hunter gatherers, and living such that healthspan = lifespan, which is why I exercise.
"Lieberman said hunter-gatherers who avoid accident and disease tend to live nearly as long as their counterparts in Western industrialized societies. The difference, he said, is that “healthspan” among this group — the number of healthy years of life — nearly matches their lifespan. By contrast, it is a common fear in modern industrialized societies that one will spend years incapacitated by disease before dying."