Via Insty, from Starting Strength:
“[A]t present there is absolutely no solid evidence that strength training—or any other exercise or dietary program—will substantially prolong our life spans. But the preponderance of the scientific evidence, flawed as it is, strongly indicates that we can change the trajectory of decline. We can recover functional years that would otherwise have been lost.”
Exactly right. Fitness for life and postponing decline. That's my goal. A generation or two ago, most American middle-aged people were overweight, weak slugs unless they did manual labor. The cultural change has been dramatic: people avoid heavy-lifting jobs, then pay for the privilege of lifting, pushing, and pulling weights for an hour.