Sure, you have to eat right — that’s another manifesto in itself — but if you just stick to a basic strength-training program, you can expect a certain wonderment about what the hell you were doing all those years, why nobody told you it was this simple before, and why nobody else in the gym appears to have heard the good news.

Specifically, he found that men who reported more than 23 hours a week of sedentary activity had a 64 percent greater risk of dying from heart disease than those who reported less than 11 hours a week of sedentary activity. And many of these men routinely exercised. Blair says scientists are just beginning to learn about the risks of a mostly sedentary day.