A smart body, he explains, knows how to convert force and speed into an almost endless menu of practical movements. Hoisting yourself onto a pole may seem as trivial as a circus stunt, but if you're ever caught in a flood or fleeing an attacking dog, elevating your body 5 feet off the ground could mean the difference between safety and sorrow.

And with that one word -- "practical" -- Le Corre exposes a key weakness in modern exercise: Our workouts are domesticated, while the world out there is still plenty wild. In a pinch, can a man put gym-generated biceps and tank-tread abs to any real use? Could it be that our treadmill-running, elliptical-gliding, well-oiled Cybex world has turned us into show dogs who can't hold our own in the hunt?

"I meet men all the time who can bench 400 pounds but can't climb up through a window to pull someone from a burning building," Le Corre says. "I know guys who can run marathons but can't sprint to any one's rescue unless they put their shoes on first. Lots of swimmers do laps every day but can't dive deep enough to save a friend, or know how to carry him over rocks and out of the surf."