With devotees among some of Hollywood's fittest—from Chris Evans to Zac Efron—the regimen is on the rise again, on and off the wall. Why? It's the fastest route to a rock-hard physique. read more
Rock is hot again. In fact, you can burn up to 700 calories an hour while hoisting yourself up the side of a cliff. When you've mastered the wall at your climbing gym, plan a trip to scale one of these beauties. read more