We Can Skip the Bench Press
Hoisting heavy weights can lead to big guns—and torn rotator cuffs. The good news: Researchers at McMaster University in Ontario have found that smaller dumbbells can be just as effective at sculpting your body. The secret isn't in the size of the weights you pump but how long you pump them. Keep lifting until you can't anymore; by then your muscles will have synthesized new proteins, which make muscles grow bigger.