Johnson hits the gym six days per week, usually focusing on one body part per day. At 40, he's a seasoned, instinctive trainer. "I go by feel," he says, and notes that when he's in the gym it's all business. "I have my headphones on. I'm listening to my music. I'm 100% focused. There's no wasted time and no wasted effort when it comes to me and the weights." And The Rock's favorite body part? Legs, which is why he leaves them for Saturday when he has extra time to train them.