Should I lift heavy weights and do fewer reps, or lighter weights and more reps?

Repetitions or resistance? That is a good question. First, you need to determine your goal. Choosing heavier weights and fewer reps is a recipe to sculpt a buff, rock-hard, sprinter’s body—and the explosive power that goes with it. Lighter weights and higher repetitions train your muscles for endurance. You’ll end up with the supple yet toned, lean look of a dancer. Both methods increase lean muscle mass and burn calories, so you really can’t go wrong.