Lifts that work muscle at more than one joint are known as compound exercises. These include the deadlift, squat, press, row, and chinup. Compound lifts recruit lots of muscle mass, making for efficient training and a big release of hormones such as testosterone that promote growth—make them the cornerstones of your workouts. There’s nothing wrong with throwing in some isolation work (curls, leg extensions), but treat them like dessert after you’ve had your main course—the compound lifts.