Short-sleeve season may still seem months away—but now's the time to get ready. Joe Dowdell, the founder of Peak Performance in New York City and the author of Ultimate You, developed this simple plan to quickly build muscle and add strength and definition. Click on photos or exercise names to launch our how-to videos.
Because these drain you so fast, don't include in the circuit. Instead, add them at the end of the workout. Grab a set of very heavy dumbbells. With your chest tall, chin up, and shoulders back, walk forward for 30 seconds. If space is tight in your gym, march in a figure-eight pattern. Do three sets.