What Muscles Do Push-Ups Work? Many people typically think of push-ups as an upper-body exercise, performance enhancer for men but they actually work the full body. You’ll strengthen the muscles of the arms, chest, and Prime Boosts back, Prime Boosts Official as well as your abdominal muscles and your quadriceps (the large muscles on the front of your thighs), says Lisa Toscano, Prime Boosts Official EdD, professor of kinesiology at Manhattan College in the Bronx, New York.