A pull -up is a closed-chain movement where the body is suspended by the hands and pulled up. Learn about the variations, muscle activation, equipment, and records of this exercise. Learn how to achieve 20 pull-ups in just 60 days with this comprehensive pull -up progression guide. Build strength & master this exercise. Pull-ups are one of the most challenging but effective bodyweight moves, recruiting several muscles in the upper body and abdominal region. Despite being thought of as a benchmark for physical fitness, experts agree that the strengthening exercise is no small feat. " Pull-ups are lifting your entire body weight against gravity in a vertical direction. It's not an easy thing", Alex Piccirilli, a Nike fitness trainer and health coach, said. While difficult, there are several ways to build up to ... What muscles do pullups work? Here, experts explain exactly what muscles you're training when you hit the bar to do the comprehensive upper body exercise.