What Muscles Does an Exercise Punching Bag Work?

Professional and some amateur boxers boast well-sculpted bodies honed by hours working with punching bags. Boxers of both levels of expertise generally train with both a small speed bag that rebounds after each hit and with a heavy bag designed to absorb more powerful blows. The more energy and effort you put into your punching bag routine, the greater the full-body muscular workout you will receive.

Arms and Shoulders

Although throwing an effective punch requires full-body muscle coordination, your arms and shoulders are the most obvious muscles that you work during a bag session. Crosses and jabs provide a particularly effective workout for your shoulder muscles, since straight punches primarily transfer force via rotation of the punching shoulder, which is controlled by your subscapularis, supraspinatus, infraspinatus and teres minor muscles. Wider punches like hooks and uppercuts rely less on core strength, as power is generated by rotational momentum from the triceps and biceps muscles. The constant stream of arm punches that you throw when using a speed bag is particularly effective for working and toning the triceps and biceps.

Body Core

Training with either a speed bag or a heavy punching bag can build strength in muscles throughout your vertical body core including the neck, chest and abs. When you hit the heavy bag with a power punch, you generate force primarily with the pectoralis major and minor muscles of your chest and your upper and lower abdominal muscles. Returning your arm to the ready position requires effort from your deltoids, lats and traps. Throwing hooks and body-level punches from different arm angles further varies your core workout by maximizing the angles at which you flex and extend your abs. Punching a speed bag continuously engages the abs and pecs as you keep pace with the rhythm of the bag. This continuous engagement results in isometric, or symmetrical, muscle training because you must extend and flex each muscle group at a constant pace to strike the bag in rhythm. Your neck also receives a steady workout from either type of bag, as the punching motion constantly flexes and extends your omohyoid and sternohyoid muscles.

Heart and Lungs

A well-crafted, strenuous punching bag regimen can add a substantial aerobic benefit to your workout. Boxers who train with a heavy bag practice moving around the bag, proper footwork and changing body position while punching. Increasing your rate of movement adds a greater cardio dimension to the workout, improving the strength and capacity of your heart and lungs. The longer you continue the punching bag workout, the greater the cardiovascular training you'll receive. For most people, a high-intensity workout of two to five minutes is optimal for maximizing aerobic benefit.

Leg Muscles

Proper power-punching technique requires a substantial contribution from your leg muscles. Your body rotation, and power generation, begins when you push off from the canvas with your legs and then pivot to transfer rotational force through your core. Your calves and quads are among your strongest leg muscles and are the most instrumental lower body muscles for initial force generation. In addition to the strength training you receive while moving around the bag, practicing proper footwork and engaging in defensive boxing movements like ducking and crouching greatly improve your lower aerobic and strength workout. Keeping your legs in perpetual motion during bag practice builds stamina and is particularly helpful for toning your calves, quads, hamstrings.