Muscular System & Jumping Jacks

Jumping jacks, a calisthenic-type exercise, brings back memories of Jack LaLanne and physical education classes. A time-tested exercise, jumping jacks are a high impact, plyometric-type movement that benefits primarily your cardiovascular system, along with your muscular system. As a compound movement, many muscle groups are targeted. Jumping jacks can be included warm ups, sport-specific drills, aerobic dance, boot camp, interval training and circuit training workouts.

Targeted Muscles

There are two phases involved in a jumping jack, the abduction, or jump apart phase, and the adduction, or jump together phase. Both phases use your body weight as resistance by placing an overload on your muscles resulting in increased muscular endurance. The muscles used to adduct your body include your outer thigh, buttocks and shoulder muscles. Abduction works your inner thighs and chest muscles. Your calves are also worked because your body lands from an airborne position. Your abdomen contracts to help you maintain correct posture and avoid arching your back.

Variations

Typical jumping jacks are performed by jumping apart and landing with your arms apart, and then jumping together and landing with your arms back at your sides. The movements are done quickly and continuously. Variations include adding a power component by jumping out and back and then landing with your legs together. Your body remains airborne while your body jumps apart and back together. Another variation of a jumping jack is done in a prone position while in a yoga plank. Your body is face down with your arms and legs extended while your hands and toes bearing your body weight. The jumping jack is done by pushing your body slightly off of the floor and landing with your hands and legs apart. This exercise works your arms and abs and is more of a strength exercise than a cardio exercise.

Benefits

As a plyometric exercise, jumping jacks add a power component to your workouts. Lower body muscles are trained to generate force in the shortest amount of time. There is a pre-stretch, eccentric, or lengthening phase, followed by an explosive concentric, or shortening phase. Muscle fibers are strengthened resulting in an increase in muscle mass. Additional benefits include increased flexibility, circulation and power. Jumping jacks are a high intensity exercise -- a 130 lb. person burns between 40 and 80 calories in a ten-minute jumping jack workout.

Considerations

Jumping jacks are not recommended for beginner-level participants or people who are overweight or suffering from knee problems. Repetitive jumping jacks can lead to shin splints. This is an inflammation of the tibialis anterior, which is the muscle in the front lower leg. Suggested surfaces for jumping jacks are hard wood floors, and matted surfaces, not surfaces that do not yield, such concrete, or carpet over concrete. Adequate footwear, breathing and technique are also important for injury prevention.