Half Jack Exercises

The half jack targets the muscles in shoulders, hips and calves. The exercise is similar to a traditional jumping jack, except you do not raise your arms all of the way above your head. Because you do not have to lift your arms as high, it is an ideal exercise for people with shoulder injuries or limited range of motion. Since it increases your heart rate, is serves as both a cardiovascular and strength training exercise.

  1. Exercise Basics

    • For optimal results, always practice proper form when doing half jacks. Stand up straight with your feet together and knees bent slightly. Rest your arms at your sides with your palms facing your legs. Jump and bring your legs out, landing with your feet shoulder-width apart. Lift your arms out to your sides at shoulder-height out as you jump. Jump again, bringing your legs and arms back into the starting position. Repeat for a total of 20 repetitions. You can do half jacks as a warmup or include them in a 30-minute workout routine.

    Variations

    • To boost the intensity of your routine, jump faster and higher. You can also do half jacks in waist-deep water. For an alternate exercise, perform the cross half jack by crossing one leg in front of the other while you cross your arms in front of your chest as you jump inward. Or do seal half jacks by starting with the palms of your hands together at shoulder-height. Jump and point your feet out, arms out to your sides and thumbs facing up.

    Tips

    • The balls of your feet should touch as you bring your feet together. Never raise your arms higher than shoulder-level. Briefly rise up onto your toes before you jump off the ground. This creates a better spring to your jump and helps strengthen the ankle area. Minimize your contact with the ground as much as possible. Perform each move as quickly as you can to help boost exercise intensity and caloric burn.

    Warnings

    • If you are new to exercise, don't jump. Instead, tap one leg out to the side while you raise your arms. Gradually work your way up to jumping as you become stronger and master the movements of the half jack. Make sure that you land on the balls of your feet and that your heels come all of the way down -- do not stay on your toes. This puts pressure on your ankles and calves and can lead to discomfort and pain. Breathe safely to help prevent blood pressure spikes and dizziness. Exhale when you jump out and inhale when you bring your feet and arms back into the starting position.