The overhead press is a compound exercise that targets your upper body, making it a natural complement to the squat. It concentrates on the shoulders, but also involves muscles in the back, arms, and abdomen, all of which act to stabilize the movement.
Here’s how to perform this exercise:
1. Stand with your feet slightly more than shoulder-width apart. Hold a dumbbell in each hand and bend your arms at a right angle, so that your forearms are pointing straight up and your elbows are pointing down.
2. Breathe out as you push the weights up slowly, straightening your arms. Keep your back straight and continue looking forward. Make sure that the weights don’t drift forward or backward as you raise them, and don’t let them touch each other when they’re above your head.
3. Breathe in as you slowly lower the dumbbells to their starting position.
To extend the arm-muscle benefits of this exercise, you can tack a bicep curl onto the beginning. First, start with your arms hanging down at your sides. Then, bend your arms pulling the weight toward your shoulders. Next, turn your palms out and raise your arms to the starting position for the overhead press. Finally, complete the overhead press exercise. This requires a bit more coordination, so don’t try it until you’re thoroughly comfortable with the basic overhead press.
In the variation described here, you do the exercise standing, but there are alternatives. If you perform overhead presses in a chair that has a firm, supportive back, you can lean back and lift heavier weights. This suits power lifters and demands more work from the shoulder muscles, but it also reduces the workout that the stabilizing muscles get in the rest of your body.
Source of Information : Oreilly - Your Body Missing Manual