You can do this exercise standing or sitting. Sitting on a stability ball while doing this exercise is a great way to engage your core, as well as exercise your shoulder muscles. If you use a ball, use one that leaves your knees at a 90-degree angle when you are seated. Start with 8 repetitions, and then increase to 10 or 12 when you are ready.
Step By Step Instructions
Stand with your feet slightly wider than hip-width apart. Hold the weights just above your shoulders at a 90-degree angle at the elbows.
Press the weights up until your arms are straight overhead, then lower weights back to the starting position. Focus on not letting your back sway too far forward. Complete until total repetitions are complete.