Your shoulder joints are among the most mobile you have, and their safety comes from the stability provided by the muscles and ligaments that surround them. That's why an imbalance in these stabilizing muscles can oftentimes result in injury.

In addition to performing rotator-cuff-specific exercises (the area of the shoulder where most injuries occur), it's important to follow a resistance training program that targets more than just your mirror muscles. Be sure that your workout includes an equal amount of pull exercises (pull-ups, rows, etc.) as it does pressing exercises (bench press, push-ups, military press, etc.), as it will create muscle balance and, in doing so, help stave off shoulder injury.

Also, be sure to listen to your body. Pain is never the goal, despite what some meatheads wearing Gold's Gym T-shirts and lycra shorts may tell you. If something feels wrong -- that is, different from the usual burn you have grown accustomed to feeling during a resistance training workout -- you should stop immediately. Failure to do so could take you out o the gym and on the D.L. for several weeks.