Muscle & Fitness magazine describes Arnold curls, also called incline curls, as dumbbell curls performed while lying on a 45-degree-angle weight bench. Stronglifts describes the overhead press as a full-body exercise in which the weight bar is lifted straight up off the shoulders. The body is straight upright with all joints fully extended and locked and the feet facing forward.
Arnold Curls improve the shape of the biceps and also help to add mass. The exercise can be done on either a flat weight bench or an inclined weight bench. The use of the bench stabilizes the body, allowing the exerciser to concentrate on moving through the full range of motion to stretch out the muscle. To get the most benefit from the exercise, the arms are curled at the same time.
The overhead press is a shoulder-isolation exercise. The knees, hips and back are all held straight upright and locked to prevent the leg and back muscles from assisting with the lifting effort. In addition to working the shoulder muscles, the exercise improves balance and works the muscles that stabilize the trunk and abdomen. The exercise is safer than a bench-press because the exerciser cannot end up trapped under the bar.