The one arm dumbbell chest press is perfect for strengthening the pectoralis (chest) muscles. Most chest exercises involve compound movements, or the use of more than one joint. Invariably, the triceps and anterior deltoid are often involved in chest exercises.
Start by resting your upper back on the ball. The dumbbells should be positioned around the chest/shoulder area until you feel a light stretch. Once in position, simply press one dumbbell up by extending the elbow. Try not to lock the elbow during the extension phase. This will help to protect the important joint structures at the elbow joint. Perform several repetitions on one side, then repeat the same movement on the other side. You should exhale as you press the weight up.
Position upper back on ball. Position dumbbells around chest/shoulder area.
Extend one arm up, just short of locking the elbow. Exhale as you press the weight up.
Return to the starting position. Be sure to perform the same number of repetitions on each side.