How to perform a dumbbell bench press on a swiss ball with an animated image showing the move. Click on the picture to see the full sized animation.

1. Lay on a swiss ball with your upper back supported by the swiss ball and your feet flat on the ground in front of you.
2. The closer your feet are to one another, the harder it will be to stabilize yourself on the swiss ball. (This is a good thing.)
3. Grasp two dumbbells next to your chest with your palms facing in.
4. Press the dumbbells up above your chest.
5. As your arms reach full extension, twist the dumbbells so that your palms are facing forward.
6. Do not lock your elbows.
7. Pause, and then lower the dumbbells back to the starting position. Reverse the twisting motion so that your palms are facing inward when you reach the lowest point.
8. The dumbbells should be level with your chest, with your elbows hanging below the swiss ball.

Depending upon how comfortable you are on a swiss ball, you want to work towards bringing your legs close to one another. The idea is to work your core to keep yourself from rolling off of the swiss ball. Your range of motion on a swiss ball may not be quite as low as it is when you are doing a dumbbell bench press on a flat bench, and that is okay.