Sit down on an exercise ball and make sure you are well balanced and keep your back straight. Grab a hold of the dumbbells and hold them down and to your side with your palms facing the front. This is your starting position.
Raise the dumbbells up until they are at your upper chest level. Then, lower them back down to the starting position but do not fully extended your arms. Always maintain a slight bend in your arms at the bottom. Repeat entire movement for the desired or prescribed number of repetitions.
Perform this exercise in a smooth and fluid motion
Don't extended your arms completely at the bottom
SPECIAL NOTES & LEVEL of DIFFICULTY VARIATIONS
To increase the level of difficulty, slow down the movement or use heavier dumbbells.
This is a great variation on the flat bench curl. Some people prefer the comfort of the ball to the fixed an immovable flat bench. If your bicep routine is stale this exercise is perfect for adding some much needed variation to your program.
One item worth noting is that the balance aspect is a bit more challenging to get used to. To keep proper balance you will need to keep your feet firmly planted on the floor and will also need to use your legs to keep yourself firmly in place.