Using an exercise ball in your fitness training adds more than you think to your workout. This soft, elastic, air-filled device also called a 'Swiss' 'balance' or 'pilates' ball causes instability when performing a move and forces you to use more core muscles to stabilize yourself. It engages more muscles basically making your body work harder.
One way to use it is for doing a squat, like pictured below, and it will make you use more of your core muscles when you have to hold it between yourself and the wall while squatting.
You can use it for a variety of exercises such as sitting on it to lift dumbbells above your head, use it to stretch your back, use it for ab exercises as well. I've included a few YouTube videos below to demonstrate some ways to use it.
Some tips:
1. Make sure you have an open area to use it. Make sure sharp corners are away from you like coffee tables or other gym equipment.
2. Brace the ball with a rolled towel or pillows until you get the hang of balancing on it.
3. Don't hold your breath while trying to balance...keep breathing through your movements.
4. Sit on the ball for awhile while you get used to the feeling of it moving around beneath you. FYI - I used one of these in labor and it helped immensely!
5. Try reclining. Keep your feet on the ground and core tight. This is a great exercise sort of like a plank all in itself!
Choose the correct size for you
These come in different sizes all measured by centimeters. The best way to tell is to sit on it and see if your upper thighs are parallel to the floor. Sometimes the package will also give an indication of the correct size for your height and weight, its best to try it out yourself.