Have you seen these big exercise balls in different colors but never known what they are for?

These balls are great for building your strength in most parts of the body.
They are also especially recommended for pregnant women. I remember using it while I was pregnant and it was really fun. I remember that one of the things I did was to sit on the ball and roll around with my hips. Which was supposed to be good for my hips and stomach muscles if I remember correctly.

When doing your exercises you have to take care not to fall or not placing your body in the right position. It is a ball after all and it can be a bit unstable.

Make sure you wear comfortable clothes and prepare yourself before starting.

The balls comes in different colors and sizes. You need to make sure you have a ball that is suitable for your body. That you won't get hurt when doing the exercises.
You want to get stronger, not getting a back pain.

Maybe your gym even has special classes for this? If not you could always suggest it.
If you haven't tried it out; have a go!