A fitness ball is one of those tools that looks like it is so simple that it can't possibly do any real good, but that is deceptively helpful in toning virtually every group of major muscles in your body. The key is in knowing how to use this tool to its fullest extent.

There are many great things about a fitness ball. They're affordable, they're easy to store because you can deflate them when they're not in use and tuck them into a drawer, they don't require batteries and they don't require any technical knowledge. They're as simple as a yoga mat and offer just as many workout opportunities. Moreover, depending on what you want to do with a fitness ball, there is certain to be one that is the perfect size for you, regardless of whether you plan to sit on it or use it for floor work.

These small inflated spheres are great for toning and slimming as well as reducing lower back pain. If you don't own one, it may be worth it to pick one up for only a few dollars and give one a try.

Here are a few ideas to get you started. This involves the use of one of the smaller sized fitness balls:

• Toning your butt – lie on a yoga mat on your back with your knees bent and your feet on top of the ball. Keep your knees and feet parallel, pressing them together. Slowly, lift your hips off the floor and hold this position for a minute, engaging your core and pressing down with your heels into the ball.

• Toning your inner thighs – lie on a yoga mat with your feet flat on the floor and your knees bent. Place the yoga ball between your knees. Use your knees to squeeze the ball, lifting your hips off the floor until your body forms a straight line from your chest to your knees. Lower to the start position.

• Strengthen and tone your core – Sit on the floor with your ball behind your back. Bend your knees and keep your feet flat on the floor. Press your lower back into the ball while leaning your body slightly backward. Extend your arms ahead of you at shoulder height. Keeping your hips still, bend your left arm and twist your torso to the left. Slowly return to center and then do the same for the right side.