1. No construction required - okay, a bit of air power that a bicycle pump can sort out, but you can thank the lord you are not getting a delivery of a 300 piece home gym - it would be a workout just putting it together.
2. All over workout - from the calves to the triceps, the exercise ball is one of the most versatile pieces of gym equipment you can find
3. It's credit crunch friendly - exercise balls are really not expensive, you can often pick one up for less than a tenner, so there really is no excuse not to workout
4. Easy storage - inflate to play, defalte to the size of an A4 notepad at the end of the day and slip in the draw if you want, exercise balls are easy to hide. Let them see the results on your body rather how you got there!
5. Fun to sit on - if you've had a great workout on an exericse ball, you can them comfort yourself by perching on it. Manufacturers don't recommend using it as a bar stool, but they are great fun for a little sit down!