Are exercise balls useful? As a precautionary measure, I recommend the following:
1. In unpacking your balls, handle with extreme care. Don't blow too hard when inflating them.
2. When touching your balls, don't squeeze too hard - exercise shouldn't be painful.
3. Remember that your balls deliver more bang for the buck than ordinary exercise.
4. Avoid excess moisture on your balls - the clean-up is too messy.
5. Avoid storing your balls in damp, dark places - expose your balls to light as often as possible.
6. Break new balls in slowly - balls take time to be rigid and perform well.
7. Please - one person per set of balls - too many people will drive you nuts.
8. If your balls remain flacid over a long period of time, get help - this will be a stroke of genius.
Over the years, I have modified my exercise routine to make regular use of my balls.