I use them when I train my clients and teach classes. They work better on carpet. They are great tools to incorporate in your classes. Use your judgment as to which clients are able to safely use them…not for use when balance and stability issues or a weak core are a concern. The gliders used for moving furniture are cheaper and as effective as those sold in fitness stores or online, and you can buy a package with several pairs in it for under $10. Check a hardware or home improvement store.