I just ordered this as I am terribly atrophied from weakness and pain for so many years. It's got resistance and won't slide across my floor supposedly. I thought some of you might be interested. I can sit in my own chair and do it a little at a time. It says it can be used by hands or feet. Can't wait to get it. It has plenty of good reviews.
Pedal Exerciser - Portable Medical Exercise Peddler - Low Impact, Small Exercise Bike for Under Your Office Desk - Designed for Either Hands or Feet