The local gym here ran a deal from Jan till April. It cost $99 to join and if you lost 12 lbs in 12 weeks you got your money back. It was a good deal for 12 weeks so I joined even though I was limited in what I could do while taking therapy on my knee. Plus during this time I took sick with a respiratory illness that was going around, so I couldn't workout much for 3 and a half weeks.
When weigh out came I had lost 10 lbs !! No money back but I was really pleased
Should help my knee too.