How good are you at getting back up again?  The optimum situation, of course, is being able to stand without using any help from your arms.  If you can't manage that, you can use one, or maybe both, arms to hoist your bulk from the chair.  Even getting up from a chair qualifies as exercise, I guess.  Please e-mail me at:  pjones41@kc.rr.com, and come join me on facebook, too.  Farmville, anyone?