A wide variety of adapted exercise equipment is available online and in catalogs geared for people with disabilities. For instance, a stationary arm-bike will substitute for a standard stationary bike, so a non-ambulatory person can get an aerobic workout. Now there are consumer versions of arm-bikes, and some models are portable; they can be set on top of a table to be used as arm-bikes or used on the floor with Velcro straps for your feet. If you can get to a good fitness center, the NuStep® is a good recumbent exercise machine.