To find the right machine for you, be sure to try before you buy. Consider these factors:
Nonfolding treadmills are about the size of a small couch. Folding treadmills are generally shorter than nonfolding models, and they can be stored upright to save space. Elliptical exercisers take up more vertical space.
For treadmills, consider your stride. If you have a long stride or you plan to run, a longer deck like those on nonfolding models might be necessary. Less expensive folding treadmills can have shorter decks.
Look for one that provides at least two to three years of coverage on major moving parts on your treadmill and a year for labor. Survey data on the probability of failure and repair costs showed that extended warranties are probably not a good deal.