Forget no pain, no gain.
Exercise can be entertaining.
This is Ellen Levine with Good Advice From Good Housekeeping. Fun fitness classes, videos, or activities may get those muscles moving again. Take Latin, swing, or belly dancing, for example. The Good Housekeeping Institute says dance classes are no substitute for crunches, but are a low-impact alternative to walking. If you're a kid at heart, some gyms offer recess classes, with everything from soccer drills to spinning a hula hoop.