Make Your Move: 8 Foolproof Motivation Tricks

"We always think we need to find willpower to do things we don't want to do, but what we really need to find is 'want power,'" says psychologist Kelly McGonigal, PhD, a lecturer at Stanford University and the author of The Willpower Instinct. In other words, to make exercise click, slap a mental sugarcoating on it. For Melissa Steinman, 28, of Findlay, Ohio, the incentive is her mission to raise money for the Arthritis Foundation, which has kept her running long after she lost about 70 pounds. Steinman, who has had rheumatoid arthritis since she was an infant, used the disease as an excuse to sit out exercise, until having knee surgery sparked a workout habit that has lasted four years and counting. "I learned that every pound I lost was like taking five pounds off my joints," Steinman says. That was all she needed to hear to get in gear, and she's putting her new lease on litheness to good use by training for a 5K charity race to support the foundation.