To get sky-high drive, know exactly why you're working out, and make those reasons true to you, says Michelle Segar, Ph.D., a motivation researcher at the University of Michigan in Ann Arbor.
"For most people, trying to meet someone else's expectations or assuage guilt isn't sustainable," Segar says. Register for a marathon just to one-up your super athletic sister, and you may never cross the finish line. Try to lose weight to please your partner and the scale could tip the wrong way. Homing in solely on better-body goals, like slimming your thighs, is a no-no, too, says Jeremy Adams, Ph.D., a sport and performance psychologist and director of Eclectic Consulting in Melbourne, Australia.
Gym goers who fixate on the physical payoff can lose their motivation in a couple of months, he explains, because it can take awhile to see the results they want. If you focus on why exercise is a positive aspect of your life, both Segar and Adams suggest, you'll be less stressed and more energized—and those sources of immediate, constant and meaningful inspiration will keep you hooked on breaking a sweat.