When it comes to getting fit, you know what you should do (hint: move more and eat less—or at least better). It's actually doing it that can be so difficult. Cold morning? I'm the first one to want to sleep in! My muscles will be too stiff to jog in the park, I tell myself. I know, I know—just get on the treadmill.

If only it were as easy to make it to the gym or order the salad as it is to concoct reasons not to, we'd all look like, well, Jillian Michaels. Which is why we went straight to the Biggest Loser trainer and SELF contributor—a woman who simply doesn't do excuses—to get her cures for wavering willpower. Keep Michaels' stick-with-it advice in mind when you're looking for a way out. Staying the course will come more easily, and so will getting a standout body!

Excuse: "I have zero time to exercise!"
Michaels says: "I feel your pain—my life is crazy, too. But good-for-you habits are the last thing that should go. If you don't take care of yourself, you'll have less energy to be that supportive person in your loved ones' lives. I tell working moms to ask for help. It used to take a village to raise kids; you can't do it on your own."

Identify your personality type for a willpower makeover.

Excuse: "I can’t afford a gym or fresh produce."
Michaels says: "Commit to a $100 investment in 10 fitness DVDs and you'll have enough variety for six months at least. You can do a whole workout—sit-ups, jumping jacks, squats—without any equipment. And imagine the cost of taking diabetes meds for the rest of your life—much more than the extra $50 a month you should spend on groceries and fish." Try this free, do-anywhere workout created by Michaels to get started.

Excuse: "The cookies in my cabinet are calling me!"
Michaels says: 'I don't keep junk in the house or let waiters bring bread to my table. I have no discipline, so I protect myself from temptation." Stock up on some of these 30 healthy snack options instead.

Excuse: "I can’t get up early to work out, and I’m tired at night."
Michaels says: "When the alarm goes off, ask yourself, 'Will going back to sleep help me reach my great goal?' If the workout isn't attached to a larger reason—like having the confidence to get back in the dating game—it won't stick." Got 10 minutes? Try this superfast workout you can do in your living room.

Excuse: "I've hit a plateau; I give up."
Michaels says: "Get selfish! Don't think you're asking too much of the world or of yourself. Push through by believing the new, improved you is your destiny. There's no reason you can't have it all."

Excuse: "I start off Monday with the best intentions, and then life takes over and I flake on my workouts."
Michaels says: "Set a daily or weekly target and reward yourself every time you meet it. I get my eyebrows done or download songs from iTunes."

Excuse: "I get so bored counting all those weight reps or running."
Michaels says: "As you exercise, think about what you're trying to achieve. Having intention behind your actions is extremely powerful. And nothing beats a good beat to keep energy high. I want to die when I don’t have my music! Any song by The Roots totally gets me psyched. Finally, you don’t have to kill yourself to get a workout. Running is one of the best ways to get smaller, but I hate it, so I do only one 10-minute mile."

Excuse: "But the couch is so comfy!"
Michaels says: "If you need a couple days off, take them. You don't want to get bitter or burn out."