Think back to the last time your fitness goals got sidetracked. Did you have a sudden craving for salt and dive into a bag of potato chips? Did you feel so tired after work that you headed for the couch instead of kickboxing class? And afterward, did you figure you just weren't motivated enough to stick with your diet and exercise program? Well, there may be a way to make sure your motivation remains intact: Look outside yourself for the external factors that derail your fitness -- and the things that will inspire it. "Being more motivated is like pushing harder," says Linda Bunker, Ph.D., a sports psychologist at the University of Virginia in Charlottesville. "You can keep pushing, but if there are barriers in your environment, all that pushing doesn't make any difference." So find ways to get rid of the obstacles and to surround yourself with inspiration, and you'll see how much easier it is to stay on track. The expert advice that follows can help.

TIP: Evict irresistible edibles

"It's very important not to exclude your favorite foods from your diet -- but if you can't resist ice cream and cookies when they're in the house, don't keep them around," says Heidi Reichenberger, M.S., R.D., L.D.N., nutritionist and spokesperson for the American Dietetic Association in Newton, Mass. Instead, Reichenberger suggests going out for those treats, or only having them on special occasions. You may even find you enjoy them more when they're not always around.

Try this Find an empty cardboard box. Go through your kitchen and, in the box, place all the fattening foods you're rarely able to resist. Bring the box to your office to give to co-workers or donate it to a food bank. Then, get a piece of paper and create a worksheet on which you write down which food you've boxed, or another favorite, that you'll allow yourself as your weekly treat (so you won't feel deprived and as a reward for keeping your kitchen free of temptation).

TIP: Stockpile and prepare

If you don't have healthful food in the house, you're not going to eat that either, so stock up on good-for-you meal and snack ingredients, such as skinless chicken breasts, brown rice, fruits and vegetables, nonfat yogurt, lowfat cheese, whole-wheat pretzels or anything light and healthy that you enjoy. Convenience is also critical, Reichenberger notes. Plan your meals ahead of time, and even prepare them on weekends and freeze them if you're too busy to cook during the week. "Have carrots peeled and cut up -- not in a bag in the vegetable bin where you'll never see them," she says. When you're hungry, you want to eat now; you don't want to take 20 minutes just to fix yourself a snack.

Try this On your worksheet, map out your meals and snacks for the week and draw up a grocery list. Set aside the time you'll need to shop and prepare your meals and snacks.

TIP: Plan for snack attacks

In malls, airports and other public places, you're surrounded by fast food, snack machines and ice-cream shops. The office can also be rife with fattening snacks and treats. "You can't expect anyone to avoid these things if they're hungry," Reichenberger says. So stash healthful snacks in your purse, she suggests. On work days, along with a packed lunch, tote a couple of nutritious snacks, such as raisins, unsalted nuts or animal crackers. Keep a glass or bottle of water at your desk. The goal is to avoid getting overly hungry, so you can steer clear of the candy dish or the cookies someone else brought in, not to mention all those tempting drive-through windows on your way home.

Try this On your worksheet, highlight a few of the snacks you'll take with you wherever you go. As a daily reminder, put a note by your key rack or on your front door that says, "Got food?" Don't leave home without it!

TIP: Dress for success

In addition to having your eat-right strategies in place, you can create get-moving motivators. For example, Bunker advises laying out your workout gear each night before bed. "Mornings can be so hectic that we forget our priorities," she says. If you're working out in the morning, put your exercise clothes on as soon as you get up. If you'll be working out later in the day, take your gear with you when you leave the house. If you exercise after work, change into your workout clothes before leaving the office. You can also jolt your mind into workout mode by placing your clothes or equipment in places you'll see them. "One of my clients got results by putting her sneakers in the mailbox to remind herself to exercise before taking the mail inside," Bunker says.

Try this On your worksheet, list your workout gear (i.e., clothes, shoes, water bottle, towel). Check off each item after you've laid it out at night. You may want to try a visible reminder that's a bit more out-of-the-ordinary, such as putting your workout shoes under your desk or on the front seat of your car.