Excuse-Proof Your Workout

"Put it in your calendar," says trainer Danny Musico, who gets the cast of Entourage buff. Hire a trainer so you can't back out, or set a date with your husband and friend. Travel too much? Pack an exercise DVD or resistance brands, which take up zero space, or hit the streets with your sneakers on. A brisk walk after a long flight can get your blood pumping and endorphins flowing.

SPRI Xertude resistance band, $14; at

amazon.com.

Breezing through the same 30-minute routine day after day isn't going to transform your shape, says trainer Gunnar Peterson. Your body gets efficient at fat storage, so unless you trick it, it's not going to let go. "The most effective way to burn fat is by interval training," says Michelle Lovitt, who trains Julianne Moore. "Do short segments of speed work, recover, then get your heart rate back up again." To get an accurate read, the Polar F6 monitor can tell you whether you're in the fat-burning zone.

Polar FT4 Training Computer, $100;

shoppolar.com

Don't let an injury totally sideline you: Experts say you need to build up the area around your problem spot. "If it's your back, you work your abs as well as the muscles that laterally bend and rotate the spine," says celebrity trainer Gunnar Peterson. Check with your doctor or physical therapist first, but for a low-impact cardio workout try indoor cycling or swimming. Or work your core with yoga or Pilates.

"Burning calories does increase your appetite," says nutrition and exercise physiologist Felicia Stoler. Satisfy your hunger with foods that are high in fiber, like veggies, whole grains, nuts and fruits. Also guzzle water. "Sometimes when you feel hungry, you're actually thirsty," she says. And don't wait until you're starving to eat. You'll be less likely to overdo it (or to go through that enormous bag of chips).

Pick something you enjoy or you won't stick with it, says Kelly Ripa's Spinning instructor, Janet Fitzgerald of Soulcycle. She also advises taking the time to create an inspiring playlist. Pure Yoga's Kay Kay Clivio suggests booking a vacation that is equal parts sports and sightseeing to kick start your routine. Escapetoshape.com and Adventurefinder.com offer cool ideas for vacations that include activities like martial arts or rock climbing.

You won't-strength training doesn't make you big. Recent studies suggest that lifting heavier free weights or kettlebells with fewer reps, two or three times a week, helps shed pounds and trim belly fat. In fact, carbs are more likely to increase your size than gym workouts, so "skip the bread basket-not your exercise plan," says Yogalosophy creator Mandy Ingber, Jennifer Aniston's trainer.

J Fit 10-pound Kettlebell, $30; at

amazon.com

Got shoes? "That's the only gear you need—other than a good bra," says Lovitt. "Many sports store a quick gait analysis to help select the right sneakers for you, whether you have flat feet, a high arch, or need ankle support." Once you're laced up, press Start on the treadmill and walk briskly for 30 minutes. Follow that with push-ups or crunches, each time tackling a separate muscle group. Most gyms offer a free orientation for new members. If yours doesn't, spring for a trainer initially to revamp your routine.

Asics Gel Kayano 16 sneakers, $140; at

asics.com.

"Cut out one happy hour and dinner per month and you can afford a gym membership," says Jennifer Lopez's personal trainer, Gunnar Peterson. Even easier, do free activities like walking, running, jumping rope, and Hula-hooping. Or go online and try a YouTube exercise class, find a fitness plan (we like Fromcouchto5k.com), or download a free iPhone app (Dailyburn.com)-and get moving.

Not with this game plan: "Wear a loose, high bun," says Tippi Shorter, hairstylist to Jennifer Hudson and Alicia Keys. After working out, sprinkle in dry shampoo to absorb oil from your scalp, then blow-dry wet pieces. (If you have wavy hair, add a curl activator before drying.) No time for styling? Tie hair in a knot, then slip on a skinny headband to hide hairline frizz.

Good Colorway Head Wrap, $4 for 6; at

target.com

"Being slim and fit are two different things," says Michelle Lovitt. You can be slender and out of shape, with brittle bones and in poor cardiovascular health. "When I work out with Lady Gaga, we try to create lean muscle," says her trainer, Harley Pasternak, noting an added benefit: Most people noticed that they have more energy when exercising regularly.

Heartbeats by Lady Gaga headphones, $100;

Lady Gaga Official Store