When setting goals, don’t set yourself up for failure by having unrealistic expectations. “One important piece of advice I give my clients is to not feel overwhelmed when they are starting a training plan,” says Joy Di Palma, Los Angeles-based personal trainer and founder of Core Conditioning CrossFit. “It took them some time to put on the weight or fall out of shape and it will take some time to lose the weight and get back in shape.” If you want to slim down for a specific event, allow enough time in advance of the event to get ready for it. “On average, you can safely lose one to two pounds per week with the right foods and exercise,” says Di Palma. “There are no quick fixes—it takes time and discipline.”

“A recommendation I give to all of my female clients is that they must include three total body resistance training sessions per week on non-consecutive days in their weekly schedule,” says Joe Dowdell, who’s worked with Natalie Portman, Anne Hathaway, Eva Mendez and Claire Danes. “I ask that they schedule these sessions in their calendar, just like they would any other appointment because accountability is super important in achieving your goals.”

Before you begin pounding the pavement or hoisting heavy weights, warm up with three to five minutes of brisk self-massage, suggests says Jill Miller, creator of Yoga Tune Up, a fitness therapy program popular with stars like Kyra Sedgwick. “Use therapy balls or a foam roller to create friction, heat and circulation in parts of your body that are being targeted for your next workout. The self-massage will help to lengthen stagnant tissues and load the muscles with oxygen-rich blood. This preps them to be aware and responsive.” For a sample foam roller routine, click here.

Committing to a strict diet and strenuous exercise from the get-go can put you on the fast track to burnout. “When I hear people say that they, ‘hate exercise’, or ‘can't stay on a workout program’, I know that they have approached it in an unrealistic way,” says Erin O’Brien creator of Strong Body, Fit Body and Kristi Yamaguchi: Power Workout DVDs. “I’ve found that when people ease into exercise, they last much longer on a workout program.” Think about it as a lifestyle change. “For the first two weeks concentrate on moderate exercise,” says O’Brien. “This means, walking, swimming, biking, taking classes and light strength training. After a few weeks, start ‘cleaning up’ your eating, and focusing more on ‘raising your ceiling,’ meaning working harder and to fatigue.”

“I am a big fan of High Intensity Interval Training or HIIT,” says MB Regan, a New York City-based SoulCycle instructor. “It takes you out of your comfort zone and that’s when change happens.” This training method alternates low- to moderate-intensity intervals with heart-thumping, lung-screaming high-intensity intervals. The best part? You don’t have to spend hours at the gym to get results—just give yourself 20 minutes. “HIIT is considered to be much more effective than normal cardio because the intensity is higher and you are able to increase both your aerobic and anaerobic endurance while burning more fat,” says Regan.

HIIT can be applied to your cardio or strength training. Here are three routines to try. Perform as many repetitions as you can in 30 seconds. And remember, says Regan, form is key.

Upper body HIIT

1. Push-ups for 30 seconds

2. Bent over rows using 10 or 12-pound dumbbells for 30 seconds

3. Tricep kickbacks using (10-12lbs) for 30 seconds

4. Bicep curls (10-12lbs) for 30 seconds

5. Rest/Recover. Repeat two more times

Lower body HIIT

1. Squats for 30 seconds

2. Standing lunges, right foot forward for 30 seconds

3. Standing lunges, left foot forward for 30 seconds

4. Plies with shoulder press (5-10lbs) for 30 seconds

5. Rest/Recover. Repeat two more times

Cardio

1.Walk briskly or jog lightly for 30 seconds.

2. Sprint for 30 Seconds Sprint.
3. Repeat nine times, alternating walking/jogging and sprinting for a total of 10 minutes.  

“When it comes to exercise, I'm a big believer in the mantra, integrate, don't isolate,” says fitness icon Kathy Smith, creator of Ageless with Kathy Smith: Staying Strong DVD. “Pick moves that incorporate multiple muscle groups with full-range, compound movements that engage the upper body, lower body and core to burn more calories than isolated moves alone.” Get started with one of Smith’s favorites:

Step Back Lunge with Cross Chop

Move: Reach your arms diagonally forward to the left as you step back with your right leg and dip into a lunge. Pull your arms across your body to the right hip as you slide your right leg back to standing. Repeat 12 times on each side.

Tips

• Step back far enough into the lunge so that the front knee is directly over the front ankle.
• When your arms reach diagonally overhead, hold your core muscle tight to keep the lower back from arching.
• The move can be done with a towel or weights.
• For a challenge, left your knee toward your chest, balancing on one foot.

To remind her clients how they can keep their workout fresh when she's not around, Reebok Global Instructor Sara Haley, who whipped supermodel Brooklyn Decker into shape, teaches them this mnemonic device: “Say thank you please.” Here’s what it means and how to use it.

Say: Single limb (for a balance challenge)

Thank you: Twist (for a rotational challenge)

Please: Plyometric (for a jump/hop/fly challenge)

JUMPING JACKS

S: Single Jack: Alternate traditional jumping jacks with hop to one leg (like hop scotch). Repeat for 30 to 60 seconds.

T: Jack Turn: Alternate traditional jumping jacks with a jack that turns your body 90 degrees to the right and then the left. Repeat 30 to 45 seconds.

P: Jack and Jump: Alternate traditional jumping jacks with a tuck jump (knees to chest). Repeat 20 to 30 seconds.

LUNGES

S: Single Leg Lunge: Elevate back leg on chair or table. Lunge down with back leg long, keeping hands on hips. At bottom of lunge pop up front heel. Hold for two counts. Lower heel and lengthen front leg. Repeat 12 times on each side.

T: Lunge Twist & Reach: Lunge with arms reaching out long. Twist to the right. Reach left arm down, but do not touch the floor. Repeat the reach four times. Twist back to center and then repeat to left. Repeat 12 times (six on each leg). 

P: Lunge Hop & Push: Lunge down, pushing off two feet into the air. Pull back leg in to chest and extend front leg long. Pointing toe towards the floor, land back down in bottom or lunge. Repeat 12 times on each side.

PLANK

S: Single Arm Plank: Balance in plank with right arm behind back and legs out wide. Work to hold up to one minute. Repeat with left arm behind back.

T: Plank & Twist: Balance in plank with feet shoulder width apart. Twist to the right initiating rotation from the hips. Drop right hip to floor. Return to center. Repeat on the other side. Repeat sequence 10 times.

P: Plank Jump: Balance in plank with feet together. Squeeze abs and jump knees into chest. Jump back out to plank. Jump legs apart. Jump legs back in. (If needed walk feet in on each one.)  Repeat sequence 10 times.

For optimal toning, complete at least 2 “Functions” (different exercises) back to back with perfect “Form” to complete “Fatigue” (muscle failure), suggests Warner.

Next: Celebrity Trainers' Favorite Fitness Tips and Toys

Want the latest beauty, fashion and lifestyle tips? Click here to sign up for our fabulous weekly newsletter!