The 5 Exercises You Absolutely Need to Lose Weight

This is the year you stop saying you want to get in great shape and finally just do it. No fad diets or boot camps, either. All you need is the body you've already got—and the willpower to take it to the next level. Start here.

My friend who recently had a baby texts me to say how much she loves her new CrossFit class. The one she takes at 6 a.m. I stare blankly at my phone, a twinge of guilt creeping in. I used to go for a run every morning, and even did a few marathons and triathlons. Now, a year and a half after my daughter was born, I'm not happy with my weight and dread workouts I once considered a warm-up. My kid keeps me busy, sure, but that's not the only thing holding me back. It's like something inside of me has switched off. My willpower is gone.

"It's not gone," insists Kris Eiring, Ph.D., director of clinical and sport psychology for student athletes at the University of Wisconsin, Madison. "Willpower is like a muscle—the less you use it, the weaker it gets." As she and I talk, I realize the problem: For months, I made exercise negotiable, something I could put aside if I needed to go shopping or finish the laundry. So now, even when I have time to work out, I can't muster the strength to do it. Worse, willpower is fleeting, says Roy F. Baumeister, Ph.D., coauthor of Willpower: Rediscovering the Greatest Human Strength. "We only have so much in a day. So someone who chooses to exercise first thing is more likely to get it done than someone who saves it for later." (See: my CrossFit friend.) Since that's not always possible, I have to work even harder to develop that mental muscle. "You can build willpower by starting small. Do squats while your baby snacks, or go on a walk after dinner," says trainer Heidi Powell, cohost of Extreme Weight Loss. It's all about proving that you can stick to something—anything—and building momentum from there, she tells me.

Since nothing will crush your willpower faster than feeling like you're not getting anywhere, I also have to make the most of my workouts. That's where the other kind of strength comes in. "If your goal is to look different, you'll see results faster with strength training than with cardio alone," says celebrity trainer Anna Kaiser, founder of AKT InMotion in New York City. While women often worry about bulking up, the reality is that for every pound of muscle you gain, your metabolism can burn up to 15 extra calories a day. What's more, research shows that women are three times more confident after starting a weight-training routine.

"You're going to feel muscles you didn't even know you had," Kaiser says. "It's like changing your body overnight." That's good news for your willpower, too: The sense of accomplishment feeds your desire to keep at it, she says.

So, like Dorothy with her ruby sneakers, I've had what it takes to get back in shape all along—all of us do.

DOWNWARD "V" PUSH-UP
The goal here: stronger biceps and shoulders. If this is too tough, try it with your knees bent, Kaiser says.

1. Get into a downward "V" position, with your feet together and your fingers turned toward one another. Stand on the balls of your feet so the majority of your weight is placed on your hands. Tuck your chin in and keep your back flat.

2. Slowly bend your elbows, as though you're trying to tap the top of your head to the floor. Straighten your arms again. Repeat 15 times.

HALF PLANK TWIST AND TAPThis move works those hard-to-reach triceps and (bonus!) your core.

1. Start in a half plank, with your knees on the ground and your upper body at a 45-degree angle with the floor; pull your belly button toward your spine. Place your right hand on your left shoulder.

2. Slowly bend your left arm and twist your torso toward it, tapping the floor with your right elbow if you can. Do 15 reps; switch sides for the second circuit.

ATTITUDE LIFTYour glutes help power you through a workout— time to firm 'em up.

1. Start on all fours, with your shoulders directly over your wrists and your hips and knees aligned. Raise your left leg slightly and turn it outward, knee bent only a few inches.

2. Engage your glutes, and lift your leg toward the ceiling. Keep the leg turned out and your back straight. Do 30 reps; switch sides for the second circuit.

HEEL CLICKSThis high-energy exercise will tone every muscle in your legs, but it'll also raise your heart rate so you get that extra burn. Do it again at the end of the circuit.

1. Start in a squat position with your feet shoulder-width apart and your hands clasped in front of you. Place your weight on your heels.

2. Throw your arms down to your sides as you jump straight up, clicking your heels in the air. Come back down into a squat position. Repeat 20 times.

STANDING AB TUCKThis exercise targets your six-pack muscles and your obliques. Do it as fast as you can without losing form.

1. Stand on your right leg with your left toe extended out to the side. Clasp your hands together overhead.

2. Quickly bring your left knee and your hands toward your chest until they meet. (You should feel your ab muscles engage.) Return to starting position. Do 30 reps; switch sides for the second circuit.