For a defined bum, it's not down to the exercises you'd expect. "Squats aren’t a great glute exercise at all, so I don’t do squats with my clients," says Pasternak.
Instead, he opts for unilateral exercises (single-sided moves), including all types of lunges: forward lunges, reverse lunges, side lunges, skater lunges, the list goes on. Unilateral movements tone both sides of your body equally, "since your dominant side doesn't have a chance to take over," he says. They also create an unbalanced environment for your body, which means your core has to work harder to keep you stable.
And when it comes to sculpting your bum, Pasternak stresses you need to work it from above and below—a.k.a. challenge your lower back and hamstrings. Strong hamstrings lift your glutes up, and a stable lower back supports them.
To strengthen your lower back, Pasternak loves superman (lying face down with your arms and legs raised) and alternating superman (raising alternate legs and arms). For hamstrings - which lift the glutes up - he loves hamstring curls with sliders or deadlifts. To target the glutes directly, he loves glute bridges.
You also need to activate the sides of your glutes—known as the gluteus medius—which you can do by adding a resistance band to moves like glute bridges or lateral lunges.
Just remember that, no matter how much you work your glutes, genetics will also play a major role, says Pasternak. "A large part of the butt area is actually fat, and genetics will predetermine where you store your body fat," he explains. "A lot of the fittest people won’t store fat around their glutes."
How to: Stand up tall, then take a large step forward. From here, bend your knees and lower your body until your legs form 90-degree angles. That's one rep.
2. LATERAL LUNGE
How to: Stand up straight with your feet hip-width apart. Take a large step to the left, sit your hips back, and lower down until your left knee is nearly parallel with the floor. Your right leg should be straight. Return to start. That's one rep. (Optional: Add weight with kettlebells.)
3. SKATER LUNGE
How to: Stand with both feet flat on the floor. Cross your right leg behind your left leg as you bend your left knee into a half-squat position. Then repeat in the other direction. That's one rep. (Optional: Hold a medicine ball in front of your chest, for a greater challenge.)
How to: Lie on your stomach, and extend your arms in front of you and legs behind you. Keep your palms facing down. Lift your legs and arms at the same time, hold, and release. That's one rep.
5. ALTERNATING SUPERMAN
How to: Lie on your stomach, and extend your arms in front of you and legs behind you. Keep your palms facing down. Lift your your opposite arm and leg at the same time, hold, and release. Then repeat on the other side. That's one rep.
6. GLUTE BRIDGE
How to: Lie on your back with your knees bent and feet on the floor 12 to 16 inches from your bum. Brace your core, then press into your heels and squeeze your glutes to raise your hips toward the ceiling. Hold the position for two seconds before lowering to the floor. That's one rep.
7. HAMSTRING CURL WITH SLIDERS
How to: Lie flat on your back, with your arms at your sides, and heels on top of sliders. Engage your hamstrings, bend your knees, and bring your feet toward your bum. Slowly return to start. That's one rep.
How to: Holding two dumbbells in your hands, stand with your feet hip-width apart, knees slightly bent. Position the weights in front of your thighs, palms facing your body. Keeping your knees slightly bent, press your hips back as you hinge at the waist and lower the dumbbells toward the floor. Squeeze your glutes to return to standing. That's one rep.
From Harper's Bazaar U.K.