Fit into Your Skinny Jeans in 4 Weeks

Stand facing stairs with elbows bent at sides.

Take a giant step up to second step with right foot, then hop up, bringing left knee toward chest.

Land on stair with right foot.

Immediately step down to the floor with left foot while bending right leg behind you.

Hold for 5 counts, keeping your abs tight to help you balance.

Do 16 to 20 explosive hops on right foot, using your arms to gain momentum; switch sides and repeat.

Stand sideways to stairs, placing right foot on the first or second step.

Keep feet wide apart and turn toes out 45 degrees.

Hold a 3- to 5-pound dumbbell in each hand, palms forward, arms extended at chest height and elbows slightly bent (not shown).

Bring weights together in front of chest while lowering hips into a plié.

Hold for 2 seconds.

Return to starting position and repeat for 16 to 20 reps; switch sides.

Stand facing staircase with right foot planted on the first or second step, holding 3- to 5-pound weights at hips.

Leaning forward slightly, lunge back with left leg, bending right knee 90 degrees and keeping knee aligned over ankle.

Remain in low position and bring left foot up to meet right on step.

Squat down, lowering hips another 2 inches. Hold for 2 counts; repeat.

Do 16 to 20 reps, alternating sides.

Get on all fours with hands stacked under shoulders and toes pressed into step.

Tuck right knee in toward chest.

Extend right leg behind you and squeeze glutes; hold for 2 counts (not shown).

Do 10 reps; switch sides.

Stand facing away from the stairs with left toes on the first step, torso straight, holding a 3- to 5-pound dumbbell in each hand.

Bend right knee 90 degrees, keeping knee aligned with ankle.

Turn torso to the right and bring weights over outside of right thigh.

Hold for 2 counts; return to start.

Do 16 to 20 reps; switch sides.

Walk up and down the staircase, pumping arms.

For the third minute, lunge up stairs two at a time; go down single stepping.

Stand with left side facing stairs.

Step up, leading with left foot and pumping arms; climb up on an angle.

Switch sides after 2 minutes.

Repeat minutes 0:00-3:00.

Hop up to first stair with left foot, tapping ball of foot on step.

Switch legs, hopping up with right foot and down with left.

Continue, switching sides and moving as explosively as you can.

Repeat minutes 0:00-3:00.

Place both hands on second or third step, palms aligned under shoulders, leg extended behind you.

Hop left knee toward chest, then bring right knee forward and left leg back.

Keep head above heart at all times.

Repeat minutes 0:00-3:00.

Stand in a half squat, knees bent about 45 degrees.

Jump up, landing on first stair.

Step down to floor; immediately squat down and jump up again.

Repeat minutes 0:00-3:00.