Stand with feet wide apart, toes pointing out, and hands on hips.

Keeping back straight and abs tight, tuck tailbone and bend knees, lowering until thighs are almost parallel to floor. Hold for three counts.

As you stand up, sweep left leg across body, as if you're kicking a soccer ball. Switch legs after each set.

Make it easier: Eliminate the leg sweep.

Lie on floor with knees bent, feet beneath knees and hip-width apart.

Keeping hips level and abs tight, press into heels and squeeze glutes, lifting hips to form a bridge.

Lower hips halfway to floor for two counts, then press back up. (Instead of pulses on your third set, do a Hip Rock: In bridge position, squeeze left buttocks and lift left hip. Repeat on right side. That's one rep.)

Make it easier: Lower hips to floor between reps.

Get on all fours, with hands beneath shoulders, knees beneath hips, and abs tight. Extend right leg behind you so it's in line with back, toes pointed and hips square to floor.

Pull knee into chest (A), contracting abs, and extend leg back out 12 times.

Next, extend right leg and pulse, lifting and lowering a few inches, 12 times. Then bend right leg so sole of foot faces ceiling and pulse 12 times. That's one set.

Repeat with left leg. (No need to add additional pulses when you progress to three sets.)

Make it easier: Place forearms on floor.

Stand with feet together, hands on hips. Step right foot forward 2 to 3 feet and bend knees, lowering until right thigh is parallel to floor. Keep right knee over ankle. Hold for one count.

In one swift movement, press off right foot and bring it behind you. (Left foot doesn't move.) Lower into another lunge so left thigh is parallel to floor, holding for one count.

Continue passing right foot through into a front then a back lunge without bringing feet together. Switch legs after each set.

Make it easier: Rather than pushing through from front to back in one swift movement, bring feet together before going into back lunge.