Glancing over your shoulder in a full-length mirror, you may notice a body part that's not immune to gravity -- your derriere. But before you start trying to camouflage it in baggy pants, try this exercise -- the hip extension -- to strengthen and firm the gluteal muscles of your butt. (They're called "glutes" in gymspeak.) Even if you haven't seen signs of sagging, strong glutes will make bounding up stairs, standing, walking and looking in the mirror easier. Combine this exercise with walking or other aerobic activities, and you'll like what you see behind you.

The essentials

Repetitions: 8 to 12 lifts are considered a set. Do 1 to 3 sets with each leg.

Sessions per week: 2 to 3; allow at least 1 day of rest between workouts.

Speed: 3 seconds to lift, 1-second pause, 3 seconds to lower.

Weight: If you can't do 8 repetitions, the weight is too heavy. When you can easily do 12 repetitions, the weight is too light.

Remember to breathe.

Position yourself

Stand about 12 to 18 inches behind a sturdy chair.

Gently hold onto the chair.

Tuck in your abs; bend forward at the waist, about 45 degrees.

Align your head, neck, and back to form a straight line.

Keep both legs straight, but don't lock your knees.

Place feet no more than shoulder-width apart, toes pointing forward.

Check yourself in a mirror.

The exercise

1. Slowly raise your left leg directly up and back without moving your upper body. Keep your toes pointing forward at all times.
2. Continue until torso and lifted leg form a straight line. Your foot should be about 10 to 14 inches off the floor. Hold, and then lower. Repeat with the right leg.

Don't

Let your upper body fall forward.

Point your toes out to the sides.

Lift your leg out to the side.

Grip the back of the chair tightly.

by Miriam Nelson, PhD
Created 1997