The Game Plan
Do the routine in Part One daily. In just five minutes, it stretches all of the muscles in your upper leg, which provide the knees with proper support.

Part Two is more intense. This 30-minute full-body aerobic and toning workout burns calories and builds muscle without stressing your knees. Perform it two to three times a week, giving your muscles 48 hours in between to rest and rebuild. On days when you do both workouts in the same day, do Part Two first.

Part One: Knee Stretching and Strengthening (Five minutes)
You'll need: A mat or carpet and a sturdy chair

Lie and Lift Stretch
Stretches fronts of thighs
Lie on your left side, with your legs stacked and your left arm extended on the floor. Bend your right knee, bringing the heel as close to the buttocks as possible, and grab your ankle with your right hand. Pull your heel toward your buttocks—you should feel a deep stretch in the front of the thigh. Hold for 10 seconds, release, and repeat twice more. Then switch positions, lying on your right side, and repeat the stretch with the left leg.

Straight-Leg Stretch
Stretches backs of thighs
Stand facing the front of the chair, and extend one foot, placing your heel on the seat. Lean forward until you feel the stretch in the back of the leg. Hold for 10 seconds, then repeat twice. Switch sides.

Star Stretch
Stretches outer thighs
Lie on your back with your legs extended. Lift your right leg, and bend the knee 90 degrees. Hold the outside of the knee with your left hand. Gently pull your leg toward the ground on the left side of your body, and simultaneously stretch your other arm to the right on the ground. Hold for 10 seconds, release, then repeat twice more. Throughout the stretch, relax your shoulders, keeping them flat on the floor, and look at the ceiling. Switch sides, and perform the stretch with the left knee.

Lock and Lifts
Strengthens quadriceps
Lie on your back with your arms at your sides. Bend your right knee, and place the foot on the floor. Now squeeze your left thigh muscles and flex the foot, straightening your leg and pressing it into the floor. Once you’ve tightened your muscles, slowly raise your left leg four to six inches (shown). Hold this position for five to 10 seconds, then lower your leg. Repeat 12 times, then switch legs. Do two sets on each side.