WORKOUT # 1: Stairs & StretchEXPERT: Katy Bowman, MS, director of the Restorative Exercise Institute in Ventura, CASECRET WEAPON: The BOSU Strengthen the small connective muscles at your knees by standing barefoot atop a BOSU, which is half of an exercise ball. Put one heel on the rounded side, the other leg lifted a few inches. Hold for 3 minutes per leg; do 3 to 5 times a week. ($100 for BOSU Balance Trainer and 4 DVDs; bosu.com)THE PLAN: Running is not the right kind of cardio for someone with knee problems. Using a stair-climber will put less wear and tear on your joints, and the vertical action will prep your glutes and quads. You’ll get stronger and reduce stress on your knee joints if you target the back of your legs too. You should do the exercises below whenever you strength-train.  MORE: 6 Moves To Keep Your Knees From Popping So Much TOP TONERS: 

  1. THE STEPMILL This moving staircase—available at some gyms—is easy on joints but still a good cardio workout. Do 15 to 30 minutes 2 or 3 times a week.
  2. BUTT BUILDERbutt-lifting stair workout Hinge forward at hips, hands on wall. Lift left leg back without moving hips. Hold for 1 minute. Switch legs. Do 3 to 5 times with each leg. (For more toning moves, try this .)
  3. DOUBLE CALF STRETCH Place balls of feet on rolled towel or yoga mat. Bend at hips, lift tailbone, and rest hands on chair or thighs. Hold 1 minute. Repeat after each strength move . WORKOUT #2: Walking WonderEXPERT: Suzanne Nottingham, fitness trainer and author of Nordic Walking for Total FitnessSECRET WEAPON: Walking Poles Because they engage the core and upper body for pushing off, a regular walk becomes a total-body workout. (Instructor poles by Leki, $150; leki.com)THE PLAN: Swapping running for pole walking will give you a heart-pumping cardio workout while protecting your knees. You can also build more joint stability by trading in your machine-based strength-training regimen for the exercises below, which involve more muscles to execute each move.  MORE: The $2 Fix For Knee Pain TOP TONERS:
  4. NORDIC WALKING Walking with poles takes pressure off knees. Train with poles at least 45 minutes 4 times a week, walking at a moderate to brisk pace. 
  5. HAMSTRING CURL Lie on back, legs extended, heels atop stability ball. Press into heels and lift hips off floor. Bend knees and roll ball in until it’s under knees. Roll out. Do 3 sets of 8 to 12 reps 3 times a week.
  6. WOBBLE LUNGE Stand with a cushion, pillow, or pad under right foot, left foot about 3 feet behind you. Bend knees and lower, keeping right knee over heel. Straighten legs. Do 10 lunges, then switch legs and repeat. Do 3 sets on each side 3 times a week. MORE: If Your Knees Hurt When You Take The Stairs, Here’s What It Could Mean WORKOUT #3: Heavy LiftingEXPERT: Jay Dawes, MS, CSCS, clinical assistant professor of kinesiology at Texas A&M UniversitySECRET WEAPON: Chocolate Milk The carbs and protein will speed muscle repair, the process that makes you stronger. Sip 8 ounces of the low-fat kind after exercise.THE PLAN: Do squats, lunges, and leg presses with weights and more frequently. Add the step-up (below) to your workouts.  TOP TONERS:
  7. HEAVIER WEIGHTS To build muscle, choose a weight that you cannot lift for more than 12 reps while maintaining good form. You should really have to push to do the last few reps.
  8. MORE SETS Instead of 3 sets of 8 to 12 reps of each move, do 4 to 6 sets. This will build more strength faster. Rest 60 seconds between sets.
  9. STEP-UP Stand facing a sturdy box or bench that’s just below knee height. Hold 5-pound or heavier dumbbells at sides. Step onto top of box with right foot, then left foot. Step back down with right foot, then left. Do 8 to 10 reps. Repeat starting with left foot; that’s 1 set. Do 4 to 6 sets. MORE: 2 Supplements For Your Noisy Knees