Lunges and squats -- they are synonymous with thinner thighs. But there's one problem with both: they can aggravate sore knees. Knees weakened by degenerative arthritis and injury are susceptible to further damage, so be careful how you tone the surrounding muscles. Tighten your thighs with low-impact cardio activities that go easy on the knees. Warm your thigh muscles and knee ligaments with five minutes of cardio before slimming your quads and hamstrings. And follow each workout with a five-minute cool-down.
Take advantage of your local pool -- and the buoyant water -- and jog in place. Float into the deep end to avoid hitting the pool's bottom with your feet. Use a pool noodle, kick board or vest to stay afloat while working the quads.
Kick your legs forward as if jogging on land for five minutes. Reverse the direction and jog backward for five minutes. Alternate jogging forward and backward for 20 minutes.
Bring each knee to waist height as you kick up, or each foot to your glutes when jogging backward. Move between shallow and deep water, if your knees can handle it.
Condition your adductors with off-the-wall outer-thigh lifts. Move to waist- or chest-high water -- just make sure your feet touch -- and hold onto the poolside.
Start with your left side against the pool. Raise your right arm, letting it skim the water's surface, or place it on your hip.
Straighten your right leg, tighten your glutes and raise your leg to the side. Lift it as high as you can and then lower it.
Lift and lower your leg 20 times before switching sides and repeating. Add 20 lifts to the front, tightening your glutes and keeping your leg straight, to help slim your inner thigh as well.
On-Land Low-Impact Aerobics
Look into cycling for a moderate- to fast-paced cardio workout that, when done right, burns calories, slim the thighs and can be knee-friendly.
Swap the stationary bikes and beach-style cruisers -- both of which can be hard on the knees -- for mountain bikes, suggests the Boulder Center for Sports Medicine's Dr. Andrew Pruitt. Hitting the mountain bike trail versus a bike trail, or your living room's exerciser, avoids constant pedaling.
Start with a one-hour off-road trail and work up to two hours. Pick trails without sharp curves and excessive path debris. Walk the trail beforehand to gauge possible dangers, determine where your jumps will be, and get a general feel for the layout. Keep from stepping on the brake, especially when going around obstacles and bends.
Check out the elliptical, but talk with your doctor first if you have arthritis. Holding onto the handles, and keeping your back straight and not hunched over the console is not only proper form, but it will help reduce the likelihood of knee pain.
Adjust your elliptical's incline between 4 and 6 percent for a thigh-trimming workout. Exercise your quads and hamstrings, alternating speeds, for 20 to 30 minutes.
- Fitness: 20-Minute Water Workout: Sculpt Your Body in the Pool
- Fitness: Cardio-Sculpting Workout: 21 Days to Loving Your Shape
- Get Rid of Cellulite: Simple Shortcuts to Beautiful Skin; Infinite Ideas
- Bicycling Magazine's Cycling for Health and Fitness; edited by Ed Pavelka
- Mayo Clinic: Are Elliptical Machines Better Than Treadmills For Basic Aerobic Workouts?
- Women's Health: Decode Your Display
- American Academy of Orthopaedic Surgeons: Warm Up, Cool Down and Be Flexible
- Talk with a doctor if knee pain prevents exercising.
Having studied at two top Midwestern universities, Catherine Field holds degrees in professional writing and patient safety. Writing since 2000, Field has worked with regional newspapers while publishing fiction online. She conducts medical communication research at a Midwestern medical institution and is slated to write a book based on her research findings.