Keeping the muscles around your knee strong, specifically the quadriceps and hamstrings, maintains knee stability and long-term knee health. If your knee tracks incorrectly, it is more prone to wear and tear which could lead to osteoarthritis. In addition, high impact and side-to-side movements place stress on your knee joints. Strong muscles around your knees prevent unwanted movement and may reduce your injury risk.
Proper Preparation and Finish
If you are new to working out, have been sedentary lately or are suffering from any illness or injury, for safety, consult your physician before you start. If you have the all-clear, spend a few minutes warming up by performing some light cardio and dynamic stretches for the muscles, such as walking for five or 10 minutes and walking lunges. On completion of your workout, cool down with another few minutes of walking followed by static stretches, such as toe touches to stretch your hamstrings and bringing your foot to touch your butt to stretch the fronts of your thighs. Warming up and cooling down minimize post-exercise muscle soreness and tightness.
Leg Extensions and Leg Curls
Leg extensions and leg curls isolate your quadriceps and hamstrings respectively and involve movement at only one joint, your knee. While machine design varies from one manufacturer to another, the principles for using these machines are similar. Sit with your knees in line with the machine's pivot point and adjust the backrest for maximum support. For leg extensions, place your legs behind the ankle pad and for leg curls, place them on top. To work your quads, extend your legs against the machine's leg pad and for leg curls, bend your legs and curl your feet down and under your butt. Use both legs simultaneously or one leg at a time.
Straight Leg Lifts
If you are currently suffering knee pain but still want to strengthen your quadriceps muscles, perform straight leg lifts. Check with your doctor first if you are currently suffering any knee issues. This is an isometric exercise which means that although your muscles generate tension, you don't move the main joint involved. Sit on the floor with one leg straight and one leg bent. Put your hands behind you on the floor for support. Lift the straight leg up 12 inches off the floor while keeping your knee straight and your thigh muscles tensed. Lower your leg back to the floor and repeat.
Lunges work all of the muscles around your knees, front and back. Since this is a single leg exercise, lunges also challenge your balance and coordination, which are important factors for knee health and sports performance. Step forward, bend your knees and lower your back knee toward the floor. Push off your front foot, stand back up and perform a second rep leading with your other leg. Alternate your leading leg for the desired number of repetitions. Make this exercise more demanding by holding weights in your hands.
Squats work all of your lower body muscle together including your quadriceps and hamstrings as well as your butt. Performed properly, squats are an effective knee-strengthening exercise. With your feet around shoulder-width apart and your toes turned slightly outward, push your butt back, bend your knees and squat down until your knees are bent to around a right-angle. Try not to round your lower back. Return to the upright position and repeat. This exercise can be performed unweighted or while holding a weight in your hands, across your chest or on your shoulders.