The quadriceps, the four main muscles that make up the front of your thigh, work mainly to extend your knee. Strong quads keep your knee joints stable -- an important consideration for maintaining knee health. Focusing on more powerful thighs can improve your running, jumping and kicking performance, and gives your legs a toned, well-shaped appearance.
Body Weight Exercises
Because body-weight exercises require no equipment, they can be performed just about anywhere and are ideal for working out at home. Body-weight exercises that target the quads include squats, lunges and step-ups. Because no additional load is used in body-weight exercises, perform as many repetitions as it takes to feel your quadriceps begin to tire.
To perform squats, stand with your feet shoulder-width apart and your feet turned slightly outward. Push your hips back, bend your knees and squat down until your thighs are about parallel to the floor. Try not to round your lower back. Stand back up and repeat.
Free Weight Exercises
Free weights such as barbells, dumbbells and kettlebells allow you to increase the load on your muscles which will, in turn, make them stronger. Gradually increasing the weight from week to week will ensure that your strength continues to increase. Effective quad-strengthening exercises include weighted front squats, lunges, hack squats and back squats. Because of the risk of injury, perform free-weight exercises with a competent spotter who can offer assistance if you are unable to complete a repetition unaided. Perform between six to 20 repetitions for best results.
Resistance machines guide the weight you are lifting so that you are free to concentrate on working the target muscles. Leg presses and leg extensions are the main machine exercises that target the quads. Because the design and operation of resistance machines often varies from one manufacturer to another, obtain instruction from a personal trainer or fitness assistant before attempting to use a machine you are unfamiliar with.
Isometric exercises strengthen muscles with little or no movement of the accompanying joint. They are especially useful where repeated movements could lead to increased joint pain and are a common rehabilitation method used by physiotherapists.
Wall squats provide an effective way to strengthen your quads without moving your knees very much. Stand with your back to a wall and your feet around 12 to 18 inches away. Slide your back down the wall until your thighs are parallel to the floor. Maintain this position by tensing your quads -- really push yourself hard against the wall. Hold the contraction until your quads begin to fatigue. The harder you push, the more demanding this exercise will be.
Programming for Stronger Quads
Because your quads are large muscle and exercising them can be tiring, they are best trained first in your program. They can be worked two or three times a week as part of a whole body program or, if you prefer, once or twice a week as part of a split routine where different muscles are trained on different days. To develop pure strength, perform sets of one to five repetitions. To develop strength with muscle size, focus on sets of six to 12 repetitions. To strength endurance, do sets of 12 to 20 repetitions. Warm up before exercise by performing some light cardio, mobility exercises and dynamic stretches to ensure your muscles and joints are ready for your planned workout.