Sit or lie down with your legs extended. Tighten the muscles at the front of your thigh (quadriceps) by pressing the back of your knee down into the floor or surface you're lying on. Hold for 5-10 seconds, then release. Repeat for several repetitions.
Lie on your back with one leg bent and the other straight. Tighten the thigh muscles of the straight leg and lift it to the height of the bent knee. Hold for a few seconds, then slowly lower the leg back down. Repeat for several repetitions on each leg.
Stand behind a chair or use a wall for support. Bend one knee and bring your heel toward your buttocks, contracting your hamstring muscle. Hold for a few seconds, then slowly lower your foot back down. Repeat for several repetitions on each leg.
Stand with your feet shoulder-width apart. Slowly bend your knees, lowering your body a few inches as if you're sitting back into a chair. Keep your knees behind your toes and your back straight. Hold for a few seconds, then return to the starting position. Repeat for several repetitions.
Use a step, staircase, or sturdy platform. Step up onto the platform with one foot, then bring the other foot up to meet it. Step back down with the same foot leading. Repeat for several repetitions on each leg.
Stand with your feet hip-width apart and hold onto a stable surface for balance if needed. Rise up onto the balls of your feet, lifting your heels as high as you can. Hold for a few seconds, then lower your heels back down. Repeat for several repetitions.
If you have access to a leg press machine at a gym, use it to strengthen your quadriceps, hamstrings, and glutes. Start with light weights and gradually increase resistance as you build strength.
Stand with your back against a wall and slide down until your knees are bent at a 90-degree angle, as if you're sitting in an invisible chair. Hold this position for as long as you can, aiming for 30 seconds to 1 minute, then stand back up and repeat for several repetitions.