Stand with your feet shoulder-width apart, bend your knees, and lower your hips as if you're sitting back into a chair. Keep your chest up and back straight. Return to the starting position and repeat.
Take a step forward with one leg and lower your body until both knees are bent at a 90-degree angle. Push back up to the starting position and repeat with the other leg. You can also perform walking lunges by alternating legs as you move forward.
Using a leg press machine, position your feet shoulder-width apart on the footplate. Bend your knees and lower the weight until your knees are at a 90-degree angle. Push the weight back up and repeat.
Bulgarian Split Squats:
Stand facing away from a bench or step with one leg elevated behind you. Lower your body by bending the front knee until your rear knee nearly touches the floor. Push back up to the starting position and repeat. Switch legs after completing a set.
Stand in front of a sturdy bench or step. Step onto the bench with one foot, pressing through the heel to lift your body up. Step down and repeat with the other foot. Alternate legs or complete a set on one leg before switching.
Stand with your feet hip-width apart and a barbell in front of you. Bend at the hips, keeping your back straight, and grip the barbell with an overhand grip. Push through your heels to lift the barbell, keeping it close to your body. Lower it back down and repeat.
Sit on a leg extension machine and adjust the pad to rest against your lower shins. Extend your legs until they are straight in front of you and then lower them back down without letting the weight stack touch. Repeat.
Use a hamstring curl machine or a stability ball for this exercise. Lie face down and curl your legs upward, contracting your hamstrings. Lower them back down and repeat.
Stand with your back against a wall and lower your body until your thighs are parallel to the floor, as if you're sitting on an imaginary chair. Hold this position for as long as you can.
Stand with your feet hip-width apart and raise your heels off the ground, standing on your toes. Lower your heels back down and repeat.