Quadriceps & Hamstring Exercises

The quadriceps and hamstrings each consist of four separate muscles that work together to perform common movements such as knee extension and hip flexion. According to the National Academy of Sports Medicine, isolating and recruiting both the quadriceps and hamstring muscles has a twofold effect of preventing synergistic dominance--one of the muscles doing more work than the other, resulting in muscle imbalances--and providing a balanced appearance with sculpted quadriceps in the front of the thigh and a rounded and firm hamstring at the back of the thigh.

Dumbbell Squats

Squats are one of the most effective exercises for upper thighs because they recruit not only the quadriceps and hamstrings, but also the gluteus maximus and the transversus abdominis to stabilize your body throughout the movement.
Hold a heavy weight in each hand and stand with feet shoulder-width apart. Slowly lower your hips toward the floor, bending knees as if about to sit in a chair. Do not allow the knees to cave inward or heels to lift from the floor; instead, press through the heels as you return to standing position. Perform three sets of eight repetitions. To make the move more challenging, squat and sit on a bench, pausing just before and after making contact with the bench.

Stability Ball Hamstring Curl

Target your hamstrings specifically with a stability ball hamstring curl performed on the floor. Although the movement does not utilize heavy weights, it will effectively challenge your hamstrings using your body weight and by recruiting additional muscle fibers for stabilization.
Lie on your back and place your lower legs and heels on a stability ball, with toes pointing toward the ceiling. Extend your arms out to your sides to stabilize yourself as you perform the movement. Contract your abdominal muscles and glutes as you lift your hips off the floor so that your entire body is in a straight line from your shoulders to your toes. Contract your hamstrings as you move your heels toward your hips, bending your knees so that the bottoms of your shoes now rest on top of the ball. Slowly lower your legs until your entire body is in a straight line again. This is one repetition. Perform three sets of eight repetitions. The American Council on Exercise cautions to avoid arching your lower back during the movement as you bring your hips into the straight body position.

Dumbbell Step-up

This exercise focuses on your quadriceps and also works your gluteus maximus. According to the Mayo Clinic, you should perform this and other resistance exercises every other day to allow the muscles to rest and repair before the next workout.
Stand with a short bench--approximately 18 inches tall--in front of you and with heavy dumbbells in each hand. Place one foot firmly and completely on the bench. Pressing through the heel on the bench, push yourself upward to stand atop the bench. Tap the top of the bench with the opposite foot, lower and bring the foot that you led with back to the floor for one rep. Perform three sets of 16 repetitions, eight on each side. To make the move more challenging, the National Academy of Sports Medicine recommends lifting your knee and standing on one leg as you reach the top of the bench. This recruits additional muscle fibers throughout your leg to stabilize your entire body.