1. Quadriceps (quads). These are the muscles at the front of the thigh, and are actually a group of four muscles. They straighten (extend) your leg at the knee and help to bend (flex) the leg at the hip joint (bringing the legs toward the chest). The quads are responsible for all your basic leg movements such as standing, walking, and kicking.
Exercises: Squats, lunges, and split squat target the quads.

2. Hamstrings. These muscles are at the back of the thigh, and are composed of a group of three muscles. They perform the opposite action of the quadriceps, bending your leg at the knee joint and help to straighten (extend) your legs at the hip joint.
Exercises: Deadlifts work the hamstrings.

3. Abductors (outer thigh). The abductor muscles are on the outside of the thighs and hips. They perform the opposite function of the adductors, pulling your thighs out away from your midline. Whenever you push your legs outward against resistance, you’re targeting your abductors.
Exercises: Clamshells work the outer thighs.

4. Adducutors (inner thigh). The adductors consist of five muscles in the inner thigh. They bring your knees together and help the other thigh muscles in moving the legs at the hip joint. The adductors are working almost any time you’re moving your legs.
Exercises: Exercise ball squeezes target this area directly.

5. Calves. Three muscles make up the calf, two major muscles (gastrocnemius and soleus muscles) which are at the back of the lower leg, and one smaller muscle at the front of the lower leg (anterior tibialis). These muscles extend (point your toes) and flex your foot (pull your foot up toward your shin), driving you forward when you walk or run.
Exercises: Calf raises sculpt and tone this area.