You can develop size in your thighs with regular bouts of weight-training that’s designed to build muscle size. The major muscles in your thighs include your quadriceps, which are four muscles located at the front of your upper legs, your hamstrings, with are three muscles that run down the back of your legs, and your hip abductors and hip adductors, which are located at the outside and inside of your thighs.
Training for Size
If you’re looking to build size in your thighs, you should follow a weight training program that’s designed to develop muscular size. According to Dr. Lee E. Brown, a certified strength and conditioning professional, this means completing three to five sets of eight to 20 reps of every exercise. A high-volume program like this is designed to overload your muscle tissue, which in turn stimulates it to grow in size as it heals. Work out your thigh muscles two days per week, giving them two days of rest in between so that they have time to adequately recover between sessions. Your workouts should include primarily compound movements, which mean they require involvement from multiple joints and thus don’t only work your quadriceps, hamstrings or hip abductors and adductors. However, according to the American Council on Exercise, compound exercises are more effective than isolation ones for building muscle size.
Building the Quads
To target your quadriceps, or quads, incorporate squats, lunges and step-ups into your workouts. These exercises also develop the glutes, hamstrings and calves. Squats are performed by setting your feet to hip-width apart and then pushing your glutes backward and bending your knees to lower until your thighs are parallel to the floor, then extending your knees and hips to return to a standing position. To perform the lunge, take a large step forward with one foot so that you’re in a staggered stance, then bend your lead leg to lower your back knee until it’s just about to touch the floor, and then rise back up, switching legs every rep. The lunge can also be performed while walking. Instead of bringing your lead foot back to meet your train foot upon coming up from each lunge, drive off your lead leg and step forward with your trail leg to go into the next rep. For step-ups, you’ll need a plyo box. Place one foot atop the box and then drive off that leg to climb up onto the box. Keep that initial foot on the box as you lower back to the floor and go right into the next rep, switching legs after you’ve finished the entire set. For each exercise, you can hold dumbbells or set a barbell on the back of your shoulders to perform the weighted versions of each exercise. There are also exercises on machines that effectively develop the quads, including the leg extension and leg press.
Developing the Hammies
Straight-leg deadlifts and lying leg curls with an exercise ball will effectively target your hamstrings. To perform straight-leg deadlifts, stand with your feet at hip-width apart and hold dumbbells or a barbell in front of your legs with your palms facing you. Keep your knees primarily straight as you bend forward at the waist, simultaneously pushing your hips back, to lower the weight toward your feet. Extend your hips and return to a standing position. For lying leg curl with an exercise ball, lie on your back on the floor with your legs straight and calves placed atop the ball. Lift your hips off the ground and then roll the ball in toward your hips to your hips by bending your knees. Extend your legs to roll the ball back to starting position. The leg curl can also be performed on a machine. Most facilities offer both seated and prone lying versions of the leg curl. You can perform the common double leg curl or do single-leg curls if you'd like to work each hamstring independently.
Inner and Outer Thighs
For your inner and outer thighs, do lying hip abduction and adduction exercises. Lie on your side with your legs straight and stacked atop each other. For hip abduction, which targets the outside of your thighs and a portion of the gluteus or butt muscles, lift your top leg up as high as you can and then lower it back to starting position. Increase the intensity of the exercise by holding a dumbbell against the side of your thigh while you lift your leg. To work your inner thighs with hip adduction, from a side-lying position, move your top leg slightly back so that your bottom leg is clear and can be lifted off the floor. Raise it until you begin to tilt your hips, and then lower it back to the floor. Hold a dumbbell against the inside of your thigh to make it more challenging.