Your thighs consist of numerous major muscles and many lesser ones. Making your muscles bigger is a process called hypertrophy. Hypertrophy is the result of pushing your muscles hard during a workout and then allowing sufficient time for recovery. Hypertrophy is more likely to occur if you perform exercises using multiple sets, a moderate to heavy weight and working within a range of six to 12 repetitions.
Squats are one of the most effective lower-body exercises you can perform. Used by bodybuilders and strength athletes to increase lower body mass, squats allow you to place a significant load on your thighs. For safety, squats should ideally be performed in a squat rack or power cage. To perform the barbell back squat, position a barbell across your upper back and hold it tightly using an overhand grip. Stand with your feet shoulder-width apart and turn your feet slightly outward. Push your hips back, bend your knees and squat down until your thighs are approximately parallel to the floor. Do not allow your lower back to become rounded because this can lead to injury. With your weight mostly on your heels, extend your legs and hips to stand up. For comfort and safety, make sure the bar rests across the fleshy upper part of your back and not across the bonier part of your neck.
Many people have one leg that is stronger than the other. This left-to-right strength imbalance often goes unseen in two-legged exercise, but leaving it uncorrected can lead to injury. Lunges work one leg at a time so as well as developing your thighs, they also ensure that both legs work equally. Stand with your feet together and your hands by your sides. Take a large step forward and then bend your knees. Lower your rear knee to within an inch of the floor while keeping your front shin vertical. Push off your front leg and return to the starting position. Immediately perform another repetition leading with your opposite leg. Continue alternating legs for the duration of your set. Make this exercise more demanding by holding dumbbells in your hands or holding a barbell across your shoulders.
Exercises such as squats and lunges are compound exercises, which involve movement at multiple joints at the same time. Leg extensions are an isolation exercise that involves movement at only one joint — the knee. Leg extensions target your quadriceps muscles which are located on the front of your thighs. Sit on the leg extension machine with your knees aligned to the machine’s pivot point and your ankles behind the leg restraint. Slowly and smoothly straighten your legs to lift the weight, and then bend your legs to lower it. Do not allow the weight stack to touch down between repetitions because this reduces the effectiveness of the exercise.
Using similar joint and muscle action to squats, leg presses allow you to work safely on your own without the use of a squat rack or power cage. The back rest of the leg press provides support which, for some exercisers, can help reduce the risk of injury. Lie on the leg press machine with your feet hip-width apart on the footplate. Extend your legs fully and release the safety catches. Bend your legs and lower the footplate towards you. Stop bending your knees as soon as you feel your lower back beginning to become rounded. Drive the foot plate up and back to full leg extension.
- Anatomy of Exercise: A Trainer's Inside Guide to Your Workout; Pat Manocchia
- Bodybuilding Anatomy; Nick Evans, M.D
- Encyclopedia of Bodybuilding: The Complete A-Z Book on Muscle Building; Robert Kennedy
- Comstock Images/Stockbyte/Getty Images
This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.