How to Master the Single-Leg Squat

Take your lower-body workout to the next level with this Single-Leg Squat guide with pictures, video and instruction.

Single-leg squats are difficult. So difficult that many of you can't even do a single rep, nevertheless add weight to the exercise.

And who wants to do something you're not good at? It's far more satisfying to Back Squat hundreds of pounds than to struggle with a Single-Leg Squat that feels awkward and unstable.

But when it comes to training, if you're not good at something then that means you probably need to do that exercise. The Single-Leg Squat is certainly no exception.

Mike Boyle, strength coach and co-founder of Mike Boyle Strength and Conditioning, explains that Single-Leg Squats are critical for eliminating strength imbalances between the left and right leg, improving knee stability and most importantly, reducing the risk of injuries.

"It's that important of an exercise for us that we're going to spend a lot of time and a lot of energy trying to perfect it," he says.

Single-Leg Squats are not a primary lower-body strength exercise such as a Front Squat, Trap Bar Deadlift or Bulgarian Split Squat, but should be included in your workouts at least once or twice a to benefit from the move. Not only will you be more resilient to injury, but you will have more strength and stability when doing any skill off of one leg, which is a vast majority of how you spend your time playing sports.

If you're new to Single-Leg Squats or have avoided them after unsuccessful attempts, odds are you will lose your balance, your knee will wobble around, you will hunch forward and it will be next to impossible to squat to parallel when you first try the exercise. But that's OK. Practice makes perfect.

Here's how to do the exercise with tips from Boyle to fix common mistakes. For a demo of the move, check out the video player at the top of the article.

Single-Leg Squat How To

Step 1: Position a knee-high box behind you. Stand on your right leg and hold a 5-pound plate in each hand at your sides with your palms facing in.

Single-Leg Squat

Step 2: Sit your hips back and bend your knee to lower into the squat and simultaneously raise your arms up to counterbalance your body. Keep your back flat, chest up and your knee aligned over your ankle.

Step 3: Continue lowering until your butt touches the box or your thigh is parallel to the ground. At this point, your arms should be in front of your shoulders and parallel to the ground. Do not rest on the box.

Single-Leg Squat

Step 4: Drive through your foot and straighten your knee and hips to stand up to the starting position. Repeat with your opposite leg.

Single-Leg Squat Mistakes

Mistake 1: Your back rounds and you hunch forward as you lower into the squat

Single-Leg Squat

Most times this is caused by poor ankle mobility. To fix this, simply place a 2.5- or 5-pound plate under your heel. However, you need to prioritize ankle mobility training to permanently correct the problem.

Mistake 2: Your knee caves inward

Single-Leg Squat

Technically called valgus collapse, this puts stress on your knee and is an indicator that you're at risk for an ACL injury. It's usually caused by a lack of glute strength or activation—especially the gluteus medius—which makes it difficult for the hip to control the upper leg and stabilize the knee.

Boyle uses a technique called Reactive Neuromuscular Training to correct valgus collapse. To use RNT, wrap a resistance band around your knee and have a partner or coach lightly pull your knee toward your midline or into valgus collapse. Your body will naturally try to resist this movement, which places your knee in the proper position and teaches your glutes to fire.

Mistake 3: You can't squat through a full range of motion

Single-Leg Squat

When you first try Single-Leg Squats, you may feel solid part of the way down and then your form might suddenly go awry. This isn't as much of a mistake as it is a strength and technique limitation.

To make it easier, simply increase the height of the box by adding pads or plates, or simply using a taller box. You can get strong in the range of motion you're comfortable in and gradually decrease the box height as you get more comfortable with the exercise. Eventually, you will be doing Single-Leg Squats to parallel with any problems.