Cossack Squat: How to Do It, Muscles Worked and Progressions

Most people meet the cossack squat in a warm-up video, wobble through two reps, and quietly go back to hamstring stretches. That is a shame, because it does something almost nothing else in a home gym does: it loads your inner thigh at long length while making you balance and stay upright at the same time. Sink into one, side to side, and you will find the tight spot in your hips within about four seconds. Fix that tight spot over a couple of months and squats, lunges and everything else on one leg improve with it.

How to do a cossack squat

Start with bodyweight and add load only when you can hold the bottom position without wobbling.

1. Take a wide stance. Feet well outside shoulder-width, roughly double, toes pointing forward or turned out slightly. Wider than feels natural is usually right.
2. Shift, don't step. Push your hips back and sit toward one side, bending that knee while the other leg stays straight. Both feet stay on the floor throughout.
3. Keep the straight leg honest. The extended leg's toes can rotate up toward the ceiling as you descend; that is normal and takes pressure off the knee. Keep that heel on the ground.
4. Sink as low as you can hold. Chest up, working heel planted, lower back neutral. Your hands can reach forward as a counterbalance or hold a weight at your chest.
5. Drive back up. Push through the mid-foot and heel of the bent leg to return to the wide stance, then repeat on the other side.

Muscles worked

• Adductors on the straight leg. The main event. Your inner thigh takes a long, loaded stretch, and lateral squatting patterns sit near the top of the list in EMG work on adductor longus activation during common hip exercises, behind only dedicated adduction drills.
• Quads on the bending leg. Deep knee flexion under bodyweight means the quads work through a long range, and squatting through fuller ranges of motion produces greater muscle activation than partial reps.
• Glute max and glute medius. The bending side's glute drives you back up while glute medius stops the knee collapsing inward.
• Ankles and calves. Keeping the working heel down demands real dorsiflexion, which is why so many people fail here first.
• Core and upper back. Staying tall with a weight in front is trunk work whether you planned it or not.

Benefits

You keep the range you build. Passive stretching gives you a position; loaded end-range work gives you a position you can use under load. That distinction shows up the moment you try a deep squat or drop into a low lunge on a football pitch.

It finds side-to-side differences you did not know you had. Almost everyone is noticeably better going one way. That asymmetry is often the missing explanation behind a hip that pinches during heavy back squats.

It builds the adductors, which almost nobody trains. Groin strains are common in anything involving sprinting or changing direction, and the adductors get very little attention in a typical home gym routine.

It needs no equipment and very little space. A couple of square metres of floor and, ideally, one kettlebell. That's it.

Common mistakes

Heel lifting on the bending leg. The classic. Elevate the heel on a small plate or work on ankle mobility, but do not just accept rolling onto your toes, because it puts your knee in a poor position.

Rounding the lower back at the bottom. If your pelvis tucks under and your spine rounds, you have gone past your usable range. Stop higher and earn the depth over weeks.

Letting the knee cave inward. Push the working knee out over your foot. A cue that works: imagine spreading the floor apart with both feet.

Going too fast. The bottom position is the whole point. Lower for three seconds, pause, and come up under control.

Loading it too early. Adding a heavy kettlebell to a position you cannot yet hold is a great way to tweak a groin. Bodyweight until it is smooth, then a light counterbalance, then load.

Progressions and variations

• Supported cossack squat. Hold a doorframe, a rack upright or a suspension trainer and use your arms to take some weight while you learn the position. The single best regression.
• Heel-elevated cossack squat. Stand the working heel on a small plate. Buys you the ankle range you do not have yet.
• Goblet cossack squat. Hold a kettlebell or dumbbell at your chest. Adds counterbalance and load together, which is why it is the version most people should live in. A pair of adjustable dumbbells or a single kettlebell covers this for years.
• Cossack squat with a pause. Hold the bottom for 3 to 5 seconds. Unglamorous and effective.
• Sliding cossack squat. Put the straight leg's foot on a slider or a folded towel and slide out as you descend. Harder on the adductors and much harder on balance.
• Overhead cossack squat. Hold a light plate or kettlebell overhead. Now your thoracic spine and shoulders have to behave too, which exposes any tendency to lean forward.

Sets and reps

• Warm-up: 2 sets of 8 slow reps per side, bodyweight or a light counterbalance.
• Strength and mobility: 3 sets of 6 to 8 per side with a goblet hold, 2 second pause at the bottom, twice a week.
• Mobility focus: 3 sets of 5 per side with 5 second holds, done most days at low load.

Give it six to eight weeks before you judge progress. The heel that would not stay down in week one usually behaves by week five, and the depth follows. Pair it with goblet squats for straight-ahead strength and reverse lunges for single-leg work, and your lower body covers every direction it will meet outside the gym.

Recommended reads

1. How to do a goblet squat
2. How to do a sumo squat
3. How to do a reverse lunge
4. The best kettlebells in the UK
5. More exercise technique guides