Cossack Squat

What the Cossack squat actually trains

A Cossack squat is a deep lateral squat in which you shift your weight onto one leg from a wide stance and descend as far as you can on that leg while the other stays straight out to the side.

The working leg does the lifting: quadriceps at the knee, gluteus maximus at the hip, and adductor magnus contributing hip extension from a very deep and abducted position. The extended leg's adductors are placed under a long stretch, and the working ankle is pushed into a lot of dorsiflexion.

It is best understood as a range of motion exercise that also loads muscle, rather than a muscle builder with a big range. The limiting factor for almost everyone is not strength. It is hip and ankle mobility, and adductor tolerance in the lengthened position.

That does not make it a waste of time. This is one of the few movements that trains a deep, abducted hip position under any load at all, and most programmes never go near it.

It also does not make it a special hypertrophy tool. Kubo and colleagues found deeper squatting produced larger increases in lower limb muscle volume than shallower squatting, which is a genuine argument for depth. But that comes from loaded barbell squats, and you cannot load a Cossack squat anywhere near as heavily. Take the principle, not a promise.

The comparison people actually need is with the lateral lunge, because these two are close relatives rather than distinct exercises. The lateral lunge is a step out to a moderate depth with both feet flat and the trailing leg straight. The Cossack squat starts from a wide stance without a step, goes considerably deeper, and typically ends with the extended foot rotated up onto its heel. It demands more adductor length, more hip flexion and a great deal more ankle dorsiflexion. That is the whole difference. Pick the one that matches the range you currently own; there is little reason to do both.

Setting up and executing

Stand in a wide stance with both feet flat and pointing forwards. Hold a light weight at your chest, as most people should.

Shift your weight onto one leg rather than stepping. That is the difference from a lateral lunge and it changes the rhythm.

Sit the hips back and down over the working leg. Let the other leg straighten out to the side and allow that foot to rotate up onto its heel, toes pointing at the ceiling.

Keep the working heel flat. If it lifts, you have hit the end of your ankle range.

Descend as far as your hips and ankles allow without rounding your back or losing the heel, and pause briefly.

Push through the working heel to stand, then shift across to the other side.

The mistakes that cost you the most

Chasing depth before you have it is the fault that defines this exercise. People see the full bottom position and try to reach it immediately, which means the back rounds, the heel lifts, or both. Work in the range you genuinely own, add a centimetre at a time, and the position arrives.

The working heel lifting is an ankle range problem, not a technique problem. Deep knee flexion demands a lot of dorsiflexion and most people run out. A small plate under the working heel removes it immediately.

Rounding the lower back is the other way people fake depth. Depth bought with spinal flexion is not useful range.

Refusing a counterbalance costs you range for no reason. A light kettlebell at your chest shifts your centre of mass forward, which is what lets you sit deeper without falling backwards. Almost everyone reaches a lower position holding eight kilos than holding nothing.

And loading it heavily misunderstands the exercise. Everything you would be trying to achieve is available more efficiently from a squat. Keep the weight light and the range long.

Sets, reps and rest by goal

Moderate reps, light loads, and no rush.

For muscle gain, three sets of eight to twelve per side with a minute rest. For strength, three sets of six to ten per side with ninety seconds, with the honest caveat that this is not a strength exercise. In a fat loss phase, three sets of ten to fifteen per side with a minute.

Progress by depth first. Moving from a half range Cossack squat to a full one is a bigger achievement than adding weight to a shallow version, and it is what the exercise is for.

Once you own the range, a light goblet load is the sensible second progression. Beyond about twenty kilos there is little point.

Pallares and colleagues found full range training produced better outcomes than partial range work, and Schoenfeld and Grgic reached similar conclusions reviewing range of motion and muscle development. Both support treating range as the variable to progress.

Schoenfeld and colleagues found a dose response between weekly hard sets and hypertrophy, a reminder that a few sets of this is an accessory, not a leg programme.

Refalo and colleagues found stopping short of failure produces comparable growth. Here the useful stopping point is the rep before your position degrades, which arrives long before muscular failure.

Where it fits in your split

In the warm up, or at the end of a leg session.

On push, pull and legs it works as preparation before leg day or as accessory work at the end. On a bro split it fits at either end. On an upper and lower split it is a secondary movement. On a full body programme it is good general preparation. On a bodyweight programme it is one of the few leg exercises where depth substitutes properly for load.

The warm up placement is the one most people should use. Two or three sets of unloaded Cossack squats before squatting prepares the hips and adductors far more usefully than static stretching.

The library already contains a back squat and walking lunges, and this competes with neither for leg size. Kubo and colleagues' finding on squat depth is an argument for squatting deep, not for replacing your squat with a lateral one.

Once or twice a week is plenty, and consistency matters more than volume for a mobility driven movement.

Variations worth knowing

The lateral lunge is the shallower relative, using a step rather than a weight shift, which makes it the sensible starting point if the full position is out of reach.

The goblet Cossack squat holds a light weight at the chest as a counterbalance and usually increases depth rather than restricting it.

The heel elevated version puts a small plate under the working heel, removing ankle dorsiflexion as the limiting factor.

A supported Cossack squat, holding a rack upright or a suspension trainer, lets you work the full range without balance interfering.

The sliding Cossack squat places the extended foot on a slider so you can move continuously between sides without standing up.

And the pistol squat trains a similarly deep single leg position in the sagittal plane, without the lateral component.

What the evidence says

Kubo and colleagues compared squat training at different depths and found deeper squatting produced greater increases in lower limb muscle volume, though from loaded barbell squats rather than lateral ones.

Hartmann and colleagues analysed knee and spinal loading across squat depths and loads, and their review does not support the claim that deep knee flexion is inherently harmful.

Pallares and colleagues found full range training produced better strength and hypertrophy outcomes than partial range work, supporting the emphasis on earning the full position rather than loading a shallow one.

Schoenfeld and Grgic reviewed range of motion and muscle development and reached a broadly similar conclusion, favouring longer ranges where they can be performed properly.

Speirs and colleagues compared unilateral and bilateral squat training and found similar improvements in strength and sprint performance, which keeps single leg work in proportion.

Schoenfeld and colleagues on volume found a dose response between weekly hard sets and muscle growth, which puts a mobility driven accessory in context.

Refalo and colleagues found stopping short of failure produces comparable hypertrophy, which fits a movement where position rather than the muscle decides when the set ends.

Common questions

How is this different from a lateral lunge?

Depth and the trailing foot. A lateral lunge steps out to a moderate depth with both feet flat. A Cossack squat shifts your weight from an already wide stance, goes much deeper, and lets the extended foot rotate up onto its heel, needing considerably more adductor length and ankle dorsiflexion. Two points on one continuum, and most people should pick one.

My heel lifts at the bottom. What do I do?

Put a small plate under the working heel. Deep knee flexion demands a lot of ankle dorsiflexion and most people do not have it. Elevating the heel removes that limit and lets you train the hip position instead.

Should I hold a weight?

Yes, a light one at the chest. It acts as a counterbalance and usually lets you sit deeper than with empty hands. This is one of the few loaded exercises where adding weight increases your range. There is little point going heavy.

Is deep squatting bad for my knees?

No. Hartmann and colleagues reviewed knee and spinal loading across squat depths and found no good support for that claim. Deep positions demand more mobility and take time to build, which is a training consideration rather than a safety one.

Will this build muscle?

A little, but that is not why to do it. The loads are capped by mobility, so it will never rival a squat for leg size. Its value is owning a deep, abducted hip position nothing else in a normal programme trains. Treat it as range work and let your squats build the legs.