Legs · Squat
Cossack Squat
The Cossack squat is a lateral squat where you sit deep into one hip while the other leg stays straight with the toes pointing up. It builds single-leg strength in the quadriceps and glutes while stretching the inner thigh and hamstring, so it works as both a strength exercise and a mobility drill.
Also known as: Side-to-side squat, Lateral squat, Cossack lunge
- Muscle group
- Legs
- Movement pattern
- Squat
- Type
- Compound
- Equipment
- Bodyweight, Weight plate or dumbbell
- Difficulty
- Intermediate
What muscles does the cossack squat work?
Primary movers
- Quadriceps
- Gluteus maximus
- Hip adductors
Assisting muscles
- Hamstrings
- Gluteus medius
- Calves
- Core
The bent leg does the lifting. As you sit into one hip, the quadriceps and glutes control the descent and then drive you back up, much as they do in a single-leg squat but with the other leg helping you balance.
The straight leg is being stretched, not worked. Its adductors and hamstrings lengthen as your body shifts sideways, which is why the movement doubles as a mobility drill. The deeper you go, the stronger that stretch becomes.
The gluteus medius on the working side stabilises your pelvis and keeps the knee tracking over the toes. The calves and the muscles around the ankle work hard to keep the heel of the bent leg on the floor.
Your core keeps the chest up as you shift side to side. A light plate held at the chest acts as a counterweight, which makes it easier to stay upright and sit deeper. If your hips or ankles feel tight, work only as deep as you can with the heel down and add range gradually.
How to do the cossack squat
Setup
- 1
Stand with your feet about twice shoulder-width apart and turn your toes out slightly.
- 2
Hold a light weight plate at your chest with both hands, or keep your arms crossed in front of you.
- 3
Stand tall with your chest up and your weight even across both feet.
- 4
Brace your core and take a breath before the first rep.
Execution
- 1
Shift your weight to one side and sit down into that hip, bending the knee.
- 2
Keep the other leg straight and let its toes point up as the heel stays on the floor.
- 3
Lower as deep as you can while the heel of the bent leg stays flat and your chest stays tall.
- 4
Pause briefly at the bottom without bouncing.
- 5
Push through the bent leg to rise back to the middle.
- 6
Repeat on the other side. Each side counts as one rep.
Common cossack squat mistakes
Lifting the heel of the working leg
The weight rolls forward onto the toes and the knee takes extra stress.
The fix: Go only as deep as you can with the heel flat, and build range over time.
Rounding the back to get lower
The spine flexes and the legs do less of the work.
The fix: Hold a plate at your chest and keep your chest up.
Letting the bent knee cave inward
The knee drifts out of line with the foot and loses stability.
The fix: Press the knee out over your toes throughout the rep.
Bouncing at the bottom
Momentum replaces control and can jolt the hip and knee.
The fix: Move slowly and pause for a second at the bottom of each rep.
How many sets and reps?
| Goal | Sets | Reps | Load | Rest |
|---|---|---|---|---|
| Hypertrophy | 3 | 8–12 per side | Moderate plate or dumbbell, 1–2 reps in reserve | 60–90 s |
| Mobility | 2–3 | 6–10 per side | Bodyweight, slow tempo | 45–60 s |
| Beginner | 2–3 | 5–8 per side | Bodyweight, hold a support if needed | 60 s |
Use Cossack squats as a warm-up for leg day or as a lower-body accessory after your main squat or deadlift. Start with bodyweight and a depth you control, and add the plate only when the movement feels smooth on both sides.
Running the cossack squat in your next block? Hercules logs every set, shows last session's numbers before you lift, and suggests when to add weight.
Get it on Google PlayCossack Squat variations and alternatives
Bodyweight Squats
EasierA simpler squat pattern before you add a lateral shift.
Dumbbell Sumo Squat
EasierA wide stance with both legs loaded and no lateral shift.
Butterfly Stretch
AlternativeA seated inner thigh stretch to improve hip range.
Curtsy Lunges
AlternativeLoads the outer glutes through a diagonal step instead of a side shift.
Bodyweight Pistol Squats
HarderA full single-leg squat that demands more strength and balance.
Frequently asked questions
What muscles do Cossack squats work?
The quadriceps and glutes of the bent leg work hardest, while the inner thigh and hamstring of the straight leg are stretched.
Why can't I keep my heel down?
Tight ankles or hips are the usual cause. Lower only as far as the heel stays flat, and build range over time.
Should I hold a weight?
A light plate held at the chest helps you stay upright, but try it without weight first.
Are Cossack squats good for mobility?
Yes. They stretch the adductors and hamstrings of the straight leg while you load the other leg, so you train strength and range together.
Hercules tracks every cossack squat you log, shows you last session's numbers before you lift, and flags when your progress stalls.
Get it on Google Play