The Single-Leg Squat with Rear Elevation — also called the Bulgarian Split Squat — is the Force Window's primary unilateral lower-body strength movement. Where the Back Squat and Trap Bar Deadlift develop bilateral stren...
Purpose
The Single-Leg Squat with Rear Elevation — also called the Bulgarian Split Squat — is the Force Window's primary unilateral lower-body strength movement. Where the Back Squat and Trap Bar Deadlift develop bilateral strength, the rear-elevated single-leg squat targets each leg independently and exposes strength asymmetries that bilateral exercises mask.
Bilateral strength asymmetries greater than ten to fifteen percent between legs are associated with increased ACL and hamstring injury risk in sprint and change-of-direction sports. The rear-elevated single-leg squat is the most effective exercise for correcting these asymmetries because it loads each leg independently and allows the coach to observe and quantify the difference in rep quality, range of motion, and stability between sides.
This is a challenging exercise. Athletes new to it will struggle with balance, depth, and stability before they struggle with the load. Do not add significant external weight until the bodyweight version is performed with full depth, stable hips, and consistent rep quality. The balance and hip stability demands of this movement are high.
Setup
The rear foot rests on a bench or box behind the athlete. The top of the foot rests on the surface (not the heel, not the shin). Too high an elevation increases hip flexor strain — 12 to 18 inches is the working range.
The distance from the box determines the shin angle on the front leg. Too close: the shin travels excessively forward. The ideal front foot position allows the shin to remain close to vertical at depth.
Dumbbell version: hold a dumbbell in each hand at the sides, natural grip. Barbell version: barbell in the high-bar back squat position. Begin with dumbbells for all athletes who are new to this exercise.
Execution
The descent is a knee bend, not a hip-back sit. The front shin remains relatively vertical as the athlete descends. The rear leg is a balance point — it should not be bearing significant load at any point.
The target depth is the front thigh parallel to the floor — the same standard as the Back Squat. Athletes with adequate hip flexor mobility will achieve this depth without the rear knee touching the floor.
The chest stays tall throughout the descent. Forward lean shifts load to the lower back and reduces the quad training stimulus. A dumbbell in each hand helps maintain an upright torso by acting as counterbalance.
The ascent is driven by the front foot — specifically the heel. Drive the heel into the floor to extend the knee and return to standing. The rear leg assists with balance only.
Common Errors
The front knee collapses inward during the descent or ascent. This is a hip abductor weakness and quad dominance pattern. Cue: 'front knee out — drive it over the toes.'
The torso leans forward into the front thigh as the athlete reaches depth. Usually caused by tight hip flexors on the rear leg or a hip-back descent pattern rather than a knee-bend descent. Cue: 'chest tall — squeeze the rear glute.'
The athlete uses the rear foot to push themselves up rather than driving through the front foot. The test: if the rear foot came off the box, could the athlete complete the rep? It should be possible. Cue: 'front foot does all the work.'
Coaching Cue
"Front knee over the toes — chest tall — drive through the heel."
This three-point cue covers the most common errors: knee alignment (front knee out, not caving), torso position (chest tall), and the drive phase (through the heel — activates the glutes and quads properly). Deliver before the first set of each leg.Progressions & Regressions
Regress to — if the athlete is struggling
Progress to — once the pattern is clean
Programming Notes
Program as a unilateral accessory movement alongside the Back Squat and Trap Bar Deadlift. Three to four sets of six to eight reps per leg with two minutes of rest between sets per leg.
Always start with the weaker leg. If significant asymmetry exists, add one extra set to the weaker side. Track the weight used on each leg separately. The goal is to reduce the asymmetry over time, not just to increase absolute load.
The rear-elevated single-leg squat is high demand and will create significant quad soreness in athletes new to unilateral loading. Introduce it progressively: bodyweight first, then light dumbbells, then progressively heavier dumbbells, then barbell.