The Bulgarian Split Squat (BSS) is a unilateral exercise performed by elevating the back foot on a bench or box while the front leg performs a squatting motion. This movement is highly effective for building lower body strength and correcting muscular imbalances between the left and right sides of the body. As a compound movement, the BSS forces the working leg to manage the majority of the load, providing a concentrated stimulus that promotes muscle growth and stability across several muscle groups.
Primary Muscles Targeted
The two primary muscle groups driving the Bulgarian Split Squat are the quadriceps and the gluteal muscles of the working leg. The quadriceps, located on the front of the thigh, are four muscles that extend the knee joint. During the BSS, the quads are heavily engaged as you descend into the squat and then contract powerfully to straighten the knee and return to the starting position.
The gluteal muscles, including the gluteus maximus, are responsible for hip extension, driving the hips forward to stand up from the bottom of the movement. As you lower your body, the glutes are stretched and initiate the concentric, or lifting, phase of the squat. Research suggests the BSS can lead to greater activation of the glutes compared to a traditional back squat. The hamstrings, located on the back of the thigh, also contribute to hip extension alongside the glutes, though their activation is secondary to the quads and glutes.
Adjusting Form to Change Emphasis
The Bulgarian Split Squat allows for modifications in form to emphasize either the quadriceps or the gluteal muscles. The first adjustment involves manipulating the distance between the working foot and the elevated back foot. A shorter stance, where the front foot is positioned closer to the bench, increases knee flexion and forward knee travel. This position places a greater demand on the quadriceps, making the exercise quad-dominant.
Conversely, moving the front foot farther away creates a longer stance, which limits forward knee travel and encourages a greater hip hinge. This increased hip flexion places a maximum stretch and load on the gluteal muscles, making the movement glute-dominant. This longer stride length forces the hips to move backward more significantly, maximizing the recruitment of the gluteus maximus.
The angle of the torso provides a second way to shift muscle emphasis. Maintaining a more upright torso minimizes the hip hinge and keeps the load directed down through the knee joint, further targeting the quadriceps. This upright posture is frequently used in the quad-focused variation, often with the knee tracking slightly over the toes.
Leaning the torso slightly forward from the hips increases the hip angle and drives the hips backward. This forward lean is characteristic of the glute-focused variation, as it increases the moment arm at the hip joint. By consciously leaning the chest forward, the lifter maximizes the mechanical tension on the glutes and reduces the stress placed on the knee joint.
Secondary Stabilizer Muscles
Beyond the primary movers, the Bulgarian Split Squat recruits several muscle groups to maintain balance and control throughout the movement. The core musculature, including the abdominals and obliques, must engage isometrically to keep the torso stable and prevent excessive side-to-side rotation. This requirement for total body stability is a key benefit of this unilateral exercise.
The gluteus medius, a smaller glute muscle located on the side of the hip, plays a crucial stabilizing role by preventing the knee of the working leg from collapsing inward. This muscle works to maintain hip and knee alignment, which is essential for joint health and movement efficiency. The calves, particularly the gastrocnemius and soleus, also act as stabilizers by helping to anchor the front foot to the ground during the eccentric and concentric phases.