The Single Leg Romanian Deadlift (SL RDL) is a powerful unilateral exercise that challenges both muscular strength and neuromuscular coordination. This movement isolates the posterior chain muscles, including the hamstrings and glutes, while simultaneously demanding significant core and ankle stability. The SL RDL is fundamentally a hip-hinge pattern performed on one leg, making it highly effective for identifying and correcting strength imbalances between the left and right sides of the body. This guide provides precise instruction for safely and effectively executing this demanding exercise.
Preparing for the Movement
Establishing a stable foundation through the planted foot is necessary for maximizing balance and force transfer. Think of the foot as a “tripod,” distributing pressure evenly among the heel, the base of the big toe, and the base of the little toe. This distribution activates the intrinsic foot muscles and provides a solid base from which to hinge.
The spine must be set in a neutral position, secured by bracing the core as if anticipating a light punch. Engaging the core stabilizes the torso throughout the range of motion, protecting the lumbar spine. To assist with balance, fix the gaze on a static point on the floor approximately three to five feet in front of the body.
Step-by-Step Execution
Initiating the Hinge
The movement begins by initiating the hip hinge, which is the defining mechanical action of the RDL. Imagine pulling your hips directly backward, maintaining a slight, soft bend in the planted knee. This posterior shift loads the gluteal and hamstring muscles of the standing leg.
Descent and Alignment
As the hips travel backward, the torso simultaneously lowers toward the floor, moving as a single, rigid unit with the spine. The free leg extends straight behind the body, acting as a counterbalance. Maintain a straight line from the shoulder through the hip to the heel of the extended leg throughout the descent.
To prevent “opening the hip,” actively ensure the pelvis remains square to the floor, meaning both hip bones should face directly downward. This controlled alignment ensures that the load remains focused on the hamstring and glute of the working leg.
Depth and Tempo
Continue the descent only until a noticeable stretch is felt in the hamstring, or just before the lower back begins to lose its neutral position. The speed of the descent should be slow and controlled, ideally taking three to four seconds. This slow tempo increases the time the muscles spend under tension.
Ascent
To begin the ascent, forcefully drive the foot into the floor and consciously squeeze the glute of the planted leg. This powerful contraction pulls the hips forward, reversing the hinge motion. The body returns to the upright starting position by maintaining the rigid torso and free leg alignment used during the descent. The movement emphasizes muscular control over momentum.
The primary muscles engaged are the gluteus maximus and hamstrings, responsible for hip extension during the concentric phase. The spinal erectors work isometrically to maintain neutral spinal posture against the force of gravity.
Avoiding Common Errors
Spinal rounding, particularly in the lumbar region, occurs when the hinge is replaced with a forward bend. This places undue shearing stress on the intervertebral discs. To correct this, maintain the braced core and limit the descent depth to the point of hamstring stretch.
“Opening the hips” involves the pelvis rotating outward toward the side of the raised leg. This compensation indicates a lack of stability in the standing leg’s hip abductors. To keep the hips square, imagine standing inside a narrow tube throughout the range of motion.
Hyperextending the planted knee removes the muscle tension necessary for control and stability. The knee should maintain a slight, constant bend, which allows the hamstrings and glutes to remain actively engaged. This soft bend ensures the joint is protected.
Relying on a quick drop and bounce incorporates too much momentum. Using momentum bypasses the strength-building benefits and reduces the time under tension. Every repetition must be performed deliberately, focusing on the quality of the muscle contraction.
Modifying the Single Leg RDL
Regressions for Stability
For those new to unilateral training, regressions help build stability before attempting the full movement. The “Kickstand RDL” involves placing the toe of the non-working leg lightly on the ground behind the planted foot for minimal balance assistance. Alternatively, lightly holding onto a stable object, such as a pole or wall, provides feedback that aids in maintaining balance.
Progressions for Load
Once the basic movement is mastered, the exercise can be progressed by adding external load, such as holding a dumbbell or kettlebell. Holding the weight in the opposite hand of the planted foot (contralateral load setup) increases the challenge to the core anti-rotation muscles.
Advanced Tempo Modification
Advanced users can modify the tempo to increase the time under tension, such as using a five-second count for the eccentric (lowering) phase. This slower, deliberate movement maximizes muscle fiber recruitment and enhances strength and stability gains.