Deadlifts are a staple in almost every strength training program, and for good reason. They build powerful glutes, hamstrings, and lower back muscles, all while reinforcing solid hip hinge mechanics.
But when it comes to stiff-leg deadlifts and Romanian deadlifts (RDLs), the two often get mixed up. While they look similar, they target your muscles a little differently and serve slightly different purposes. Knowing which one to use can help you train smarter, not just harder.
The Stiff-Leg Deadlift
As the name suggests, the stiff-leg deadlift is performed with minimal knee bend. You start from the floor, like a traditional deadlift, but keep your legs almost straight throughout the movement.
This variation places a strong emphasis on the hamstrings and lower back, as the limited knee bend means less help from the quads. Because of this, it’s often used to develop posterior chain strength and flexibility rather than raw power.
Key characteristics:
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Knees: Nearly straight (just a soft bend for safety).
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Range of motion: Bar starts and returns to the floor each rep.
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Focus: Stretch and strength through the hamstrings and spinal erectors.
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Common mistake: Rounding the back. Keep your spine neutral and hinge from the hips.
Best for:
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Improving hamstring flexibility.
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Building posterior chain strength and endurance.
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Accessory work for more advanced lifters with solid mobility.
The Romanian Deadlift (RDL)
The Romanian deadlift, on the other hand, starts from a standing position rather than the floor. The movement begins with the bar in your hands, and you hinge at the hips while maintaining a slight, consistent bend in the knees. You lower the bar down to mid-shin (or wherever your flexibility allows) before returning to standing.
Because the knees are more bent and the bar doesn’t touch the ground each rep, the RDL keeps constant tension on the hamstrings and glutes. It’s one of the most effective exercises for building muscle and strength in the posterior chain, especially for athletes and lifters focused on performance.
Key characteristics:
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Knees: Slight, fixed bend throughout the movement.
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Range of motion: Bar stops just below the knees or mid-shin.
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Focus: Controlled eccentric movement (the lowering phase).
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Common mistake: Turning it into a squat — remember, it’s a hip hinge!
Best for:
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Building hamstring and glute strength.
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Improving hip hinge mechanics.
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Muscle hypertrophy and athletic performance.
Which One Should You Do?
Both movements have their place, and the right choice depends on your goals and experience level.
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If you want to build muscle and strength in your hamstrings and glutes (but bias the glutes) → go with the RDL.
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If you want to increase flexibility, stretch, and strength of your hamstrings whilst strengthening your lower back → try the stiff-leg deadlift.
Many lifters benefit from using both, rotating them throughout their training cycles to target different aspects of posterior chain development.
The Takeaway
While they look similar, the RDL is more about control and tension, while the stiff-leg deadlift emphasizes range and stretch. Both build strength, stability, and power from the hips down — key ingredients for athletic performance and injury prevention.
So next time you hit the weights, choose the version that aligns with your goals, focus on your form, and feel the difference in your hamstrings the next day!