What is the difference between stiff-leg deadlift and Romanian deadlift?

The SLDL uses minimal knee bend and a longer stretch range, often lowering the bar closer to the floor. The RDL uses a slight knee bend and stops when the hamstrings reach full stretch (usually mid-shin). The SLDL places more demand on hamstring flexibility and lower back control.

Why is my SLDL lighter than my deadlift?

Minimal knee bend means less quad contribution. The longer hamstring stretch under load limits how much weight you can control. There is no floor reset between reps if performed from standing.

What muscles does the stiff-leg deadlift work?

Primarily the hamstrings, glutes, and erector spinae. The SLDL also challenges hip flexibility and lower back endurance more than conventional or Romanian deadlifts due to the straighter leg position.

How often should I do stiff-leg deadlifts?

1-2 times per week is typical. The eccentric stretch creates significant muscle soreness, especially early on. Start with lighter loads and build volume gradually.

How do I improve my stiff-leg deadlift?

Focus on hamstring flexibility, controlled 3-4 second eccentrics, progressive overload with 6-10 reps, and accessory work like Nordic curls and good mornings.

Standards + comparisonsSLDL vs RDL clarified

Stiff-Leg Deadlift Strength Standards Calculator

Q: What is a good stiff-leg deadlift?

For intermediate male lifters, roughly 1.3x bodyweight is a solid SLDL benchmark. For females, around 1.0x bodyweight. These are lower than conventional deadlift standards because the SLDL is a more restrictive movement.

See how strong your SLDL is, compare with RDL and conventional deadlift, and understand your posterior chain strength.

SLDL standards setup

Enter your stiff-leg deadlift, bodyweight, and age.

Unit

Sex

Stiff-leg deadlift (kg)Strict form: minimal knee bend, full stretch.Bodyweight (kg)For standards lookup and ratio.

AgeMaps your age band.Round targets (kg)Loading increment.

Romanian deadlift (kg)Optional. For SLDL vs RDL comparison.Conventional deadlift (kg)Optional. For SLDL vs deadlift comparison.

Standards assume strict SLDL form: minimal knee bend, controlled eccentric, full hamstring stretch.

SLDL standards result

Enter your details and press Calculate

See your SLDL category, comparisons with RDL and conventional, and age-adjusted standards.

Main metric

Category + ratio

Comparisons

SLDL vs RDL vs deadlift

Tables

By bodyweight and age

Core concept

What is a stiff-leg deadlift?

The SLDL is a hip-hinge movement with minimal knee bend that emphasizes hamstring stretch and eccentric control under load.

Unlike the Romanian deadlift, the stiff-leg deadlift uses even less knee bend, creating a longer lever arm and greater demand on hamstring flexibility. The bar typically travels lower (closer to the floor or even from the floor) compared to the RDL, which stops when hamstring stretch limits range [1].

This distinction matters because many lifters confuse the two exercises. The SLDL is stricter, typically lighter, and places more emphasis on hamstring length under load rather than the controlled eccentric that defines the RDL.

SLDL vs RDL: the key difference

Feature	Stiff-Leg Deadlift	Romanian Deadlift
Knee bend	Minimal (nearly locked)	Slight (soft knees)
Range of motion	Deeper (closer to floor)	Stops at mid-shin
Primary emphasis	Hamstring stretch	Eccentric control
Typical load	Lighter (80-95% of RDL)	Heavier
Flexibility demand	Higher	Moderate

Benchmarks

Stiff-leg deadlift strength standards

Bodyweight- and age-adjusted standards from Beginner through Elite.

Male stiff-leg deadlift standards (kg, 1RM)

Standards for male lifters aged 18-39 using strict form: minimal knee bend, full hamstring stretch.

Bodyweight	Beginner	Novice	Intermediate	Advanced	Elite
50 kg	35	48	68	90	113
55 kg	39	54	76	101	126
60 kg	43	60	85	113	140
65 kg	47	66	94	124	154
70 kg	53	73	103	135	168
75 kg	56	78	110	145	180
80 kg	60	83	118	155	193
85 kg	64	88	125	165	205
90 kg	68	93	133	175	218
95 kg	70	98	139	184	229
100 kg	73	103	145	193	240
105 kg	76	108	151	201	251
110 kg	80	113	158	210	260
115 kg	85	119	167	221	275
120 kg	90	125	175	233	290

Female stiff-leg deadlift standards (kg, 1RM)

Standards for female lifters aged 18-39 using strict form.

Bodyweight	Beginner	Novice	Intermediate	Advanced	Elite
40 kg	18	28	40	55	73
45 kg	21	33	46	63	81
50 kg	25	38	53	70	90
55 kg	28	41	59	78	99
60 kg	30	45	65	85	108
65 kg	34	49	71	96	118
70 kg	38	53	78	103	128
75 kg	40	57	83	110	138
80 kg	43	60	88	118	148
85 kg	45	64	93	124	155
90 kg	48	68	98	130	163

SLDL bodyweight ratio standards

Quick reference ratios for SLDL relative to bodyweight.

Level	Male (x BW)	Female (x BW)	Description
Beginner	0.70x	0.45x	Learning strict SLDL form
Novice	0.95x	0.70x	Building hamstring tolerance
Intermediate	1.30x	1.00x	Solid posterior chain strength
Advanced	1.75x	1.35x	Strong hinge mechanics
Elite	2.20x	1.75x	Top-tier SLDL strength

What is a good stiff-leg deadlift?

For intermediate male lifters, ~1.3x bodyweight is a solid SLDL benchmark. For females, ~1.0x bodyweight. These are lower than both RDL and conventional deadlift standards because the strict knee position limits total load.

Why your SLDL is lower than your deadlift

• Minimal knee bend means almost no quad contribution
• Longer effective lever arm increases hamstring demand
• Greater stretch at the bottom limits how much weight you can control
• Less total muscle mass contributing to the lift compared to conventional or RDL

Progression

How to improve your stiff-leg deadlift

Build hamstring strength and flexibility for a stronger SLDL.

1. Build hamstring flexibility first. If you can't reach past your knees with straight legs, mobility is limiting your SLDL more than strength.
2. Use 3-4 second eccentrics. The slow lowering phase builds strength at long muscle lengths.
3. Add Nordic curls and good mornings. These strengthen hamstrings at different angles.
4. Progress with 6-10 rep sets. SLDLs respond well to moderate volume with strict form.

FAQ

Stiff-leg deadlift questions

Common SLDL questions answered.

Related tools

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RDL Strength Standards

Compare your Romanian deadlift to the same framework.

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Deadlift Standards Calculator

Conventional deadlift standards by bodyweight and age.

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RDL to Conventional Calculator

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Deadlift 1RM Calculator

Estimate your one-rep max.

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References

Research sources

Data and biomechanics references.

[1] Understanding the Deadlift and Its Variations
ACSM's Health & Fitness Journal. 2020.
Overview of SLDL mechanics, muscle emphasis, and comparison with RDL and conventional deadlift.
[2] Muscle Activation Comparing the Romanian Deadlift and Lying Leg Curl
McAllister MJ, et al. J Sports Sci Med. 2014.
EMG context for hip hinge variations and hamstring activation patterns.
[3] Stiff Leg Deadlift Strength Standards for Men and Women
Fitness Volt. Based on 2.5M+ verified competition results.
Competition-verified SLDL strength benchmarks across bodyweight categories.