The stiff-leg deadlift is a hinge with the knees held nearly straight, usually starting from the floor. The straighter leg is the whole distinction from an RDL: it lengthens the hamstrings further and lets you reach a deeper stretch, at the cost of handling noticeably less weight and leaving the lower back with more to hold.
How to do it
- Knees almost straight and fixed, which puts everything into the hamstring stretch.
- Keep the bar close; it should brush the legs on the way down.
Common mistakes
- Rounding the back to reach lower. Range comes from flexibility, not from the spine.
What it trains
- Hamstrings
- control the hips travelling back with the knees locked out long — the prime mover, and stretched harder than in any other hinge
- Glutes
- drive the hips through to stand up
- Lower back
- holds the spine flat with the load furthest from your hips — it works harder here than on an RDL
- Traps and grip
- hold the bar for the length of the set
Variations and alternatives
Common questions
Are my legs meant to be completely straight?
Nearly, but not locked hard. A tiny amount of knee bend keeps the load in the hamstrings rather than hanging off the back of the joint — fully locked knees are where people tend to round the lower back to reach the bar.
Should I do stiff-leg deadlifts off a deficit?
Only once you can reach the floor with a flat back on the regular version. Standing on a plate adds range at the exact point where most people are already at their limit, so it magnifies a rounding problem rather than adding stretch.
Why is my lower back more sore than my hamstrings?
Usually because the bar drifted away from your legs, which turns a hinge into a long lever against your spine. Keep the bar brushing your thighs the whole way down; if it still happens at a given weight, that weight is too heavy for this lift regardless of what you pull conventionally.
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Legs
