The dumbbell stiff-leg deadlift (SLDL) is one of the most confusing exercises for beginners – mainly because it’s so similar to the Romanian deadlift (RDL).
If you aren’t sure what to do, I’ll be explaining the utility of the DL stiff-leg deadlift and how it differs from other deadlift forms – most notably, the RDL.
I have covered the dumbbell Romanian deadlift – check out that guide as well to get a clearer understanding of both the RDL and the SLDL.
What Muscles Do Dumbbell Straight-Leg Deadlifts Work?
At a high level, stiff-leg deadlifts work the same muscles as the Romanian deadlift:
- Hamstrings. Like the RDL, the stiff-leg deadlift engages the hamstrings more than the conventional deadlift because of the slightly flexed knee. Comparatively, quads work very little in this exercise.
- Glutes. Since quad engagement is low in the SLDL, the gluteus maximus muscles receive a greater emphasis than in the conventional deadlift.
- Core and muscles of the upper, middle, and lower back. These muscles work to stabilize your spine throughout the exercise’s range of motion (ROM).
- Forearms. Your forearms are loaded because they are responsible for your grip strength.
However, unlike the RDL, stiff-leg deadlifts (both barbell and dumbbell variations) put a greater emphasis on lower back strength and hamstring flexibility. This is because the SLDL typically implies straight or nearly straight knees and ideally no change in knee angle. The RDL does allow for changes in knee angle as you lower and lift the weight.
Benefits Of The Dumbbell Stiff-Leg Deadlift
Since the form of the stiff-leg deadlift is so drastically different from that of the conventional deadlift, let’s try to understand why one would even want to incorporate this exercise into their routine.
As already mentioned, the SLDL is very similar to the Romanian deadlift, but there are slight differences. I’ll cover these below as well.
In addition, I’ll compare barbell and dumbbell stiff-leg deadlifts to let you know which would be better for your needs.
SLDL vs. conventional deadlift
When it comes to the SLDL vs. conventional deadlift comparison, the benefits of the SLDL are basically the same as with the Romanian deadlift.
More specifically, as I outlined in my Romanian deadlift guide, the SLDL can help you understand how to move from the hip, which can be really helpful in squats.
Many newbies don’t understand what it means to “properly engage their hips.” As far as squats are concerned, beginners typically flex their lumbar rather than sit down with their hips. Not only is this a big mistake that undermines the effectiveness of the squat, but it also can lead to injury.
Hip movement aside, the SLDL (and the RDL) hit the hamstrings and glutes harder than the conventional deadlift. In the conventional deadlift, a good bit of the load goes into the quads instead.
SLDL vs. Romanian deadlift
Compared to the Romanian deadlift, the stiff-leg deadlift places a heavier load on the lower back and hamstrings. Likewise, the SLDL requires a fair amount of flexibility – if your hamstrings are stiff, you may not be able to sufficiently lower the weight while keeping your spine neutral.
So even though the SLDL and the RDL are very similar movements, the SLDL is more lower back- and hamstring-centric.
Dumbbell VS barbell SLDL
Finally, dumbbell vs. barbell SLDL. Well, here, I’ll just repeat the points from my RDL vs. conventional deadlift comparison in the RDL guide since there is nothing really new to add:
- The dumbbell stiff-leg deadlift is easier to master because the dumbbells don’t get in the way of your shins, unlike a bar.
- With dumbbells, your weight is distributed more compactly, making it easier to keep your balance throughout the ROM.
- You can quickly ditch one set of dumbbells to grab another one, which can be very useful for drop sets.
- Dumbbells occupy less space than a barbell and are therefore more home gym-friendly.
- Dumbbell SLDLs are typically performed lighter than barbell SLDLs, which should translate to a lower risk of injury.
Dumbbell Stiff-Leg Deadlift Form - How To Do The SLDL?
Here’s how the dumbbell stiff-leg deadlift is ideally performed:
- Grab a pair of dumbbells of an appropriate weight. If not sure how heavy to go, start lighter and work your way up.
- Stand with your feet about hip-width apart (though you may go shoulder width if that’s more comfortable for you). Keep your legs straight or nearly straight. You may also lock your knees to stretch your hamstrings more (though this will make holding your spine neutral more difficult).
- Take a deep breath, brace your core, and pull your shoulder blades back to keep your upper back tight.
- Hinge at the hip and bend down, lowering the dumbbells toward the ground.
- Go as low as you can while maintaining a neutral, braced spine.
- Ideally, keep your knee angle fixed throughout the entire range of motion. If you can’t keep your back neutral with extended legs, you may slightly bend your knees when your hamstring and lower back are at their peak stretch.
- Exhale and engage your hamstrings to pull yourself back up.
3 sets of 10-12 reps should be a good starting point.
One note here – the classical barbell stiff-leg deadlift usually starts from the floor. The range of motion is more or less the same as in the conventional deadlift – your body is fully extended at the highest point, while the weight rests on the ground at the lowest point.
With the DB stiff leg deadlift, unless you are really flexible, you probably won’t be able to start lifting from the floor. You could try, but since the dumbbells will force you to bend lower due to their smaller size, you will probably need to start standing.
Another thing to keep in mind is that people sometimes describe stiff-leg deadlift form quite differently. This adds to the confusion even more, though I think you should have a look around and see what other bloggers and YouTubers have to say about the SLDL – for a fuller picture.
The form I described earlier seems to be the most widely-accepted one, so I think you should follow it. If necessary, tweak your form to meet your training goals.
SLDL Mistakes To Avoid
In my RDL guide, I pointed out three common mistakes to avoid:
- Locking the knees.
- Rounding of the back.
- Looking up or down.
When it comes to the two latter points, they remain unchanged. You should keep your back neutral for stability and to prevent injury, and you should not look up or down to avoid neck strain. Your neck should be in line with the rest of your back.
As for the knees, locking them wouldn’t necessarily be a mistake in stiff-legged deadlifts. In fact, if you lock your knees, you will be able to hit the hamstrings harder.
However, you will also need to have a fair amount of flexibility in your hamstrings to be able to adequately perform the exercise with your knees locked. Besides, locking out the knees may put excessive stress on them, which may matter if you have knee pain.
In the SLDL, you should keep your knees as straight as possible. You may try the exercise with and without locking your knees out (though I prefer unlocked knees).
3 Dumbbell Stiff-Leg Deadlift Alternatives
Many people find the stiff-leg deadlift challenging because it requires a minimal bend in the knees. Fortunately, there are a bunch of alternative movements that you may incorporate in your routine to target more or less the same muscles as the stiff-leg deadlift – without the strain.
Dumbbell/barbell Romanian deadlift
The barbell hip thrust is a wonderful exercise for glutes and hamstrings. Furthermore, it’s not as demanding on back strength (although you will need to keep your core tight).
Here’s how to do the hip thrust:
- Place your upper back against a bench, with a barbell across your hips.
- Place your feet flat on the floor, with your knees bent.
- Keeping your core engaged, squeeze your glutes and push your hips up.
- Pause at the top, lower the bar, and repeat.
10 to 12 reps in 3 sets should be great for most people.
Bulgarian split squat
The Bulgarian split squat allows you to improve balance and treat uneven strength in your glutes and hamstrings. It’s also a great hamstring and quad exercise.
The load in Bulgarian split squats is typically light, but the exercise is still challenging since it is demanding on one’s balance.
Here’s how to do Bulgarian split squats:
- Find a bench that is at about your knee level.
- Stand about 2 feet in front of the bench.
- Place your left foot on the bench.
- Lean forward a bit from the waist and lunge on your right leg.
- When your right thigh is parallel to the floor, push with your right foot to stand up.
Do 10-12 reps on each leg in 3 sets.
Hopefully, I’ve added some clarity to dumbbell stiff-legged deadlifts! The exercise is fairly simple, but it confuses a surprising number of people.
In the end, if you want to hit your hamstrings and lower back harder, the SLDL should be better than the RDL. But if you don’t feel comfortable with your knees straight, the RDL should hit the mark regarding the activation of hamstrings.