RDL vs SLDL: Details, Cues, and ProgrammingThe RDL and SLDL are supplemental lifts for the deadlift. As compared to the full deadlift, they involve much less knee extension, changing the amount of muscle mass and some of the basic mechanics of the deadlift. Here we look at the similarities and differences between these two lifts.
The RDL and the SLDL: Details, Troubleshooting, and Programming
This week, we released a how-to video on the Romanian deadlift (RDL) and the stiff-legged (or straight-legged) Deadlift (SLDL). Below, we will take a closer look at these lifts to highlight their similarities, differences, and how they might fit into your training program.
There is no single way to approach your strength training, but we will talk about the RDL and SLDL as supplemental lifts in the context of Minimum Effective Dose (MED) programming structures that we’ve talked about before. If you are unfamiliar with MED programming, we will cover some of the basics below. But you can find more information here:
- How to Apply Minimum Effective Dose to Training
- M.E.D. Master Class #1 (Podcast)
- Four-Day Split Programming with MED Principles
- M.E.D.: A Practical Approach for the Intermediate Trainee
MED programming follows a few basic principles, including (1) a preference of simplicity over complexity, particularly when it comes to exercise selection; (2) basic, widely applicable programming gives way to more Individualized programming over time. With those principles as guidelines, MED programming calls for small changes that will have big Impacts on someone’s training. This means that for most lifters following MED programming, they will not add supplemental lifts until they are well into intermediate stages of training.
At the intermediate stage, each workout will be made up of some combination of the four main lifts, supplemental lifts, and accessory work. These may be programmed for different kinds of stress events—typically focusing on stress from volume and stress from intensity as the primary drivers of strength gains. If you think of each combination of exercise, sets, and reps in a workout as a training slot with a volume or intensity goal, your programming variables become more easily interchangeable as you need to make adjustments.
Four Main Lifts. The four main lifts are the squat, bench press, overhead press, and deadlift. These lifts best drive general strength for most people. They also a means to measure progress, causing most barbell-based strength training to revolve around improving these four lifts. They also make up the contested lifts for the sports of powerlifting and strengthlifting, giving an alternate setting to test a lifter’s strength and progress over time.
Supplemental Lifts. Supplemental lifts are variations on the four main lifts. They train the same muscles as the four main lifts in different ways, with changes to some aspect of the main lift’s mechanics—the range of motion, the setup, or some aspect of the execution. Sometimes supplemental lifts lend themselves to greater loads than the four main lifts, sometimes lesser. Like the main lifts, they are big, multi-joint movements that usually highlight some aspect of the main lift. When you choose a supplemental lift, you put a magnifying glass on one part of the lift, focusing on one link in the chain, usually to improve a weakness and improve the main lift itself.
Accessory Work. Accessory work includes those lifts and movements that do not mirror, mimic, or directly translate to the four main lifts. Accessory work tends to come with some limitations on long-term progress: small amounts of muscle mass being trained, not incrementally loadable, or with limited use to overall strength gains. Curl, dips, leg presses, dumbbell lifts, and bodyweight movements all get filed under accessory work for a barbell-based strength program. The main purpose of accessory work is to add volume to your training and build or maintain muscle mass. Alternatively, accessory slots in training may serve for conditioning work. (For more on using accessories for conditioning, read our ebook on Strength-Based Conditioning.)
Volume and Intensity. Main, supplemental, and accessory work are organized according to the desired stress of a training program. MED Programming tends to point toward a basic four day split for most intermediate lifters. A four-day split is not necessary and may not be the best setup for everyone, but it is an organization that lends itself to supplemental and accessory work better than a three-day, full-body program. A basic four-day split might look something like the following:
Squat (intensity; or intensity + back-off sets)
Bench Press (intensity; or intensity + back-off sets)
Deadlift (intensity; or intensity + backoff sets)
|Day 4 |
Press (intensity; or intensity + back-off sets)
Bench Press (volume)
For purely illustrative purposes, this example has three training slots for each day: an intensity slot, a volume slot, and an accessory or conditioning slot. And it uses only the four main lifts, prioritizing intensity and volume work for each lift in an upper-body/lower-body split.
We’ve written and talked at length about how to adjust volume and intensity within a four-day split to make progress, but at some point, a lifter will require more variety than just the four main lifts. This is where supplemental lifts come in. Supplemental lifts, used judiciously, can substitute for the main lifts in any of the above training slots. Where the supplemental lift fits will depend on the lift and the lifter. Supplemental lifts that allow someone to overload their main lift will often first fall on the intensity slot. Whereas supplemental lifts that make a lift more difficult, use less muscle mass, or require lighter loads—such as RDLs and SLDLs—will usually fall to the volume slot or back-off slots.
By breaking down a program into types of lifts and slots for different kinds of training stress, you get a kind of plug-n’-play aspect to the four-day split program. This is both a bug and a feature. Used wisely, being able to adjust a stale program with supplemental lifts can be a boon to a lifter who has been stuck and is unsure what to do next. Used arbitrarily, constant changes or plugging in the wrong lifts too early may make sense on paper but not fit the lifter’s needs.
Back to the RDL and SLDL
The RDL and SLDL are supplemental lifts for the deadlift. They use much of the same muscle mass and close to the same range of motion. Each of these lifts puts the magnifying glass on the extensors of the hip. As compared to the full deadlift, they involve much less knee extension, changing the amount of muscle mass, and some of the basic mechanics of the deadlift.
Even though these supplemental lifts use less muscle mass than a full deadlift, they are still big lifts. Hip extension is primarily the domain of the gluteus maximus, which recruits your hamstring muscles (the biceps femoris, semitendinosus, and the semimembranosus), and the adductor magnus of the inner thigh. The gluteus maximus is the largest muscle in the human body. Nearly all big, powerful movements require some extension or rotation of the hip muscles, and these supplemental lifts put most of the right on them. That makes these lifts capable of producing significant amounts of stress.
Similar in how they use muscle mass to move heavy loads, these lifts differ significantly in several other ways.
The RDL starts from the rack at about the height of your midthigh. You take the bar out of the rack, step back, unlock your knees slightly, and bend at the hips to slide the bar down your legs. The range of motion will depend on the lifter’s ability to maintain a rigid back without bending the knees. At some point, the hamstrings reach their full extension. Going farther down will require either bending the knees or flexing the lower back, neither of which should be allowed. From the bottom, the lifter will slide the bar back up the legs and return to the starting position. At no point during the RDL does the lifter set the bar down.
The SLDL starts from the floor, with the bar over the middle of the lifter’s feet, just like the deadlift. The “stiff-legged” or “straight-legged” deadlift is a little bit misleading, as few lifters will be able to deadlift from with completely straight legs. To set up for the SLDL, unlock your knees only enough to allow you to set your back, maintaining vertical shins. This will place your hips higher than they would be in a full deadlift, in which you bend your knees as much as allowed by the position of the barbell over the middle of your feet. The goal of the SLDL is to emphasize the hamstrings and glutes and to force the lifter into a difficult bottom position. Bending the knees too much defeats this purpose; keeping the knees locked does the same as it will usually prevent you from setting your back.
Each repetition of the SLDL starts on the floor, from a dead stop, just like the deadlift. You must set your back in this difficult position on each rep, placing more focus on the act of extending the back, squeezing into position, and squeezing the bar off the floor for each repetition.
Range of Motion
One of the most obvious differences between the two lifts is in their ranges of motion. Few lifters are able to lower an RDL to the floor without bending their knees and while maintaining a rigid lower back. While some coaches prefer a style of RDL that reaches the floor, this will involve more knee flexion during the descent and more knee extension on the way up, trading some of the focus on the hip extensors for a bigger range of motion. The more traditional way to perform the RDL has lifters stop the descent when they cannot maintain their lower back extension without bending their knees. At this point, the hamstrings will be very tight.
The SLDL starts on the floor. In terms of work against gravity, it has the same range of motion as the full deadlift. The movement about the hip, however, is increased by the more horizontal back angle at the bottom of the SLDL.
Once the novelty of these lifts has worn off, and a lifter is able to perform both with competence, the lifter will usually be able to lift more weight with the RDL. The RDL has two things going for it. First, the shorter range of motion means less mechanical work for each rep. Second, because the RDL does not start from a dead stop, the lifter benefits from a stretch reflex during the concentric portion of the lift. Depending on their build and confidence with the lift, some lifters are able to move massive loads with the RDL.
Time Under Tension
One of the things that make the deadlift such a stress-inducing lift is the dead stop aspect. Starting each rep from the floor, setting your back hard every time, and having to muster the muscular tension to break the bar off the floor is difficult. And it is that difficulty that makes it such a great lift for training your back to be strong, healthy, and capable of handling anything you encounter outside of the gym. The SLDL makes the act of setting your back even more difficult by extending the hamstrings and making the bottom position an even tighter squeeze. This is useful for a lifter who is trying to improve the bottom portion of the full deadlift by forcing a start from a more difficult position.
While the RDL does not carry that same focus on setting the back for each rep, it does increase the time under tension for each set. From the moment you unrack the bar and step back until you walk the bar back into the rack, you are “on.” There is no deload at the bottom and no real rest at the top of the lift. The RDL does not force you to set your back over and over again. It forces you to set your back once and maintain that posture for the entire set. This increased time under tension can benefit lifters who are struggling with fatigue in their lower backs during difficult deadlift sets.
Because you do not set the RDL down between reps and you do not pause at the bottom of the movement, it benefits from a stretch reflex, not unlike the squat. Muscles are sensory organs, reacting to changes in their own lengths by sending signals to your brain for certain regulatory actions. When muscles stretch under load, they will automatically cause the muscles to contract in order to maintain stability, preventing one muscle from pulling a bone clear out of its joint by activating antagonist muscles. This same reflexive action helps contribute to a forceful concentric action following an eccentric movement. As you lower the bar during an RDL, the extensors of your hips are using the feedback from the muscles lengthening under load to resist the bar and generate force. They are, in a sense, already spooled up or primed for a shortening contraction. When you switch from down to up, they are capable of a quick and forceful shortening, extending the hips and helping to lift the bar back to the starting position. When you start from a dead stop as in an SLDL, it takes time for your muscles to generate maximum force. Peak force production does not occur instantaneously.
The big eccentric portion of the RDL means that you can often move bigger loads. It means that the lift is usually less systemically stressful for similar tonnages than the SLDL. But it also means that someone who is new to the RDL can cause themselves a good deal of soreness with the movement. If you’ve never done these before or are returning to them after a while, start modestly and give your muscles a chance to get used to the eccentric loading.
Watch the video linked at the begging of this article for the “how-tos” of performing these lifts. In addition to the basic movements, there are some common errors of which to be aware to avoid issues and help you troubleshoot the lifts.
RDL: Common Errors
The two most common errors in the RDL are (1) bending your knees during the descent and (2) unlocking or rounding your back. Both of these errors come from the lifter’s attempt to force a bigger range of motion than the hamstrings are keen to allow.
The bottom of the RDL is extremely tight for the hamstrings. Some people believe that they should reach a certain point on their shin or close to the ground. The RDL is different from, say, the squat, which has a clearly defined range of motion to be considered valid. The range of motion for the RDL is defined by hamstring extensibility.
Your knees should be unlocked at the top but not by much. Think of a “soft bend” in your knees. Once slightly unlocked, your knees should not move until you are ready to re-rack the bar. If, as you descend, you bend your knees, you will be able to reach farther down, but you will be taking the focus off your hip extensors, which is the point of the lift.
Similarly, as you reach the bottom of the lift, assuming your knees aren’t bending, your hamstrings and back should be very tight. If you continue to descend, and you suddenly feel relief in those areas, then you have unlocked your back. Both of these errors can be difficult to identify while you are lifting. So, use your camera and film your lifts to watch for bending knees and a rounding back. And remember that tightness trumps range of motion for this lift.
Not a form error, but often a mistake, is the failure to use straps on this lift. Having to unrack the bar, walk it out of the rack, perform an entire set, and walk it back into the rack can only be done at relatively light loads without straps. Sets of RDLs will punish your thumbs if you hook grip and should not be performed with a mixed grip. Use straps to get the most out of the lift.
Common Errors: SLDL
The main issues with the SLDL come from the setup and the lifter either having their legs too straight or not straight enough. Knees locked will prevent you from actually setting your back in extension before you pull. Most people will need to bend their knees slightly in order to set their back properly. Limit the bend to what is necessary to set your back and no more. Too much bending of the knees defeats the purpose of this lift. You might as well deadlift.
And speaking of the squeeze, the bottom of the SLDL is even more uncomfortable than the bottom of the deadlift. This often causes lifters to want to rush through setting their backs. Due to the difficult position, take an extra moment to finish squeezing your back into extension before you pull. Don’t rush. It is supposed to be hard.
Note also with the SLDL that the bar should remain over the middle of the foot. That means that when the bar leaves the floor, it will not be touching your legs, as it should be at the beginning of a full deadlift. As you lift, aim to “grab your shorts” with the barbell as it passes your knees, or think about dragging the bar up your thighs. Make sure to drag the bar back to your legs and not scoop your knees forward to the bar.
In general, the SLDL has a more difficult bottom position and puts emphasis on setting the back in a difficult place for each rep. This lift is good for training lower back fatigue that allows someone to handle heavier deadlifts. It also trains hamstring strength and hypertrophy.
The RDL’s greater time under tension helps improve muscular endurance and the ability to maintain a rigid spine with less of a focus on actually setting the back repeatedly. The RDL is also an excellent hamstring stretch, which often feels good to lifters who have a tweaked back.
Assuming you are using these lifts as supplemental lifts to add volume to your program in place of your full deadlift, then you can program them a few different ways. A basic strategy is to start these lifts at higher volumes and relatively light loads, then decrease the reps per set as the weight gets heavier, adding sets to add volume.
For example, you can start either of these lifts with three sets of five to eight repetitions at a moderately challenging weight. From there, steadily increase the load over several weeks. As you increase the load, you might decrease the repetitions to five reps per set, continuing to add weight. Then, when you cannot add weight anymore, back-off 5-10% and add a set, going to four sets of five repetitions. Repeat the same process—adding weight until you cannot anymore, backing off again, and adding another set. Now you are lifting five sets of five for volume and again adding weight steadily.
Given the differences between the lifts, the SLDL usually will stay in the five to eight repetitions per set range, focusing on strength and hypertrophy through moderate to higher repetitions. The RDL, however, having built-in time under tension means you can benefit from fewer repetitions per set and more total sets. You might perform five to eight sets of three at the top of your volume for heavier loads.
In addition to improving parts of the deadlift execution—setting the back, lower back fatigue, and focusing on hip extension—these lifts also work well if you are focused on hypertrophy, being big lifts with an intense focus on the glutes and hamstrings.
It All Depends on You
Ultimately, how you use these lifts will depend on your needs, your current programming, and your goals. Do not be afraid to experiment with different lifts and build your lifting repertoire. Throughout the life of your lifting career, you will use and return to different lifts over and over again. It is good to know not only how to perform these lifts but how you respond to them as part of a comprehensive strength program.