In this article, you’ll find out which exercise activates your posterior chain muscles the most effectively, according to a new study.1
The deadlift is one of, if not the, most versatile exercise for training most of your body. It strengthens the muscles in your back, your thighs, and your glutes.
The basic deadlift and the sumo deadlift are dynamic lifts. You bend and extend your knees in a squat-like movement. In contrast, the stiff-legged deadlift and the Romanian deadlift are isometric variations where your knees maintain a constant angle during the movement. The stiff-legged deadlift is usually performed with extended knees while you bend them slightly when performing the Romanian deadlift.
All deadlift variations are excellent exercises for your posterior chain muscles, specifically the glutes, hamstrings, and erector spinae muscles that straighten and rotate your back. However, the Romanian and stiff-legged deadlift hit your posterior chain muscles even more than regular deadlifts and the sumo deadlift.
Your buttocks are made up of several muscles, but the largest and most well-known are the gluteus maximus, gluteus medius, and gluteus minimus.
Your hamstring muscles bend your knees and extend your hips, like when performing a leg curl or a Romanian deadlift, respectively. The three hamstring muscles are the semitendinosus, semimembranosus, and biceps femoris.
Erector Spinae Muscles
The erector spinae is a set of several muscles, including the erector spinae longissimus and iliocostalis. They stabilize, straighten and rotate your back.
You activate all these muscles when you perform a stiff-legged or Romanian deadlift.
A New Study: Which Deadlift Variation Is the Best?
A new study looked at three deadlift variations: the Romanian deadlift, the Romanian deadlift standing on a step, and the stiff-legged deadlift. The researchers wanted to see which exercise best activates the posterior chain muscles. They used a technique called surface electromyography, a procedure that measures and records the activity of the muscles during a specific exercise using electrodes.
Meet the Participants
For this study, the researchers recruited ten competitive bodybuilders around the age of 30. They had all competed for an average of 10 years, continuously monitored for drugs and steroids.
Most studies use untrained or recreationally trained subjects, which doesn’t necessarily translate to someone who has been working out for years. The fact that the participants were high-level bodybuilders makes this study extra exciting. We can be sure that they can perform the exercises correctly and hit the intended muscles.
The study took place over six different training sessions.
- In the first session, the participants were instructed how to perform each exercise. They probably knew that already, but the researchers wanted to ensure they all performed the movements in a comparable way.
- In the following three sessions, the researchers measured the 1RM in the Romanian deadlift, the Romanian deadlift standing on a step, and the stiff-legged deadlift, one exercise per session.
- Then, in the fifth session, the participants familiarized themselves with the selected loads and the placement of the electrodes.
- They performed the actual lifts during the sixth session while the researchers measured their muscle activity. They performed a set for each exercise in a random order, with a 10-minute rest interval between sets.
Each session was separated by at least three days of rest, and the participants did not perform any strength training during the study. That might have skewed the results.
The participants performed the Romanian deadlift standing with their feet hip-distance apart with the knees slightly bent. They bent over with the spine straight, gripped the barbell lying in front of them, and lifted it to a position with fully extended knees and hips.
The Romanian deadlift on a step was performed the same way. The difference was the participants standing on a 15 cm step. Performing the exercise in an elevated position allows for a longer range of motion.
While performing the stiff-legged deadlift, the participants used the same technique as the Romanian deadlift but with locked knees.
The participants performed two warm-up sets with 15 repetitions. After that, it was time for the actual work set, six repetitions using 80% of 1RM. The participants performed one set of each exercise, in randomized order, with 10 minutes of rest between sets.
Having placed electrodes in the appropriate spots, the researchers measured the muscle activity of the gluteus maximus, gluteus medius, biceps femoris, semitendinosus, erector spinae longissimus, and iliocostalis as the participants lifted and lowered the weight.
Let’s look at the muscle activation of the different muscles during the three deadlift variations.
- RD = Romanian deadlift
- step-RD = Romanian deadlift standing on a 15 cm step
- SD = stiff-legged deadlift
Glute Muscle Activation
Hamstring Muscle Activation
Erector Spinae Muscle Activation
While lifting the barbell, the Romanian deadlift on a step activated the gluteus maximus, the semitendinosus, and erector spinae longissimus more than the other two lifts. Other than that, the stiff-legged deadlift activated the gluteus maximus more than the regular Romanian deadlift. In contrast, the hamstring muscle semitendinosus was activated more during the Romanian deadlift than the stiff-legged deadlift.
As the participants lowered the barbell, the researchers observed similar muscle activation patterns but fewer differences between the exercises.
Take-Away and Practical Observations
In general, standing on a step while performing Romanian deadlifts means better activation of your posterior chain muscles than regular Romanian deadlifts and stiff-legged deadlifts standing on the floor.
The regular Romanian deadlift seems to be a bit better for activating the semitendinosus part of the hamstrings, while stiff-legged deadlifts activate the big gluteus maximus more.
Of course, to take advantage of the elevated Romanian deadlift, you need the flexibility to lower the bar enough. If you can’t get any lower than when you perform a regular Romanian deadlift, you won’t see any difference in muscle activation.
This is an interesting study featuring competitive bodybuilders, which is a rarity. Overall, if you’re flexible enough, it might be a good idea to stand on something when you perform the Romanian deadlift to get a longer range of motion.
Electromyography (EMG) studies don’t necessarily predict actual muscle growth, but if you want optimal activation of your hamstrings and glutes, performing your Romanian deadlifts with a full range of motion is likely the best course of action. Previous research has come to similar conclusions.2
If you want to know more about how to train different muscle groups, check out our guides:
Or see all of our muscle group training guides here.
- Int. J. Environ. Res. Public Health 2022, 19(3), 1903. An Electromyographic Analysis of Romanian, Step-Romanian, and Stiff-Leg Deadlift: Implication for Resistance Training.
- SAGE Open Med. 2020; 8: 2050312120901559. Effects of range of motion on muscle development during resistance training interventions: A systematic review.