The stiff-leg deadlift (also called straight leg deadlift or SLDL) and the Romanian deadlift (also called RDL) are two deadlift variants that are very similar. However, there are a few essential differences.

STIFF LEG DEADLIFT

The deadlift with straight legs (and back straight) eliminates the involvement of your knees in the movement; your butt now mainly gets help from your lower back in lifting the weight, and the role of your quadriceps, on the front of your legs, is taken over by the hamstrings, on the back of your legs.

ADVANTAGES

• The SLDL can help your conventional deadlift, especially if your lower back fails on the lockout;
• The SLDL strengthens the hip joint and flexible hamstrings; you have no choice but to lift from your hips while keeping your knees relatively straight.

ROMANIAN DEADLIFT

The Romanian deadlift is somewhat similar to the stiff-leg deadlift discussed above and is a great exercise for your glutes, lower back and hamstrings.

The funny thing is that in the strict sense, the RDL is not a deadlift at all because the weight never touches the floor during the reps. The RDL also differs emphatically from the stiff-leg deadlift in this respect. Another important difference is that while performing the Romanian deadlift, you keep your knees slightly bent at all times.

ADVANTAGES

• You can deadlift a fairly heavy weight while focusing on your glutes, hips, and hamstrings;
• You can strengthen the lockout for the conventional deadlift with it.

WHICH OF THE TWO?

If you had to choose between the two deadlift variants, which one is the best?

MUSCLE GROWTH

Starting from a bodybuilding perspective, in other words with a focus on muscle growth. Both exercises, RDL and SLDL, guarantee muscle growth in the lower body. With the RDL you keep the bar close to your legs. This ensures that the power mainly comes from the hamstrings and glutes. With the SLDL, the barbell is held slightly away from the legs, which ensures that the power comes mainly from the lower back muscles.

And yes, with the SLDL you feel a big(er) stretch in your hamstrings, but a stretch is not the same as mechanical tension, the primary stimulus for muscle growth. The SLDL also has a smaller range of motion than the RDL.

If you want to effectively train your hamstrings and glutes, go for the RDL. It is generally used more for muscle growth, while the SLDL mainly serves as a strength-assist exercise by powerlifters.

SAFETY

There is another aspect that can determine your choice of the RDL or SLDL, which is safety. The SLDL is seen as a risky exercise. After all, the quadriceps are sidelined in the exercise, putting most of the stress from the weight on your lower back and hamstrings. You can minimize the risks by keeping your lower back straight, using relatively light weights (10-20 reps), and doing the reps slowly and smoothly.

But why do a relatively risky exercise like the SLDL, when there is a safer and (for muscle growth) more effective alternative, namely the RDL? Coach Menno Henselmans about this:

The SLDL is a relativerly high risk, low reward exercise compared to a pure RDL focusing on basically moving as much weight as possible through a full range of motion, without actively lock out the knees or anything.

CONCLUSION

For the average strength athlete who trains for muscle growth, the RDL is, in addition to the conventional deadlift, the appropriate exercise for training the hamstrings and buttocks.

Are you still going to do the SLDL? Then check out this list of common mistakes.