RDL or SLDL: Which is better?

​If you have no idea what these terms mean, let me take a minute to explain. A RDL is a Romanian Deadlift. A SLDL is a Stiff-Leg Romanian Deadlift. These strength training exercises are similar to conventional deadlifts, but with a few key differences. You would not want to do both in the same workout, so which is better?

Both the RDL and SLDL are hip hinge movements that strengthen the posterior chain muscles. Ultimately, both exercises can be effective for building strength in the hamstrings, glutes, and lower back. It is a good idea to try both and adjust based on your individual needs or biomechanics. 

​​Do you really need to do either of these exercises?
You should be doing some variation of a Deadlift, which is a hip hinge movement. This movement is important because it allows you to effectively engage and strengthen the glutes, hamstrings, and lower back. Walking, running, jumping, and lifting heavy objects, are activities that are directly influenced by this hip hinge movement pattern.
 
RDL
The Romanian Deadlift targets the hamstrings, glutes, and lower back, but more emphasis is placed on the glutes due to the slight bend in the knees. During the RDL, dumbbells (or barbell) are lowered down the front of the thighs until you feel a stretch in your hamstrings. Then using your glutes and hamstrings, pull the dumbbells back up to the starting position. 
 
It is important to note that with a conventional deadlift, you start the movement from the ground.
 
SLDL
The Stiff-Leg Deadlift looks almost identical to the RDL, but legs are straight; no bend at all. This places more emphasis on the hamstrings and less on the glutes. During the SLDL, you lower just like you do in a RDL, feel the stretch in the hamstrings, and return to the starting position. 
 
Summary
Both the RDL and SLDL are great exercises to have in your programs. I find that clients who cannot perform a conventional deadlift, really enjoy both of these variations. I include a RDL in my training program for a few weeks, then switch to a SLDL. Are you currently using one of these movements in your training?