RDLs are my favorite. I won't even try and hide that fact. I recently began playing around with this contralateral offset hold in addition to a contralateral reach.
The contralateral offset holds further adds to the stability demands of the exercise (that's already on one leg). By holding the weight in your opposite hand, you are adding a LONGER LEVER to the exercise aka it will take MORE MUSCLE ACTIVITY to stabilize and move the weight. Remember, TORQUE (muscle activity in this case) = LEVER ARM (perpendicular distance from weight to axis of rotation) x APPLIED FORCE (weight of the kettlebell). So we can increase muscle activity ie make the exercise harder by either increasing the amount of weight we are holding in our hand, or by increasing how far away the weight is from our hip joint.
Adding the contralateral reach with the weight also acts to further increase the lever arm. But what I really like about the reach is that you can significantly increase the amount of muscle stretch and eccentric load on the glutes. We are getting as much hip flexion, internal rotation, and adduction as we possibly can with this variation at the bottom, all being controlled eccentric by the glutes (and hamstrings). Simplified…but more eccentric muscle stretch = more conducive environment for hypertrophic gains!
Give it a shot and tag a friend whose looking for some booty RDL gains! Exercise Library