Hey Dr. Bell, Is it better to do Deadlifts on leg day or back day? Why would it make a difference?
Traditionally, Back Day refers to the Superior (upper) muscles of the back. The Deadlift targets the Inferior (lower) muscles in the back, the Quadratus Lumborum, the Gluteals and the Legs. Therefore, Deadlifts are almost always performed on Leg Day.
Some will argue that the other spinal extensors, the Erector Spinae Group, extend the spine from the hip, all along the length of the spine to the skull. Therefore, Deadlifts should be done with Back Day. However, I think you will find it far more effective as a Bodybuilder, to keep your Deadlifts with Leg Day.
Some Powerlifters dedicate one training day exclusively for Deadlifts as they typically do for their other competitive lifts: the Bench Press and Squat.
Give it a try and see how it works for you!