If heavier variations considered more fatiguing why are rack pulls used?

[Slightlyaboveaverage]

As far as I know flat bench is considered to be more fatiguing than incline bench because flat bench is heavier (even though the range of motion is shorter). So why is it that regular deadlifts are considered more fatiguing than heavy rack pulls with a shorter range of motion?

Same concept as doing beltless variations, doing less weight is less fatiguing even if the range of motion is higher (example would be beltless deficit deadlifts). Isn't the whole point of doing those to still train the movement while creating less fatigue? In this context Rack pulls are to deadlifts what deadlifts are to beltless deficit deadlifts - so why are comp deadlift just treated as the defacto most fatiguing variation?

[Smokes]

I think there are a few reasons, but one I'm pretty sure of is effective range of motion matters as well. Incline vs flat bench doesn't really have a difference in terms of range of motion. Deadlift definitely has a larger range of motion than a rack pull.

[4l3x]

Where are people saying regular DL is more fatiguing than rack pulls? I find rack pulls more fatiguing (assuming same reps,sets & RPE).

The concept is not exactly to train the movement while generating less fatigue, the concept is to optimize the stimulus:fatigue. I personally find that including a small number of sets of block pulls is a great stimulus for myself. Repping something close to my max makes me feel really confident and reduces the intimidation of my regular DL 1RM. regular DL does not offer that particular stimulus, neither does a lighter variation.

Rack pulls are a worse hypertrophy stimulus:fatigue than regular DL for most people, they are quite fatiguing and eat into your training resources, however some people find that overloading a movement is a particularly potent strength stimulus for them.

Generally if I'm gonna program overload variations, they would come in closer to a meet, when the focus isn't really on hypertrophy, and it is more important to be comfortable with maximal weights.

You're right that most of the time variations improve the stimulus:fatigue ratio by reducing the fatigue (sometimes they reduce fatigue and increase stimulus) and overload variations are more fatiguing, but it's worth considering what unique benefits they may have for increasing the stimulus, possibly to the point where it's worth the training resources.

As an aside someone may be training rack pulls to target a sticking point, because they have pain with a regular DL and they're rehabbing, because they are unable to comfortably reach a bar that's at the height of a regular DL and they aren't a PL, or they hate barbells and are on a mission to warp all barbells.

[philibusters]

A smaller range of motion could lower the amount of muscle fibers worked. Compare quarter squats to full depth squats or block bench to normal bench, which are more fatiguing if done at RPE 10. I honestly don't know.

[4l3x]

I've heard that cutting ROM reduces the # of muscle fibers, but I've never looked into it, is there anything you'd recommend reading on this topic. I do think that a partial squat tends to be worse for hypertrophy than a full squat, but I mostly attributed this to less time under tension and less tension in a more stretched position. I've read a little about different muscles being used for full vs partial squats (namely the hip adductors are engaged for full squats but not really for partials), but I'd be interested if some quad muscle fibers (or even motor units) are used in full squats but not partial squats.