I talked about this with Ron (NWLifter) via email a few months back, but it's probably worth sharing with the class.
I think part of the reason 'high reps' in lower body lifts knock the living crap out of people is because of how they are usually performed.
Example...
In squats, deadlifts, or even a leg press, in a high rep set, people tend to knock out a bunch of reps with very little rest (maybe 5-8), and then start sucking in a bunch of wind between reps to keep going. I notice this happens to people even with 'light' weights.
In reality, the way people USUALLY perform 15 reps, then, in something like HST, is tantamount to a 15 rep rest/pause set. And for lower body work, that is BRUTAL as you can actively recover strength between reps of squats, deads, and leg presses.
What I found is that, if I knocked off the weight to an impressively girly amount, I could do 'high reps' in a continuous fashion (avoiding locking out) without having to suck in air between reps, instead breathing "naturally" throughout the course of the set, focusing in particular on exhilation.
The net effect of this was that my legs felt MUCH more on fire (impressively so), but the systemic drain on my body was also considerably less than usual. I.e. I could repeat or exceed the performance pretty easily a couple days later, even when training to failure.
So, it's the old Dorian Yates "continuous tension" principle at work here. I think this is less of an issue for upper body work, but for lower body, instead of the "usual" manner of sucking in a bunch of air between reps to hit your 15 rep target in lower body exercises, try knocking off weight and making them continuous, avoiding fully locking out the movement.
By doing so, I think you are accomplishing the "spirit" of the 15s, which is light loading but flooding the muscles with a crapload of lactic acid. Turning 15 rep sets into a form of quasi rest/pause, imho, is getting away from the point of things, and making the 15s much harder (systemically) than they have to be.
I think part of the reason 'high reps' in lower body lifts knock the living crap out of people is because of how they are usually performed.
Example...
In squats, deadlifts, or even a leg press, in a high rep set, people tend to knock out a bunch of reps with very little rest (maybe 5-8), and then start sucking in a bunch of wind between reps to keep going. I notice this happens to people even with 'light' weights.
In reality, the way people USUALLY perform 15 reps, then, in something like HST, is tantamount to a 15 rep rest/pause set. And for lower body work, that is BRUTAL as you can actively recover strength between reps of squats, deads, and leg presses.
What I found is that, if I knocked off the weight to an impressively girly amount, I could do 'high reps' in a continuous fashion (avoiding locking out) without having to suck in air between reps, instead breathing "naturally" throughout the course of the set, focusing in particular on exhilation.
The net effect of this was that my legs felt MUCH more on fire (impressively so), but the systemic drain on my body was also considerably less than usual. I.e. I could repeat or exceed the performance pretty easily a couple days later, even when training to failure.
So, it's the old Dorian Yates "continuous tension" principle at work here. I think this is less of an issue for upper body work, but for lower body, instead of the "usual" manner of sucking in a bunch of air between reps to hit your 15 rep target in lower body exercises, try knocking off weight and making them continuous, avoiding fully locking out the movement.
By doing so, I think you are accomplishing the "spirit" of the 15s, which is light loading but flooding the muscles with a crapload of lactic acid. Turning 15 rep sets into a form of quasi rest/pause, imho, is getting away from the point of things, and making the 15s much harder (systemically) than they have to be.