Your edit shows that there is no good rule for the threshold where pain would indicate too much load vs. still being in the beneficial range. We don’t even have a good way to assess subjective pain (one’s 3 is another one’s 7, etc.). “Optimal load” is really just a tautology.
"As soon as it starts to hurt" is not some hopelessly complex and useless standard that involves delving into philosophies of subjective pain sensation. It is actually obvious and easy to follow.
Use it, but when it hurts, stop.
Yeah, but given the huge variations in pain tolerance, some will reinjure it while others will never use it again.
Clearly, you have never worked in healthcare.
Sleeve tattoos but needs an IV? “Oh, I’m not good with needles, you need to sedate me first.”
> “Optimal load” is really just a tautology.
It's not just a tautology, because it correctly implies that the right amount of load is not zero.
And it's hard to expect an acronym by itself to be very specific.