That’s not how pain works. Pain is a noisy and error-prone signal that gives you a good approximation for “stop doing that.” But the edge of pain sensation doesn’t indicate what is or isn’t a good idea during recovery. It’s not a bad place to start, but everyone has different pain tolerances, some injuries are in nerve-poor areas, and repetitive stress or tendinitis are definitely not going to appreciate getting lit up right away.

I’m in PT and dealing with orthos right now, and according to them, that IS how pain works for the vast majority of ortho injuries

Sorry, which comment are you affirming?

Go until just before it hurts, which is a moving target that you will have to calibrate carefully

Would you give the same advice to someone with a chronic pain condition?

I don't know, I'm not a doctor and I'm not giving advice to anybody!

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.

> “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.

"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.

tolerating it doesn't mean you can't detect it.

no amount of pain tolerance will help you if something is broken.

you WILL feel it. simply stop when you do.

it's not a hard thing to grasp.

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.”

How is that relevant?

Perception of pain is highly individual. Like I said, people who have tons of tats will complain about an IV. You aren’t afraid of needles, you just don’t like them when they are used for your health instead of marking up your body.