I believe women use the shit test for the same reason we carry heavy weights in a gym to test PR: to test our ability to protect them.

When a woman gives you a mild shit test, its like you using your muscles to carry a weight. If your muscles cannot carry that weight, you know it is weak. If you lose your shit test to the woman, she loses attraction.

Of course when a woman gives you a nuclear shit test it's on YOU to fuck her off. Much like you shouldn't be attempting to squat 500lb if you know you can't squat 350lb and your last PR was 300lb. It's on you to leave her within a heartbeat, just like you leave that 500lb barbell alone and not pick it up to squat it because it will crush you.

Men do not have the luxury of being able to go to a hospital or muscle factory to change their muscles for better ones. Men have to create the better muscles by working out diligently and lifting heavy. Women believe in hypergamy: being able to swap an inferior man for a superior one. Women do not believe in training the man the way a man trains his muscle. This is a core principle of TRP.

If you think you can squat a little more than 300lb (and your last PR was 300lb), you rack the plates on the barbell to total >300lb and then carry it with your back and see how much you can squat. If she thinks you can protect her, she shit tests you.

If you are able to squat it, you celebrate. Your muscles can carry that 300+lb once. If you pass her shit test, she likes you more.

If you are unable to squat it, you fail properly like a gym man who failed his squat safely and you go back to training. Your muscles are unable to handle that weight and are too weak for say 320lbs.

If you are unable to pass her shit test, your attraction decreases in her eyes and she soon looks for another male.

The woman shit tests you for the same reason you test your PR: to test your/the muscle's ability to protect her/you when need arises.

You have to be able to pass it to continue being attractive. Muscles are just the passive part, as men we also have to master the active part.