Or, maybe, it’s weakness leaving your mind.
Will Gadd has a discussion on pushing the boundaries of pain – especially mental pain – in order to get better at climbing.
“…but I make my best training gains when I push into areas of pain, especially mental pain, and all pain is mental.... I think embracing pain and becoming comfortable or even desiring it in training and in performance is essential to getting better as an athlete. The amount of pain someone will tolerate is directly related to the desire the person has for something on the other side of that pain…I see some athletes (and I'll use climbers as an example) get a little beaten down and then just give up and say, "take" or stop running back up the field or whatever. They then wonder why they're not progressing, why they're "training" and yet the same old level of exertion still feels hard. The reason it feels hard is that they are letting it feel hard.”