True. No pain no gain hey?
In weightlifting, the pain is there because you are using your body to push weights, till the muscles just cannot take it anymore (failure). Also the pain afterwards is from healing etc. (I am not going to get technical one bit here as you would already know this shit)
PE is different. Your not training your cock like your chest or your arms, you are manipulating it through a series of stretches and jelqing (pumping blood). If you are feeling pain whilst stretching or jelqing I would say you are doing it wrong- I wouldn’t expect to feel the same pain as in the gym!
Sometimes you will feel pain, or a dull ache, as I once did at the base of the dick. That was a sign that I was over-stretching. In PE, if it starts to hurt, you take it easy.