I’ll elaborate what I said previously about it boosting enthusiasm tremendously
Imagine you are going to the gym with the goal of looking better. You go there 1 month, 2 months, 3 months… and while you do look better, no one mentions it - brain be like “wtf why are we wasting time and energy then?”
and now imagine that a lot of woman that you find attractive start flirting with you, pointing out your gym progress and that you look amazing - don’t even have to have sex with them, though that’s gonna be a bonus. And the original chain of “Go to the gym → feel pain and suffering (while lifting) → get attractive woman complimenting you → feel great” turns into “go to the gym → feel great”.
I mean, working out can’t feel good by itself, it’s impossible in theory. Like imagine just going somewhere where you can spend a ton of precious energy, tear down muscles and wear down CNS for an hour and then just leave. It only starts to feel good when you see how it affects your Social/Sexual dominance or gives you more resources that you want. The brain then changes its opinion of the thing because of the dopamine and testosterone boosts that you get from the proof of becoming a better, more dominant specie
Yet you also mentioned porn and PMO, I fully agree that it’s a very negative habit.