Earlier quoted context omitted.
That is exactly what I was saying. Those ”endorphines”, i.e. endogenous morphines, are opioid molecules and have opioid effects in the human body, including addiction, dependency and withdrawal . Some do anything for a fix. Many vehemently deny this and that they like getting high from it. Interesting that you would compare ”unnatural” food ingredients to the exercise high.
Getting addicted to exercise? Sounds fantastic.
Cardio is definitely good for you, even though it releases the same peptides. In cardio you progress by going longer.
Lifting is a different beast. In it you progress by increasing weights, because increasing reps does not gain muscle as fast. Each trip to the gym causes muscle damage, which also releases opioids, and it is completely possible to become dependent on that in the same manner that someone cutting themselves becomes dependent on the opioids released by cutting.