Comment by deinonychus

I've wondered about that too.

My personal thoughts and anecdote, assuming you're not talking about the kind of "bro I got in a killer workout yesterday, my biceps are still sore" Delayed Onset Muscle Soreness humblebragging:

I have a controlled autoimmune disorder like arthritis that causes me some joint pain. But it basically goes away if I do regular strength training. If you do strength training or any sport long enough you'll eventually hurt yourself. Usually that's just a pulled muscle because you woke up on the wrong side of the bed and it goes away after a few days. These micro-injuries actually seem to happen to me a lot, probably because of my condition I'm just prone to this stuff. But I prefer it to the pains of inactivity.

Even for people without arthritis, you have a question to answer: which would you rather suffer from? The pains from not working, out like having a weak core and bad posture and the discomfort of being unable to climb a few sets of stairs? Or the pains from working out, like pulling a back muscle because you didn't warm up or some shin or knee pain from too much running?

The answer is obvious to me. You're going to get hurt either way. I'll go with the path that makes me feel better, live longer, look hotter, and is a rewarding challenge.