Good comment on type of pain. It’s important to realize that there is going to be some discomfort. Another thing is that the more a person lifts the less sore they get. The most sore I get now is when I come back from a 1-2 week vacation. My strength is always great, but that DOMS is rough.
Indeed -- those first workouts after an idle period - ouch!
The other thing to notice about pain and muscles vs joints (tendons & ligaments), is that you get good feedback from the muscles about how hard you are pushing -- the tiredness & burn -- so you can tell how you are doing. you need to go into that zone to really stimulate the muscle (but not so much or for so long that you break it down).
In contrast, tendons 7 ligaments give very little feedback until they are already damaged, sprained, pulled, etc. The first you hear about it is when you've gone too far.
That's why you need to be intelligent about loading them up when starting to work toward significant increases in previous strength!
