Muscle pain if I don't exercise

[Livestrong7]

I want to know if anyone else experiences this and what causes it

It's pretty simple; I get a pain in my muscles (especially pecs) if I don't exercise a muscle for about three or more days it's usually a dull ache and the only thing that seems to subside the pain is to flex the muscle tightly or to hit it I would assume bc that gets the blood flowing in the muscle and I never experience it as long as I hold to my routine
I couldn't find anything similar on Google but maybe some of the bodybuilding community can relate
Relevant answers appreciated

[maximilian2000X]

Inactivity / infrequent training of a muscle causes DOMS. Try doing a set of an exercise for those muscles because it will trigger recovery. I get the same thing if I train infrequently.