Woke up aching after a workout? Good news — that's usually not damage. That tender, stiff feeling a day or two after exercise even has a name: delayed onset muscle soreness. It's simply your muscles responding to being challenged and getting to work, repairing themselves a little stronger than before. It's a sign of adaptation, not injury. So you don't need to stop or worry. In fact, gentle movement — a walk, some easy stretching — often eases it faster than resting completely. Do learn the difference, though: soreness is dull, achy, and spread across a whole muscle. Sharp, sudden, one-sided pain in a joint is a different story, and that's worth resting and getting checked. But that all-over "I clearly did something yesterday" feeling? Wear it like a small badge. It means you showed up, you challenged yourself, and your body is answering the call.
This is general information, not personal medical advice. If you have a health condition, or aren't sure whether an exercise is right for you, talk to your own doctor.