Answer:
Muscle Build and Building a tolerance
Step-by-step explanation:
As you work out or even just moving excessively, your muscles tear in tiny amounts to heal the body sends cell to patch up that area over time the cells will just keep stacking up. This is where the tolerance comes in since their is so many cells built up its harder for them to "rip" It sounds like a huge rip but its more of a tiny little rip not even enough to hurt.(until the next day.)