Fun fact: When your muscles experiences enough strain (but not too much), microscopic muscle damage (also known as micro tears) happen all over the affected area. These tears are a normal response to the stress placed on muscles, and actually causes you to become stronger after it is repaired. This can also be thought of as a mini-Zenkai boost, in which the base power of a Saiyan suddenly increases after they heal from a more substantial and critical injury.
Hope this motivates whatever DBZ fan reading this to get shredded.