I think back to last year early and remember how I felt after a lift session. I was barely feeling anything so I would (stupidly) add set after set on areas I wanted to grow, throwing 10rep set after 10 rep set on them. I always recovered and was ready for my next workout.
Now that the weights are heavier…(far from heavy), I have workouts that I do half or a third of the reps or sets and I’m crushed for two or three days.
Here is my bro science talk from my experience.
When I was weak, my muscle tissue was able to handle the demands of the weights with only minimal tissue damage. I think it’s reasonable to assume all human beings have some sort of general muscle threshold for muscle damage. Think a shoestring. All break under load but the general level is similar for most shoestring brands.
When intensity goes up and more muscle is recruited due to improved mind to muscle connections…more muscle fibers recruited it’s like adding shoe strings to the bundle. But the weights are reaching levels where no matter how many bundles are recruited there is still damage to non conditioned muscle fibers. (Too long, too short, not stretchy enough, too rigid). So the body destroys them and reconnects the damage.