system
Given the following post, respond as if you're commenting on Reddit:
human
How come when you work out you don't get sore till the next day?
gpt
We don't know. The term is called delayed onset muscle soreness if you were wondering though.

Our current theories are that

* high tensions (particularly those associated with eccentric exercise) in the contractile/elastic system of the muscle result in structural damage

*  cell membrane damage leads to disruption of Ca++ homeostasis in the injured fibers, resulting in necrosis that peaks about 2 d post-exercise
* products of macrophage activity and intracellular contents accumulate in the interstitium, which in turn stimulate free nerve endings of group-IV sensory neurons in the muscles leading to the sensation of DOMS.

The most commonly accepted theory is that it is due to the activities of the macrophages.