Comment by machomaster
4 hours ago
Muscle soreness is not necessary for hypertrophy, but often enough (but not always) it is a good measure of the effort/volume/weight/technique (so a proxy for the mechanical tension, the thing that we want, but it hard to measure directly).
Depends, its also an indicator of novelty, and that by itself isnt useful. Once you are used to a movement and training volume, getting sore is difficult unless you ramp up the volume continuosly.
id say, never being sore at all is maybe a sign you dont do enough for optimum results, but frequently being sore means the load is too high. And for health outcomes it probably matters less.