Can breath work restore CNS back to normal/optimal?

hi.

say ie something traumatic happened and now it is gone. but you had a shock and your CNS is disrupted. or let's say you're idle a lot so all that excess adrenaline can't burn. or or or, you get the point.

now, if I do breath work for hours per day, for days, and weeks, can that cause permanent restoration/changes to the CNS, BP etc? meaning if one quits after ie 12 months, is that progress lost? and is more better?