I can only speak from limited experience but when I started back lifting (only a year ago) I went all out .... and ended up fatigued and with an injury ... basically set me back to the start and forced me to all but start over.... this time out, I am starting slow and building up progressively... too soon to tell but it certainly feels better. We will see. I believe it was Lee Haney who said " stimulate don't annihilate".
When a person reaches beyond the limits of their ability; they shall they make progress. There is no other way.