I used to mainly block to avoid repetition. I do all of the common facial and body ticks, panic, and get out of breath when I block. I turned 40 last year and I've just decided to stutter freely and stop worrying about making other people comfortable. So, I've started allowing myself to do repetition when it happens and I rarely block anymore. People react the same way and get uncomfortable but at least now I don't run out of air or tire myself out so much. Having a stutter isn't the problem. It's people's reaction to it.