So after a while of pushing my register up i have noticed it has become easier (yay for practice). But have noticed my emouchere has changed a little (quite un-conciously) and im getting a real burn on my surrounding mouth area not quite my lips. I reckon this is my muscles. My question is how long should i hold the burn? Until i cant no more, or, just take it easy and rest intermitantly? Main reason for asking is i obviously want it to develop but not burn out or do hindering damage? Thanks, that is all.