I've noticed myself that if I take too much of an inhale for a power note, I create tension that keeps me from holding back air pressure properly (this is called breath control). Without control... your note is in trouble and so is your throat.
You need to do like Goldilocks (in the fairy tale)... take the breath that's not too big and not too little... but juuussstttt right.
Anyone out there ever recognized this problem in yourself? Do share.