Ok so I finally, after a few years, had a revelation and realized that I'm a huge idiot. I gas out terribly when I'm throwing punches, etc during classes. My face is beet red after just 15-30 minutes and I lose all of my energy. I'm not exhaling while striking. At all. In fact I tighten up my whole body while holding my breath. Then after throwing a combo I take a huge breath in before repeating. This is probably bad. The whole not getting oxygen efficiently deal. What do you guys do? I know a lot of boxers make a "sssstt" sound in order to exhale but I'm not sure what to do. I try to breathe out of my nose most of the time but my nose/sinuses are.... narrow, tight, I don't know. It's a physical problem that is just my genetics/biology. Basically it's more difficult for me to breathe out of my nose at all times. Any advice?