Breathing is important and fundamental. So fundamental you might think you're doing it right, just because you've always done it...but it turns out you might not be breathing right!
Learn the most efficient way to breathe, using your stomach, instead of breathing up into the chest. It helps you get air and helps you calm down after a workout. For people training strength, it's a good way to fill and tighten your torso.
And lastly, Traver explains the reasons behind why fighters breathe through their noses.