Believe it or not, playing the drum set does require controlled breathing.   No, you
don't have to take a special class to learn how to breathe.  It's just being mindful
of how you breathe as you play.  I have seen myself in the past as well as some
of my students, at times doing a beat or fill, hold their breath.  It's a great indicator
of being tense which can lead to sloppy playing.

A good way to help eliminate the tension and regain controlled breathing is to
inhale deep breaths and exhale slowly.  Perform these breathing exercises as you
play.  Start out slowly and breathe through the parts that are challenging.  This will
help you focus and relax.