There are many things that will keep you safe while performing stage combat. The most important is breathing.
This may sound elementary, but pay attention to your breath the next time you are in a stage fight. In our attempts to add tension or to focus on parts where we are unsure we direct energy away from breathing for a temporary boost.
Obviously you need to breath to keep doing physical activity. Hold your breathe long enough trying to look intense and eventually you will become light headed or pass out. Neither is good on stage.
Lesser known are the other sacrifices your body makes to compensate. The following information is paraphrased and based on the facts in the book On Combat by Lt. Col. Dave Grossman:
Controlled breathing can keep your heart rate down during activity. Under normal physical stress a normal elevated heart rate isn’t a bad thing. We simulate emotional stress from violence. Most of the time our heart rate escalates before we have even begun to fight because of the emotions of the scene.
Under this type of stress the body starts shutting systems down to defend itself. Once you pass 115 bpm you start to lose fine motor skills. Fine hand movements and parts of speech begin to break down. Past 125 bpm you start to lose larger muscle coordination/accuracy. Past 175 bpm all hell breaks loose. At that point you are basically a clawing, grunting, animal.
If you don’t breathe your heart rate jumps up a lot faster. Keep control, keep your heart rate in “mellow yellow” between 115-125 bpm.
Breathe or Die.