I'm unsure of your past experiences and/or training. If you get a chance to read any of the books written by Lt. Colonel Dave Grossman, do so. His DVDs would probably be too cost prohibitive for an individual to purchase. But, if you have any friends who graduated West Point in the last decade, have had any advanced combat training involving effects of hormonal or fear induced heart rate, autogenic breathing, PTSD, etc., or who are in law enforcement and have recieved advanced training from Grossman, ask if they have any material they would share with you.
I can tell you this, you can run in place and do all sorts of crazy exercises and not get your heart rate over 180. But, if you are lacking stress inocualtion through your experiences and training for arrowing a deer, you can experience "buck fever" which is a hormonal induced heart rate increase of well over 200 beats per minute steady with spikes to around 250! At 175bpm your cognitive processing deteriorates, you lose peripheral vision, you lose depth perception, and you lose complex motor skills. At this point it is impossible for you to focus. You should learn how to avoid going into this condition black which is the same as buck fever, it is not difficult with proper training.
If nothing else, try these two things:
1. Realistic Simulation in Training Transfers to Reality. This is why realistic practice on realistic targets is so important as this is a Stress Inoculator. Round Targets will not do this. I repeat, round targets are not and cannot be a Stress Inoculator for arrowing a deer. This cannot be stressed enough.
2. Learn Autogenic (Tactical) Breathing. This will help you stay in the 115 to 145bpm optimal performance range. Most of the top pro basketball teams hire Lt. Colonel Grossman to teach this to their players so they can bring the heart rate down while making free throws. It is used in combat, high risk tactical environments, sports, etc. etc.
Good Luck