You don't rise to your expectations, you fall to your level of training…
Well your level of training with an adrenalized brain, and a body that has lost fine and most complex motor skills. The chemical cocktail pumping through your body cannot be accurately simulated through training. The closest that can be simulated is elevating the heart rate through cardio vascular training and artificial stress through time limits, competition, and qualification. In upcoming blog posts I'll share some ways I do this at the Dojo, and with the SWAT team, but for now try this experiment:
Do a drill / training exercise your students enjoy, are good at, and have done on a regular basis for awhile (your level of training)
Then do 1 minute of hard 100% effort exercise. Say 50 burpies or squat thrusts
Next you do the original exercise again however, before you start you announce that only the top performer / winner of the drill or training exercise will be promoted to the next kyu/grade level (or some other prize or bragging rights).
See how much your student's performance drops off under artificial stress. That is closer to the body and brain you will have in combat.