Inhale all the way to the bottom of your lungs. You maybe surprised how good it feels. I recommend doing this at least twenty times a day during this exam period. It will help you keep your sanity. The entire act of running is based on the breath.
Runners have to breathe.
Good old runner humor. But that isn't our intention. We prefer to not pass out, truth be told. Training can be soothing. The rhythm of our steps on the ground keeps us going from one step to the next.