Resting Metabolic Rate Testing - advice needed.

PlunderBunneh

I have an appointment in the morning to have my resting metabolic rate tested to get a better idea of my nutritional needs.

When they called to make the appointment, I was in the car and not in a position to write down information. I recall that I'm not allowed to eat past midnight, and I'm pretty sure they said don't workout in the morning, but
A) can I drink water? I'm pretty sure I can, but I just want to be sure.
should I not do my run tonight? I had planned to run 30 minutes, but have to wait for kiddos to go to bed, so it will be late.
C) any other advice? The doc's office uses "Medgem® indirect calorimeter" to test this, anyone have any idea what I'm in for?

Thanks for any advice you've got! I feel silly, but I'm nervous about this appointment.