It depends if you are running or jumping ?
Great question!
When you understand that the person you are talking with is unable to shift his/her opinion, and starts getting mad. That's the best time to compromise, since not doing so might bring stress and conflict as you mentioned.
Answer:
"I will need to lie on my stomach during the procedure."
Explanation:
The most efficient way to eliminate waste is obviously to reduce. If we reduce the intake there wont be as much outtake.