How does the next paragraph end?

How to pretend to be asleep
Slow your breathing.
Why do you think people look so peaceful while they're sleeping? When you're asleep, your breathing slows down slightly.
You can practice a breathing exercise to relax and slow down your breath.
Try breathing in through the nose for a count of four, and then out through the nose for a count of four. When you are sleeping, your heart rate also slows.