4-6 Breathing for Stress Relief and Sleep Enjoy this 4-6 breathing exercise. Here's how to do it: Breathe in for 4 seconds Breathe out for 6 seconds Breathing in a slow, steady rhythm helps signal safety to your nervous system. It activates the parasympathetic "rest and digest" response. Your muscles relax and your heart rate may go down. You may even notice your mind getting quieter. With regular practice, you can feel calmer, think clearly, and drift off to sleep more easily. Should you breath