Taking a few deep breaths before you begin your meditation can trigger a relaxation response, which is essentially the opposite of your nervous system’s fight or flight response. When the fight or flight response is triggered, the body gets ready for danger, but when the relaxation response is stimulated, the body begins to feel safe and at ease.
Then, as you start the meditation, your breathing should return to a normal rate. Paying attention to your breathing will be important throughout the meditation, and this type of mindful breathing can lower stress levels in the body.