Breathing to Lower Blood Pressure (4-8). Breathe in 4 seconds. Breathe out slowly for 8 seconds. Slow deep breathing for five minutes has been shown to reduce blood pressure and heart rate in people who practice it. The long exhale helps activate the parasympathetic nervous system, which is responsible for lowering blood pressure and heart rate. Slow breathing can be used as an adjunct therapy for hypertension individuals to reduce blood pressure. Try the Pocket Breath Coach app for more slow br