4-8 Breathing: Lower Pulse Rate Immediately (when elevated from stress or exercise) The 4-8 breathing technique is a powerful "down-regulation" tool. By making your exhale exactly twice as long as your inhale, you prioritize the parasympathetic nervous system, which acts as your body’s natural brake pedal. This helps many people lower their pulse rate when it is elevated from stress or exercise. The Flow: - Inhale (4s): Breathe in slowly through your nose. Feel your belly expand. - Exhale (8s):