Lower Cortisol with 4-8 Breathing. This guided breathing exercise helps lower cortisol—the body’s stress hormone—naturally and gently. By inhaling for 4 seconds and exhaling for 8 seconds, you stimulate the vagus nerve and activate your parasympathetic nervous system. This helps reduce cortisol levels, slow your heart rate, and bring your body back into balance. How to do it: Inhale for 4 seconds (through the nose if you can). Exhale for 8 seconds (gently through the mouth or nose). Let your bel