How To Breathe Properly | Brian Mackenzie | Modern Wisdom Podcast 121

Breathing through the nose naturally limits airflow, engages the diaphragm, humidifies and filters air, and keeps you in a more efficient aerobic state; chronic mouth breathing accelerates sympathetic activation and pushes you toward unnecessary anaerobic metabolism.

A simple max exhale test after a few controlled breaths can reveal mechanical diaphragm control, physiological CO₂ tolerance, and your reactivity under stress; times under ~20 seconds indicate a highly reactive, overcooked system that needs down-regulation and recovery.

Adding 5-minute breath protocols in the morning (to focus/activate) and evening (to downshift for sleep) can improve HRV, sleep quality, CO₂ tolerance, and emotional regulation; apps like State personalize rhythms based on your responses rather than using one-size-fits-all methods.

Temporarily performing all training with the mouth closed forces your physiology to become more aerobically efficient, lowers unnecessary stress load, and can unlock better performance for strength, power, and endurance athletes once the adaptation period passes.

You can’t will your heart rate to change directly, but you can reliably lower it and shift nervous system balance through longer, controlled exhales and slower breathing; this is the fastest lever for transitioning between ‘on’ (sympathetic) and ‘rest/digest’ (parasympathetic).