Nasal breathing during your morning work session does something mouth breathing cannot replicate.
Your nose produces nitric oxide with every breath, a vasodilator that increases oxygen delivery to brain tissue by up to 18%.
Mouth breathing bypasses this entirely, reduces CO2 tolerance, raises cortisol, and lowers HRV over time.
Five slow nasal breaths before you open your first document. Nasal breathing through your first hour of work.
The cognitive shift is measurable and most people have never deliberately tried it.