Uploaded February 2026 | Updated September 2026, 2 weeks ago

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I break down the real science behind nose breathing, why your body is literally designed for it, and when it's actually okay to breathe through your mouth once a while

In this video, I cover:

- Why nose breathing helps your lungs absorb more oxygen
- How diaphragmatic (horizontal) breathing reaches the most oxygen-rich part of your lungs
- The built-in filtration system inside your nasal cavity
- How nose breathing produces nitric oxide, a natural vasodilator
- Why mouth breathing can lead to crooked teeth, bacteria buildup, and more
- The vagus nerve connection to lower cortisol and blood pressure
- Why 500 mouth breaths a day won't hurt you (according to scientists)
- How inspiratory muscle training makes your nose breathing even stronger

I also tackle the common criticism that the O2 Trainer promotes mouth breathing and explain why that argument doesn't hold up.

Check out the O2 Trainer: o2trainer.com
Watch my vagus nerve video: youtu.be/3g5kJGKJEGg?si=woFZEu2u6EoLWZRW.

Visit the official Bas Rutten website: https://basrutten.com.