Daily Workout

Breathing – Aerobic Function

You may be able to run/bike/row… at a certain pace, but can you control your breath? Are you choosing your response to the stress of the activity (and it is a stressor) or are you just learning how to suffer? ⁠

You will notice this from now on (hopefully). Once you see it, it’s tough to ignore it. Those people walking around, sitting to eat a meal, sleeping…. with their mouths open.

Our use of oxygen is only guaranteed if those oxygen molecules are kicked off our red blood cells for use with mitochondria (the powerhouse of the cell). Our mouths offload an exorbitant amount of carbon dioxide. The way that oxygen gets to the mitochondria is when carbon dioxide molecules replace where those oxygen molecules are. The nose limits the amount of carbon dioxide that flows out. It actually allows us to absorb more oxygen (bang for buck compared to mouth) and it filters, humidifies and launches an immune response to any air that passes through it. Did you know that nasal breathing forces your body to burn fat stores? Mouth breathing burns sugar/carbs.


This is how we function aerobically. Shut your mouth when you’re not talking, or you blunt that process. We are literally shutting down basic aerobic function when that mouth opens unnecessarily. It’ll change your physiology for the better! Your mouth is there for a reason; to help in times of high stress. At no point should anyone take themselves to the point of negative response in any environment outside their level of comfort. This goes for any environment. We just shouldn’t always be in high stress training situations.

We realize there are many people whose egos will have them absolutely destroying themselves or doing irreplaceable damage. We can only give them the information and trust they will change. For the rest of us, let’s examine this deeper….


Nose (nasal) only breathing refers to backing off to the point that you can manage doing the work required to get done while keeping your mouth closed. If you continue to work harder and have not properly developed the ability to manage the more limited airflow – and there are several longer-term adaptive processes here – you can hurt yourself in the long run.


Our breath centers in the brain stem, which helps us react psychologically to your state (of mind). This is a top down game; cortex (stories/context) – limbic system (emotions) – brain stem (reactions). Our physiology responds by inhaling because of carbon dioxide (CO2) levels and pressure. This is how we get oxygen (O2) to move and get used.

We inhale O2 into the lungs. This is transported through our blood where CO2 then pushes that O2 off to be used for energy with mitochondria or to help buffer more acidic anaerobic processes. The leftover/waste of energy is CO2 and water (this is why you need to blow your nose while nasal breathing. It’s just water.). This same CO2 is moved back through circulation to help get more O2 available and also (again) triggers breath in brain stem (conscious/unconscious). Nasal breathing puts your nervous system in a parasympathetic state. In other words; it calms you down. Mouth breathing changes your state and gets you in a fight or flight state – excellent for anaerobic work like a 1 rep max or a sprint, not great for longer workouts, running, etc. If a bear is chasing you, I doubt you’ll be nose breathing!

When you are in a compromised position (aka poor posture), your ability to fill your lungs becomes limited. This is when you are tired. Your use of your diaphragm is limited. This triggers pressure sensors and limits your ability to move necessary air for efficient use of O2. This in turn compromises your ability to not only use appropriate energy systems, which compromises your reactive nature as a whole. Again, back to that brain stem and your breath. Why use 15 breathes mouth breathing when you could potentially use 10 with your nose? With training, you will get better. You will be able to do more. Isn’t this the goal – to be better every day?

The main takeaway is to try it. The more you try it, the easier it becomes. This is a practice.