We can think of our bodies as literally having a fire inside. We generate energy by consuming food as fuel and then combining it with oxygen in the cells of our body. This is essentially the same chemical reaction that goes on in a fire.
It looks like this:
Our rate of breathing plays a central role in regulating this fire.
Much like any other fire, given too little air, you may smother it. Given too much you may cause it to sputter or blow the fire out.
The way this works is like so:
The breathing needs to match the amount of fuel released into the bloodstream or energy produced will be sub optimal. If not enough oxygen is taken in then this will of course mean that the fuel does not have enough oxygen to combine with to produce as much energy as could be produced. But what about too much oxygen?
Well the body is careful and does not want to let its internal fire get out of control. Much like a fire in a fireplace or stove in your home can be great for warmth, cooking and so on but you do not want to let it spread to your curtains or sofa, you body needs to keep this burning process strictly controlled and contained. Oxygen in the wrong place can do serious damage to the cells of your body. The process of burning is called ‘oxidation’. There is a reason why ‘anti-oxidants’ are touted as having such great health benefits, because unwanted oxidation ruins your cells.
To make sure that no more oxygen is let into your cells than they can handle and need for burning the fuel that they have been supplied the body actually relies on the level of carbon dioxide in the blood.
Water and carbon dioxide combine to make carbonic acid in the blood. This regulates the acidity of the blood. If the bloods acidity drops too low due to lack of carbon dioxide, then the cells are no longer able to take in oxygen as easily.
This is quite a neat control system, because if the cells need more oxygen, then they should be putting out carbon dioxide from having just burned up the oxygen and fuel they recently took in, so taking in more oxygen will be easy. The problem arises when we breathe too heavily for the level of activity we are undertaking. When we do this we tend to exhale the carbon dioxide from our lungs, drawing it out of the blood, faster than it builds up from the activity we are doing. This leads to a fall in blood acidity, and reduced oxygen uptake into the cells.
So in order to have our fire or metabolism function most effectively to support our activity, we need to find the sweet spot where we breathe in enough to provide the oxygen the cells require, but we don’t breathe so much that we blow off too much of the carbon dioxide in our blood and stop the oxygen from getting into the cells where it is needed.
This is further complicated by the fact that the way we breathe also has a significant effect on the muscle activation and structural strength of our bodies. Remember that breathing through the nose will tend to leave the postural muscles relaxed, and breathing through the mouth will tend to activate the postural muscles bracing the body more firmly.
Understanding the breathing stimulation cycle in the previous section can be useful in matching your breathing appropriately to the activity you are doing. You always want to breathe at the lowest level of stimulation that is comfortable for the activity you are doing. At rest or easy levels of exertion, this should be in and out through your nose, for moderate exertion this should be in through the nose and out through the mouth. In and out through the mouth should only be used for very intense exertion.
It is helpful also to work your way through each stage of the breathing stimulation cycle as part of your physical activity. This will help to ease your blood chemistry into the right mix for the activity level and help to make sure that you recover well afterwards. When you stoke a fire up, initially the flame may be small and will not be able to handle much wind without being blown out, but as it grows it will be able to handle more and more wind with that wind strengthening the burning of the fire. Start relaxed breathing in and out through your nose, do some sniffing to stimulate your hormones, then move to moderate activity breathing in through your nose and out through your mouth before doing very intense activity which may require you to breath in and out through your mouth, finish with some recovery breathing in through the mouth and out through the nose before relaxing into pure nasal breathing again.
Even if you only reach a moderate level of activity in which you breathe in through your nose and out through your mouth, completing the cycle and doing some mouth breathing and recovery breathing is still useful as the mouth breathing will allow the body to blow off any gaseous metabolic wastes and metabolize any hormones released during the activity. The recovery breathing will then make sure that you build your carbon dioxide levels back up to normal so that you can relax fully after you activity.
Later on in this section we will look at how these factors apply specifically to different types of activity, but first we have another structural aspect of breathing to consider…