4-count breathing is well-known as a relaxing exercise, a form of meditation, and a tactical combat tool. This is a very useful tool for runners, because it helps the body function aerobically at a very high level of performance. For those who don’t know what I’m referring to, 4-count breathing is a technique that consists of the following steps:

1) Breathe in for 4 counts until the lungs are completely full.

2) Hold breath in for 4 counts

3) Breathe out for 4 counts until the lungs are completely empty.

4) Hold breath out for 4 counts

4-count breathing is said to calm the mind, to develop “mindfulness“—which is too vague a term for me—and to control our stress response.  Although I could leave it here and say “just do it,” I prefer the long-form physiological discussion, to drive home why these things work as they do. This discussion begins with why it is so useful for people that are stressed out, those seeking contemplative states, and soldiers in combat. It is the physiological underpinnings of 4-count breathing, not its commonly-accepted benefits, that make it so broadly useful.

4-count breathing increases the synchronization of the cardiovascular system with the respiratory system and with the metabolization of oxygen. This is why:

When the diaphragm flexes, it pulls our lungs down into the abdominal cavity, bringing in air. The lungs are suddenly occupying a much bigger space in the torso—and all the blood that used to be in the torso has to move somewhere else as air fills the lungs up. And where does it go? Into the extremities.

This doesn’t seem very remarkable, except for this little fact: The reason the heart speeds up is to maintain peripheral blood pressure (in the extremities). But if the lungs are moving large amounts of blood into the extremities, peripheral blood pressure increases, and so the heart doesn’t need to beat harder to keep up the same amount of work.

Now, we all know how linked our heartbeat is to our stress response. When we’re stressed, our heart beats faster, even if we’re sitting down. Thanks to 4-count breathing, three things happen:

1) We become less stressed because blood pressure is being maintained without a rapidly-beating heart. 

2) The body learns to rely on lung expansion to maintain and increase blood pressure, meaning that we can begin to operate at very high levels of activity without a corresponding stress response, and while maintaining our tissues heavily fueled with oxygen.

3) Because the flow of blood and oxygen becomes highly predictable (thanks to the practiced periodicity of the 4 counts), the body’s cycles—which all depend on oxygen—organize themselves around this cycle of breathing.

Let’s discuss point #1. The point of the stress response is to keep the extremities properly supplied with blood in order to allow the body to fight or run away. Because the easiest and most sure-fire way of doing that is by increasing heart rate, the stress response is inextricably tied to it. For this same reason, if blood pressure is being maintained at a higher level without an increase in heart rate, the stress response will die down; its raison d’être was already satisfied. For a runner, this means that a higher muscular output can be maintained without a corresponding increase in heart rate.

Point #2 means that the body can function aerobically at a higher rate. For complex hormonal/evolutionary reasons that I’ll discuss further in the future, the stress response is also tied to anaerobic exercise. 4-count breathing increases oxygen supply, CO2 output, and it lowers the stress response, meaning that all of the important barriers to aerobic exercise have been brought down.

But in my opinion, the most interesting is point #3: Of all the organs in the body, the brain is the most immediately (and highly) dependent on oxygen (taking up to 20% of the entire oxygen supply, despite only corresponding to 2% of body weight). When a particular mechanism controls and regulates the flow of oxygen, the brain’s cycles (more so than the cycle of any other organ), become powerfully linked to that mechanism. 

Which is why it helps “mindfulness.” With 4-count breathing, we use the brain’s dependence on oxygen to link it to this consciously-controlled cycle. Once we become competent in creating this cycle, we can very quickly take control of any mental process: the brain’s neural oscilliations—our brainwaves—will fall into lockstep with our consciously-controlled oxygen supply like a little toy soldier.