Life in the Fast Lane

Why do we breathe harder and faster when we run quickly?

The laws of nature demand that for your body to do anything requires that it have enough energy to do it.  Your cells get the energy they need by releasing it from the glucose molecule with the help of oxygen and about twenty other specific molecules in a process called cellular respiration.  At complete rest, your body uses a basal amount of energy to keep its organs working.  But, just like a car racing up a hill uses more fuel than when it's sitting still, so too, when you're running quickly your body must use over ten times the amount of oxygen than what it uses at rest.  So, to get that much oxygen into your body you have to breathe harder and faster. 

How your body knows when to make this adjustment in breathing so you can do what you want to do is poorly understood.  However, scientists think that it involves, not only using sensors in the main arteries leading to, and within, your brain to monitor the blood levels of oxygen and carbon dioxide while you run, but also within your muscles to detect their level of activity and certain chemicals produced by their metabolism. 

The information from these sensors is sent to the respiratory center which in response sends out stronger and more frequent signals through the spinal cord and motor nerves to your muscles of respiration.  You then begin to take in bigger and faster breaths by using your diaphragm and rib muscles and even your neck, shoulder, back and other chest muscles as well.  When you do this you're able to bring in over ten times the amount of oxygen than you can when you breathe more slowly at complete rest.  The oxygen travels down the airways of the lungs until it reaches the alveoli, the grape-like sacs surrounded by hundreds of capillaries, where it enters the blood and most of it is sent to the heart and the muscles so you can keep running. 

So what you experience when you breathe harder and faster while you run is the respiratory center using information about your blood levels of oxygen and carbon dioxide and muscle activity to make sure you breathe hard and fast enough to stay in the fast lane. 

Three Questions for Mr. Darwin

1) Where did the information come from for my body to know how to make my lung capacity large enough, and my respiratory muscles strong enough, for me, and all those who came before me, to run quickly enough to survive?

2) Where did the information come from that not only told my body how to make the sensors in the muscles but also to place them exactly where they’re needed so the respiratory center can know when to make me breathe faster, and how do they work? 

3)  How does my respiratory center know how hard and fast I should breathe to run quickly (or do any activity) and where is the information stored that tells it when and how to get this done? 


Also see Dr. Glicksman's Series on

"Beyond Irreducible Complexity"

"Exercise Your Wonder"

Howard Glicksman M. D. graduated from the University of Toronto in 1978. He practiced primary care medicine for almost 25 yrs in Oakville, Ontario and Spring Hill, Florida. He now practices palliative medicine for a Hospice organization in his community. He has a special interest in how the ethos of our culture has been influenced by modern science’s understanding and promotion of what it means to be a human being.


Copyright 2017 Dr. Howard Glicksman. All rights reserved. International copyright secured.