How Breathing Affects Muscle Oxygenation, Energy Production and Endurance

3 minute read

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Summary

• A steady supply of food and oxygen is required to produce energy for exercise. The amount of oxygen getting into muscles to produce energy is a function of how you breathe.
  
• A chemical reaction involving carbon dioxide occurs in the blood, releasing the oxygen from the hemoglobin for muscle cell absorption; the Bohr Effect. If not enough carbon dioxide is available in the blood, less oxygen is released.
• Breathing small breaths during exercise is key to retaining carbon dioxide in the blood. Big breaths blow off too much carbon dioxide with each exhale.

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nergy production for physical exercise relies on the food we eat and oxygen. A steady supply of both to our muscles is required for endurance and speed.

It's probably obvious that how we breathe determines how much oxygen is available in our body for energy production. It turns out that how we breathe also governs how well oxygen is absorbed by the muscles. Now this next sentence is really important. Having oxygen available in the body does not guarantee enough oxygen will be absorbed into our muscles for energy production. Let's take a look at what's going on.

How Muscle Cell Energy is Produced
Most athletes, especially endurance athletes, work hard to increase their strength, endurance and anaerobic threshold. Once we cross the anaerobic threshold, less energy and more lactic acid is produced. 

During aerobic respiration, muscles produce energy by combining glucose, from the food we eat, with oxygen. From the glucose (one molecule) and oxygen (six molecules) union, 38 molecules of adenosine triphosphate (ATP) are produced. On the other hand, anaerobic respiration only produces two ATP molecules along with a whole lot of lactic acid. Staying aerobic is key.

Getting Oxygen into the Body is the Easy Part
Often I hear athletes say they wish they could get more oxygen into the bodies during exercise. I respond by saying, trust me you are getting plenty of oxygen, actually more than you need. 

To prove this, I ask them to exercise with a pulse-oxyimeter on their finger. A pulse-oximeter measures pulse rate and the amount of oxygen found in the blood. Even during maximum effort, most healthy athletes find their blood/oxygen saturation levels are normal, 96% - 98% saturated. They could not get more oxygen into their bodies if they had to.

The Key is Getting The Oxygen Into the Cells
Hemoglobin is a molecule inside the blood that carries oxygen from the lungs to oxygen hungry muscles and organs. Hemoglobin offloads the oxygen as needed for absorption by working muscles.

However, hemoglobin is "sticky" keeping the oxygen tightly attached; tight chemical bond. To loosen up the oxygen, a chemical reaction is required. A mixture of carbon dioxide and water, changes the pH of the blood  a tiny bit (pH change from 7.365 to 7.35), releasing the oxygen. The oxygen is now available for muscle absorption. The process of unloading oxygen from the blood and into muscles was first discovered in 1904 by Christian Bohr, a Danish scientist. His discovery became known as the Bohr Effect.

Small Breaths During Exercise is the Key
As noted, the Bohr Effect states that carbon dioxide and water must be present to release the oxygen from the hemoglobin. Now, if there is not enough carbon dioxide available in the body, only some of the oxygen is released to the muscles. When this happens, the aerobic respiration process is hindered, anaerobic respiration is turned on and lactic acid production begins.

Now here's the part most athletes usually grimace over. Breathing big breaths during physical exercise, blows off valuable carbon dioxide, making less available to release oxygen from the hemoglobin. Breathing slow and small breaths, similar to what you breathe during a walk, is essential to maintaining proper carbon dioxide levels, optimal cell oxygenation and maximum ATP (energy) production. Learning to breathe these small breathes is key to an athletes endurance and speed.

The Close
Cellular energy production is highly dependent on oxygen getting into muscle cells, which is highly dependent on the amount of available carbon dioxide. Carbon dioxide's availability is governed by small breathes not the large ones we athletes normally breathe when exercising. Retraining your breathing, making each breath slow and small even at maximum effort,  is not only possible but increases endurance and speed. How we breathe really matters.

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