By Brian MacKenzie, Jason Donaldson and Rachael Colacino
The Bohr Effect was first described by Danish physiologist Christian Bohr in 1904. In very simple terms, it says that if one takes in enough carbon dioxide, oxygen can be used more effectively throughout the body. Bohr discovered that your blood, or more specifically your hemoglobin’s ability to bind oxygen, is inversely related to acidity and the concentration of carbon dioxide in the blood. So your blood releases oxygen when in the presence of carbon dioxide.
According to Bohr, the lower pH, caused by an increase in carbon dioxide, will cause your blood to deliver more oxygen to your muscles.
Experiments by the Art of Breath Team
Our breath work started with experiments using the training mask, which worked well to stimulate the diaphragm to become more connected to breathing. The Training Mask works by resistance, and trapping some of the air when exhaling, and carbon dioxide (CO2) is in part also trapped, signaling us to breathe more deeply and creating more of a need for air of poorly adapted. It also showed to have a great influence on motor control as well, teaching many athletes how to set up mechanically better than they were. This experience inevitably pushed us to explore many other things surrounding the pulmonary / respiratory systems.
History with several “methods” in Yoga, Tummo, Wim Hof, Buteyko all lead to very similar things. We started to find a pattern: higher levels of CO2 tolerance seem to be indicators of healthy physiology. Not just a great AErobic or ANerobic threshold, muscular power or endurance, mobility, or inactivity. Most of us seem to be fairly CO2 intolerant to a large degree, meaning we can’t handle a healthy (> 5% CO2 in the lungs) dose of CO2 that actually optimizes that O2 “infusion.” This also forces more of a hyperventilation to not only our work, but throughout the day. When we exercise, our oxygen levels fluctuate between 95 and 99 percent; those are the optimal levels to release oxygen into the system. If you’re performing super ventilation practices and using a pulse oximeter to measure your oxygen saturation, you may see your oxygen concentration measured at 100%. Unfortunately, that oxygen isn’t available to your cells. It hasn’t been released if it’s at 100%. Over-breathing & deep breathing can cause too much carbon dioxide to be removed from the blood, tissues, lungs and cells as the hemoglobin holds onto the oxygen. You may have a high oxygen saturation level, but it’s not where it’s needed most. Instead, optimal seems to be between 95%-99%, but that’s not the entire story.
If we are CO2 intolerant, we may have a chronic “hyperventilation” issue that is blowing off excess carbon dioxide, all day. We may also be able to correlate carbon dioxide tolerance with eating habits, respiration, how our body breaks down, and disease; the lower your tolerance, the more susceptible we are. We can also see carbon dioxide intolerance in people who exercise, who huff and puff when they work out. They may not be absorbing oxygen well either.
Experiments in Nasal Breathing
We’ve been playing with the concept of nasal breathing a lot lately, and it’s been a tremendous catalyst in showing us how efficient and inefficient we are. When we train with nasal inhales and exhales only, switches start to flip. Our body becomes more efficient at working harder through nasal breathing, whether we’re walking or running or lifting. We’ve seen increased efficiency and faster recoveries, in part because respiration is now slowed, and due to the higher levels of CO2 in our systems which allow our bodies to recover more quickly.
There are side effects as well: less heavy breathing, calmer beings, better sleep. Overall we are becoming less sympathetic dominant creatures. The transition has been awe-inspiring in that we can see how if you overuse any of your body’s systems, you become inefficient and less likely to recover. We see how important sleep becomes, how important it is to not overreact, not to stress, to avoid anxiety. These are all amalgamations of a sympathetic-dominant existence. Which, although some of us are wired to be more sympathetic, it’s learning to down regulate (parasympathetic) more efficiently that becomes the more important piece of our autonomic nervous system.
We’re certainly not devoid of that sympathetic stressed state in athletics. If we’re constantly worried about mile splits or the weights we’re lifting, it has an effect on everything we do. It’s self-sabotage. Focusing on our breathing helps us understand that no matter how else we fuel our bodies, we need to use CO2 properly. The chicken or the egg concept plays out here too, but the fact is if we actually apply some of the principles (not to be confused with methods) we can hack the basic foundation of an ill adapted system just through breathing.
Experiment on Yourself
How do you know whether your body is using carbon dioxide and oxygen efficiently? One way is the exhalation breath hold: hold your breath until you feel the first sensations of having to breathe again. How did you do?
- A score of below 10 secs is a problem. It means your ability to retain CO2 is very low.
- A score of 10-20 secs is pretty normal these days, but as we now know, that’s not a good thing.
- 20-30 is getting better and you’re above average.
- Efficient breathers have a score of over 40 secs. That’s the goal. Get your exhalation breath hold score above 40 secs.
In a previous blog we discussed using nasal breathing only as you begin your workout, to warm up your pulmonary system along with your cardiovascular and muscular systems. The next step would be attempted to use nasal breathing during your workout for as long as possible.
Try the CO2 Tolerance Exhale Test
Check out our CO2 Tolerance Exhale Test, where you take a 5-minute, at-home assessment that measures your CO2 Tolerance. Based on your results, you will receive a customized breathing plan to help improve your CO2 Tolerance!