By David Csonka
Anaerobic Oxygen Deficit
Anaerobic exercise is exercise intense enough to trigger anaerobic metabolism, where insufficent oxygen is available for oxidation, and the body switches over to the creatine pathway or glycolysis. As long as enough oxygen is available one can stay aerobic, the domain of more moderate or lower-intensity activities. If one is well trained though, they might be able to run at a good pace while staying in that oxygenated aerobic zone.
High intensity activities of more than a few seconds will drive up the demand for oxygen tremendously however, and if activity like this continues for several minutes (like with a CrossFit WOD or sports) then the body will dip into an oxygen deficit. In recovery, oxygen is used in the processes that restore the body to a resting state and adapt it to the exercise just performed. Scientifically speaking, the process is called “excess post-exercise oxygen consumption”, but in layman’s terms it is simply referred to as “sucking wind”.
Your body needs oxygen badly, and in general the least resistant and highest volume throughput entryway for oxygen into your body is your mouth. I always thought I was mentally weak for not holding my mouth shut through a workout, but it seems that my preference for high intensity training put me in a position where nose-breathing was inadequate for my oxygen needs.
If you recall Lieberman’s comments above, the turbulence and resistance created by our nose is incredibly useful, but this benefit diminishes when there is a corresponding need for higher-intensity work output. Ultimately, you’ll have to decide what is more important to you.
There are definitely advantages to breathing through one’s nose. It humidifies the air better, maintains a more constant air temperature, conserves moisture upon expiration, produces nitric oxide for use by the body, and helps protect against foreign pathogens.
For people who suffer from exercise-induced asthma, nose breathing can be a remarkable cure. The underlying cause of this type of asthma appears to be the large volume of cool, dry air inhaled during strenuous exercise. For many, it seems to improve when the air inhaled is more fully humidified and closer to body temperature, something accomplished by the nose.
Unfortunately, it seems that many people may have been inadvertently steered towards predominant orinasal breathing due to poorly developed facial and nasal structures. Even if staying inside the aerobic zone, the volume of air that could be pushed through our narrow noses might never be sufficient for our muscular needs. Further, my preference for high intensity training makes it even less likely that my nose will do me much good.
While aerobic training might be popular for many runners, high intensity interval training systems like Crossfit, and high impact sports like football aren’t going anywhere. People will need to accept that there isn’t one exalted breathing technique that is appropriate for all occasions. If you can sustain your activity level with your mouth kept shut, that’s great, and will probably provide some respiratory health benefits. But if you find you can’t keep pace, or tire quickly from a feeling of labored breathing, relying solely on your nose just to satisfy a romantic ideal of prehistoric runners is folly.
No matter how stoic you might be, the suffocating feeling you get is actually your body telling you that you’re suffocating. Do yourself a favor and take a deep breath – with your mouth open if need be. It doesn’t mean you’re weak, or less of an athlete. It just means you need air.