Recently my colleagues and I were talking about the efficiency and benefit of mouth breathing vs. nose breathing and if there is a difference based on the sport an athlete plays. What is the oxygen consumption of nose vs. mouth? Does anybody have any input or research to back either one up?
Those are two excerpts (with the references) from "A Course In Breathing" that I created last year.
MSc Strength Coach.
Inhalation through the nose filters and warms up or cools the air inhaled. Inhalation through the nose also tends to slow down the inhalation, because the air is ”sucked” through a pipe with a smaller diameter compared to inhalation through the mouth. The reduced speed of inhalation supports relaxation. A second effect of the smaller diameter is a strengthening of the inspiratory muscles, especially in breathing techniques that include a fast inspiration through the nose. Further, inspiration through the nose is coupled to an increased downward movement of the diaphragm compared to inhalation through the mouth. (21)
It is recommended to breathe through the nose for as long as possible during any type of endurance event and only breathe through the mouth in situations with extreme demands for oxygen.
During exercise an individual really doesn't have a choice, with increasing oxygen demand, the brain will signal the individual to breathe through their mouth.
The following is from Exercise Physiology: Nutrition, Energy, and Human Performance (7th Ed) by McKardle, Katch, and Katch pg 264
"Conscious manipulation of breathing usually disturbs the exquisitely regulated phsyiologic adjustments to exercise. Attempts to modify breathing during running or other general physical activities off no benefit to exercise performance. During rest and all levels of exercise, a healthy person should breath in a manner that seems most normal."
I think that it is quite self evident that at low to moderate intensities and within certain durations of activity athletes DO have a choice to breathe through their mouth or their nose. Then, at certain intensitites and durations the oxygen demand requires breathing through the mouth - there is no longer a choice, if the athlete wants to keep up the pace.
McKardle, Katch and Katch are to my knowledge a great and reputable book, however in my experience, most athletes DO NOT breathe in an optimal manner unless they are taught.
- Almost any athlete breathes paradoxically during rest before they are taught.
- Almost no athlete optimally uses the diapragm to create an optimal intra abdominal pressure during lifts. I can nearly always cue athletes to instant increases in strength through proper breathing techniques.
In 20 years, I have seen maybe a handfull of athletes not needing to be taught how to breathe. Those were the same athletes who became world champions.
It is interesting to note that on this particular topic, McKardle, Katch and Katch - this science based book - do not offer any evidence to support their three claims??????
You stated that breathing through the nose "warms up or cools" the air inhaled, which is it. It probably depends on ambient air temperatures, but even at pretty extreme temperatures regardless of whether you breath in through your nose or mouth the air is normalized to a tempurature that optimal gas exchange at the alveoli.
You stated that inhalation through the nose slows down the inhalation, and supports relaxation. This is fine at rest and low intensity activities. But inadequate at higher intensities, and why would you want to think about your breathing pattern during a run or when playing a sport? This is why we have a centeral nervous system that can offer outstanding subconscious control of systems.
The article you cited after these statements has nothing to do with breathing during exercise and if you look it up on pubmed it states that the article is in Japanese. (Maybe you speak Japanese?)
Next you state that one shoudl breath through the nose as long as possible during endurance activity referencing, "Mind-Body Breathing. Body, Mind, and Sport" by Douillard. Does Douillard have rigorously tested scientific evidence that shows that this breathing pattern enhances performance? I believe the evidence in McKardle, Katch, and Katch is the neurological control of the cardiopulmonary system.
Where is "optimal" breathing defined? How do you evaluate or assess if they have "paradoxical" breathing".
The original question was not about the control of breathing during the development of force but rather during activity, which is ultimately centrally controlled. Its well established that proper breath holding increases spinal stability and may have a strong effect on the development of force. Of course this is simply not a function of simply breathing or diaphragm alone, but rather the development of tension in many muscles throughout the abdominal wall and the entire body. And for most people this is a natural phenomenon. Research by Hagins and Lambert published in 2006 in the Eurpean Journal of Physiology titled "Natural breath control during lifting tasks: The effect load", found that untrained individuals naturally altered their breathing in a task dependent manner. Inspired air volume and breath holding increased as subjects lifted heavy loads. Though I will note that other research has found that breathing patterns and associated muscle activity MAY be altered in SOME individuals with lower back pain.
You note that you "can nearly always cue athletes to instant increases in strength through proper breathing technique". Pretty neat. If I ask someone to open a pickle jar lid that is stuck very tightly they breath in, bear down, and tension many muscles throughout the body to increase force. I don't even have to cue them, its natural.
Breathing can be conciously altered in a task dependent many. Olympic lifters, Powerlifters, martial artists in particular use breathing and muscular contraction and relaxation patterns to achieve different tasks.
I thought you made some statments that were not nearly relevant to the original question and that had very little scientific support in relation to exercise. I do not know you, but I respect you professionally. You appear to be very well educated and you have a wealth of experience in training people. If someone offers a viewpoint that differs from yours simply provide more strong supporting evidence for you viewpoint.
Thank's for the comment about my education - I respect you too! I will try to answer your questions briefly and then we can probably agree to disagree on this particular topic :-)
This is fine at rest and low intensity activities. But inadequate at higher intensities, and why would you want to think about your breathing pattern during a run or when playing a sport? - achieving optimal tension (not to low or not too high in sports like tennis). To achieve that aim most will exhale, maintain some IAP at the point of impact.
Research by Hagins and Lambert published in 2006 in the Eurpean Journal of Physiology titled "Natural breath control during lifting tasks: The effect load", found that untrained individuals naturally altered their breathing in a task dependent manner. Inspired air volume and breath holding increased as subjects lifted heavy loads. ..I think that is an important study and it corresponds, I think, to most coaches observations in the gym. However, the fact that the subject changes their breathing patterns does not mean that it is optimal (=resulting in optimal stability and maximal strength with minimal increases in blod pressure)
Does Douillard have rigorously tested scientific evidence that shows that this breathing pattern enhances performance? Yes - unless he is misinforming the reader.
The article you cited after these statements has nothing to do with breathing during exercise and if you look it
up on pubmed it states that the article is in Japanese - You are right, it is not a study about exercise. I originally assumed that it was the case in exercise as well. I have worked more with strength training than with endurance training and I find that inhaling through the nose, results in more strength and stability (as per athlete feedback and lifting performance).
How do you evaluate or assess if they have "paradoxical" breathing" = chest breathing (as defined in most yoga books)
If I ask someone to open a pickle jar lid that is stuck very tightly they breath in, bear down, and tension many muscles throughout the body to increase force. I don't even have to cue them, its natural. ...I agree, every one will tension more muscles, but it does not mean that by being cued, they could not have done it better.
I appologize, if you felt I made comments not relevant to the discussion.