Normal respiration rate in adults at rest is
12 breaths/min. Normal breathing, as we discussed, is strictly
nasal (in and out), mainly diaphragmatic
(i.e., abdominal), slow (in frequency) and imperceptible
(or small/shallow in its volume). Scroll down for values during exercise.
The physiological and medical norm for respiratory minute
ventilation at rest is 6 liters per minute for a 70 kg man (see references for
textbooks below: Guyton, 1984; Ganong, 1995; Straub, 1998; Castro,
2000; etc.). These textbooks also provide the following
numbers for normal breathing at rest:
- normal TV (tidal volume or air volume breathed in during a single breath): 500 ml;
- normal Rf (respiratory frequency or respiratory rate): 12 breaths per minute;
- inspiration: about 1.5-2 seconds;
- normal exhalation is 1.5-2 seconds, followed by an automatic pause (no breathing for 1-2 seconds).
Respiratory Rate Chart (Graph)
This graph represents the normal-breathing pattern at rest
or the dynamic of the lungs' volume as a function of time. You can see that
it corresponds to the normal breathing rate of 12 breaths per minute.
We cannot measure our own breathing frequency or
respiratory rate since our breathing
immediately changes once we pay attention to it. We breathe slower and deeper.
Your result can be 2-3 times smaller than your real number during your basal-breathing
pattern at rest (e.g., you will count 7 breaths/min, while your actual
breathing rate is about 18-20 breaths/min). Hence, you can breathe faster
than the normal respiration frequency, but your test can show that you breathe
slower than the normal breathing frequency (12 breaths/min). This is a common
Other parameters of normal respiration
“If a person breath-holds after a normal exhale, it takes
about 40 s before breathing commences” (McArdle et al, 2000).
Hence, the normal breath-holding number (immediately after usual
exhalation and after an exhale) is around 40 s. This indicates normal
oxygenation of cells and tissues.
The current medical norm for CO2 pressure in the alveoli of the lungs or arterial
blood is 40 mm Hg. This number was established about one century ago by famous
British physiologists Charles G. Douglas and John S. Haldane (Oxford University).
Their results were published in 1909 in their article "The regulation of normal
breathing", Journal of Physiology (Douglas & Haldane, 1909).
What is known about other parameters of normal breathing? It is invisible
(no chest or belly movements), regular, and inaudible (no panting, no
wheezing, no sighing, no yawning, no sneezing, no coughing, no deep
inhalations or exhalations).
Important note. Clinical evidence suggests that respiratory rates
in healthy children are near the lower limits or even below it.
Respiration rates and volumes during exercise
During physical exercise, respiratory rate is individual and can vary from
about 30 to 60 breaths per minute, while minute volume (ventilation) can range
from about 50 to 100 liters per minute.
How to measure one's own breathing at rest?
In order to define your breathing pattern, measure your body oxygenation or
breath-holding time after your usual exhalation at rest, after 5-7 min of
sitting. Do this test only until the first stress or discomfort. After doing this CP
test, one can define their health state using the Buteyko Table
of Health Zones.
The person with normal breathing is going to have about 40 s for the body
oxygen test. In the case of chronic overbreathing, breath holding time becomes
shorter (see links to Tables and studies below).
Sick people have deep and fast breathing 24/7, as well as reduced body oxygenation
(usually about 10-20 s of oxygen in tissues). In severely sick and critically
ill patients, body oxygenation is below 10 s.
Dr. Buteyko, based on his studies of thousands of healthy and
sick people, suggested different norms for breathing (e.g., Buteyko,
1991). What are his norms? For example, his normal respiration rate
is only 8 breaths/min. Here are his numbers for normal breathing:
- normal minute ventilation: 4 l/min;
- normal tidal volume (air volume breathed in during a single breath): 500 ml;
- normal breathing rate or frequency: 8 breaths per minute;
- inspiration: about 1.5 seconds;
- exhalation: 2 seconds;
- automatic pause (or period of no breathing after exhalation): 4 seconds;
- breath holding time (after usual exhalation and without any
stress at the end of the test): 60 seconds;
- CO2 concentrations in the alveoli or arterial blood – 6.5%
or about 46 mm Hg (at sea level).
If you share this page on one of your social networks, you will find out
which exact and amazing physiological effects are commonly observed in people
who breathe at rest and during sleep (that may take months or years to retrain).
These details, which I also observed in dozens of my best breathing students,
relate to very short natural sleep and other factors.
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Buteyko KP, Method of voluntary elimination of deep breathing, Buteyko method [in Russian], in Buteyko method. Its application in medical practice, ed. by K.P. Buteyko, 2nd ed., 1991, Titul, Odessa, p.148-165.
Summary of values useful in pulmonary physiology: man. Section: Respiration and Circulation, ed. by P.L. Altman & D.S. Dittmer, 1971, Bethesda, Maryland (Federation of American Societies for Experimental Biology).