# What do people colloquially mean by deep breathing? Slow, large, or diaphragmatic?


Some version of the idea of "relax, take a deep breath" is common
across cultures. But what does the "deep" in "deep breath" mean to
people? I've come across three plausible interpretations, and I'm
curious what people colloquially mean (I suspect it's a mix or
conflation of the meanings).

## Deep as in slow (low number of breaths per minute)

One interpretation of "deep" is "slow", from the idea that "going
deep" into something takes time. So, deep breathing just means slow
breathing. This is particularly relevant to somebody who's doing a lot
of breaths per minute: "relax, take a deep breath" means "slow down."

## Deep as in large (high breath volume)

Another interpretation I've seen of "deep" is "large" -- take a lot of
good air in, and expel all the bad air out. Get a fresh start by
cleansing the bad air from inside you.

The [Johns Hopkins page on
hyperventilation](https://www.hopkinsmedicine.org/health/conditions-and-diseases/hyperventilation)
uses the term "deep breathing" (in a critical fashion) equating it to
rapid, large breaths.

## Deep as in diaphragmatic

Here,
the term "deep" seems to be referring to the location of the trigger
for breathing (the diaphragm is deeper down/inside in the body
compared to the upper chest?).

This is the most scientifically "correct" definition of deep
breathing; see for instance
[Wikipedia](https://en.wikipedia.org/wiki/Diaphragmatic_breathing) or
[Harvard Health
Publishing](https://www.health.harvard.edu/mind-and-mood/relaxation-techniques-breath-control-helps-quell-errant-stress-response).

## All three?

See [this WebMD
article](https://www.webmd.com/balance/stress-management/stress-relief-breathing-techniques)
that seems to combine all three meanings: slow, large, and
diaphragmatic. A lot of breathing instruction and direction I see in
popular culture does seem to combine all three elements when using the
term "deep breathing".

## Are the meanings in conflict?

Generally speaking, diaphragmatic breathing is likely to be slower,
and slower breathing is likely to be diaphragmatic, so those meaning
are not in conflict, though they still mean different things.

However, the relationship between breath rate and breath volume is
very unclear, with any of the 2 X 2 combinations possible.

In particular, it's very much possible to take breaths that are
"shallow" in terms of breath volume, while being slow and
diaphragmatic, and in fact the whole idea of "reduced breathing" (as
seen in things like the [Buteyko
method](https://en.wikipedia.org/wiki/Buteyko_method#Reduced_breathing_exercises))
is to try to reduce total breathing volume per unit time by doing some
combination of slow breathing (reducing the rate of breathing) and
"shallow" breathing (in the sense of reduced breathing volume). In
this viewpoint, then, the "slow" part is good but the "large" part is
bad in a way that cancels out the slow part. So the ideal is "slow,
small"; both "fast, small" and "slow, large" are worse (as they mean
more breathing volume per minute), and "fast, large" is the worst
(hyperventilation at its worst.

The 2 X 2 from a Buteyko-style reduced breathing perspective (which I
believe to approximately match my scientific understanding so far,
though I'm still learning):

|      | slow | fast |
|  --  |  --  | -- |
| small | best | mid |
| large | mid  | worst |

On the other hand, if your theory of breathing is the colloquial one
where you're trying to "cleanse" yourself as much as possible with
each breath, your 2 X 2 would look like this:

|      | slow | fast |
|  --  |  --  | -- |
| small |  mid | worst |
| large | best | mid |

So I'm curious how people interpret the term "deep breathing" and how
they couple or decouple different potential interpretations!

*Thanks to [Issa Rice](https://issarice.com/) for some helpful
discussions that led me to this post. Issa did not review the post.*