Assess Recovery & Internal State With the CO2 Tolerance Test

00:00:00.000 | - Hey Brian, great to see you.

00:00:03.480 | - Good to see you, Andrew.

00:00:04.800 | - Brian McKenzie, world expert in human performance,

00:00:08.520 | breath work, AKA respiration physiology

00:00:10.700 | and its application to things related to mental health,

00:00:13.160 | physical health and performance.

00:00:14.400 | So if you're an athlete, a student, a parent, a teacher,

00:00:17.700 | or just somebody interested in the use of respiration,

00:00:20.000 | AKA breath work, in order to understand

00:00:22.800 | and regulate your physiology and psychology,

00:00:25.400 | the work that Brian does is absolutely first rate

00:00:27.840 | and important, I believe, to know about.

00:00:30.320 | Without further ado,

00:00:31.160 | let's talk about the carbon dioxide tolerance test,

00:00:33.160 | what it's good for and how to do it.

00:00:35.260 | - Yeah, well, the carbon dioxide tolerance test

00:00:38.760 | was something that we created

00:00:42.440 | kind of like it's our own little HRV, right?

00:00:45.640 | - Heart rate variability.

00:00:46.720 | - Yeah, heart rate variability screen

00:00:48.720 | without using the technology, right?

00:00:50.680 | Keeping us as the technology.

00:00:53.200 | So ideally the setting is you're either lying down

00:00:57.100 | or you're sitting up.

00:00:58.120 | It's the same thing every time you do it.

00:01:00.120 | You don't need to do it every single day per se,

00:01:02.400 | but when you first get started with this,

00:01:04.640 | that is the best bet and doing it the same way each time.

00:01:09.160 | If you don't, you're gonna be changing

00:01:11.760 | a number of the variables that could be occurring,

00:01:15.880 | much like you would do with an HRV assessment

00:01:18.320 | in the morning, right?

00:01:19.760 | So ideally you're sitting or relaxed for a couple minutes.

00:01:25.100 | You're either lying down or seated

00:01:26.520 | at the first time you're doing it.

00:01:28.280 | And then what we do after a couple of minutes

00:01:32.040 | is you would take a full inhale through the nose

00:01:35.640 | and you're going to exhale as long

00:01:38.960 | and or as slowly redundant as possible

00:01:43.480 | through the nose only.

00:01:44.960 | The reason we don't use the mouth

00:01:47.320 | is because I can purse my lips

00:01:49.040 | and I can control a lot of the variables

00:01:51.680 | that we're looking at here.

00:01:53.560 | One of those variables is a mechanical issue

00:01:56.940 | that may be occurring with,

00:01:58.660 | let's say the diaphragm and intercostals

00:02:01.200 | on the eccentric control of that exhale

00:02:04.420 | and glottal control, right?

00:02:06.340 | That goes kind of out the door if I can purse my lips.

00:02:09.020 | So people can actually extend this

00:02:11.820 | or prolong it with a mouth exhale versus the nose inhale,

00:02:16.820 | but you can get good at this with the nose exhale

00:02:19.540 | and essentially do the same thing.

00:02:21.540 | - So let me make sure I understand.

00:02:22.800 | So sit down, relax, or lie down, relax.

00:02:25.980 | - Couple of minutes.

00:02:26.820 | - Then a big inhale.

00:02:28.980 | - Full inhale.

00:02:29.820 | - Lungs full.

00:02:30.660 | And then a slow controlled exhale,

00:02:33.420 | what you're calling the eccentric portion of the breath

00:02:36.780 | through the nose.

00:02:37.620 | - Through the nose.

00:02:38.460 | - Because doing it through the mouth,

00:02:39.740 | there are just too many variables

00:02:41.820 | related to all the things you mentioned

00:02:44.700 | that can allow someone to adjust that duration.

00:02:48.120 | But through the nose, it's more objective.

00:02:49.900 | Is that right?

00:02:50.740 | - Correct, correct.

00:02:51.560 | And obviously you're gonna have a timer with you.

00:02:54.140 | So the moment that you hit the top end of your inhale,

00:02:57.260 | the timer starts and you begin to exhale.

00:03:00.800 | If you're questioning the exhale at all,

00:03:03.580 | the easiest thing to do is just to cover your nostrils

00:03:07.180 | and you should feel a slight pressure

00:03:09.380 | that's still occurring due to the exhale happening.

00:03:12.660 | You can cover the nostrils and there will be pressure

00:03:15.100 | and you can just remove them once you have the pressure,

00:03:17.260 | once you feel the pressure and continue to exhale.

00:03:20.180 | - So before we go any further,

00:03:21.600 | maybe we just try that first piece.

00:03:23.560 | - Go for it.

00:03:24.400 | - All right, so when it hits that five mark, I'll go.

00:03:28.080 | (inhales)

00:03:56.320 | All right, all right.

00:03:57.720 | - Which is actually, I mean, and your time is pretty good

00:03:59.820 | considering the fact that we're sitting here talking.

00:04:01.880 | You didn't have time to relax, right?

00:04:04.360 | That's not, I would not use this,

00:04:06.600 | even though you did that right here,

00:04:08.680 | that wouldn't be an accurate assessment

00:04:10.320 | of what your morning kinda,

00:04:11.960 | let's call it readiness would be, right?

00:04:14.800 | - So ideally I'd take that two minutes or so rest,

00:04:17.960 | sitting or lying down.

00:04:19.600 | Okay, then do that.

00:04:20.880 | The duration there for me was a little over 25 seconds

00:04:23.720 | or something on the exhale.

00:04:25.040 | I noticed that when I inhale all the way,

00:04:26.920 | the temptation is to hold my breath before I start,

00:04:29.240 | but you said you immediately wanna reverse into the exhale.

00:04:31.840 | - Yeah, you wanna start into that exhale.

00:04:33.480 | - So at a very coarse level,

00:04:34.560 | if somebody has a very short exhale time,

00:04:36.360 | let's say the total duration for them

00:04:38.960 | to get to lungs empty on that exhale is 10 seconds or less,

00:04:42.880 | versus 20 to 30 seconds, versus 60 to 90 seconds.

00:04:47.880 | What general sorts of information is that giving them

00:04:51.240 | about the state of their physiology?

00:04:53.640 | - That's a really good question,

00:04:54.720 | because what we've been able to uncover,

00:04:57.120 | and this, you know, with the help of Andy Galpin

00:05:00.600 | and his lab, for the lower scoring,

00:05:03.080 | that there is definitely a lean towards

00:05:05.920 | more of a state anxiety.

00:05:08.320 | Now, I say state for a very important reason.

00:05:11.840 | This is not a diagnosis, right?

00:05:14.160 | I am not diagnosing anxiety that is not what the,

00:05:17.200 | we're talking on a scale of arousal,

00:05:20.180 | my state is probably a little more anxious.

00:05:22.280 | So I've probably been a little more revved up.

00:05:24.440 | You just fit into that category.

00:05:26.480 | Under 30 seconds is where we start

00:05:29.520 | to fit into that category, right?

00:05:31.280 | But that would make sense for somebody

00:05:33.240 | who is more in, you know, had no practice,

00:05:36.520 | no calming down effects.

00:05:39.080 | - I've been drinking a little bit of caffeine.

00:05:39.920 | - You've been drinking a little caffeine,

00:05:41.240 | we're ramped up a bit.

00:05:42.200 | Like you didn't have any, right?

00:05:43.960 | Like, so having a lower score is going to just mean

00:05:48.080 | I'm a little bit more ramped up, things going on.

00:05:51.000 | - Sympathetically leaning, right?

00:05:53.960 | So I've got more sympathetic tone going on.

00:05:56.560 | - Some people will hear that and they'll think sympathy.

00:05:58.320 | We're talking about the so-called sympathetic arm

00:06:01.320 | of the autonomic nervous system,

00:06:02.680 | which is nerd speak for the aspect of our nervous system

00:06:06.160 | that's associated with alertness and arousal

00:06:07.920 | as opposed to parasympathetic,

00:06:09.480 | which is generally associated with states of more calm,

00:06:13.080 | sleep, the so-called rest and digest system.

00:06:14.960 | So we say sympathetic leaning for somebody

00:06:17.400 | who has a carbon dioxide discard rate of, you know,

00:06:21.920 | 30 seconds or less, it's that they're kind of,

00:06:24.000 | they're alert, they're awake.

00:06:25.240 | It doesn't necessarily mean they're having an anxiety

00:06:27.240 | or panic attack, they're just alert.

00:06:28.840 | - Yeah, I mean, if you're working out,

00:06:30.280 | you're not going to exhale very long, right?

00:06:31.880 | Like you've got a lot of buildup of a lot of things going on

00:06:35.960 | including your sympathetic nervous system and CO2

00:06:40.240 | because of the energy demand of what's going on.

00:06:43.320 | So that said, when we, with people who score

00:06:48.320 | under that 30 second mark, when applying this assessment,

00:06:53.360 | we have them start with more basic protocols, right?

00:06:57.280 | So this would just simply be more of an equal in and out,

00:07:00.560 | just working that in and out based off of the scoring

00:07:03.940 | that was going on with that.

00:07:05.840 | Then as we get up above 30 seconds

00:07:08.360 | and move into the 30 to 45 second range,

00:07:10.800 | that gets a little bit more difficult in ranging, right?

00:07:14.080 | So what we use with rhythms starts to change.

00:07:17.200 | We go to a more complex rhythm.

00:07:18.860 | Ultimately, as we get up into the higher ranges

00:07:21.980 | of the exhale assessment or the--

00:07:23.440 | - So 60 seconds, 90 seconds.

00:07:25.160 | - Yeah, yeah, getting up above roughly 60, 70 seconds,

00:07:28.520 | you're going to see your apnea protocols, right?

00:07:31.360 | These are things that are more advanced protocols

00:07:33.520 | and in fact, you would get into more

00:07:34.920 | of the breath hold work per se,

00:07:36.680 | like let's just say static apnea work.

00:07:39.560 | - Okay, so carbon dioxide blow off time,

00:07:41.720 | which means it takes X number of seconds

00:07:44.920 | to go to completely lungs empty,

00:07:46.840 | the way you described before,

00:07:48.560 | of 30 seconds or less is more sympathetic leaning,

00:07:51.600 | meaning more alert, maybe a little bit anxious.

00:07:53.960 | 35 to 45, maybe 60 seconds, calmer.

00:07:59.380 | - Yep.

00:08:00.220 | - 60 to 90 seconds.

00:08:01.040 | - You're in your normal range around 45.

00:08:02.820 | This is an absolutely normal range

00:08:04.760 | with somebody who hasn't tested, who's calm.

00:08:07.960 | That is a very normal range.

00:08:09.440 | - So 45 second discard rate would be a good goal for people.

00:08:13.400 | - Correct.

00:08:14.460 | - Okay, got it.

00:08:15.480 | So if we take a step back and we just look at this test,

00:08:19.120 | what is it good for?

00:08:20.880 | When could one use it?

00:08:22.280 | I know it has multiple uses.

00:08:23.840 | In other words, why do this test

00:08:26.720 | in order to determine one's underlying physiology?

00:08:28.880 | Is it, for instance, post-exercise as a way to determine

00:08:33.080 | whether or not you've calmed down

00:08:34.200 | and entered a recovery state?

00:08:35.660 | I know Dr. Andy Galpin's really big on this.

00:08:37.820 | He talked about it on our podcast and elsewhere

00:08:40.440 | that after a hard workout,

00:08:42.500 | it's a great idea to do three to five minutes

00:08:45.440 | of down-regulation breathing, exhale-emphasized breathing,

00:08:48.120 | or something to down-regulate meditation,

00:08:49.960 | just something to calm down, enter the recovery phase.

00:08:52.440 | I suppose one could then do

00:08:53.760 | the carbon dioxide tolerance test at the end of that

00:08:57.280 | to determine whether or not they are, in fact, calm.

00:08:59.220 | Would that be one potential use?

00:09:00.800 | - Yeah, you could implement it there.

00:09:02.920 | The easier thing would just, knowing,

00:09:06.400 | you're gonna see a much shorter assessment.

00:09:11.400 | - So people should be aware.

00:09:12.280 | What about on waking?

00:09:14.480 | When people wake up first thing in the morning,

00:09:16.360 | is it a good idea to do it in bed in the morning?

00:09:18.720 | - I wouldn't say in bed.

00:09:20.000 | I would say give it like 15 minutes, get out of bed,

00:09:22.800 | do a few things, go to the restroom,

00:09:24.720 | get some water in you, then go lie down or go sit down,

00:09:28.840 | chill out for a couple of minutes, then do it.

00:09:31.800 | - When else have you applied this?

00:09:33.120 | Like when you teach it to athletes, military,

00:09:35.240 | CEOs, high performers, is it something to do

00:09:38.480 | before they go out on stage,

00:09:41.400 | something to do mid-competition?

00:09:44.520 | What are some other applications?

00:09:46.440 | - So what I do, the application I use it for

00:09:49.240 | is to identify breathing protocols

00:09:51.580 | where that individual's at.

00:09:52.760 | Once we get good at this, once we have a rhythm

00:09:55.040 | and where I can see a baseline is,

00:09:57.440 | I stop doing it every day.

00:10:00.060 | We then apply it maybe weekly or even monthly

00:10:03.120 | based on, I give them breathing protocols.

00:10:06.320 | Based on that assessment, for the general population,

00:10:11.080 | for everybody, obviously we've got rhythms

00:10:14.280 | that are associated with that and a calculator

00:10:17.040 | that people can input to actually get those rhythms

00:10:20.560 | and to apply those rhythms for roughly three to five minutes

00:10:24.840 | whatever after they're done.

00:10:26.320 | - Hey Dozer, Brian's dog Dozer has got a giant head

00:10:31.040 | and he's a beauty, goodness gracious.

00:10:32.880 | He's got, his head's easily as big as Costello's.

00:10:35.240 | - Oh yeah, he's-- - Okay.

00:10:36.480 | So he's a nasal breather, if you notice.

00:10:38.840 | He's a calm dog.

00:10:40.000 | At this point, it's clear what the carbon dioxide

00:10:41.960 | tolerance test is and that the number

00:10:44.120 | that you get consistently over time,

00:10:45.880 | say in the morning-- - It's important.

00:10:47.720 | - Sounds like it's a good idea to do in the evening too.

00:10:49.680 | - Let's apply a scientific method

00:10:51.320 | to your own world here, right?

00:10:53.720 | And this is easy for people to do

00:10:55.120 | because we've got all the information up

00:10:56.880 | that they can actually input and go,

00:10:58.280 | oh, I've got a different protocol in the evening

00:11:00.960 | than I do at night, oh, and I'm also very different

00:11:03.800 | after training, so just using this assessment

00:11:06.400 | gives you an actual timeframe for what's happening

00:11:09.800 | and we've collected and had enough information

00:11:12.040 | to understand where you would fit inside of a,

00:11:16.000 | you know, the schema of, hey,

00:11:18.280 | whether I'm up, ramped up sympathetic

00:11:21.480 | or I'm actually more parasympathetic charged, right?

00:11:24.280 | Or down-regulated, I should say.

00:11:26.480 | - Yeah, I've found the carbon dioxide tolerance test

00:11:28.640 | just to be a great available anytime measure

00:11:32.080 | of internal state.

00:11:34.200 | And by doing it in the morning,

00:11:36.400 | and now it sounds like I should also do it in the evening,

00:11:39.280 | interesting, I mean, the whole thing

00:11:41.120 | only takes three minutes total.

00:11:43.680 | And you can just note the number in your mind

00:11:45.720 | or write it down, put it in your phone.

00:11:47.880 | It gives you this baseline evaluation

00:11:50.320 | of sort of how you're progressing through life

00:11:52.880 | in terms of managing your internal state.

00:11:55.400 | So thank you for explaining carbon dioxide tolerance test.

00:11:58.200 | - Yeah.

00:11:59.040 | - Give it a try, folks.

00:11:59.880 | It's very informative.

00:12:00.700 | It takes only about three minutes, zero cost.

00:12:02.040 | Very easy to do.

00:12:02.920 | You'll get interesting information

00:12:04.260 | about your particular physiological state at that time.

00:12:07.980 | But if you do it a few times consistently,

00:12:10.400 | you'll get really interesting information.

00:12:12.240 | And Brian McKenzie and colleagues have developed

00:12:15.420 | a terrific zero cost website.

00:12:17.600 | It's shiftadapt.com/breathwork,

00:12:21.320 | where you can take your carbon dioxide tolerance time,

00:12:24.260 | you enter it into a table there,

00:12:25.720 | and it will give you really useful information

00:12:28.480 | about certain breathwork protocols

00:12:30.600 | and how to do them specifically.

00:12:32.120 | The duration of inhales, breath holds, and exhales.

00:12:35.320 | Again, that's completely zero cost.

00:12:36.600 | So a terrific resource.

00:12:38.080 | Thank you, Brian, for providing that resource.

00:12:39.760 | Shiftadapt.com/breathwork is where you can plug in

00:12:43.780 | your carbon dioxide tolerance test results

00:12:47.240 | and apply those to improve any aspects

00:12:49.760 | of your mental health, physical health, or performance

00:12:51.640 | that you're interested in.

00:12:52.940 | [BLANK_AUDIO]

Assess Recovery & Internal State With the CO2 Tolerance Test | Brian Mackenzie & Dr. Andrew Huberman

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