By now, most of us probably know that sleep is an integral part of our ultimate performance, whether we're on the job or not. Maybe you'll pick up some audio in the background of our dog, Cash, saw on some logs, he's fast asleep over here next to me. But let's dive into some basics of sleep on episode 34 of the Firefighter Cosmorship podcast and dive into really what do we actually kind of need to know about sleep, what are the different stages of sleep, and what do they actually mean.
What are some different things that might get in the way of all of these stages of sleep or one stage specifically. And then let's dive into maybe some routines that we can implement to make sure that we're capitalizing on our opportunities for sleep, both if you have an opportunity to sleep at work if you're on a 24 hour style work, or while you're off the job.
Welcome to the Firefighter Cosmorship podcast where we coach you to deal with the stressors of the job as a first responder, as well as how to thrive off duty. My name is Kevin Housley, a human performance coach and a firefighter since 2005. I've been able to coach over 1000 emergency responders on ways to be more resilient, better prepared for the job, and how to be happier and healthier at home. So let's get to it. So the basics of sleep.
So for most of us, we try now, we understand that, you know, when you wake up maybe five times if you're a firefighter and you wake up five get ups, it hurts the next day. It doesn't matter how old you are, it still hurts a little bit or it takes us a while to recover from on our days off.
If you're a department that works at modified Kelly where you work every other for three shifts and then get four days off, you might notice that those days in between your shift work days are just completely focused on recovery, the more that you progress in your career or based on what company assignment that you have.
Or even if you're on that 2448 schedule, you know that first day or if you're a little bit older, maybe the first day and a half or both days that you have off might be dedicated to trying to catch back up based on what happened during your tour. For some of us we work nights and so stages of sleep or circadian rhythms have actually adjusted meaning when we are trying to be asleep versus when we're trying to be awake.
And that goes against just the commonalities of how everyday life works when you're supposed to get errands done and go to appointments and all that stuff or when people are ringing your doorbell. And so there's a lot of things with circadian rhythms specifically for shift workers that we just need to be aware of. But today on the podcast, we're going to just kind of dive into super, super basic quick hitter episode, what are the stages of sleep?
And a really important thing to understand is these stages of sleep, there's four in total and they're made up of three non REM, so non rapid eye movement, sleep stages and one REM sleep stage, rapid eye movement. So four total stages of sleep and each stage lasts roughly 90 to 120 minutes. And it's really important that we need to understand that each of us is a unique beast. We are influenced by how we're made and lots of different inputs and factors go into that.
But each of us has a little bit of a customized cycle. And so we know that most people are sleeping roughly 90 to 120 minutes per sleep cycle. And an optimal number of sleep cycles for 90 to 120 minutes each, let's just call it 90 for ease is five to six full sleep cycles in a night. And we're going to kind of talk about why five full sleep cycles is really, really important. And so the old adage of, well, I'll sleep when I'm dead needs to get thrown out.
And Dr. Matthew Walker has done a fantastic job of really bringing to light from his book, Why We Sleep, of why that concept is unfortunately very, very true and it actually might speed up disease process, which could lead to a catastrophic event at the end of the day. So within the stages of sleep, we have four total stages and they're made up of three non-REM and one REM cycle total.
Now throughout the night, those four stages are going to kind of ebb and flow based on how long each stage lasts. And so when I talk about these different stages, this is kind of where that goes into play. So we start off with stage one and they're very, very creative when they name their sleep stages. So we have stage one, which is also called N1 or non-REM1. And that really lasts for one to seven minutes.
And that's, you know, sometimes you're basically kind of still awake, you know, you might still be having like auditory inputs and things that you're kind of processing somewhat of a daydream sort of state. And that can be perceived, you know, as well, I wasn't actually asleep or if you've ever been in a really riveting training session and you're like, Oh, I paid attention that whole time, but your buddies were laughing at you because your head was kind of bobbing over there.
You're probably in that stage one and one sleep. And that stage one can last from one to seven minutes. Now for those of us that maybe struggle falling asleep or falling back asleep after a call, if you're in the fire service, getting out of stage one sleep might be the big catalyst. That's kind of a barrier for us getting back to sleep as, you know, your brain might start spinning in that stage one. You can't turn your brain off and then you become conscious again. And here you go.
You're up and maybe you're visiting the fridge for a late night engineer kind of snack. So from stage one, one to seven minutes, roughly, that's when that lasts. Then we get into stage two, which N2 is what that is creatively called. And stage two can last anywhere from 10 to 60 minutes. Stage two is typically called light sleep and typically naps kind of last within stage one and stage two specifically.
So stage two is where your heart rate starts to slow down, your body temperature starts to drop and you start to get real comfortable and actually fall asleep. And so that's where, you know, if you take a catnap or something like that, you know, this could be within that stage two sleep. Stage three called N3 is where we get into deep sleep. And this is really where sleep starts to give us some really, really cool benefits that leads to ultimate performance.
So in deep sleep, we have restoration, we have bone repair, we have muscle repair, you know, and this cycle lasts roughly 20 to 40 minutes, but we have most of our deep sleep or our stage three N3 sleep at the beginning of the night. So we're going to have longer stage three sleep cycles in those first two to three sleep cycles out of the five to six sleep cycles that we go through.
Stage three is actually going to take up a larger chunk of time than some of the subsequent stages, which is really important for us to understand. So if we've been training really hard tactical fitness, really hard things like that, or we're tired, we're sore, maybe we're injured. It's really important that we have good quality, non interrupted stage three sleep, which happens in those first two to three sleep cycles in the night. It happens earlier in the night versus later in the night.
So if we are working for a fire department specifically where we're getting up a lot, you're probably entering stage two, and then during stage three, you might be getting interrupted. And so one of the problems with that is, you know, that's kind of when maybe you're waking up and it feels like somebody kicked you're right in the stones is you were in that deep restorative sleep. And it's probably earlier in the night from when you actually fell asleep.
And so sometimes this is called slow wave sleep because of how they're measuring brain waves and you're entering into Delta brain waves. It can also be called Delta wave sleep. And so that's kind of where the body is really starting to rejuvenate and recharge. And so if we are interrupting this stage specifically because of whatever your work environment is, it's harder for us to recover.
And then when you couple that with years on the job, things like hypervigilance and age specifically, it becomes harder and harder to recover overall. And this is a correlated spot to disease process on diseases that we don't necessarily want to get is because we're getting interrupted in this stage three sleep consistently. Here stage three, we go into stage four sleep, which is REM sleep. So rapid eye movement sleep and REM sleep is pretty cool. This is where we generate or solidify memories.
We process memories throughout the day. So this is really important for mental wellness that we're entering into REM sleep that we can process this. This is where our body cleans our brain in REM sleep. This is where we have most of our dreams, very, very vivid dreams. And we process learning. So if you, let's say you're training or you're studying or you're learning, you have to sleep. You can't just pull an all nighter and then hopefully you're going to retain that information.
You might pass your test, but you're not going to retain any of that information. And so the more research that comes out about sleep specifically in relation to learning, we understand that it's actually better to sleep more in a learning process. So think about this.
If you're developing curriculums for, especially for new recruits, whether, whatever, regardless of the emergency services branch that you're within, if you're developing training and things like that, how much information are you giving them throughout the day? How much are you expecting them to do after they leave the facility, whether it's class or academy or whatever you want to call it, and then how much sleep are they getting?
How much sleep is allowed based on the coursework and the course load? And are you building some of those days in where maybe they have a later start to help them process, solidify learning? Because the point of the, the fact of the matter is when we have training programs and we have training facilities and we have things like academies, the point is to learn it.
And the point is to not only learn it, but then be able to do it in a high stakes, high speed, constantly changing environment where they've never been on that exact call with that exact patient or with that exact house on fire or that exact issue in police services specifically.
So very, very important that we need to start to change the narrative on what does sleep look like for our learning environments and how do we intentionally build curriculums to allow people to be challenged, to learn, to grow, to fail, to succeed, but also to process and solidify information. And this is where sleep is so, so important. The cool thing about REM sleep is you have these crazy, if you've ever watched somebody sleep when they're in REM sleep, they have very breathing patterns.
And I'm not talking about obstructive sleep apnea where they're having long periods of time where they're not breathing at all, but they'll breathe kind of funky sometimes. And you can see their eyes fluttering back and forth or moving all over the place. They're obviously still breathing. However, in REM sleep, you actually have sleep paralysis, which is pretty wild.
And so for those of us in the fire service, if you're on the job long enough, you will absolutely at some point wake up in the middle or be woken up in the middle of a REM sleep cycle and be somewhat conscious, but not be able to move. You will be completely paralyzed. And there's this crazy little like cognitive disconnect of I'm awake. I know I need to get up and I got to get out to the bay and put on all my stuff, but I can't move. And it's pretty scary to be honest when it happens to you.
It's happened to me, it happens to me more frequently now than it used to when I was younger, but now I kind of know what's happening. And so you just kind of enjoy the ride and laugh a little bit of like, I can't move. It's freaky. I'm all right. I know what's happening. All right, here we go.
And it's usually a fraction of a second probably, but it feels like it's a few seconds for the brain and the body to kind of catch back up, especially if you've been woken up multiple times in a night and they're nice and spread out where you have the ability to get into that REM zone, really, really wild chain of events there.
And so, you know, some people talk about sleep paralysis where maybe they have a sleep disorder where they're waking up quite frequently and they have sleep paralysis and really, really scary stuff. If you don't understand what's going on. So just a rehash or we have four total stages of sleep, the first three are non REM sleep, which means we don't have the rapid eye movement. And then the fourth one is the rapid eye movement sleep and all of them are very, very important.
Another reminder, we get most of our stage three sleep in the first part of our sleep cycles throughout the night. And then at towards the end of the night, because the sleep cycle is still 90 minutes long and we're basically not going back into stage one after the first time we fall back asleep, we go back into stage two, which is that light sleep. And so REM sleep towards the end of the night is when we get most of our REM sleep.
And so if we are consistently shorting ourselves, especially when we're not at work and we have lifestyle choices that we're making like staying up and watching a movie or staying up and playing a video game or reading or whatever it is. And you are waking up four or five hours and you're not getting seven hours, six minimum, six minimum, but seven, eight is even better and optimal. You're shorting yourself on REM sleep.
And that's really, really important because REM sleep is where we process learning, we process memory, we process potentially traumatic events and we let our body clean. The brain. And so this could be correlated to pretty scary diseases that all of us in emergency services have seen when we go into some of these facilities that we certainly do not want to have happen to us. There's a lot of research currently happening to see if this is directly tied to REM sleep or not.
So something to be aware of that's why getting six, but even seven and eight hours, seven as a minimum is really what you should be shooting for. This is the reason why, because towards the end, you know, three, four, five, six is when those REM stages of sleep start to get longer and solidified for that ultimate cleaning performance function that we need sleep to accomplish.
So there's the basics really, really quickly on sleep and why it's important because it ebbs and flows throughout the night and you'll kind of, if you start wearing wearable technology, it's tracking some of this stuff for you based on which device you have. Really important thing to understand is that alcohol, even one drink impacts REM sleep. So again, REM sleep, cleaned your brain. And when we don't clean our brain, we know that bad stuff can happen. Is the simplest way to put it.
So when we drink even a single drink of alcohol, our body has to process that alcohol, but that ETOH specifically gets in the way of our body being able to enter into a full REM sleep cycle. So be very, very aware. If you just have a habit when you're not on duty and you always have a drink with dinner or you have a few drinks before you go to bed or you think that alcohol helps you fall asleep. That may be true on the surface level.
It might relax you and help you fall asleep, but you're not actually getting the full benefit of sleep because that alcohol is specifically blocking or interrupting or chunking out stage for REM sleep. Not great. So the recommendation now is a minimum of four hours between when you have your last drink and when you go to sleep. But they're talking like one to two drinks max because of how long it takes alcohol to process through the body in relation to sleep specifically.
They're not talking about seven or eight beers and then falling asleep four hours later. That's not what they're talking about because your body's still going to be processing that alcohol. So those first few sleep cycles, it's still processing alcohol and it's interrupting that REM cycle specifically. So something very, very important for us to be aware of.
So the easiest way to really kind of look at this is if you have a wearable device, whether it's a woop device, an Apple watch, ring, or a ring, whatever they're called, is to start to look at your HRV when you don't have alcohol, especially when you're not at work if you have the ability to sleep at work. But what's the impact of alcohol when you are in your home safe environment and you can control all the control balls? What about that one little factor there?
How does alcohol impact your sleep and your HRV overall? And HRV is that heart rate variability, which is measuring basically the symbiotic relationship between the parasympathetic, rest and digest, and the sympathetic fight or flight. And it is a marker that it can be used for recovery and training specifically. So a lot more content to come about HRV specifically from some experts. But for today, that's kind of the short and sweet is heart rate variability.
What's the variable between each beat in the heart measured in milliseconds and which part of your autonomic nervous system is being impacted the most? So let's dive into a little bit of routines here. So we just kind of talked about alcohol. So what are the routines that you have at home that maybe are a barrier to getting good sleep? Or what are the routines that you have at home that are a good addition to getting quality sleep?
So things that we know about sleep specifically is we want our sleep environment to be as dark as possible. We want it to be as cave-like as possible. So really trying to have no light exposure. That's why blackout shades, blackout curtains are such a great thing. And a lot of fire departments around have jumped on this, which is fantastic. They don't cost very much money to implement.
So this is a very easy solution for you to help sleeping quarters out is to put out blackout curtains, blackout shades, things like that. So cold and dark, meaning cold around 65 to 67 degrees as optimal. And you can have as many blankets as you want, but the overall environment should be cold and as dark as you can possibly get it. So there's a good solid routine. And then also limiting that blue light input. So are you sleeping?
And when you go to your bed, especially you see this in the fire service a ton and open dorm concepts, you know, the dorm might be pitch black and nice and cold. And then you have all these little teeny super computers on their phones right there in six inches from their face, just emitting negative light, which can trigger different things with our circadian rhythms, specifically neurochemicals and those sorts of things that are blocking melatonin release. It's replicating.
Oh, it's not time to sleep. That's a really, really bright light. Kind of like the sun. It might be time to start waking up. And so we've heard a lot about blue light exposure, especially from our devices up to 90 minutes before bed. So what is your routine? What's your routine at home? Are you going in your brush and your teeth and then you have a nice dark cold room and you're going to sleep and you haven't had blue light exposure for the last hour or so.
Or you have lights that are out table lamps, not lights overhead. And so it's starting to calm us down, helping with that melatonin release. Maybe you're getting outside as the sun is setting, which helps release melatonin as that sun sets that's tied into our neurology and biology of releasing melatonin based on the wavelength of light of a setting sun. And so start to kind of pay attention to what those routines are and then take those routines with you to work.
And so if you're able to sleep at work based on your work schedule, do you have the same routines or completely different routines at work? Are you staying up till two o'clock in the morning at work to have family time in the day room and watch movies and tell jokes? We're at home. Maybe you're crazy about it and you go to bed at eight, 39 o'clock at night or something like that. How do those things differ?
And can we start to create consistency in our routine regardless of the environment that we're in to start to set ourselves up for success? And over the last two episodes, we've talked about a couple of different sleep replacements or sleep aids, the first one being a yoga nidra to help us calm down basically a progressive muscle relaxation technique. And then we also talked about exploring taping your mouth to help with parasympathetic nervous system activation by simply breathing to our nose.
And so here we go. This is the tie back into why does it really matter? Well, we have these four different stages of sleep that are impacted by those external factors on things like alcohol, hydration, light exposure, um, and environmental cues of temperature and how dark is my room? So as we say at firefighter craftsmanship all the time, awareness is foundational. So just start to become aware of sleep specifically and start to become aware of what are your routines around sleep specifically?
And how can you maybe change those to level up just a little bit? A couple more fantastic episodes, longer form episodes coming up in this little series about sleep with firefighter craftsmanship. Reach out if you have any questions, happy to help. However, I can, you can find us on Instagram, Facebook, or you can hit me up at Kevin Housley on LinkedIn. Thanks for spending your quality time with us here on the firefighter craftsmanship podcast.
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