Speaker A
So, we all know that a bad night's sleep can leave us groggy, irritable, and short-tempered the next day. And I know this all too well right now with a baby in the house, as I'm sure most of you
Discover how high-intensity interval training (HIIT) can protect your health from the damaging effects of poor sleep, especially for shift workers.
Key Takeaways
- Poor sleep directly causes insulin resistance and high blood sugar, increasing chronic disease risk.
- High-intensity interval training (HIIT) can blunt the metabolic damage caused by sleep deprivation.
- Shift workers and others with unavoidable poor sleep can benefit greatly from short, intense exercise.
- Exercise is a practical tool to protect long-term health when improving sleep is not an option.
- Consistent blood sugar control is essential for preventing major diseases of aging.
Summary
- Poor sleep causes insulin resistance, raising blood sugar and increasing risks of heart disease, stroke, kidney damage, and type 2 diabetes.
- Sleep deprivation keeps stress hormones high, leading to metabolic disruption and increased hunger for unhealthy foods.
- Night shift workers, new parents, and those with insomnia are particularly vulnerable to the health risks of poor sleep.
- A 2017 study showed that 2 weeks of HIIT significantly reduced metabolic damage from a sleepless night.
- Additional studies confirm that high-intensity exercise protects glucose tolerance during periods of bad sleep.
- HIIT works by improving muscle glucose uptake, helping to burn off excess blood sugar even after poor sleep.
- Short, intense exercise sessions are practical and effective for people with disrupted sleep schedules.
- While exercise cannot fully counteract chronic poor sleep, it can mitigate some of the long-term health harm.
- Maintaining good blood sugar control is crucial for protecting the heart, brain, kidneys, and overall health as we age.
- Dr. Alex shares personal experience as a former night shift doctor and emphasizes the importance of practical solutions.
Chapters
- 00:00Introduction: Impact of Poor Sleep
- 00:59Personal Experience with Night Shifts
- 01:47How Poor Sleep Affects Blood Sugar
- 02:49Insulin Resistance Explained
- 03:49Stress Hormones and Metabolic Effects
- 04:59Who Is Most at Risk?
- 05:55Health Risks for Night Shift Workers
- 06:592017 Study on HIIT and Sleep Deprivation
- 08:07Additional Research Supporting HIIT Benefits
- 09:15Why HIIT Helps: Muscle Glucose Uptake
Full Transcript — Download SRT & Markdown
Speaker A
watching this will as well. But what most people don't realize is how much damage poor sleep actually does to your body under the surface, to your metabolism, your heart, and your brain as well. What I want to talk about today
Speaker A
is one type of exercise that the research suggests can actually blunt some of that damage. And it is especially relevant if your sleep is disrupted for reasons that you can't easily change, like being a nurse or a doctor
Speaker A
in the NHS. My name's Dr. Alex. I'm an emergency medicine doctor, as all of you already know. And this one is close to home for me because I worked night shifts for many, many years, permanent night shifts. That is all I did because I was
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a locum doctor, and it paid a bit better. So, I know all too well what it's like when fixing your sleep simply isn't an option.
Speaker A
So, in this video, I'm going to explain what bad sleep does to your blood sugar and your long-term health, who is also most at risk of these things, and the exercise that can help to protect you if this is relevant to you. And all I ask
Speaker A
is that if you find it useful, if you get some value from this video today, then please support what I'm doing here by giving the video a like, also hyping the video as well, and also subscribing to the channel. It really, really does
Speaker A
make a massive difference when you guys do that, and it allows me to keep making these videos for you every single day.
Speaker A
So, let's start with talking about what bad sleep actually does to your blood sugar in particular. The evidence here is about as solid as it gets in sleep medicine. So, when you cut your sleep short, when you get, you know, just a
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few nights of bad sleep in a row, your body literally, and I mean literally, becomes more resistant to insulin. You develop an element of insulin resistance. And that is an actual fact, full stop, end of. You can trust me on
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that. To see why this actually matters though, we need to know what insulin does. So, every time you eat carbohydrates, whether that is bread or cereal or a processed snack, those carbohydrates break down into glucose, which is just sugar in your
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blood. Now, insulin is the hormone that works like a key, unlocks your cells so that sugar can leave the blood and then get burned in the cells for energy.
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But when your cells stop responding to that key, which is what insulin resistance means, when they become resistant to insulin, that sugar has nowhere to go. So, it builds up and stays high in your bloodstream. And high blood sugar is really damaging because
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sugar is sticky, and over time it injures the delicate lining of your blood vessels called the endothelium, which is the very first step on the road to heart attacks and strokes and kidney damage and type 2 diabetes. Now, the
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reason that losing sleep does this sort of damage comes down to, well, really what sleep is actually for. So, sleep is when your body repairs and resets, when your hormones rebalance, and your stress system begins to wind down overnight. So, when you
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don't get sleep properly, your body reads this as a threat, and it stays stuck in a low-level fight or flight state.
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What that means is that your stress hormones, your cortisol and adrenaline, stay high. It tells your liver to pour extra sugar into your blood while making your cells ignore insulin. So, lots of different things happen here. Short sleep also drives up inflammation and it
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pushes your hunger hormones the wrong way. So, you wake up craving the exact sugar and fat combinations that your body is now struggling to handle. So, remember a tired body is very much a stressed body and a stressed body runs
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its blood sugar really high. That is why sleep is not a luxury that you can just sort of take it or leave it. It is something that is absolutely a main pillar holding your metabolism and how your body functions together. Now,
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obviously this matters for everybody, but it's particularly relevant for people who can't simply choose to sleep more. So, I'm talking specifically about night shift workers and, you know, this includes people like police officers and nurses and doctors and, you know, factory
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staff, anybody that works overnight who has a bad sleep pattern, as well as obviously new parents and carers and anybody with insomnia for whatever reason.
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So, as I said earlier, I worked permanent night shifts for years, partly because they paid around 30% more per hour. To me, it made financial sense and it helped to save up to buy this farm and build our dream home, which is
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still not finished yet, but that's a different story. In terms of my health though, it has absolutely suffered as a result of all of those years of night shifts and I'm so glad I stopped them when I did.
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And that concern isn't just a hunch. You know, a large 2024 review pulling together 10 different studies in one big one, they found that night shift workers had around a 30% higher risk of developing type 2 diabetes than people
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working normal daytime hours. And for people on rotating shifts, that risk climbs even higher. And it makes sense because those small metabolic hits from each bad night don't just vanish, they stack up night after night, year after year. So, telling
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a busy nurse or health care assistant or a new mom to simply sleep more obviously is next to useless. What they need is something practical that they can do to offset some of the harm from the poor sleep that they can't avoid. And that's
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exactly where this particular exercise comes in. So, let me take you to the research study that actually started this entire conversation, and I'll put links in the description below for you.
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So, back in 2017, researchers ran a really interesting study with 11 healthy young men, where each man was tested under different conditions. So, he sort of acted as his own comparison.
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On one occasion, they kept him awake for a full 24 hours with no exercise beforehand. And as expected, his glucose and insulin and the fats in his blood all climbed really sharply, which is the classic fingerprint of insulin
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resistance. On another occasion, he faced the same sleepless night, but this time after 2 weeks of high-intensity interval training, just six short, hard sessions.
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And the difference was really clear. With these really hard, intense interval sessions behind him, that same [clears throat] metabolic damage from the sleepless night was significantly blunted. So, this HIIT workout that they did every day massively reduced the
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damage that the poor sleep was having on them. But the thing is that 2017 study isn't alone. In another study, 19 men had a single night of restricted sleep, which again dented their insulin sensitivity, but a session of really
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short, hard sprint intervals helped to soften that drop. And also, a 2022 review, and again, I'll put a link below for you, it concluded that exercise, and high-intensity exercise in particular, really does seem to protect your glucose tolerance during periods of really bad
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sleep. And this is obviously super important because how well you handle sugar is one of the biggest factors in whether you stay healthy as you get older. Good blood sugar control protects your heart, it protects your brain, your
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kidneys, your blood vessels, while it very slowly drives almost every major disease of aging that I talk about all the time. And the thing is, even though this is a fairly new area of research, the biology makes sense, and the
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downside of a bit of HIIT training is close to zero for most people. Just if the worst-case scenario is that the research is rubbish, doing a HIIT session a day is still going to be really good for you. Now, the reason
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that really short, hard exercise helps so much comes down to your muscles again, and it is beautifully simple.
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Your muscles, as you know, if you've watched any of these v
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to get blood into the muscles, you need insulin, which is that key that I mentioned earlier. But, the great part about all of this is that when you contract your muscles during hard exercise, or to be honest, any exercise,
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they open a completely separate door and pull sugar straight out of your blood without needing insulin at all. And that is the exact door that bad sleep cannot touch. So, even on a day when your insulin isn't working well because
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you've slept badly, a really hard, sharp burst of exercise can still drag the sugar out of your blood and burn it off.
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On top of that as well, HIIT, H I I T, high intensity interval training, it leaves your muscles more sensitive to insulin for a day or two afterwards. The effect doesn't just wear off when you stop exercising, it continues for many,
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many hours. And over time, it obviously builds your fitness, especially your VO2 max, which again, I talk about all the time on this channel, because it's one of the strongest predictors of a long and healthy life. Really, when you think
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about it, a short workout does two jobs at once. It clears the sugar from a bad night right now, and it slowly rebuilds the very system that poor sleep keeps wearing down. Now, the great thing about HIIT workouts, especially if you're a
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shift worker, or you're a shattered new parent, is that they are quick to do.
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You only need short bursts of near maximal effort with easy recovery in between. So, a session takes just 15 or 20 minutes, or maybe even 10 minutes if that's all you can manage. So, that might be 30 seconds of really hard
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pedaling on a bike followed by a minute or two of easy spinning, repeated six or eight times. Or it could be the same with sprinting up a hill or just sprinting on the flat as fast as you can
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or on a rower or even just running up a flight of stairs. The aim here, the goal really, is to be properly out of breath, really really panting during the hard parts, not just a bit warm and a bit out
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of breath. You want to be you know, like 90 or 100% of your maximum effort. And even with a chaotic schedule, like if you're a new parent or you're a doctor or a nurse or whatever, you know, anybody can slot this into their day
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somewhere. You just need 15 or 20 minutes. That is it. So, you can do it before your shift or after the school run or while the baby naps. And two or three sessions a week is all you need to
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start seeing a difference. Obviously, the more the better, but really two or three a week is, you know, what we would recommend to people who do nothing. The only word of caution here is that if you are a bit older, if you've got any
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health problems, if you're brand new to exercise, or again if you've got any heart problems at all, then build up very very gradually and get the all clear from your doctor first who knows your medical record and knows your
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medications. Now, obviously none of this means that you can out-train or out-exercise a lifetime of bad sleep.
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The exercise in the research, it looks like it can limit some of the damage, but it is damage control. It is not a cure. And sleep itself really is still the foundation that everything else is built on. Now, the usual advice with
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trying to get good sleep is obviously a dark, cool bedroom, no screens in the last hour before bed, going really easy on caffeine and alcohol, and trying to get a strict bedtime and wake time as well. But, we have to be realistic,
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don't we? Because for most of the people I'm talking to, you know, the people that this video is aimed at, the problem isn't really any of those things, and it's certainly not laziness. It's that their life simply dictates their sleep pattern, whether
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that is shift workers or, you know, somebody who's got a newborn baby or a job that just demands this way of living. So, for them, the goal should be to use HIIT, you know, interval training to limit some of the harm
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through the exercise they do during the day. And the second goal should be to try and get back to a proper sleep routine as fast as your life allows, whether that's a different job or promotion or simply your baby getting
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better at sleeping. Now, speaking for me, if I get less than about 7 hours, I really feel it the next day. So, I protect my sleep ferociously whenever I can. But, I get that it's not as easy as
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that for everybody, which is why I did this video. So, to recap what this video is about, if you cannot fix your sleep and it is broken at the moment, then that doesn't mean that you're completely powerless, and you don't just have to
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accept the damage that it brings. A few really short, hard sessions of exercise a week really does seem to shield your body from some of the harm that the poor sleep does to your blood sugar and your long-term health. So, if you are a shift
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worker or you are a new parent or anybody running on too little sleep, then start this week. Start today if you can with one short HIIT session and then build from there. And the simplest way to do that is sprinting as hard as you
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can for a minute or if you're particularly old or, you know, not used to exercise, just walking as fast as you can for a minute and then resting for 2 minutes and then doing all of that repeating it 15 or 20 minutes. You
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cannot always control your sleep, but you can give your body a powerful way to fight back and protect itself.
Topics:poor sleepinsulin resistancehigh blood sugartype 2 diabeteshigh-intensity interval trainingHIITshift work healthmetabolismstress hormonesblood sugar control
