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good sleep, bad sleep: how to get your internal body clock on track
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if your sleep is disturbed, you are going to feel tired and groggy when you get up. but poor sleep affects so much more than simply feeling less than refreshed—it's linked to heart disease, diabetes, mood disorders and cognitive decline.
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how many of us are going outside for a walk in the morning soon after we wake up?
that’s one way to help fix the sleep-dysfunctional society we’ve become—and a practice that a family physician and sleep expert is planning to start himself to get the most out of his own sleep.
getting proper sleep is challenging, to say the least.
“our bodies are designed to sleep at a certain time when it’s dark and wake up with the light cues to be alert,” says dr. sanjive jain of thornhill, ont. he’s a proponent of habits for good sleep hygiene, and the morning walk is a great strategy to incorporate. modern living, however, stacks the odds against us.
“now with edison inventing the light bulb and then the internet and video games, kids and adults are playing video games all night and then they wonder why they can’t function during the day.”
biological programming of sleep
why exactly comes down to our biological coding. light is stimulating, acting as a signal to the brain for wakefulness, whether that light comes from a screen, a lamp or the great outdoors. “what happens biologically is that when our eyes are exposed to light, the light is processed and then the signal goes to the hypothalamus in a specific nucleus,” he explains. when light exposure goes down, the signalling releases melatonin to tell us that a couple of hours from now it’s time to go to bed, but not right away. “so when people take melatonin and they say it doesn’t do anything for me, it’s because they’re not taking it two or three hours before their desired bedtime.”
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as an overall trend, dr. jain says we have become a much more sedentary, more obese society where he sees younger individuals with sleep disorders, including insomnia and sleep apnea, that he used to see in people middle-aged and older.
our circadian rhythm is out of whack
he describes the main sleep deficit problem as circadian misalignment. our internal body clock, or circadian rhythm, is out of sync with the external environmental cues of morning light and nighttime darkness. we don’t have to be in bed by 9 p.m. but we should be winding down from our daytime hustle.
most importantly, our circadian rhythm regulates sleep-wake cycles, alertness, metabolism and hormone release, so misalignment is not a good thing. people who work shifts or get up in early darkness to commute to work are at a disadvantage, with work routines upsetting their natural circadian rhythm.
adolescents are another disadvantaged group, dr. jain says. ”teenagers actually have a delayed sleep phase because they release melatonin later, so they are not just being defiant, they want to be up late physiologically.” teens are biologically programmed to stay up later and sleep in later in the morning, although the education system isn’t designed to accommodate it. this melatonin release changes in adulthood at age 22 or 23.
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basically, though, we all have similar sleep cycles, moving through four to five cycles each night, with non-rapid eye movement (rem) sleep: n1 (light sleep), n2 (stable sleep), n3 (deep sleep for restorative processes and hormone release) and rem sleep. all phases of sleep are important, but rem sleep is often the most talked about because it plays a critical role in brain health and function. it’s responsible for memory consolidation, attention and focus.
“your first rem episode usually lasts for just a few minutes. they lengthen during each subsequent sleep cycle. toward the end of the night, you may spend up to half an hour in rem sleep.” this is when most of your dreams occur. women tend to have longer non-rem sleep duration than men and aging typically decreases non-rem and rem sleep in both women and men.
if your sleep is disturbed, you are going to feel tired and groggy when you get up. but poor sleep affects so much more than simply feeling less than refreshed—it’s linked to heart disease, diabetes, mood disorders and cognitive decline. as dr. jain says, sleep is so important that whales and dolphins, for example, have the ability to sleep with half their brain at a time because they live in a predatory environment and need to be alert.
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sleep is an active state
dr. michael mak, sleep medicine specialist and staff psychiatrist at the centre for addiction and mental health in toronto, says the science of sleep is fascinating, and there’s still so much more to learn.
“the thing i find most interesting about sleep is that it’s something that we can all relate to. we all have to do it. we spend about a third of our lives in sleep and it really ties together all of health. you can have a great diet, you can have great exercise, but without the recovery from sleep, all that goes away,” he says of actions like learning. while we study during the daytime, we consolidate our learning and memory during sleep.
what appears to be a passive bodily process is very active.
as much as we know sleep is crucial for good health, he says canadians in general are not sleeping the seven to nine hours of recommended sleep duration, with as many as one-fifth of adults aged 18 to 64 definitely not. like dr. jain, dr. mak points to industrialization and technology use at night, impairing sleep. he, too, sees more insomnia, snoring and sleep apnea, with sleep apnea often associated with overweight and obesity.
in terms of sleep cycles, after we fall asleep, we usually go from light sleep to deep sleep, which is the type of sleep that we want more of when our brain waves are the slowest and we’re most at rest. “it’s the time when our growth hormone is released. so in our younger days, we’re growing vertically. when vertical growth is complete, it’s involved with muscle and bone repair and it’s the time when the glymphatic system shuttles away the waste products of your brain. and then you go from deep sleep to dream sleep,” he says of rem sleep.
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what can we do to give ourselves the best chance of a good sleep? note the following:
- a healthy sleep routine starts with a quiet sleeping room without noise and other stimulus (like screens before bed). “if you live within a short distance of an airport, that sleep disruption from that excessive noise increases the risk of dementia,” dr. jain explains. calming practices like meditating and having a bath promote better sleep as well.
- warmer temperatures make it harder for us to achieve good sleep, so keep the room temperature lower. “we facilitate sleep by dropping temperature. our body temperature drops and is at its lowest around 3:30 in the morning,” he notes. “that’s why you feel cold in the middle of the night if you get up.”
- exercise is great for sleep, but don’t exercise close to bedtime. the same goes for eating large meals, nicotine or caffeine. “we actually tell people try to avoid any caffeine within six hours of your sleep initiation,” says dr. mak. “if you have a coffee six hours before your bedtime, you’ll still lose an hour of sleep on average compared to the version of yourself that didn’t have any caffeine at all.”
- while you can vary your bedtime to some extent if you’re out late socializing, try to maintain a consistent wake time. and use light-emitting lamps or devices upon waking to boost alertness.
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as well, dr. mak notes the connection between sleep and depression. “when the patient’s sleep gets better, then you’re looking at about three times more likelihood of having the person see improvements to their depression.” he calls sleep the vital sign for mental health. “if you have good sleep, you’re going to have good mental health. and if you have bad mental health, you’re going to have bad sleep. so that relationship is bidirectional.”
the takeaway here is that we need to recognize sleep as a top health priority.
dr. mak reflects on the misconception that sleep is something lazy and getting by on fewer hours is a badge of honour.
“there are cultural attitudes around the world that somehow, if a person is prioritizing sleep, they’re lazier, they’re less competent or they’re less productive compared to somebody else who’s willing to tough it out and not sleep, which is the farthest from the truth. the people with the best sleep have the best performance.”
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