Archive for the ‘Science’ Category

We need it the most, and we are the worst at getting it. Early lectures, late nights, long weekends, alcohol and caffeine – we are the great unslept, which is why with exams looming and an ever-growing pile of reading material I was tired, tired of feeling tired and tired of being told I was tired by very sober people who are sensible about sleep. If only there was a way to sleep less and do more that I didn’t have to buy in a bag from a man in Hackney.

What is biphasic sleep?

If you’re like 99.9% of the world, you sleep in one big block during the night. Perhaps surprisingly, then, this is not naturally how people sleep. If it were, we might expect – when looking at the body’s activity throughout a 24 hour cycle – to see a steady curve, with alertness and activity peaking in the middle of the day and respectively picking up and tailing off in the morning and evening.

This, as you have probably already experienced, is not what happens. In the middle of the day we experience a dip in alertness, usually after lunch. This is because instead of being a simple curve, our bodies follow the “circadian rhythm”; a repeating pattern of waking and sleeping, alertness and drowsiness in a roughly 24 hour cycle. And that rhythm dips pronouncedly in the middle of the day.

Why not, then, instead of fighting against our natural inclination to nap, embrace it and sleep twice a day instead? This is biphasic sleeping – the practice of breaking up your sleep into two stages to save time and energy, and a technique I got to test drive for a while first hand.

Why should I switch to biphasic sleeping?

Because, for starters, by sleeping twice a day you actually need less total sleep than you do when doing all your sleeping in one go. Our sleep occurs in cycles and each cycle lasts for around 90 minutes. The average person sleeps for 5 or 6 cycles per night (7.5 or 9 hours, respectively), but by changing your cycle, as I did, to include one medium sized block (the “core” block of 4.5 hours) and one short block of 90 minutes, not only did I feel more awake, but I was freeing up an extra three hours out of every 24. Nice.

There’s a second benefit for students switching to biphasic sleeping. Memory consolidation occurs in the first part of a good night’s sleep (which is why people often recommend revising and learning just before bedtime). By dividing up your sleep into two blocks, you can pull this trick off twice in one day, learning more information faster. This wasn’t just a way of creating more time without sacrificing academics – my work was actually getting easier.

To top it all off, if you fail to stick to the new routine, all that happens is you end up reverting to your normal sleep pattern, no danger, and it only costs a week to try out. It also feels wonderfully decadent sleeping in the afternoon.

How to switch to it?

First of all you need to figure out your timetable. For a six hour sleep schedule you’re looking at 4.5 hours at night, and 1.5 during the day. Probably the trickiest problem with sleeping biphasically as a student is finding a workable time for the afternoon segment. It doesn’t have to be exactly the same every day (an hour’s shift earlier or later should be ok), but you still need to find 90 minutes every day to get your nap on. Once you figure this out, you can make the change in under a week. Your next challenge will be getting to sleep in the middle of the day before you’re used to it. We achieve this by hacking the body’s “sleep cues”.

Sleep cues are stimuli that give our brains the message that it is time for sleep. Some of them are learned, emotional reactions (things that make us feel safe; the smell of home, the feel of our own bed), while others are hard-wired into our bodies (sensitivity to light, sound and temperature, for instance). The last three are the easiest to cheat.

When we fall asleep naturally at night (assuming we are falling asleep at a regular-ish time) the onset of sleep is preceded by a steady drop in core body temperature. This is something we can trick into making happen. When we’re exposed to intense heat or cold for a prolonged period, our bodies compensate by trying to heat us up or cool us down (this is why we shiver when cold and sweat when hot). Taking an extended cold shower will raise our core body temperatures over what they would normally be, resulting in a faster and more pronounced drop in temperature when we’re done showering. Over the course of an hour, this makes us drowsy.

The second cue we can hack is light sensitivity. Both electric and natural light sources can disturb and prevent the onset of sleep. I bought a blindfold to counter this, because my room has cheap Ikea window blinds that don’t keep out light. Perhaps the sun is less bright in Sweden.

Sound is the final sleep cue we can use to our advantage. During the daytime nap, you’re going to become acutely aware that the rest of the world is at best ambivalent toward your new sleep schedule. You could use ear plugs, but for the first few days when you’re using alarms to wake yourself up you don’t want to risk sleeping through one and having to start over.

I used a pair of sound-isolating earphones (ones with the rubber foam that expands to the shape of your inner ear) to block out ambient noise. When used with the alarm on a phone or MP3 player, they’re a good way of controlling sleep duration. Finally, I used a recording of white noise (an unchanging sound like the static you hear from an untuned radio) to drown out any noise loud enough for me to hear through the earphones. As white noise is just an unchanging drone, we filter it out and ignore it, just like we do when we’re sleeping in a room with an air conditioning unit or a humming computer.

used an application from Apple’s app store for this (called “White Noise”, if you’re an iPerson), but if you prefer you can download samples of white noise online, load them onto an MP3 player and set them to loop for the same effect (try www.simplynoise.com for free, 30 second tracks. I like “brown noise”).

Once you’ve tricked yourself into sleeping in the afternoon the first time it will keep getting easier. The end of the first week and the beginning of the second will be the hardest period you go through (the end of the initial adjustment stage) so if possible avoid caffeine and alcohol as best you can on those days (both will mess up your sleep if taken to excess, although it may be tempting).

Don’t get disheartened and fight the temptation to nap when you’re not supposed to. Make it through the first two weeks and you’ll come out perkier and with three extra hours per day to play with. Good luck.

Want more on sleep, including the schedule I followed during my biphasic month? Stop by my very new and very jazzy slacker’s blog, www.betternotharder.com. Any questions or comments on making the switch can go to richardjwordsworth@gmail.com If you’re really savvy, follow me on Twitter @rjwordsworth

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