How to mess with your sleep - at a whole new level

Most people work with a monophasic sleep routine ie. sleeping in a single stretch (as grandma says, 8 hours). Others prefer biphasic, where you get your one chunk at night and a nap sometime in the middle of the day - a very popular routine, with entire cultural phenomena (eg: the concept of 'siesta') designed around it.

But why one over the other? Or put differently, which is best? If you want to squeeze the maximum out of each day, consider time spent sleeping a waste, or simply have an exam coming up and syllabus to cram, read on -

Now, there is evidence that humans evolved on a biphasic or polyphasic adaptation. It would be hard to believe that our old monkey ancestors would get their forty winks at a stretch. There'd always be something or the other trying to eat you. *Not* being comatose for eight hours seems to give you a better chance to survive.

Research on napping and circadian rhythms also suggests that sometime in the middle of the day (around afternoon) there is a natural drop in body temperature - which is why sleeping *after* lunch is a good idea. You'll be sleepy anyway, might as well put it to use.
NASA's research on its trainees found that a 25 minute nap in the afternoon had the maximum positive effects on the human system. In fact, since the natural body rythm makes us drowsy seven or eight hours after we wake up, that also gives us the best window to nap - thiry minutes, seven or eight hours from the time you get up.

But that's simply biphasic sleep. It'll increase your energy levels, restore mental alertness and has a positive correlation with sustained memory. What if we could have all of that, while doing away with the one-third waste of a life associated with sleeping eight hours a day?

Behold, there *are* people nuts enough to do this. Enter polyphasic sleep, where you aren't going to get your total sleep requirement in one (or two) blocks. Your sleep requirement is dispersed over the day. In other words, you *dont* roll-over-and-get-up-many-hours-later sleep. You're awake, napping as needed. Clearly, staying up continuously and napping every few hours isn't the best way to go about this.

Enter a study which found a statistical correlation between man-made disasters, car accidents, fires and night-time sleep. That's right, boys and girls, they mapped the time of the day with the severity of loss. As you'd expect, both in number and scale, the "dead zone" period won. The time between 2 AM and 5AM is largely beyond reach for the majority of the population. People will drop off, and this needs to be accepted and dealt with accordingly. A night-out isn't the best idea for a student, and a construction worker handling heavy machinery needs to get some shut-eye during *that* time. So remember to allocate a 2 hour sleep period somewhere in that.

Also, remember that according the our natural circadian rhythm, a four-hour wake period seems optimal. Give or take a bit for individual stamina, but four hours is the most you should go without a nap if you're running polyphasic. Less than that and you won't get sleep, and more than that might make you crash for longer when you do finally get sleep.

So there you have it. Biphasic reduces your night core sleep and gets your day's total sleep to around five hours, giving you an extra two-three hours in the day and stable energy levels throughout. Polyphasic means you'll be napping for half an hour every four odd hours, which means you've cut your sleep down to under three hours in a day. If you go back to monophasic, keep in mind that most people function on a core requirement of five, so any improvement on that is a bonus.

If you're just looking for a quick fix to get through a few days without sleep, remember that sleep in humans is largely a 90 minute sub-cycle within our normal 24-hour rythm. In other words, if you need a nap longer than half an hour, plan for multiples of 90 minutes for maximum efficiency. You'll manage your sleep debt and functioning, yet save on a large chunk of time.

And now, I'm off to sleep. G'nite folks.