A little less than two months ago, I said that I was going to try using a biphasic sleep schedule to cut down my sleep time to about six hours a day. My experiment with that schedule is over and I will share my results, since one of my frustrations with researching sleep schedules online was that people promised to start a schedule, then it seemed like they stopped for no apparent reason.
As I said, my goal was to cut down my sleep to six hours a day by splitting my sleep time into two blocks: a main (“core”) block at night for 4.5 hours and a nap in the late afternoon for 1.5 hours. This schedule is called biphasic because there are two blocks of sleep per day. Both blocks are whole multiples of 1.5 hours so I finish sleeping at the end of a sleep cycle, maximizing the effectiveness of the sleep block.
Before this experiment I was already in a biphasic schedule, but the core block was usually 7 to 8 hours and the nap ranged from 45 minutes to 3 hours. I think the most successful component of this new schedule was identifying my sleep cycle and changing my blocks around that 1.5 hour multiple. Since recognizing that cycle time, Ive noticed that whenever I wake up on my own in the morning, after my nap, or even in the middle of the night briefly, it’s almost always in 1.5 hour increments from when I drowsed off.
The attempt for 6 hours of sleep a day failed. I was tired during the day and my naps often extended into 3 hours because I was wiped out from not getting enough sleep during my core block. On weekends I slept even longer, because I was still catching up on my sleep debt. Ultimately, I loved the fact that I was able to stay up so late at night, but the trade-off was a loss of alertness and productivity the next day.
Accepting that I need more sleep, I’ve slightly adjusted my schedule and finally found a good balance. I’m still sticking to a biphasic schedule because that is what works best for me (I have always loved naps and, for me, they are an essential part of keeping my energy levels high throughout all of my waking hours). However, now my core block is 6 hours long and my nap is 1.5 hours long. I’ve found that keeping my blocks in multiples of 1.5 hours maximizes the effectiveness of the sleep.
Extending my core block keeps me awake and alert during the day at work, because I’m well rested from the night before. After work is over, I’m able to take my nap and I usually only sleep for 1.5 hours, rather than crashing hard for 3 hours. After that, I’m still able to stay up pretty late and be productive. And my total sleep time is usually 7.5 hours (sometimes on the weekends my core block will extend to 7.5 hours, pushing the day’s total to 9 hours if I’m able to get a nap in).
In conclusion, I’m still a supporter of biphasic sleep and especially of trying to time your sleeping times to coincide with the end of sleep cycles. However, you need to recognize your sleep requirements and meet them. In my case, I need 7.5 hours of effective sleep a day.
Finally, a quick note on naps. If you are able to get in that long 1.5 or 3 hour nap, you’ll probably wake up a bit groggy. That clears after 15 minutes or so, but it is called sleep inertia. Even though you have to deal with a second tough wake-up by taking that long nap, that sleep does get added to your total for the day and you’ll see a raise in energy and alertness for at least 4 hours (if you are caught up on your sleep). If, however, you are short on time for a day and suddenly find that you can’t take that nap you have been looking forward to, go ahead and take a 20-30 minute nap to recharge yourself. It won’t help much with your sleep debt (you’ll still need to make up that missed nap), but that nap will give you a boost in energy for a couple of hours.
Just don’t try taking a nap for more than 40 minutes and less than the full 1.5 hours. You’ll end up waking up with worse sleep inertia than the full 1.5 hours and it will be less effective than either of the two alternatives.