biphasic sleep - Could it help me?

[Gia]

Hello everyone,
I work a crazy schedule and always find myself short on sleep. I get up a 2am to go to work and return home around 11am. I work a second job from home that is very flexible. I average about 5 hours sleep a night, and come home from work exhausted(very labor intensive job). Most days I don't nap since it always makes me feel groggy for the rest of the day, but I realize that I need to change something since I am tired all the time. I also don't work weekends and find my self sleeping up to 12 hours on Friday night, and pretty much a zombie all weekend. With both jobs and a family I really need to get on a better schedule that gives me more energy. I have read through all the information about biphasic sleep but haven't found anyone that works the hours I do. It seem most people are getting their core sleep when I am off to work, and napping when I am going to bed. Could this work for me?

[Kaspian]

I don't see any reason why you couldn't sleep earlier at night, perhaps 9:30pm-2am, and take a nap sometime during the day, possibly at 11am when you get home. Stick to the schedule even on the weekends, and if you still feel tired after a week or two, try adding a second nap in the late afternoon.

Nap Length: I wake up more alert if my naps are between 20 and 25 minutes long. Longer, and I wake up groggy; shorter, and I can tell I haven't slept enough.

Core Length: I feel more refreshed after the core sleep if I wake up at the end of a sleep cycle. Likewise, if something wakes me up in the middle of a sleep cycle, I'm groggy for several hours afterward. Most people's sleep cycles are ~90 minutes long, so if yours is too, you'll feel best after sleeping 90 minutes, 3 hours, 4.5 hours, or 6 hours. (Mine are 80-85 minutes long.)

[Gia]

I tried it this week and discovered something interesting. I went to bed for my core sleep at 9:30pm and was very tired when I got up but was fine after I got going. Came home and set the alarm for a 1.5 hour nap and fell quickly asleep but woke up in exactly one hour feeling pretty good. One hour is all I would sleep for my nap all week no matter what I did I cannot sleep that extra 1/2 hour. I am a very sound asleep - don't hear the phone ring and remember dreaming(I have very vivid dreams that I usually have no trouble recalling). So I wondered if my cycle is 60 minutes. I adjusted my core sleep to 5 hours, 9pm to 2am and awoke much more refreshed. Is it possible that I am on a 60 minute cycle instead of a 90 minute cycle?

[Kaspian]

Sounds like it. I'd say it's more important to find the core and nap lengths that you wake up most refreshed and alert from than it would be to stick to 90 minutes just because that's "normal."