Hi Slayer. Good questions. And the answers will be unique to you, as we all are unique individuals with unique needs.

That said, I can say that in general we as human beings have evolved over the eons to sleep in one more or less unbroken period. Unlike cats and dogs, which are polyphasic sleepers (usually catching several naps throughout a 24 hour period), we are more more monophasic. That's the way our sleep systems have evolved and seem to work best.

Two of the most important controllers of sleep -- circadian rhythm and sleep drive -- are keyed to one unbroken period for sleep at night when it's dark, and one more or less unbroken period for wakefulness and activity, during the day when it's light. A number of our physiologic and neurologic systems support this pattern.

One common exception to the unbroken monophasic pattern is the early to mid-afternoon nap, when the circadian rhythm dips. This dip in fact is built into a number of cultures as a siesta, Many of us find it easy and very refreshing to take advantage of a short cat nap in the early p.m. without much disruption to our homeostatic sleep drive.

The short afternoon siesta should not be confused with a 4 or 5 hour period for sleep, when your mind and body would presumably go through several deeper NREM-REM cycles. That would understandably reduce sleep drive significantly that night, making it much harder to sleep well.

However, some people can temporarily become more polyphasic in certain situations. Long distance competitive sailors come to mind. These are people who compete in long trans-oceanic races. They may catch several short power naps throughout a 24-hour period, enabling them to trim sails, make course corrections, monitor currents and so forth as they cross long distances over many days.

Astronauts, firefighters, combat soldiers, and others are more examples of people who can temporarily become more polyphasic and yet still perform at a very high level. (That's hope for the rest of us living our normal every day lives who may not get the perfect 8 hours of sleep. This is evidence we can still function at a reasonably high level the next day.)

Regarding your specific schedule, I don't know. Maybe you can try it for a couple weeks and see how you do, although I suspect if you already have insomnia this won't help.

My best suggestion would be to instead go for the most consistency possible in your sleep-wake schedule. My take is that you might do better with scheduling one unbroken period for sleep, rather than two. I realize this is tough with your work schedule. Shift work is very challenging for sleep.

At age 19 you are probably right about probably needing more than 7 hours. You could pin that number down a bit more by keeping sleep logs.

Later in life some of us can go with 7 and be fine. That's about where I'm at. Again it's unique to you. But overall I would encourage you to prioritize sleep, meaning schedule one block of time as much as you can.

If you try the polyphasic schedule, I hope you'll keep us posted. Would be interested in how it goes.

Thanks for the reply. By question are humans really better monophasic sleepers or is that just the way they've typically trained their bodies to meet societies jobs/needs? Even though it's very poor sleep habits, in the past I have even gone or at least felt like I didn't sleep all night , or I woke up early and couldn't go back to bed but always am able to fall asleep around 9 A.m. or so. That's why I wonder if my plan would work.

I know for a fact I'd feel very tired when I first wake up for the first while , but I wonder if over time if my body wouldn't feel tired if I did those two sessions at the times I said. I'm pretty sure the second shift is far enough away from my bed time that it wouldn't interfere. Right when I woke up from the second shift is when I would either work for 8 straight hours or exercise for probably 2 or so hours and then work 5 hours. So I think I would be tired enough to go to bed, but the question is just would I feel refreshed apon waking up?

If I don't do this method do you see any other way I can fit in both running and lifting? It gets to be about 100 degrees in summer so the temperature part becomes a real issue. Running takes about an hour counting the drive time and stretching after. Lifting takes for ever, like 2-3 hours counting travel time because I'm doing a pretty intense program right now. With what time I'm scheduled to work, what keeps on happening is I'm only having time to do one of the two things before work. I usually end up having to either run or lift after work at 11 at night and then I end up not getting that great of a workout and not getting to bed till even later.

It would also be very nice if I was able to wake up early for fishing without being tired. Overall I'm just a picky person. Right now I'm just not very happy because everything I want isn't getting done. When I use my days off to either exercise or fish, I don't have time for the other. I'm just very frustrated right now. The worst part is I don't have a set schedule so the days of the week I work are different all the time. I might try talking to them about that and see if I can get that changed.

Good questions again. Can't say that I have definitive answers, but it's interesting to speculate.

From the theories I've read, early hominids were more polyphasic like other mammals. This is going back millions of years. Then, as we evolved with the use of tools, fire, shelter building, and so on, as all that increased and cooperative clan units developed , humans could sleep more securely through the night and eventually we became more monophasic.

So this would explain a phylogenetic predisposition to monophasic sleep. And that's why sleeping at night and being active during the day should theoretically go with rather than against your natural sleep system. And again, a number of our physical and neurologic systems support this.

All your ideas for activities and exercise sound great to me. Along with gainful employment, these are all important parts of living a healthy balanced life.

At your age, having a biological clock that runs on more of a 26 to 30 hour cycle rather than a 24-hour day is fairly common. So it wouldn't be surprising if this is part of what's going on with your sleep.

There is a potentially easy solution, though: just get up at the same time every day, as much as possible. This enables you to re-set and synchronize your circadian rhythm, sleep drive, and biological clock every day. All of these are important for good sleep.

Given the circumstances you've described, I would go for as much consistency as possible in your overall sleep-wake schedule, including one unbroken block of time for sleep, and prioritizing as much as possible a consistent wake up time.

The last sentence you wrote may be the best solution to do what you want and increase the likelihood of good sleep.