Ok, let’s say that four nights from now you know that you will only have a maximum of 4 hours of sleep when you’re used to eight. Is it more befinicial to get extra sleep the next few nights or to get less and less sleep each night to prepare for the four hour night?
I’d say, if possible, get more sleep the night(s) before the short night. At the very least, get the normal amount. In my experience trying to get used to little sleep doesn’t work and will make you more tired, reduce your reaction time, and impair your judgment.
All totaled, I have over a decade’s experience working on night shifts. Here’s my opinion.
Try to get a few extra hours sleep in the nights before and after the short night. It will help if you can nap sometime in the day before the short night. Making decisions will be harder as you get tired. Beyond that, stand up and walk around every once in a while and limit your starches and sugars if they make you tired. Coffee may wake you up, but drinking a whole lot of it doesn’t always translate into productive energy for me.
If you can, try to schedule the things you can do by rote for when you’re more tired, and take a short nap if you find that you’re slowing down. I’m a deep sleeper, and I’ve been able to convince myself that I have to wake up in 20 minutes. Obviously, you don’t want to drive or operate machinery when you’re tired.
Honestly though, four hours of sleep in a night isn’t that bad. I’ve done entire weeks on four hours sleep per day. I don’t want to repeatthe experience, and my eyes were dragging the floor at the end, but I made it.