48 hour day

Is there anyone who try to live 48 hours a day, e.g. stay awake for 36 hours and sleep for 12 hours

1 Like

I’m not aware of anyone trying that. Have you tried it?

I have done it for a week. I noticed:
(1)On the second day(due to stay awake for longer time), i will shift into hypomania mode. I personally very enjoyed it. It make me super motivated. Fear and anxiety vanished. I will be more talkative which in turn increase my social ability.(2)I reduced the friction between different consciousness state(awake vs. asleep). In the past, i will usually spent at least 90 minute before sleep to calm down myself.
(3) My sleep quality improved dramatically
(4)On the first day, my cognition(better attention and reaction speed) were improved because of extended sleep(12-16 hours)
I still did not noticed any downside


wow!.. I would love to hear more if you continue!! I just slept for 11+ hours and will not sleep for 30+ hours…

would be curious about the interaction of this with fasting, caffeine/nicotine,… etc…

1 Like

Hi guys! I’ve tried a 48 hour sleep cycle for 2-3 weeks at a time back in December - February 2020 when I was writing my thesis. My productivity was through the roof, but covid happened and it became unsustainable.

I have an unfortunate natural sleep pattern. I wake up after ~8 hours and take ~20 hours to get tired enough to fall asleep instantly (when I drink a double shot espresso early in the day). Without coffee it’s about 8/18, but I’m a bit of a coffee nerd and love the taste.

However, the 28/26 hour day cycles are incompatible with most people’s schedules. I also prefer being awake when there’s light outside cause you don’t get that many lumens in the cloudy UK anyway. Most businesses are only open during the day, so I ended up trying the 48 hour day cycle.

I would sleep for 12h, 8pm - 8am, before the first 24 hour day and then be awake for 36h. As you can imagine, I would be pretty tired by 5pm on the second day, but I tried to stay awake until 8pm. I would drink a double shot espresso ~10am on each day. The glue keeping everything together turned out to be doing a long intense physical activity on the morning of the second day. I would rock climb between 7 - 9am which left me pretty energised for the day. Then covid happened, the climbing gyms closed, and I couldn’t find a suitable replacement for the glue.

I’ve obviously had the same benefits (3) and (4) of @Jialin’s comment. I don’t smoke, and I don’t really know what you consider to be fasting, but I only eat one big ~1000-1200 kcal meal a day, and a couple of ~300kcal snacks.


I tried pulling a couple of all-nighters and then sleeping a lot in the last 2 weeks, they were great, except for the bit when I was falling asleep for about 4 hours during the night and couldn’t do anything to stay awake. Coffee was the only thing that helped.

@notfermi - instead of rock-climbing for 2 hours in the morning, why not just sleep in these hours?

1 Like

I feel like I can’t time the sleep properly to feel at least slightly rested. Rock climbing is way more fun and lets me energised for at least 6-7 hours after that. I’ve tried drinking the 2nd coffee of the 48h cycle around 3-4 am during the night which definitely helped with that slump, but after a couple of these cycles, I didn’t feel that tired even without the coffee and drank it around 10-11am (after climbing).

Yep, after several cycle, you do not feel tired anymore

Not quite 48/12, more like 48/6, but I had a similar experience when I was writing my thesis, too. I worked as long as I could, and I slept as little as I could for like a whole month it took me to finish my work.

Sometimes the state I was in triggered a hyperfocus (not always on the work though! I could also spend like 10 hours on Wikipedia reading about George Soros and whatnot), the other times I was so physically absent and distracted I could not think clear at all. In the end, I’m proud of how much novel unfamiliar work I’ve done in that period, but it took me almost two months to recover lol.

Now that I told that, I should say that I don’t recommend conducting such experiments if you have important hard-deadline work to do. Not sleeping for such long periods of time can bring needless anxiety and you better be ready to handle it.

Another important thing is that it becomes easier to lose touch with reality: forget what day it is, forget when you ate last time, forget for how long you are not sleeping. It becomes so easy to make a wrong decision, rationalizing some stupid stuff you would not rationalize if you were well rested. Like even if you sleep for 12 hours and then don’t sleep for 48, you may start convincing yourself you could stay up even more for some reason.

It may be interesting to try at some point in one’s life, but I fail to find a use case for such a weird lifestyle. I’d rather learn how to concentrate and get tired with an average sleep cycle.


I feel like if you have strong light at the evening, you still will not feel tired. I recently install a new lamp which made 48 hour day effortless.

1 Like

Which lamp?