> I don't completely agree with that. People who achieve amazing things working even 16 hours a day are pretty common. I have done that many times in the past. When I did my engineering here in India. Preparing for public exams, and entrance exams- I have regularly worked on subjects like Math and Physics almost 15-17 hours a day. Most of friends who cracked the exams did the same. It happens all the time.

I disagree. I spent part of my high school in India and I have worked on Indian engineering entrance exams. They did involve extensive amount of working through problems. There was more memorizing rather than abstract problem solving. I am not convinced the amount of clear headed thinking that was needed to perform practice drills on problem sets is the same as I need when I need to design something new or write theoretical proofs.

Not that you can't go rage hard and convince yourself you can pull an all-nighter or whatever. I have only found that at the end of the day there are two results:

a) The stuff that you make is not up to spec.

b) You are tired the next day and your productivity is fucked.

I prefer the long race.

> There was more memorizing rather than abstract problem solving.

FWIW, you need sleep for memorizing as well. Stuff just won't stick if you don't cement it with a good night's rest.

Cramming it all the night just before an exam does work though, I did that myself too, but I think it only worked because I already had a solid foundation. Also that will never work for "insight" type of questions, just rote memorization.

>When I did my engineering here in India. Preparing for public exams, and entrance exams- I have regularly worked on subjects like Math and Physics almost 15-17 hours a day.

And did you cut this down to (even) 10 hours and observe real changes in productivity?

>Most of it psychological.

No. You get physical symptoms from sleep depredation. You can't think these problems away but you can convince yourself you aren't having them. Doesn't actually change your body's need for sleep.

http://www.webmd.com/sleep-disorders/excessive-sleepiness-10...?

From the article:

Sleep Loss Impairs Judgment, Especially About Sleep

Lack of sleep can affect our interpretation of events. This hurts our ability to make sound judgments because we may not assess situations accurately and act on them wisely.

Sleep-deprived people seem to be especially prone to poor judgment when it comes to assessing what lack of sleep is doing to them. In our increasingly fast-paced world, functioning on less sleep has become a kind of badge of honor. But sleep specialists say if you think you’re doing fine on less sleep, you’re probably wrong. And if you work in a profession where it’s important to be able to judge your level of functioning, this can be a big problem.

“Studies show that over time, people who are getting six hours of sleep, instead of seven or eight, begin to feel that they’ve adapted to that sleep deprivation -- they’ve gotten used to it,” Gehrman says. “But if you look at how they actually do on tests of mental alertness and performance, they continue to go downhill. So there’s a point in sleep deprivation when we lose touch with how impaired we are.”

Sleep plays a critical role in thinking and learning. Lack of sleep hurts these cognitive processes in many ways. First, it impairs attention, alertness, concentration, reasoning, and problem solving. This makes it more difficult to learn efficiently.

Second, during the night, various sleep cycles play a role in “consolidating” memories in the mind. If you don’t get enough sleep, you won’t be able to remember what you learned and experienced during the day.

>You will be surprised how long you can go sleepless, when that is the only option you have

Doesn't mean it's healthy. Doesn't mean that you are performing at max capacity.

Well said. I personally know someone who just recently qualified with a first in medicine. She claims that she achieved this by getting a good nights sleep every night (i.e. 9 hours). She claims that this is what enabled her to qualify to do medicine also. All her classmates in college did exactly what kamaal describes (I have done it myself). They worked all the hours they could get because they were so afraid they wouldn't make it. And they passed their exams. But they didn't get a first. She said she spoke to a few of them a few times saying how ineffective this was, that medicine is hard and to build up a mental map and solid understanding you need sleep. As a well slept person she could see how ineffective they were. But it takes discipline and confidence (and maybe a bit of devil may care) not to panic and most people don't seem to be able to do this in the face of what they think are very tough odds.

My own observation on programming (significantly less taxing than studying medicine - no matter how you slice it) is that you can do a few late nights but after that it becomes drastically ineffective and the people involved get more and more dunning kruger about it. In the end the whole "push" consists of almost entirely ego and bullshit and the code is appalling.

In my own experience, in the "short term" it really comes down to motivation / inspiration. If you are sufficiently motivated, overworking yourself seems to be far less painful, and productivity doesn't really seem to be impacted. I've certainly pulled all-nighters before with code going into production pretty successfully.

I specifically put short term in quotes because I'm not sure how I would define it. It probably depends on a lot of factors, but I wouldn't stretch it past several weeks. Way past that, motivation also seems to be highly impacted, and you become the kind of tired, error prone zombie who stretches out their 8 hours of work over 16.

One of XP's guiding principles is "Never work overtime for longer than one week."

It's OK to work an 80-hour week. You can get a lot done. But the next week needs to be a 40-hour week, or the pace isn't sustainable.

It isn't necessarily an iron-clad rule, but it's a pretty good rule of thumb. Past one week, you're just hurting your productivity.

My experience bears this out as a fairly accurate guide.

I agree.

Actually its about knowing when to sleep than sleeping less always, more like when to accelerate and when to brake. I guess that's what Edison did too.

Many times over a period what you really need is long stretches of un interrupted time to get something big done. You will have to take a break after that. Come back with a fresh purpose, an new challenge and start again.

> Most Indian IT giants who get outsourced projects routinely over work their employees

I've had to oversee a number of those for very large orgs and can vouch that the quality was consistently beyond terrible and caused no end of problems. Most of the work done that way was eventually thrown away.