Check this article.
https://medium.com/design-ux/ef4772e3c628
This guy is right. I can confirm his theory.
It actually happened to me, and when I stopped working too much, I was actually more productive than ever.
That’s because you give yourself time to think of an issue, and find a best solution.
The result is quality, in a decent time.
Here’s a true story that happened to me last year:
I had to write a small project once. I worked two days and a night with only some coffee breaks.
At some point, I came across a feature which took me about 10 hours to implement, because i haven’t looked for an easier way to do it. There was no time for that.
After the project was completed, that “10 hours” feature was not doing it’s job and there was no way i could just “fix” it.It took me a few minutes of thinking and I found a better way to aproach that issue. It was implemented in 1 hour, and it’s working even today with no problems.
This story confirms that working hard is not productive at all.