Art by Matty M. Cipov (purchased on Etsy)
The archetypal startup mentality is working grueling hours deep into the night and through the weekend to achieve extraordinary goals. However, there is some science to suggest that working without the proper rest leads to more errors. These errors could lead to shoddy work requiring even more effort and expense to fix later. I'd also add that this approach lowers morale.
A fundamental principle of sleep science says the brain is either awake or asleep. However, new studies show that when individuals are deprived of sleep, some neurons will quit and take a nap. Researchers at the University of Wisconsin-Madison studied the cerebral cortices of rats and recorded their brain activity by electroencephalography for several weeks.
Rats are sophisticated and noble mammals, so comparing them to startup developers should in no way be construed as anything but a compliment. Anywhoo, this research team discovered that for normal hours of activity, cortical neurons were firing as expected during wakefulness. Likewise, when sleeping, brain activity showed the characteristic patterns of deep sleep.
However, when the little guys were kept up past their bedtime, stimulated by a miscellany of interesting new toys, cortical neurons began shutting down. Although fully awake according to the electroencephalography patterns, the rats made ever more errors in simple tasks designed to release a treat upon completion. They were practically zombie rats!
Why different parts of the brain would shut down in waking individuals is unclear. Maybe it's part of some overall grey matter energy saving protocol. Or, it could be the manifestation of a brain operating at potentially unhealthy if not dangerous degrees of fatigue. Forcing people to work without proper rest is likely impractical and may even be punishing.
In my experience, it's far more motivating to be part of a team that has an appropriate work life balance including the right amount of rest. People are more creative, more efficient, and generally more fun to be around when they're not sleep-deprived zombies. So, my advice is to work effectively and get your rest. Also, in my opinion, you're doing a great job.