In the movie “Matrix“, Morpheus’ is the ship “Nebuchadnezzar” of which he is the captain. But we are not talking about a movie here. Morpheus’ realm is sleep. Why is it important to sleep, and how much sleep do we need?
Sleep loss = brain drain. This is what developmental molecular biologist John Medina says. In his book, “Brain Rules”, he explains which mechanisms underlie sleep. You can listen to it and watch some graphs explaining what he says here. In a video, he explains why sleep is necessary.
Dr. Medina comes to a number of conclusions:
- Sleep is crucial for learning. If we don’t sleep enough, our learning is impaired. But not only that. Sleep loss is also detrimental to attention, executive function, working memory, mood, quantitative skills, logical reasoning, and even motor dexterity.
- We have a certain circadian rhythm that also includes the need for a nap in the early afternoon, and if we follow that need and take a nap of around 30 minutes, it is likely that we can improve our performance. If we can for some reason not take a nap, at least we should try not to do very important things that require a lot of attention during that time.
- How much sleep we actually need is not clear yet. It is likely that it changes with age, gender, pregnancy, puberty, and so on. At least it seems that most people who claim to need only five hours or less are not promoting their health and performance because they end up chronically sleep deprived, as former American Academy of Sleep Medicine president Daniel J. Buysse states in an interview with the Wall Street Journal of which there is a short summary in “The Atlantic Wire”.
So how much sleep do we need? Studies by David Dinges, the head of the Sleep and Chronobiology Laboratory at the Hospital at University of Pennsylvania, and Gregory Belenky, now head of the Sleep and Performance Research Center at Washington State University, Spokane, found in their studies that on average, we need eight hours. The studies are reported in the New York Times. However, as already mentioned, there is also a small percentage of people who need less than five hours or more than nine. Everyone has to find out for him- or herself. A good indicator is not setting an alarm on weekends and see if we sleep more on weekends than during the week. If this is the case, it is likely that we do not sleep enough during the week.
To use John Medina’s words: Sleep well, think well!