Chris Kresser: So yeah, our sleep needs change as we go through life. It’s no surprise to anyone who has kids that very young children need much more sleep, sometimes up to, depending on the kid, 11 or 12 hours at certain stages. Our daughter right now, Sylvia’s almost five, and she typically goes to bed around 7:00 or 7:30 and wakes up at about 6:00, anywhere between 5:30 and 6:30 so she can get between 10 1/2 or 11 1/2 hours, and that’s appropriate for this age. Then later in childhood they go through a stage where the sleep needs drop down almost more into the adult range, and then in teenage years and college years that number goes up again.
Some people have argued that teenagers might need as much as 9 1/2 or 10 hours of sleep, which is one of the reasons why school the way it’s designed is so problematic because kids are staying up late, texting, using electronic media, etc. It’s certainly a big part of teenage culture now, and then they have to get up at 6:00 or 6:30 in the morning in order to get to school, sometimes as early as 7:00, sometimes 7:30 or 8:00. So most teenagers that I know are totally sleep deprived. Most college students are totally sleep deprived.
There’s just very little awareness about this, and the direction that our lifestyle is taking is kind of in direct conflict with what we know from the research. It does stand to reason that if a college student has an intense schedule with exams or is highly physically active or both, or a teenager for that matter, that they might need more like 10 hours of sleep. Again, there’s very little awareness about that. Naps can be helpful certainly and they can count towards that total, but getting to bed at an early hour or at least being able to sleep in if that’s not possible is the best approach, and that’s just unfortunately really difficult the way that things are set up right now.
In terms of biphasic sleep, which is what you’re referring to, for a while there were a lot of articles saying that the way we sleep is wrong and this is how our ancestors slept. They went to bed at sundown and then they woke up in the middle night of the night, maybe spent some time just kind of looking at the stars or in a state or reverie or contemplation. Maybe they walked around or they had sex or something like that and then they went back to sleep and slept for another several hours. They would end up getting eight hours of sleep, but it was in two stretches of four hours. What I said was that’s all well and good for people who are going to bed at sundown, but how many people do you know that go to bed at sundown or even could go to bed at sundown if they wanted do. I don’t know very many people that do that or ever could do that. So I think those articles were a little click-baity and didn’t really point that out. It’s meaningless to say this is what our ancestors did and this is what’s natural for humans if that’s just going to be practical or applicable for 99.9 percent of the population. Certainly nothing is wrong with sleeping that way. Arguably it is a more natural pattern for us as humans, but it’s beside the point because very few people can actually do that and pull it off.