The Interview: Sleep Expert Charles Czeisler

Many sleep doctors say naps are bad because they might interfere with nighttime sleep. I don’t happen to subscribe to that. For the average American who is sleep-deprived—when I work with sports teams, for instance—I’m a strong advocate of naps. The siesta cultures have a built-in nap in the middle of the afternoon. They have, let’s say, a five- or six-hour sleep episode at night, and then a one- to two-hour nap during the day, so they get at least seven to eight hours of sleep in a 24-hour period. It’s on a consistent schedule. When we became industrialized, it was not very convenient to have people going off to take a nap and then coming back to the factory.

Is that changing?

People are starting to install nap rooms into offices or work environments. For example, one of the most successful things that I did with the Red Sox is to install a nap room in Fenway Park—and now the players are fighting to get into it.

The Sox aren’t the only team you’ve worked with. You have helped the Bruins, the Celtics, and the Portland Trail Blazers, among others. Any interesting lessons from working with professional athletes?

One of the things that’s interesting is that sleep is taken for granted and they don’t really have a strategy to make sure they get the sleep that they need. It was very surprising to me because they had huge programs around nutrition and, obviously, huge programs around exercise. The third pillar of good health, which is sleep, was just sort of “whenever you have a chance to get it,” with no plan. Many times both acute and chronic sleep deprivation were built into their schedule.

In terms of sleep, who has it worse: a new parent, a Fortune 100 CEO, or an NBA player?

New parents—that’s probably the worst. The parent almost needs to adopt the strategy that if the kid is sleeping, they need to be sleeping.

When you had kids, did you do anything that typical parents might not think of?

[Laughs.] We did a few things that were unusual when we had our three kids. First of all, we drilled a hole through the roof in the nursery and put in a solar collector up top and then a luminaire that did complete dawn-to-dusk transitions so the kids would be exposed to the natural light-dark cycle. And when my wife was breastfeeding—she was working and doing her residency—we would label the breast milk with the time it was pumped, because the children are synchronized to the 24-hour day by the melatonin in the mother’s breast milk. So if the father is giving breast milk that has been pumped by the mother, then you want to label those. Ideally, at 3 a.m. you have breast milk that was pumped around 3 a.m. The child is depending on that temporal signal for their synchronization to the 24-hour day. As I said, we’re not the usual parents.

Does devoting your life to understanding sleep become stressful if you’re lying in bed and having a hard time falling asleep?

Thank God I don’t currently have any issues falling asleep, but it has, at times, been an issue. For example, when my sister died and when my mother died—one of the things that happens with a loss like that is early-morning awakenings. When I was a freshman in college and my mother died, I was suddenly waking up at 3 or 4 in the morning hoping it was just a bad dream.

Is that just a natural part of the grieving process?

It’s something that naturally occurs. Obviously, when I was a freshman, I was 19 and didn’t know what was going on. When my sister died in 2008, I was already a sleep researcher and I knew that when I was suddenly waking up at 4 in the morning there was nothing I could really do about it. But at least I knew what was happening, which is actually reassuring.

How can I beat jet lag?

When traveling across time zones, one thing that will help facilitate resetting your circadian rhythm is melatonin. Another thing I’ll say about jet lag is that many times you can split the difference in your schedule and begin to make changes before you leave—start going to bed a little earlier and waking up a little earlier than usual the week before you leave. You may decide you don’t have to shift at all. If you’re going to Paris to go out to nightclubs, then do not shift to Paris time. If you normally go to bed at midnight here, that’s 6 in the morning in Paris and that’s when the nightclubs close. So you can stay on Boston time and have a blast. And if you’re traveling for business and going eastward, try to schedule your meetings for later in the day if you can.

Let’s say I have a chaotic week coming up at work and I know that I’ll only get four or five hours of sleep each night. Should I clear my weekend schedule when it’s over and snooze until noon?

In the week leading up to it, you should tank up on sleep as much as possible. The military used to have a strategy where they would sleep-deprive soldiers to get them ready for when they had to be sleep-deprived in the field, but that makes it worse. You can’t train for sleep deprivation. It’d be like saying,“Okay, I’m going to starve myself because I’m going to be in a situation where I’m not going to have enough food.” Well, if you’re thin as a rail and you have no reserve, you’re not going to be able to survive. Why do people think they’re going to starve themselves of sleep to get ready for a time without sleep? You want to tank up on sleep—your body and your performance that week will be better if you go into it well rested. Take naps, sleep at night, whatever—just make sure you’re getting your sleep the week before.

But can I make up for it?

You need to be careful about not shifting your circadian rhythm by sleeping in. But studies in kids have shown that if they don’t make up for it by sleeping in, they’re actually worse off the following week. Just try to be as consistent as possible and set aside an adequate amount of time in a cool, dark, and quiet place.