About one-third of American's aren't getting the right amount of shut-eye on a daily basis - but how many hours should you really be getting? Can you make up for poor sleep with a nap? How can you fall asleep - and stay asleep? Dr. Michael Grandner, Director of the UArizona Sleep and Health Research Program and Director of the Behavioral Sleep Medicine Clinic at the Banner-University Medical Center, gives us the secrets to a better night's sleep. The professor of several disciplines also tells us why good sleep is not just important for our mood, but it's essential to promoting cardiovascular health, as well as preventing obesity and diabetes.
LR: What led you to choose this field of study, and what keeps you invested in it?
MG: I'm a clinical psychologist by training, but I didn't get into sleep to study psychology. I got into psychology because I was interested in studying sleep from the very beginning.
In high school, I used to work at the mall bookstore. Every time we got a book in about sleep and dreams, I thought it was the coolest thing. I didn't know studying sleep was a job you could have, but in college, one of my friends had gotten a job as a tech of a sleep lab on campus. One of the guys who was running it was teaching an undergraduate course on sleep, so I took that course and loved it. I felt like this is where I belonged. I volunteered to work in the lab, which turned into an independent study, which turned into an honors thesis, which turned into going to grad school and then postdoc and so on.
I got into sleep health in graduate school. We were looking at how people who either don't get enough sleep or oversleep actually don't live as long. I wanted to know why, and the answer seemed very complicated, which made it interesting.
When I started my postdoc in 2007, and I wrote my first grants, I could not for the life of me get any of this work funded. Nobody was interested.
The sleep people said, “This isn't basic sleep neuroscience. This isn't the biological machinery of sleep. We don't care about that.” Or you had the sleep disorders people saying, “Well, this isn't a disorder. What disease does this? This is just sleep.” Then you go to the public health people, and they’re saying, “Well, this isn't smoking, diet or exercise. What is this? Isn't on our radar.’
Wherever I went, the question of sleep health fell between the cracks. So anytime I had an opportunity to speak publicly about my research, I did it. I let the data speak, but I also help translate it into something that's real world valuable for people. If enough of us do this, we can change the conversation around sleep.
I think we have done that. Sleep is one of the pillars of health now alongside diet and exercise and stress. We've still got a long way to go. That's why there's still a lot of unanswered questions, but I think we finally made it to the stage…and that's super exciting for me.
BU: We'll often hear people say, “I'll sleep when I die,” or, “I can go about my day without a problem on five or so hours of sleep.” How much sleep should we really be getting every night, and why is hitting that number or that range so important to our health?
MG: Think about it this way: What are the biological requirements to support human life?
We need to eat food, breathe air, drink water and sleep. It's short list, and sleep is on it.
A lot of the social attitudes around sleep are not biologically based. A lot of people see sleep as unproductive time - and there is nothing worse than unproductive time in our society. There's never enough time to sleep because it becomes a cost of time, just like exercise. Now, we're starting to see people taking time to go for a run or go to the gym, even in the middle of the day.
Nobody says things like, “You know what, breathing unpolluted air - that's a luxury for people with too much free time on their hands. When I retired, I'm going to drink clear water, but until then, I’ll make do with this brown stuff.”
Nobody says that because that would be ridiculous!
But we do say that with sleep, and that's because of social pressures and evolution. If we were being chased by the proverbial bear in the woods and it was time to sleep, and we all of a sudden curled down, we wouldn't survive.
We have these mechanisms to prolong wakefulness in times of stress to promote survival, but we've abused the privilege. We tamed fire and then invented electric lights, and now the night is optional. We have all these things that are pushing sleep to the side, but it doesn't make it less of a biological requirement.
So how many hours do we need? It’s kind of like asking, “How many calories do we need to function?” Everyone's probably a little bit different. If you get a little bit less, it's probably not going to kill you. You'll get a little bit more, it's probably not going to kill you, but too much or too little is probably not a good thing. It's also not just about the number of calories. It's about the nutrition.
Like nutrition, sleep is multi-dimensional. If you look at the literature, most adults optimally perform on seven to eight hours per night. People sleeping six hours aren't going to suddenly drop dead for no apparent reason, and the more you go over eight, maybe that's a little too much – just like you can exercise too much.
Then you have to look at the sleep quality. Is it restful? Was it fragmented? Was it shallow? Is it regular? Was it at the right time?
It doesn't have to be perfect for it to be perfectly fine, but it is multi-dimensional.
BU: To keep playing with the nutrition analogy, if we haven't eaten enough during the day, we can make up for it with a snack. Say you haven't slept as much at night - can you make up for that with a nap?
People ask me all the time, “If I sleep deprive myself during the week, how much sleep do I need on the weekend to make up for it?” That's like saying, “I eat nothing but cheeseburgers and pizza all week. How much kale do I need to eat on the weekend to make up for it?”
The bad news is, you did what you did, and the kale is certainly better, but you don't have to pay back every calorie. You don't then starve yourself for a month - it doesn't work that way. You just approach balance as close as you can. The closer you get to some sort of balance your body will start getting used to it.
If you slept relatively well, and you have a couple nights of crappy sleep, who cares! It's like if you have a pretty good diet and then you have a big meal, don't panic. Your body will adjust.
If you didn’t sleep well one night, you'll be fine the next day. The data showed one or two nights of impaired sleep is really not that big in terms of performance if you're coming from relatively well-slept state.
The other thing is that naps can be effective, but you’ve got to time it right. For example, if you're hungry and you're snacking all day, you're not really getting good quality food and nutrition. If your snacks are too close to your meals, you're not going to have the room for the food with all the nutrients and the vegetables. That'll keep you going, but it won't check all the boxes.
The same is true with naps, where a brief nap in the middle of the days tends to improve performance, especially if you're otherwise relatively well-rested. But if you nap for too long, you often feel groggy and terrible because you got into a deep sleep and your body didn't like waking up from that. If you nap too close to the evening, you'll wake up feeling super groggy and then your sleep that night will be shallow.
If you're eating healthy meals, a snack can keep you focused and going. But if you're starving all the time, is it because you're not eating enough? Or is there something wrong with your diet? If you're sleepy during the day and having trouble staying awake, I would look to your sleep and ask if you’re getting enough and if it’s good quality, because a nap can’t fix those problems.
LR: As I get older, I notice my sleep isn’t as long or as sound. Is that normal? If so, how can we manage that as we age?
The relationship between sleep and aging is a little paradoxical.
It's true that as we get older, our sleep becomes a little shallower and a little more broken up. You might have more awakenings during the night, and it might take longer to fall asleep. Our clocks also might shift a little earlier where people get tired earlier and wake up earlier – that’s all normal.
When people say they want to sleep like a baby, I wonder if those people ever had children because nobody wants to sleep like a baby. What they want is sleep like an adolescent. Part of that has to do with adolescent brain development. They need more sleep than adults, but as people get older, yes, it gets a little shallower.
Insomnia also increases with age.
There's a difference between insomnia as an occasional problem and insomnia as a clinical condition. Here's a rule of thumb: If it takes you at least 30 minutes to fall asleep, or you're awake for at least 30 minutes during the night, and that's a struggle at least three nights a week, and it's associated with some sort of daytime impairment, you probably have a clinical insomnia condition. Any sleep tips I give you are probably not going to be enough. The first-line recommended treatment is non-medication, it's actually CBTI, and we do it here. It tends to outperform medications, at least in the long-term, if not also in the short term, by reprogramming your body's natural ability to sleep.
The paradoxical part is that as people get older, satisfaction with sleep increases after you adjust for any kind of medical and health issues. As people get older, their priorities change, they get perspective, they have experience, and they have more resilience.
There are a few studies that take older people and younger people in the lab and sleep deprive them, and then look at performance. These studies show that the older and younger people perceive about the same degree of impairment, but the younger people massively underestimate how impaired they were. They were actually falling apart, and they had no idea, whereas the older group managed just fine, despite knowing they were impaired.
LR: What are your top tips for better sleep?
MG: The first tip is to get up at the same time every morning, and as soon as you get up, do not linger in bed. Have your feet on the floor as quickly as possible, and if you can get movement and light - outside light is best – it will not only program in an anchor point for your circadian day, but it will also help shift your rhythm a little earlier to wake you up a little bit faster and ignore sleep inertia, which is that feeling of sluggishness. Sleep inertia should go away within 10, 15, 20 minutes. If it doesn't, then that's a sign your sleep was a little shallow.
The next thing you've got to do is wind down.
A lot of people say, “I get into bed and I just can't turn my mind off. I can't stop thinking. My mind is just very active.”
All our minds are very active, so what’s happening with your trouble falling asleep is one of two things. First, you could have programmed that to happen by repeatedly getting into bed when your mind is active. When you do that enough, your brain is going to realize the bed is a thinking place, especially where you don't have distractions and other things to do. You have to get all that stuff out of your head before you get in there.
The other issue with that is that it’s like saying, “I'm driving my car, and I want to stop at the stop sign, but when I press on my brakes, I'm still moving into the intersection.” Then I ask, “How fast were you going?” “Pretty fast.” “When did you start tapping the brakes?” “Oh, two millimeters before the stop sign.”
There's nothing wrong with your car - your brakes are probably working fine. There's nothing wrong with the stop sign - that didn't come too quickly. You had plenty of notice. The problem is you decided not to start slowing down. That's just how the world works, and your brain is the same way.
We don't just turn ourselves on and off like a machine. You have to give yourself lead time, and watching TV is distracting, especially if you're very focused on. If you're doing something that you're having a hard time stopping, it's too mentally activating, and you're not giving your mind the time it needs to wind down.
The key is to budget in the time to wind down, about 30 to 60 minutes. We have to invest in our sleep so we can be productive the next day. All the data show that people who sleep less are less productive, even though they think they're getting more done, they're actually less effective because they're not invested.
The third tip, which is counterintuitive, is that if you can't get back to sleep, the most important thing you can do is get out of bed. If you're going to be awake anyway, spend as little time as possible conscious in bed. You want it so that when you get into bed, it's paired with sleep so that the bed itself becomes a stimulus for sleep. Just let time pass, and don’t do anything too mentally stimulating.
The technique of pairing the bed with sleep is just basic learning theory - leveraging the basic learning principles in the brain is stimulus control, and it was developed at the University of Arizona back in the 1970s and really made Arizona one of the leading places for sleep research in the world.
We need to stop seeing sleep as a cost. We need to have time. We need to see it as an investment in the next day’s efficiency.
When I go to bed, I don't think about how much more I have left to do today. It's more about how effective I need to be tomorrow, so I think, “When do I need to be in bed so that I maximally effective tomorrow?”