The Sleep Debt

Can you really catch up on lost sleep?

How Is Your Sleep Health?

Just because you don’t have insomnia doesn’t mean sleep's doing its job for you.

When you come across yet another magazine piece about sleep disorders, you pass it by. You know lots of people who have sleep problems—but as far as you’re concerned, you don’t. You don’t lie awake for hours hoping for some shut-eye, or wake up in the middle of the night, or find it really hard to sleep on a schedule that works with the rest of your life.

Great! Congratulations! But…

Not having a particular problem is not at all the same thing as being healthy. We know that when it comes to our general health, just because you're not in bad shape physically doesn’t mean you're in good shape. Good is at least one or two steps beyond so-so or okay. That’s true for health, it’s true for diet, it’s true for energy level and mood. And it’s definitely true for sleep.

This point is brought home in a recent issue of the scientific journal Sleep. The author is Daniel Buysse, MD, a top authority in the field of sleep medicine. He raises the point that sleep medicine—a field that goes back at least 30 years—has focused on disorders, diseases, and their treatment. Of course this effort has been momentous, as anyone who has tried to deal with a sleep problem will gratefully agree. But what is needed in addition is a positive frame of reference that gives us a way to know how well we are doing.

KEYS TO HEALTHY SLEEP

What makes for a healthy sleep pattern, one that reinforces good general health? Dr. Buysse suggests that five simple questions can give you a sense of where you stand:

  • Do you fall asleep easily and get back to sleep easily if something wakes you during the night?
  • Do you sleep between six and eight hours a night?
  • Do you stay awake and alert during your waking day, without dozing?
  • Is your sleep schedule appropriate to your lifestyle (for most of us, this means sleeping during the nighttime)?
  • Do you feel you typically get a “good night’s sleep”?

Researchers can get objective answers to most of these questions by observing someone in a sleep lab. But as a rule, that isn’t really necessary. Practically all of us are able to say whether our personal answer to each question is Rarely/Never, Sometimes, or Usually/Always. And that is enough to give us a general idea of our current state of sleep health, but most importantly, a target to aim for—being able to say Usually to every question.

If you fall short of that, like so many of us, what can you do about it? To answer that question, we need to understand something of the basics of sleep itself.

MECHANISMS OF ACTION

The most widely accepted physiological understanding of sleep involves the joint action of two independent brain processes. We want them both to be in sync. The first is sleep pressure. From the moment we wake up, our bodies start building up a need to sleep again. Once we do go to sleep, this need starts to recede. The second process is the circadian cycle, which rises and falls across the twenty-four hour day, under the control of the inner clock. When these two reinforce each other, the result is healthy sleep. But the more they come into conflict, the more our sleep health declines.

The good news is that both sleep pressure and the circadian cycle can be brought under our control. Getting on a regular sleep/wake schedule helps ensure that sleep pressure builds to its high point at bedtime. We detail the ways to adjust the circadian cycle in our paperback guide, Reset Your Inner Clock. For example, if you expose yourself to bright light during the hours shortly before bedtime, it can overwhelm the clock’s sleep signal and make it harder to fall asleep. But if you cut down on light exposure—and especially light in the blue-ish part of the spectrum—you can avoid this interference. Holding back on television and computer use during the evening hours is one simple but effective step toward sleep health. How you arrange your nighttime and morning environment is just as important. Put together the ingredients, and you can rate yourself Usually—or even Always—on the positive side of the sleep equation.

 

Michael and Ian are co-authors of the 2013 Penguin paperback, Reset Your Inner Clock. They invite you to follow them on Twitter for news updates, opinions, and challenging Q-and-A’s. If you want to stay on top of body-clock matters, light therapy, and more — and take advantage of confidential, online self-assessments of inner clock time, depression, and seasonality — you should become part of the nonprofit Center for Environmental Therapeutics community. Email PTuser@cet.org so we can stay in contact.

The Sleep Debt