If you struggle to get the rest you (so desperately) need, imagine there was one simple thing you could do to improve the quality of your Zs. According to neurologist and sleep medicine specialist W. Chris Winter, MD, it's as simple as setting your alarm for the same time every day—no matter how late you hit the hay the night before. In this excerpt from his new book The Sleep Solution ($26; amazon.com), Dr. Winter explains how sticking to that wake-up time will eventually train your brain to doze off at a consistent time too.

I have been asked frequently over the years the following question: “What is the single most important piece of advice for achieving your best sleep?” To me, it’s easy: pick a wake up time and stick with it!

When I ask you, “What time do you wake up in the morning?” the answer should be one simple time. If your answer to that question is, “I get up at 6:45 and usually go to the gym or run outside,” you get a gold star.

However, you probably have a problem if you answer something like this: “I usually go to bed at 11:00 except on the weekends when I go out with my friends and we stay out until 2:00 or 3:00 easily. I’m usually up around noon . . . no later than 2:00 p.m. on those days. On Tuesdays I try to go to bed early, like 9:00 because on Wednesday, I have to get up early for this boot camp exercise class. On those days, I go out to my car at lunch and sleep for 45 minutes. I feel pretty beat by the end of the week and often fall asleep early in the evening. If I do, I struggle to stay asleep and often have trouble falling asleep later. It’s really hard to get up for work on Monday . . . I’m often late. Every now and then, no more than once a month, I’ll use a sick day and stay home from work so I can sleep all day . . .”

Wow, I blacked out there a little bit from acute boredom during that long explanation. But I have to tell you, that was a real patient story. Optimally, an individual should have a consistent bed time and perhaps more important a consistent wake time. Unfortunately, this isn’t usually the case with individuals who have sleep problems. Sleep times can vary wildly in these people and they sadly do not seem to recognize that this haphazard lifestyle is a big part of their problem. In fact, they strangely often see it as working toward a solution.

Some people are in complete control of their sleep schedule. No matter what happens in their lives, they are up at 6:00 a.m. and soon after in the gym getting their BodyPump class on. These individuals are dogs who wag their tails (the dog is in control, and it wags its tail). Other individuals get up and exercise if their evening goes perfectly to plan, but if their sleep is problematic one night, their schedule goes down the tubes. If it takes them an hour or two longer than normal to fall asleep, they ditch their exercise plans and sleep in. For these individuals, their wake time depends on their sleep quality. They are not in control, so instead of the dog wagging its tail, for these individuals, the tail wags the dog. I call them “dog waggers.” Their sleep schedule is dictated by their sleep successes or failures.

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Here are some examples of dog waggers:

“I went to bed early last night because I had a rough night of sleep at my girlfriend’s apartment the night before.”

“My alarm went off at 6:00, but since I couldn’t fall asleep until 3:00 a.m., I hit the snooze and called in to work later saying I was sick.”

“My wife was driving me crazy because I masked the basement last month but haven’t painted yet, so I just did it . . . stayed up most of last night to do it. I took a huge nap when I got home from work, now I’m wired.”

When an individual sleeps in this way, all kinds of bad things are happening. You are teaching your body to sleep only when it’s exhausted. Like a cow grazing for food, you’re grazing for sleep. If you are independently wealthy and have no need to work, congratulations! Maybe the schedule of the world doesn’t apply to you and you can keep up your freewheeling schedule as long as you wish. For the rest of us, the world is full of appointments, deadlines and plenty of times we need to be awake.

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I joke with my patients all the time that if I can’t fix their sleep problems, they should enlist in the military. The army is such a wonderful environment for sleep. They do everything sleep related perfectly. Their wake up time is precise. Fall out at 5:00 a.m. Tired? You’ll get over that quickly as you and your platoon head out for physical training. Change for breakfast at exactly the same time every day. Activities, more exercise, lunch, dinner, and finally back to bed so you can get up and repeat the exact same schedule the next day. Within a few days of boot camp, you will have all sorts of wonderful and exciting problems . . . falling asleep at night will most likely not be one of them. I always think about these soldiers when a patient tells me he has trouble settling at night because his “mind won’t shut off.” I imagine after a day of engaging in grueling exercise, being screamed at and belittled, and missing your family as you wonder what in the hell you’ve gotten yourself into, you might have some thoughts racing through your mind. But still, these men and women sleep.

So when should you go to bed? When should you wake up? I think you see by now why we have to start with the latter. You need to select a wake time that works for your life. If you have to be at work by 9:00 and your commute is 30 minutes, getting up an hour earlier might work for you. Unless you want breakfast or maybe a shower? Unless you want to exercise or maybe you have kids who need to get up for school? The point is to pick a time that’s realistic. And be sure to include time to actually feel awake. Nobody opens her eyes and feels like Mary Sunshine in the morning, at least nobody over three. So be sure to give yourself some time to go from groggy to human.

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One more important detail: There is no such thing as a good or bad wake time. Yeah, depending on whether you are a night owl or a morning lark, one schedule might work better than another. Are you a morning person? Getting up at 6:00 might be better than noon. Always been a real night owl? That 5:30 a.m. wake time to meet some friends for a bike ride might not be ideal. Brain schedule aside, I’m not here to judge. People in the South talk about sleeping in like they talk about sex: in embarrassed whispers. There is nothing wrong with being a night owl. It’s not a sin.

Excerpted from The Sleep Solution: Why Your Sleep is Broken and How to Fix It by W. Chris Winter, MD, published by arrangement with New American Library, published by Berkley, an imprint of Penguin Random House LLC. Copyright © 2017 by CNSM Consulting LLC.