Let's also talk about sleep drive as part of harnessing your body's ability to sleep.

What is sleep drive? 

Sleep drive is another aspect of the body's natural sleep ability which plays an integral part in the symphony. It cannot be ignored if you want to have restful sleep. 

Let's go back to thinking about the body in terms of drums again. You can think of sleep drive like a drum, playing softly in the background. Over time, it gets louder and louder, slowly rising until it hits a peak and gives you that push to fall asleep. After the drum hits its peak, then the drum is quiet while you sleep.

I have mentioned circadian rhythm, focusing upon light exposure, melatonin, and cortisol release as helping you to be sleepy and to be alert at the right times. In that scenario in which I was talking about good sleep, I left off with light waning, stress hormones/cortisol decreasing and Melatonin rising to the point that we are nicely ready for sleep.

Sleep drive is something that our body "collects" and rises while we are awake. Your sleep drive starts to rise when you awaken. It increases to higher levels the longer you have been awake. When it gets to a very high level, then you will be pushed into sleep! You are more likely to fall into a deeper, restful sleep when you have adequately collected enough sleep drive. When you time it with the other parts of the body's natural sleep abilities, like a healthy circadian rhythm, then you have multiple systems coming together for good sleep.

Sleep drive is drained or "lost" when we sleep, even if just briefly. 

Take a look at this video for a visual of the process:

As I was just saying in the video, you do not want to try to sleep when your sleep drive is in a lower range. It will not go well. At best, you may fall into a light sleep. At worst, you will lie awake in bed and not fall asleep at all. 

Remember: How much sleep drive you have hoarded during the day is related to the quality of your sleep at night. If you are having frequent wake-up's during the night or early morning, I'm willing to bet that one aspect at play is that you are trying to sleep when you don't have enough sleep drive collected.

I'd like you to memorize the picture below when you are getting ready for sleep. Use the gauge below to know your likelihood of restful sleep:

Obviously, the meter on the right is ideal: 

You have a full day, including some exercise and do not engage in napping or even in hours of resting (which often leads to a slight doze). 

The most common example of the meter on the far is when you have been sleeping for a portion of the night and try to return to sleep (I'll address what can help you in this situation in the Third Pillar of Good Sleep). 

Another common version is the meter in the middle. If you've had a long daytime nap, a short evening doze, or a just lot of hours of being sedentary, then you are likely to have a sleep drive meter like the middle example. This option leads to sleep, but not to high-quality, restful, and restorative sleep. If you want to make smart choices about your sleep, you will want to examine your sleep habits honestly and figure out where you may be losing sleep drive. 

Let's take a look at a typical disrupted system:

Mary has a project for work coming due soon. She is feeling stressed and has been feeling kind of "amped up" on most days (physiologically, this means that there is likely higher cortisol during the day instead of the normal peak in the morning followed by lower levels).

She stays in bed later than she wanted because she doesn't want to face her day (she rests longer than usual). She doesn't feel hungry in the morning with the stress, so she rushes, skips breakfast, and works through her lunch. When she gets home, she is ravenous and eats a really big dinner with whatever she can find in the fridge (the really big dinner delays/inhibits Melatonin release).

After dinner, Mary works a little more at home and worries about the project on and off through the evening (keeping cortisol higher). She later realizes that she didn't exercise, so she puts in 20 minutes on the treadmill (raising cortisol just before bed).

Because she is feeling sort of alert and not wanting to face the day tomorrow again, and feels like she hasn't gotten any downtime during the day, Mary scrolls through social media on her phone (potentially exposing herself to unnecessary blue light, which delays/inhibits Melatonin release) to catch up with what had gone on during the day and to distract herself from worry. She dozes a little on the couch (draining sleep drive) and then goes up to bed, but she tosses and turns for a while, eventually falling asleep, but not getting enough sleep to feel rested. 

In the morning, the alarm goes off, and even if she is already kind of awake, she hits snooze a few times (potentially draining sleep drive for the next night). By the time she gets out of bed, she's running late and exhausted, thinking that she is going to want an extra cup of coffee. The cycle starts over. 

You can see from this example how Mary is interrupting the body's natural sleep powers in multiple ways. I haven't even mentioned the last Pillar of Good Sleep!

As a review of the main points that I want you to take away:

Sleep drive - as you stay awake, your body "collects" more drive to fall asleep for every hour/minute that you are awake. It is depleted when you doze, nap or sleep. It seems also not to be so well accumulated with a lot of rest or a sedentary lifestyle. I want you to hoard your sleep drive. Greater drive means more likelihood of getting into deeper, restorative sleep and more likelihood of staying asleep through the night.

2. Melatonin/bright light - everyone has heard of it and nobody uses it correctly. Melatonin release in the brain is dictated by exposure to light. Naturally, as your sunlight exposure decreases in the evening, this sets off Melatonin release, which rises in the evening and reaches a point, combined with sleep drive, to push you into sleep. Sensitivity to light varies, but in general, I find that people who are using their cell phones, whether it is the light or the stimulating content, seem to be affected.

3. Cortisol - the stress hormone. Cortisol plays multiple functions, but one is that it helps us to feel alert. Notice how it is the highest at about an hour after awakening, and then continues to basically fall throughout the day. It's timed to be at its lowest in the middle of the night when Melatonin is at its highest. You can mess with this timing by doing things like having high stress, fight or flight mode all day -- you can't expect it to fall immediately if you have high stress and worry right up until bedtime. You can't expect it to fall if you are so busy that you forget to eat all day and then eat a big meal at night (it causes a spike in cortisol) and then fall asleep and get a good night's sleep. If you are cranked up reading news on your phone right up to bed, you are sabotaging the process of stress hormones.

Now, bring this back to how this relates to you: 

Can you think of ways that you might be depleting your sleep drive? dozing in the morning, napping in the afternoon, and dozing at the tv at night right before bed. Napping in the afternoon or night is usually obvious to people. Those are easy places to start. Just get rid of any napping longer than 20 minutes, as long naps interfere with sleep drive. The more subtle ones are microdozes while watching t.v. in the evening, as well as that time when you are sneaking in some extra time in bed in the morning or sleeping in -- these things, too, may deplete sleep drive.

Can you also identify any ways that your use of light or management of stress is affecting you? Smartphones are notoriously a source of light and stimulation (stress), and sleeping in late on weekends, especially when you are delaying light exposure, is another way that you may be sabotaging your circadian rhythm. 

Before you move on to the next lesson, do yourself a favor: Take a few notes, ideally written down on paper rather than mental, regarding some options you have for the greater harnessing of your sleep power so that your body's natural sleep ability is maximized. You can choose from the following processes: sleep drive, Melatonin, and cortisol. 

I'm wondering...are any of you trying to fall asleep when your sleep drive is less-than-optimal...less than the max that you can hoard in a day? Having a maximum amount of sleep drive at the time that you are closing your eyes for sleep will best help you fall asleep, stay asleep, reach deep sleep, return to sleep if wake up to go to the bathroom, and sleep through the night and into the morning. Remember that there are other instruments in the symphony, like melatonin release, but we'll cover greater details of melatonin in our more advanced training, as it's beyond the scope of this course. 

To help you solidify your knowledge, do this 3-question exercise. Just scroll down. I'll review the answers in the Takeaway section.

Takeaways

Was the exercise in sleep hoarding easy? I hope so. I want to review the answers for you so that we are on the same page. 

Question 1: What is a good go-to coping mechanism after a poor night of sleep if you are prioritizing sleep drive?

Answer: The only correct answer is to follow your usual routine. This means that you wake up at your usual time, you avoid naps (especially long ones), you do not give yourself extra rest time or avoid physical activity, and you go to bed on time and definitely not early. This is a situation where conventional wisdom is not correct. You do not want to go to bed early!

Question 2: I presented you with several scenarios and assuming that everyone has a need to sleep 8 hours of sleep to feel rested (which, by the way, is just hypothetical and not everybody needs 8 hours), which person hoarded the most sleep drive?

James got 8 hours, been awake since Noon. He has not napped or dozed. 

Jessica got 6 hours of sleep last night, woke up at 4am, and took a 20-minute nap around 1pm. It's now 10pm.

Jennifer got 6 hours of sleep last night, has been awake since 4 am, and took a 2-hour nap at 1pm. It's now 10pm.

Jonathan got 6 hours of sleep, has been awake since 4 am, and took a brief nap before bed while watching t.v. It's now 10pm.  

If you were trying to choose between Jessica and Jonathan, you are on the right track. If you answered Jessica, then you picked the best hoarder. The brief nap (only about 20 minutes) is likely to be less impactful than dozing right before bed and that dozing right before bed is what Jonathan did. 

The two who were likely to have less sleep drive were James and Jennifer. James got his 8 hours of sleep and has the least number of hours awake before 10 pm. Jennifer had a long nap that could affect her sleep drive significantly, even though it was earlier in the day.

Now, to summarize:

Well, we've talked about the way that the body sleeps its best when everything is working together in harmony, like a symphony. I showed you several aspects of physiology that come together for good sleep. They are melatonin release and the associated light exposure, stress hormones, and sleep drive. 

In your own notes: make a note if there are any ways that you might be draining sleep drive instead of hoarding it.