Key points

Sleep is dictated by two biological processes: sleep drive and wake drive.
Sleep compression involves involves manipulating your sleep drive.
Waking at the same time each day is critical for regulating wake drive.
Drugs are also an important consider.

Research demonstrates a clear relationship between better sleep quantity and quality and improved mood. Due to its importance, seven to nine hours of quality sleep are recommended for adults each night.

How Does Sleep Work?

There are two processes that regulate sleep: circadian wake drive and sleep drive:

Wake drive is stimulated by light entering your eyes (particularly blue light). So, wake drive usually increases through the morning with exposure to light and decreases into the evening, as it gets dark.
Sleep drive gradually increases as the neurotransmitter adenosine accumulates and binds to adenosine receptors in the brain. As you sleep, adenosine breaks down, resetting to baseline by the next morning. So, sleep drive increases slowly for every hour you're awake and resets overnight.

Ideally, by the end of the day, sleep drive is high as wake drive declines, and by morning, wake drive increases as sleep drive returns to baseline.

Where Sleep Goes Wrong

Problems with sleep include taking too long to fall asleep, or waking up too frequently during the night or too early in the morning.

Thankfully, you can correct these problems by aligning the peak of your sleep drive and the trough of your wake drive at the time you want to sleep (you can see this in the following diagram). In doing this, you will train yourself to fall asleep faster and to sleep more solidly through the night.

Improve Sleep Through Sleep Compression

One technique is to compress your sleep.

Set a standard wake time that you will get up every day of the week. Let’s say 7:00 am.
Figure out how much time you are sleeping currently. Let’s say you’re only getting five hours.
Go to bed the amount you are currently sleeping + 30 minutes before your set wake time. In this case, it would be 1:30 am.
After one night, estimate how long you spent awake in bed (including time before sleep onset, awakenings during the night, and time awake before getting up).
If you lie awake in bed for 30+ minutes, go to bed 30 minutes later the next night. If you lie in bed for < 30 minutes, go to bed 30 minutes earlier the next night.
Repeat steps 4 and 5 until your sleep stabilises or until you hit your sleep goal.

This may seem crazy, as you may temporarily incur a sleep debt, but it will eventually train your body to sleep soon after getting into bed and solidly until morning.

Improve Sleep Through Circadian Rhythm

You may also find that you have problems with your circadian wake drive.

Circadian wake drive is often referred to as circadian rhythm because of its clock-like capacity to bring us out of sleep. You might sometimes have the eerie experience of your body waking you a minute before your alarm is set to go off. This is a sign that your circadian rhythm is working well. However, you may also have had the experience of your alarm tearing you from sleep, leaving you wanting to snooze or groggy. This is a sign that your body has been woken during a deeper stage of sleep (e.g., deep sleep) instead of a lighter sleep stage (e.g., REM sleep).

For those who have inconsistent wake times, it can make it difficult for your body to plan when you enter deep sleep. The result may be that your body slates you for a deep sleep cycle at the time you need to wake. However, if you establish a regular wake time, your body will ensure you’re in a lighter sleep stage when you need to wake.

So, the best thing you can do for your sleep is to wake up at the same time every day to help establish a consistent circadian rhythm. Unfortunately, this means no sleep-in days, even on weekends.

Lifestyle and Sleep

If you find your body naturally doesn't get tired until late into the evening, consider using blue light filters on screens in the evening, avoiding eating or alcohol intoxication within a few hours of bedtime, and engaging in relaxation meditation or controlled breathing to induce sleep. Also, it’s important to exercise and avoid napping during the day to maximise your sleep drive for when you need it at night.

Sleep Drugs

You can also consider speaking to a medical professional about melatonin, which can be used to wind down your circadian wake drive at the time you need. Alternatively, valerian and magnesium are evidence-based sleep supplements4 you can grab off the shelf to help increase sleep drive.

Caffeine and Sleep

Caffeine increases our wakefulness by blocking adenosine from binding to the adenosine receptors. So, if caffeine is in our bloodstream when we sleep, it can significantly impair sleep.

It takes about six hours for half of the caffeine you consume to leave your bloodstream. For example, if you have a cup of coffee at midday, you'll have the equivalent of half a cup of coffee in your system at 6 pm and around a quarter of a cup of coffee in your system at midnight. So, if you think that having a quarter of a cup of coffee at midnight might affect your sleep, you may want to reconsider your lunchtime latte.