Ask a sleep specialist about the relationship between caffeine and sleep and they'll tell you they go together like oil and water.
While caffeine has a detrimental effect on sleep for most people, it can be a lifeline for others for its ability to increase alertness, help you avoid daytime sleepiness, and a number of other benefits (including potentially improving your sex life).
Below is a closer look at the relationship between sleep and caffeine, including how caffeine works, how it interacts with your sleep processes, as well as how you can use caffeine efficiently to stay awake and alert.
Understanding the best way to use caffeine can ensure you get the most out of this naturally occurring nootropic.
How Does Caffeine Work?
Most people are familiar with the caffeine found in a cup of coffee, energy drinks, and green tea, but what exactly is caffeine?
Caffeine is a nootropic. Nootropics (pronounced noo-traah-puhks) are compounds or molecules that enhance cognitive function or performance.
Caffeine is a molecule with a unique effect on the brain, leading to an increase in alertness and wakefulness in addition to stimulation of the central nervous system, which causes an increase in heart rate and respiration. Here's how caffeine works in the body.
Caffeine and Adenosine
Caffeine impacts your brain chemistry meaningfully. The caffeine molecule closely resembles a neurotransmitter in the brain known as adenosine. Adenosine in the brain promotes feelings of sleepiness.
Throughout the day, adenosine is released in your body, slowly binding to adenosine receptors in the brain. As adenosine accumulates throughout the day, it begins to slow nerve firing and promote sleepiness. When you go to sleep, your brain essentially "cleans the slate" by unbinding adenosine, and the process can resume the next day.
Because caffeine closely resembles adenosine in chemical makeup and structure, it prevents adenosine from binding to these usual receptors, delaying feelings of tiredness. In binding to adenosine receptors, there's no room for adenosine to do its usual thing.
Caffeine's effects tend to last a few hours and are only able to block adenosine receptors temporarily. The half-life of caffeine is typically around five hours, and as time progresses its effects wane and you get tired.
Caffeine and Adrenaline
Another impact caffeine has on the body is that it stimulates the release of adrenaline, which is the chemical messenger responsible for your body's fight-or-flight response. This arousal of your sympathetic nervous system causes an increase in respiration, heart rate, and "readiness" for action.
The physiological effects of caffeine have made it a go-to for those looking to get the most out of their exercise, for example. Caffeine tends to be a primary ingredient in pre-workout formulas for this exact reason.
How Can Caffeine and Healthy Sleep Go Together?
Many people view caffeine as the antithesis to quality sleep.
While having caffeine late in the day can certainly impact your sleep, there are ways to maximize the benefits of caffeine for sleep in general.
Below is a closer look at how caffeine consumption can help you get the most out of your day and potentially help you avoid sleepiness.
Avoid That Mid-Day Slump And Quit Naps
One of the most detrimental things you can do for a healthy sleep pattern is take long daytime naps. Naps under an hour tend to be nothing of concern, but if you find yourself taking long naps in the middle of the day or when you get home from work, it can lead to a difficult time going to sleep in the evening and may be a detriment to sleep quality.
If you've made a habit of taking long daytime naps, caffeine may be able to help you kick the habit.
Your body’s internal clock, known as your "circadian rhythm", relies heavily on your sleep schedule to set itself, and it helps your body anticipate sleep by becoming tired around the time that you usually to go to bed.
Drinking coffee or having another caffeinated beverage a few hours before you might regularly take that mid-day nap can help you fight fatigue and skip nap time. Over time, this can help break that nap habit and help you get a better night's sleep at the end of the day.
Prevent Premature Sleep
Another problem that disproportionately affects older adults is waking up too early and then feeling tired during the early evening.
Older adults tend to fall asleep relatively early in the evening and, as a result, tend to wake up much earlier.
Consuming some caffeine in the late morning can provide an energy boost that can help prevent premature sleep and subsequent premature awakening in the morning.
Done consistently, caffeine can help to "reset" your circadian rhythm to sleep longer and wake later in the morning.
Help You Power Through the Morning
Waking up groggy is one of the worst feelings, and unfortunately, it can happen even if you do get a healthy amount of sleep. Caffeine in the morning is a great way to push past that initial grogginess and get you to your normal, daytime functioning self.
An added benefit of a few milligrams of caffeine is that it can help prevent you from going back to sleep, which late risers find a saving grace.
Caffeine can be helpful especially as you transition to a new schedule. College students, for example, might be used to late evenings and late mornings, but entering the workforce after graduation can require a total shift in work and wake schedules. For the first few weeks of transitioning to an earlier wake time, caffeine can help you get a jumpstart and shift your "awake time" a little earlier in the day.
How Do Caffeine and Sleep Work Against Each other?
While caffeine and wakefulness go hand-in-hand, caffeine is a common contributing factor in sleep disorders and other sleep-related problems.
In turn, a lack of sleep can contribute to many medical issues, too, including insomnia, poor sleep quality, and even erectile dysfunction. Below is a closer look at how caffeine can be detrimental to sleep quality and length, and what you should do to enjoy the benefits of caffeine without impacting your sleep health.
Delay Sleep
The major issue with caffeine has to do with its effect on the body's natural sleep-wake rhythm. As discussed previously, caffeine inhibits the neurotransmitter adenosine from its usual processes, which is one way that the brain tells the body to get ready for sleep.
Without this normal adenosine function, caffeine can make you feel alert and wakeful even when you're trying to catch some shut-eye.
The best way to avoid this is to cut off caffeine consumption at or before noon, or at least 6 hours before you plan to go to bed.
This timeframe allows for caffeine molecules to be broken down in most people, and for normal adenosine binding to occur once again, allowing you to fall asleep more easily.
A Vicious Cycle of Caffeine
Another problem with caffeine intake and sleep is that if used irresponsibly, it can lead to a vicious cycle of caffeine consumption to feel awake, leading to poor or not enough sleep.
This cycle tends to begin with using caffeine to stay up late. When you finally get to sleep, your sleep is low quality, and as a result you may consume more caffeine in the morning to feel more awake once again.
To continue feeling awake throughout the day, you reach for an energy drink or another coffee. By the time you go to bed, you have so much caffeine in your system that your sleep suffers, and the problem of low sleep quality persists.
This vicious cycle can lead to caffeine reliance, but it can also contribute to sleep deprivation and other "co-morbidities." Abstaining from caffeine for short periods and getting proper sleep may help in this instance. Many people who build up a reliance on caffeine, however, develop withdrawal symptoms when cutting out caffeine.
If you find yourself in this situation, you may want to try slowly weaning yourself from caffeine to avoid unpleasant side effects.
The Takeaway
Overall, caffeine can be a great tool for that occasional pick-me-up, but it can also cause a variety of sleep-related problems.
The best way to avoid sleep issues is to leave your caffeine consumption to the morning, where it can have a smaller impact on your ability to get to sleep later.
Sources
Pharmacology of Caffeine - Caffeine for the Sustainment of Mental Task Performance | NCBI
Spilling the Beans: How Much Caffeine is Too Much? | Food and Drug Administration (FDA)
