When I first got to college and moved into the dorm, I quickly realized that sleep is not a high priority for most students. Late into the night, the dorm is still alive with activity. It’s pretty unusual to go to bed early or to have a consistent sleep schedule. In fact, it’s even somewhat of a badge of a honor to describe how late you stayed up last night doing homework, studying for a test, or goofing off. However, isn’t that just a part of college? Is it really worth it to use valuable time every night to lay in a bed for eight hours when you still have a list of things to do?
To help us better understand this, let’s take a look at what is actually going on during sleep.
Sleep is not merely the absence of wakefulness, but rather a highly regulated active state for our bodies. After a long day of using your brain and, therefore, using adenosine triphosphate (ATP, a molecule our bodies use to store energy), adenosine begins to buildup in the brain. This signals to our bodies that it’s time to sleep.1 Caffeine works because caffeine molecules compete to bind to the same receptors as adenosine, tricking our bodies into thinking there is less adenosine buildup than there is. Exposure to daylight prevents us from producing sleep hormones, so when it begins to get dark, our pituitary glands are allowed to release the hormone melatonin. It then enters the bloodstream, telling our body it is time to go to bed and later helping to control our sleep cycles.2
Once we lie down and begin to doze off, our brain waves begin to become slower and less frequent during light sleep. After around half an hour we enter deep sleep and our brain waves become very slow and are considered delta waves. Our heart rate becomes slow, our blood pressure and body temperature drop, and our breathing slows down. During this time, our bodies begin to repair muscle, build bone and strengthen our immune systems. Much of this physical restoration is achieved by growth hormone that is released during this phase.
After 70-90 minutes of sleep, we enter what is called the rapid eye movement phase (REM sleep), named for the observation that our eyes rapidly dart back and forth under our eyelids. During this phase, our brain waves look as though we are awake. Our muscles are in a state of paralysis yet our breathing becomes more rapid and irregular, our heart rate speeds up and our blood pressure rises. REM sleep is the time when most of our dreams occur.3
The brain’s self-cleaning mechanism is also about 10 times more active during sleep. Cerebrospinal fluid (CSF) flows across the brain’s surface and picks up metabolic waste as it drains into our lymphatic vessels (a system of vessels with many functions, including removal of waste and fluids).4
After cycling through these 90-minute stages around five or six times, our adrenal glands will secrete cortisol, which will begin to raise our body temperature, heart rate, and blood pressure as we wake up.
Does going through this cycle every night actually make much of a difference for us college students? A recent article in the journal Nature and Science of Sleep addressed this question.5
Clarity of mind and ability to pay attention are essential for learning effectively. Even if you aren’t so tired that staying awake in class is hard, having sleep debt will prevent you from learning as much as you could while rested. Once you get through lecture and studying, it is essential to sleep effectively, as sleeping is when new pathways from what we learn during the day are solidified in the brain. Having a busy and stressful schedule like we often do, sleep debt will not only reduce the positivity of your outlook on your tasks but also decrease your efficiency in completing these tasks.6
Sleep deprivation doesn’t just decrease your ability to be an effective student; it also can seriously compromise your body’s immune function.7 While sickness is never pleasant, the fact is that it can seriously affect your ability to do well in school.
Among the other ways that sleep deprivation may negatively impact you is that it may affect both our metabolism and the hormones that cause us to crave foods, leading to weight gain and an increased risk for type 2 diabetes.8
Now that we have seen some of the reasons getting good quality and sufficient sleep (seven to nine hours)9 is important especially for college students, what can we do to help us sleep more effectively? Here I have compiled some of the most important habits of sleep hygiene that we can use to improve sleep quality:
- Prioritize time for homework during the day, so that you don’t have piles to do at nighttime.
- Avoid caffeine at least six hours before you sleep.10
- Be sure to get at least 30 minutes of activity (even walking) during the day, but don’t do strenuous exercise within three hours of sleeping as it raises your core temperature and increases levels of the stress (and wake up) hormone, cortisol.11
- Set a bedtime routine. Leave at least 30 minutes before sleeping to not think about school work and do something relaxing to clear your mind.
- Avoid screens within those 30 minutes before sleeping, as the blue light hinders melatonin production.12
- Use your bed only for sleeping, so your mind will associate your bed with sleeping, not eating, etc.13
- Limit afternoon naps to less than 30 minutes, after which sleep inertia may further impair your cognitive state.14
- Set a consistent bedtime and wake-up time, and your body will recognize these patterns and fall asleep and wake up when it needs to (without an alarm)!15