Observe an early bird and a night owl in their natural habitats and you’ll notice distinct differences. The early bird rises with the sun, full of energy, but gradually becomes more exhausted as the day progresses, often crashing around sunset. On the other hand, the night owl wakes up long after the sun has risen, initially groggy but gradually coming to life, especially after a cup of coffee. They hit their stride later in the day, comfortably coasting past sunset and only heading to bed in the early hours of the morning.
Many people can relate to either being an early bird or a night owl. But how many people truly fit these categories? And are our natural sleep schedules predetermined at birth, or can we change them? The truth is, there’s a lot of space between these extremes, and most people fall somewhere in the middle. These behaviors are determined by our circadian system, which is anchored by a pair of nerve cell clusters located in the anterior hypothalamus. These nerve cells respond to light exposure coming in through your eyes to track the day-night cycle that dictates your body’s internal clock, or circadian rhythm.
The steady rhythm of the circadian system helps determine the body’s flow of hormones, with the broader circadian system acting like a conductor that keeps your organs functioning in time with one another. A major part of this performance is managing the body’s transitions between being awake and being asleep. By tracking how much light you typically get and when in your waking hours you usually get it, the system can make predictions about when you’re likely to need sleep and prepare your body accordingly. For example, if you consistently go to sleep around 10 pm, your circadian system will start producing sleep-inducing melatonin around two hours before then to tell your body it’s time for bed.
Everyone’s bodies are unique, so even two people with the same sleep schedule might have different experiences based on their circadian system’s hormonal quirks. For example, where early birds generally flood with cortisol just before waking up, night owls often have their cortisol peak roughly 30 minutes after getting up. Hormonal differences like these determine how you experience your circadian rhythm. And while these factors can shift with age, you’re unlikely to grow out of your body’s preferred sleep schedule. However, you can cultivate habits to help or hinder your circadian rhythm.
Keeping consistent sleeping hours helps your body accurately predict when to send out hormones, making it easier to stick to your schedule. Conversely, research in sleep-deprived college students has found their unpredictable sleeping habits weaken their entire circadian system. Compromised circadian rhythms are less effective at coordinating organ functioning and can incur health risks like metabolic disorders and vulnerable immune systems. But perhaps just as important as sleep hygiene is light hygiene. Getting sufficient contrast between bright daylight and dimmer nighttime light is essential for synchronizing your circadian rhythm, and nothing establishes this contrast better than sunlight. Even on overcast days, sunlight is much brighter than standard indoor lighting. So if you’re typically awake during the day, try getting outside as soon as possible to teach your body when to be active and alert.
It’s difficult to maintain a sleep schedule that pushes against your body’s preferences. And even if you succeed for months, it only takes one bad night to send your circadian system back to baseline. But whether you’re an early bird, night owl, or somewhere in between, it’s important to remember that as long as you’re consistent, there’s no wrong time to wake up or go to sleep. What matters most is getting enough rest for the day ahead.
Keep a sleep diary for one week. Record the time you go to bed, the time you wake up, and how you feel throughout the day. At the end of the week, analyze your sleep patterns and determine if you are more of an early bird or a night owl. Discuss your findings with the class.
Conduct an experiment to see how light exposure affects your circadian rhythm. For three days, spend at least 30 minutes outside in the morning sunlight. For the next three days, avoid morning sunlight. Record any changes in your sleep patterns and energy levels. Share your results in a class discussion.
Split into two groups: early birds and night owls. Each group will research and present arguments on why their sleep schedule is better for health and productivity. Engage in a debate, using evidence from the article and additional research to support your points.
Based on the information from the article, create a personalized sleep hygiene plan. Include strategies for maintaining consistent sleep hours and improving light hygiene. Implement your plan for one week and write a reflection on its effectiveness.
Create a flow chart that illustrates how the circadian system regulates hormone production throughout the day. Include key hormones like melatonin and cortisol, and explain their roles in sleep and wakefulness. Present your flow chart to the class.
early bird – a person who likes to wake up early in the morning
Example sentence: I’ve always been an early bird, waking up at 5 a.m. every day to go for a jog.
night owl – a person who prefers to stay up late at night
Example sentence: My sister is a night owl, she stays up until 2 a.m. watching movies.
sleep schedules – regular patterns of sleep and wakefulness
Example sentence: It’s important to maintain consistent sleep schedules to ensure a good night’s rest.
predetermined – decided or arranged in advance
Example sentence: The meeting time was predetermined, and everyone was expected to be there on time.
circadian system – the internal biological clock that regulates various physiological processes over a 24-hour cycle
Example sentence: The circadian system influences our sleep-wake cycles and other bodily functions.
hormones – chemical messengers produced by the body that regulate various bodily functions
Example sentence: Hormones such as melatonin play a crucial role in regulating sleep and wakefulness.
circadian rhythm – the natural 24-hour cycle of physiological processes in living organisms
Example sentence: Our circadian rhythm helps us feel awake during the day and sleepy at night.
consistent sleep – regular and uninterrupted periods of sleep
Example sentence: Getting consistent sleep is important for maintaining good overall health.
light hygiene – practices that promote healthy exposure to light and darkness for better sleep
Example sentence: Avoiding bright screens before bed is a part of practicing good light hygiene.
sleep schedule – a planned routine for sleep and wakefulness
Example sentence: I need to set a strict sleep schedule to ensure I get enough rest each night.
