When I wake up at the same time every weekday using an alarm, I wake up at that same time on weekends, even though I fall asleep a lot later Friday evenings.
I’ve been told there was an inner clock, but how does the body measure time? (Sorry if this is unclear)
In: Biology
The *Circadian Rhythm* is the “internal clock” of the human body. Many stimuli affect it (Habits, mental state, physical state, genetics, environmental factors, medication, etc).
One of the main components of it is a hormone called Melatonin, produced mainly in the *pineal gland* of the brain. It is mostly influenced by light (hence, using smartphones at night might cause insomnia and other sleep-related issues). Cortisol is also important in the alertness process (Waking up).
This process is also influenced by learning, i.e. the thing we call habit. If you wake up at a certain time for a period of time, the Circadian Rhythm will adjust.
There are a lot of factors tgat play into it, but as far as I understand it is a mix of melotonin onset (dependent on light, caffeine intake, excersize,cortisol levels, food) and circadian rhythm. Adjustment of wake up time and sleep patterns doesnt happen overnight (thus being jetlag and adjustment period when you travel).
Your sleep consists of light NREM, deep NREM and Rem sleep that normaly shows in a pattern if you have good sleep hygene (dont drink redbull before bed or stare at flourescent lights ie). So eventhough sometimes you go to bed way later, the body can sort of “skip” the parts of sleep, hence why the people with sleep apnea feel alway tired (they cant enter deep NREM sleep – cortisol levels may be too high), and tries again thd next day to adjust to the pattern of hormones and wake up cycle that you have created. Thus you can keep on waking up on the same schedule if you keep the same hormon cycle. When people are jetlag it is the only recommended time to take melotonin by sleep expert, because that is what essentially dictates the phases of sleep.
To the people anecdotally talking about their uncle dad etc that keep on waking up in the morning years after they left their job: The body actually accrues sleep debt that cannot be repaid, its not like you can undersleep all week and then sleep all weekend and be good – no. The few e is production of other hormones that allow you to get into NREM sleep that happens once in middle of the night and once just before to u wake up, that can decline if you are cronically underslept. They decline with age, so if you were depriving yourself in your youth from sleep (up to 45 yrs old) your ability to get the sleep you need declines. It has been proven that chronicly underslept people – are more likely to develop alzheimers because of a build up of plaque (i forgot what its called) that usually gets removed from the brain during REM sleep.
Anyways sleep is fascinating, and if you would like to know more I would highly reccomend Why We Sleep from Mathew Walker. If you dont have time to read/listen, google at least an interview with him, it is very interesting.
Latest Answers