We all know sleep is a key building block to a healthy life. However, as Dr. Halstrom discussed in a video a couple of months ago on COVID-19 – sleep is about more than just the time we spend laying in bed.
The time we spend laying in bed is called our “Sleep Opportunity.” This is the time we set aside for actually sleeping, but as most of us know, we do not immediately fall asleep upon getting into bed. The time we actually spend sleeping is what you want to pay attention to.
Circadian Rhythm – the tempo of your day
Your circadian rhythm works to control your daily functions such as wakefulness, body temperature, metabolism, digestion, and hunger.
Because of the tempo established with our circadian rhythm, some people are “morning people” while others prefer to stay up late.
How much sleep do you need?
The amount of sleep we need varies with age, but it is often recommended for adults to get 7 to 9 hours of sleep each night. You can find a table on the Mayo Clinic’s website that displays a breakdown by age here.
Remember though, this is the amount of time you actually are asleep (not the amount of time you spend laying in bed). If you go to bed at 11 pm and must wake up by 6 am, you have a 7 hour sleep opportunity. Because of this, it is unlikely you will actually fall asleep immediately and thus you will get less than 7 hours of sleep that night.
How does sleep impact your mood?
Even if you are meeting the 7 to 9 hours per night recommendation for adults, your mood can still be negatively impacted if the time you are waking up fluctuates from day to day.
In an article on Harvard Health, they discuss a study that suggests that in particular, those who are “night owls” (stay up late and wake up late) have particular difficulty adjusting to changes in their circadian rhythm. This comes in contrast with those who commonly go to sleep earlier and wake up earlier as they are able to better adapt to these changes.
Frequent changes in your circadian rhythm can result in mood disorders such as depression, anxiety, bipolar disorder, and seasonal affective disorder.
What about Melatonin?
Melatonin is commonly used as a sleep aid and is a naturally occurring chemical in your body. When it begins getting dark outside at night there are signals that are sent to your pineal gland which in turn releases melatonin to make you feel sleepy.
Because of this, the timing of the release of melatonin plays a valuable role in ensuring you start to feel sleepy at the right time of the day.
Can I change my Circadian Rhythm?
Changing your circadian rhythm can often prove difficult as it is largely determined by your genetics. In general, your rhythm will shift over the course of your lifetime.
While your rhythm may shift towards staying up later at night in your teens, it tends to shift towards waking up earlier as you age farther into adulthood.
While it is often easier to shift your lifestyle around your circadian rhythm, the importance is consistency. Commit to getting up at the same time each day to establish a consistent wake-up time.