Sleep Wake Cycle & Circadian Rhythm

Trouble sleeping? Understanding your sleep wake cycle and circadian rhythm can be a great tool to help you fight jet lag and disturbed sleep patterns caused by a stressful or hectic schedule.

So how does it all work?

Your circadian rhythm or biological clock is ruled by the suprachiasmatic nucleus, which is located in the hypothalamus. Other physical body parts that regulate your circadian rhythm are your eyes and the pineal gland (a pea-size gland located in the middle of your brain).

In a perfect world, all humans would get up when the sun rises and go to sleep when the sun sets….

Difficult to do, especially in the northern regions where there is no or little sunshine in the winter months.

So what CAN you do to improve your sleep wake cycle and circadian rhythm?

Understand Your Sleep Wake Cycle

Our body responds to the changes between light and darkness through the production of melatonin.

Here is how it works:

Your retina senses light and a signal is transmitted to the pineal gland. At night, when there is no light sensed by your eye, the pineal gland secretes melatonin into the bloodstream.

During the day, the light from the sun actually inhibits the synthesis of melatonin. At night, synthesis of the hormone is complete, and it results in our body getting ready for sleep: decreased body temperature, alertness and performance.

This diagram (courtesy of Wikipedia) illustrates some of the physical responses to your circadian rhythm.

sleep wake cycle & circadian rhythm

As shown above, your sleep wake cycle is regulated by a 24-hour clock. If you happen to travel across time zones, your body will not get its full 24 hours, which causes a hiccup in your circadian rhythm. Also, for those of us who work nights, our body works against its natural tendency, and this results in difficulty falling asleep, getting up or staying asleep.

Additionally, when you work long hours at work and get home late or when you feel nervous or sleep deprived, your body has trouble following its ideal sleep wake cycle, which disturbs your natural circadian rhythm.

So what can you do about it?

Restoring Your Circadian Rhythm

There are a few things that can help you restore your sleep wake cycle:

  • Aim at getting 7 to 8 hours of sleep per night. Everybody is different and some people need more sleep than others, but studies have proven that the majority of people need 7 to 8 hours of sleep per day.
  • Don’t sleep in on weekends. Although you may want to enjoy lying in bed for an extra hour or two, you body finds it difficult to change its schedule for a day or two and then return to the regular earlier wake up time on Monday.
  • Sleep in a dark room. When your work schedule forces you to sleep while there is still daylight outside, make sure that your curtains are drawn and opaque.
  • Open the curtains when you get up. By letting the sun shine in, your body will react and adjust its circadian rhythm accordingly. If it’s dark outside, turn on the lights.
  • If you’re traveling across time zones, give yourself a few days of adjustment time if possible. Although it may be tempting to stay in your “old time zone”, the best option for your sleep wake cycle is to try to match the “new time zone” as soon as possible. Sometimes this will mean sleeping (or trying to sleep) 9 or 10 hours in a row or perhaps 5 or 6 hours only… Try to avoid scheduling important meetings on that first day if your jet lag is significant (4 hours or more).

If all of these fail, there are also sleeping aids available on the market but you should be aware of the dangers of addiction or other side effects.

Note: Always talk to your doctor before using sleeping aids on a regular basis.

Some natural supplements also exist. These supplements contain melatonin to adjust the sleep wake cycle and restore your circadian rhythm.

Note: As with all natural supplements, make sure to thoroughly research possible side effects and reaction to other medication or supplements you are already taking. When in doubt, consult your doctor.