Wednesday, 14 May 2014

Are We Ignoring Our Body Clocks?

The body clock (or circadian rhythm) is a system of smaller cellular clocks that is responsible for our daily cycles, we have peaks and troughs in almost all aspects of our biology, including alertness and stress. This rhythm is tuned to the day/night cycle, and helps to make sure our bodies are prepared for the behaviours that are appropriate for that time of day eg becoming sleepy when it gets dark. 

However, recent research suggests that our 24/7 society is causing an increasing number of us to become out of sync with our natural rhythm and that this may be having adverse effects on our physical health and mental well-being.

All animals, in fact all cells as far as I'm aware, have an internal clock. these cellular clocks are controlled by a larger network of cellular clocks in the brain, called the suprachiasmatic nucleus (SCN). this cluster of cells is kept in harmony by the day/light cycle. Using ancestral light receptors in our eyes called retinal ganglion cells, they detect light but aren't used for vision (we have other cells for that). The SCN sends signals to a lot of different regions of the brain, however one of the most important is the hypothalamus- which controls our hormone levels.

There are dozens and dozens of hormones, each controlling aspects of our bodies that result in subtle but important daily rhythms. For example, the sleep hormone melatonin is at it's peak during the dead of night and steadily drops until we reach the time we should wake up 9 (which is naturally around or a bit after sun rise). In contrast, adrenaline is at it's lowest during the night and peaks during the day– we also experience a brief burst of adrenaline just around the time we wake up to kick-start the body.

These daily rhythms help us to survive by making sure we are the most alert at the most stressful times of the day, making sure our organs run smoothly with our meal times and making sure we fall asleep at the right time. The BBC has a feature about body clocks that makes it easy to understand our daily rhythms, what is best to do at what time of day, and to see whether we are still in tune with our natural rhythms or not. 

We all have that temptation to skip on a couple of hours of sleep in order to get more stuff done during the day, especially if assignments or exams are coming up! But by doing this, you're not only not working at your best at the time, but the rest of the next day you'll be too tired to really work to the best of your ability. A rule of thumb I've seen thrown around is, for each extra hour you stay awake working, you lose 1–2 hours of quality thinking the next day. You're better off getting that extra sleep, waking up early and getting the job done when your brain is functioning much better. 

In order to make sure you are able to get the right amount of sleep at the right time, you might want to consider your "sleep hygiene". Do you use your phone in bed just before trying to go to sleep? Do you try and work all the way up until the last moment before going to bed, without taking the time to wind down? Is your room too bright, noisy, the wrong temperature? Do you drink caffeinated drinks in the afternoon/evening? All of these things and more can have an effect on your sleeping patterns and can disrupt your daily rhythms. 

So take a look and figure out how in tune you are with your natural daily cycles, and see how you can structure your daily routine to capitalise on these peaks and troughs throughout the day! There are 3 main ways that you can do this; do your hardest work between 9am and 12pm, exercise between 3pm and 6pm and try to sleep from 11:30pm to 8am. 

Sources and Further Reading


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