Circadian clock and sleep and their relation to physical activity

It has been in my mind to write few words regarding sleep as it is clearly one of the most important though many times neglected factors affecting human health. As Nobel Prize in Physiology or Medicine was awarded this week for the researchers who had made significant contributions in the area of circadian clock, I thought that this is good moment to emphasize the importance of sleep for our wellbeing.

You can read and listen about the importance of circadian clock and why the researchers wo found it were awarded with the Prize. Bottom line is that it is important to “respect” this clock, and this means sleeping enough and sleeping during those day hours that you are meant to, thus during night time. For most of us this means at least 7,5-8 hours, but easy way to determine your requirement is to sense if you feel tired or not when you wake up. If you feel tired you have not slept enough and sleep time should be extended until you wake up fresh and rested. Nowadays we know quite much about sleep and how sleep deprivation, even slight one particulary if prolonged, causes severe health problems such as metabolic disturbances leading to heart disease, diabetes and cancer. In relation to circadian clock, “evening chronotype” seems to be particulary unhealthy.

Despite all this knowledge and feeling tired, many people are not sleeping enough although that would be one of the easiest means to improve our health, wellbeing and mood as well as creativity and productivity. Furtunately physical activity could help as there is at least some evidence that it can correct disturbed circadian clock if that is the case contributing to sleep deprivation. However, increasing physical activity might not always be the best option when struggling with tired body. I personally favor and practise that kind of behaviour that when I feel tired and sleep deprived, I take 1-3 days bit more easily exercise-wise, and try to get enough sleep. Some easy physical activity during those days is still good, which in my case means only normal cycling or kick biking to work (60 min in total) but no other or heavy exercise, which I would normally do almost daily in addition to commuting. This usually helps to find the right balance again. Sleeping more might also be good starting point if you feel you are too tired to exercise, and gradually body is rested enough that your body even insists to get some exercise!


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  1. You could certainly see your expertise within the paintings you write. The sector hopes for more passionate writers like you who are not afraid to mention how they believe. All the time follow your heart. “In America, through pressure of conformity, there is freedom of choice, but nothing to choose from.” by Peter Ustinov.

    • ilkka

      Thanks Nguyet, let’s stick to those principles!

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