The biological clock causes many processes in the body – temperature, blood pressure, metabolism – are aligned properly at the time of the day. Thus, your blood pressure and body temperature overnight low and they are brought up to standard again stand up for you. At other times of the day makes your clock for example, that you are alert and can digest food.
In order to function properly has the biological clock requires no light. If you’re completely isolated from daylight, the body retains its natural rhythm of sleep and wakefulness in 24 hours. Well that own pace slightly slower. On average about 12 minutes. Without daylight rhythm you would so move every day 12 minutes. Daylight makes the biological clock is put right again.
Light causes your body to stay awake, you’re alert and that you can be active during the day. The hormones cortisol and adrenaline play here an important role. They are also called waking hormones.
In your eyes are special photoreceptors (rods and cones) that respond to light. As it darkens, your body produces the sleep hormone melatonin to. Thanks to this hormone fall asleep, but it could during the day – in low light – also make sure that you are sleepy. The more light you see during the day, the more your body makes melatonin at night to.
In winter you need more sleep than in summer. In summer it is slightly longer, giving you more active and less tired. The melatonin production is also later started and it will create just more adrenaline and cortisol. This will keep you awake easier.
The photoreceptors in your eyes are particularly sensitive to the blue part of the light spectrum. The morning light has a lot of blue, so your biological clock reacts strongly to this light. Not only natural morning light, however, contains the blue light spectrum. Also, halogen lamps, televisions, LED screens, tablets and smartphones produce lots of blue light.
If you bedtime long peers into blue light, make less melatonin and harder you fall asleep. Candles and traditional lighting add more red light and therefore less impact on your sleep pattern. Yet it is – if you sleep badly – important to dim light. Sleeping in the dark is therefore best for your sleep.
To wake up early to move fresh out of bed, it is therefore important to be out during the day as possible. Your biological clock is in fact very useful when daylight; which is much more intense than artificial light.
In the summer daylight in full sun namely a strength of more than 100,000 lux (unit of illuminance). In indirect sunlight is 10 to 20,000 lux and 1000 lux on a cloudy day. At home you will not get much further than 150 lux, office 300 to 500.
The strong light on a cloudy day (1000 to 2000 lux) is about the minimum that your body needs for the biological clock to function optimally. The light inside is so far too weak.
Basically 10 minutes outside is enough to turn your clock back ‘right’. Have you not been outside for a few days? Try at least two hours to go outside. Go preferably in the morning or early afternoon out if you have trouble falling asleep . Are you always wake up early, you can better later in the day to go out.