Are you having trouble falling asleep? Then read on. You can fall asleep 15 minutes earlier and wake up less often at night if you put on a pair of socks before going to sleep.
To understand how this works, you first need to know more about the relationship between core body temperature and sleep. During the day, your human body thrives at an average temperature of 37 °C. At night, however, your core body temperature drops by as much as 1.2 °C at a sleep of six to seven hours.
It appears that this gradual decrease in core body temperature plays an important role in falling asleep and staying asleep. So the faster you can lower it, the faster you fall asleep.
One of the ways in which the core body temperature is regulated is through the blood vessels in your skin. If the brain decides that the body is too warm, the blood vessels will dilate (vasodilation). As a result, warmer blood is redistributed from the core of the body to the rest of the body to cool it down. If the body is too cold, the brain signals the opposite, limiting the flow of blood to the surface (vasoconstriction).
That is when your feet start to play a role. This is because your palms and soles of your feet are the most efficient heat exchangers in your body, because they are hairless and less isolated than other skin surfaces. Researchers have shown that warming your feet before bedtime, for example by taking a warm footbath or wearing socks, promotes blood vessel dilation. As a result, the core body temperature is lowered faster than when you go to sleep with cold, bare feet.
It turns out that the temperature difference between your limbs and your abdomen is the best indicator of your sleeping chances. It is even stronger than hypnosis or taking melatonin before going to sleep.
But there is more! Scientists assume that sleeping with socks also has a neurological effect. The ‘thermostat’ of the brain is in an area called the pre-optical/anterior hypothalamus (PO/AH). The PO/AH contains a heat-sensitive neuron (WSN). This neuron increases its speed when there is a difference in temperature between the body core and the extremities, such as the feet.
It’s a bit like the chicken and the egg story, but research has shown that the WSN speed increases at the beginning of ‘slow-wave sleep’ or ‘deep sleep’, and gradually decreases before you wake up. WSNs can therefore play a role in the feeling of sleepiness that helps to get and stay asleep. And if that’s the case, warming up your feet before going to sleep gives WSNs an extra boost.
In a small study, South Korean researchers discovered that wearing a pair of special sleeping socks – which apparently is one thing there – not only speeds up falling asleep, but also extends the overall sleep time by an average of 30 minutes and halves waking up at night.
A final tip: are you afraid that wearing socks in bed will make you too hot? Then opt for socks made of naturally breathable fibres.
Hey, that’s cool!
If you think wearing socks in bed isn’t sexy, a study showed that 80% of couples who wore socks reached orgasm, compared to only 50% of non-sock wearers. Apparently, having cold feet is very distracting!