What are the benefits of foot bathing?
Of course there are benefits, the biggest benefit is comfort.
Imagine that in the winter, especially those who have cold hands and feet, in their spare time, soaking the whole basin with hot water and soaking their feet, not only solves (even temporarily relieves) the problem of cold feet, but the whole body can also sweat slightly. Feeling whole body Shutai is naturally comfortable.
Or some people say that the “benefits” mentioned here are various health benefits that are widely spread around the world, not just comfort.
If so, the so-called health benefits of various foot baths, including footbaths with foot massage, are lacking evidence.
In addition, there is limited evidence that people with cold feet may soak their feet before going to bed.
Changes in sleep and body temperature
Soaking your feet before bed may help sleep, which is mainly related to changes in body temperature during sleep.
It is known that both human sleep and body temperature have a typical circadian rhythm.
Moreover, this change in body temperature is required for good sleep.
It can be seen from the figure above that the person’s body temperature gradually decreases from the usual sleep time to the lowest level in the middle of the night.
Research evidence shows that the drop in body temperature at night is not simply sleep-accompanied behavior, but is required for sleep.
This is because entering the sleep state, the metabolism of the human body and the physiological activity rate of most tissues and organs also enter a relatively low state, which requires that the body temperature also needs to be reduced accordingly. If the body temperature cannot be lowered to a suitable level in time, it will interfere with sleep, and even affect Sleep quality.
We know that the regulation of body temperature is the result of a dynamic balance of body heat production and heat dissipation.
The decrease in body temperature requires more heat dissipation to the environment to achieve this, which requires increasing the temperature difference between human skin and the environment.
Different types of skin in different parts of the body have different roles in regulating body temperature.
Among them, the palms of the hands, feet, auricles, and some parts of the face are hairless skin, with abundant blood circulation and arteriovenous anastomosis (the direct path between arterioles and venules); and they are often exposed.
These features are intended to serve as the “conventional heat exchanger” for the human body.
That is, under normal conditions, body temperature regulation is preferentially adjusted by vasoconstriction and relaxation of the skin in these areas, and sweating.
The so-called hairy skin in other parts is more suitable as a thermal insulator, which is conducive to preserving body heat rather than heat exchange.
As mentioned above, falling asleep requires the core body temperature to be lowered first. This reduction is achieved through increased heat dissipation from the skin of the hands and feet.
Warm hands and feet are good for falling asleep
In this way, in order to get good sleep and fall asleep as soon as possible, on the one hand, the bedroom needs to be kept relatively cold. The suitable sleeping room temperature recommended by the American Sleep Foundation is 15 ~ 19 ℃.
On the other hand, the skin of the hands and feet needs to have a relatively high temperature, that is, hands and feet warm.
On the contrary, if your hands are cold and your feet are cold, and the blood vessels continue to contract, it is not conducive to heat dissipation, which will affect the decline in body temperature, thereby extending the time to sleep, that is, the sleep latency.
In real life, many people have this experience. In the cold season, if you have cold hands and feet, it is not easy to fall asleep.
Some scientific research also provides some evidence.
The basic conditions for this type of test are to perform a foot bath before going to bed, the water temperature is about 40 ° C, and the foot bath time is between 20 and 40 minutes.
The test results show that a foot bath can effectively raise the temperature of the foot without significantly affecting the core body temperature.
The effect of this foot bath before bed on sleep is mainly reflected in the fact that it can shorten the sleep latency and promote falling asleep as soon as possible.
However, the effect of this sleep aid is mainly seen in people with cold feet, and people with warm feet have no obvious effect.
As for the effect of footbath before bed on overall sleep quality, the results are inconsistent.
It is generally believed that there may be improvement for people who have poor sleep quality; for people without sleep disorders, there is no effect.
It can be seen that the benefit of soaking the feet before going to bed is only to help people who have cold feet to fall asleep faster.
This benefit does not require the trouble of soaking your feet. A hot water bottle or hand warmer can solve it:
Go into the bed and use them to warm your feet and step a little farther.