When it comes to Japan, many people associate it with ‘hot springs,’ making Japan the country most fond of baths in the world. The abundance of hot springs is one reason, but even in ordinary households, there is always a bathtub, and many people boil and immerse themselves in hot water every day. Bathing not only has a relaxing effect but also offers numerous health benefits. This article will explore Japan’s bathing culture and the benefits of soaking in the tub. The habit of taking baths in Japan can be considered one of the reasons why the Japanese maintain good health.
History of Bath
Japan’s bath culture began around the 6th century. At that time, the word “bath” referred to either natural hot spring water from volcanoes or steam bathing in stone baths built in natural caves. Even in Buddhism, taking a bath was considered a good thing to do, and many people enjoyed bathing for their health.
In the Edo period (1603-1867), public bathhouses called “Sento” were created as a facility to keep the body clean regardless of Buddhist teachings. Sento is not the modern form of bathing in a large bathtub filled with hot water. In the Edo period, a sento was a “todana-buro,” a wooden tub filled with hot water up to knee-high and used to cleanse the upper half of the body with steam generated by pouring water over burning stones. When replaced in modern times, it resembles a sauna more than a bath.
In the Meiji period (1868-1912), the style of sento changed dramatically, with large baths filled with hot water and a washing area becoming the norm. Later, sentou became more modernized, with bathhouses tiled and equipped with running water, much like today’s bathhouses.
Benefits of Bathing
Improving blood circulation
Soaking in a bathtub exerts water pressure on the body. This pressure is expected to improve blood circulation by applying moderate pressure to the blood vessels under the skin. Along with the activation of blood circulation, the flow of lymph is also promoted, leading to the elimination of cold and swelling. In particular, those who suffer from coldness and swelling in the lower half of the body are likely to feel immediate results. Because the abdomen also shrinks under the influence of water pressure, the frequency of breathing also increases. This creates a virtuous cycle in which “blood that has taken in a lot of oxygen is carried to every corner of the body.
Elimination of fatigue
When the body temperature rises, metabolism is activated and fatigue substances are expelled from the body. As fatigue is reduced, muscular stiffness is naturally relieved. Shoulder and back pain are also likely to improve with bathing. The parasympathetic nervous system, which controls relaxation, becomes dominant when the body is warm. In other words, bathing is a way to relieve both physical and mental fatigue at once.
Relaxation of the whole body
In the water, buoyancy naturally floats the body. It is said that when immersed up to the shoulders, the body weight is reduced to about one-tenth of its normal weight. Being free of body weight allows muscles and joints to rest, and the entire body relaxes. In many cases, people are able to move parts of the body that are painful and difficult to move on land, little by little in the water. When bathing, the warmth of the water combined with the comfort of floating can be expected to double the relaxing effect.
Skin beauty benefits
Human skin is said to be repeatedly reborn in a cycle of approximately 28-29 days. This phenomenon is called turnover. Soaking in a bathtub increases body temperature and promotes perspiration, which improves blood flow and facilitates the flow of waste products from the skin. The increase in metabolic power through bathing also promotes skin turnover. Sweat also serves to expel waste products, so bathing with pores firmly open and lots of sweat can be expected to have a detoxifying effect as well.
Improved effect on falling asleep
Sleepiness is believed to be induced by a decrease in the core body temperature in the deep parts of the body. If you can effectively lower the core body temperature at the right time when you want to sleep, it can lead to a smooth transition into sleep. An efficient way to lower the core body temperature is to “raise the body temperature once and then release heat.” Pre-bedtime bathing creates a body that can more easily lower its temperature in the end. It might be surprising, but the “increase in body temperature due to bathing before sleep” is the key to inducing the “lowering of core body temperature” that leads to a comfortable sleep.
Health Benefits of Bathing
In recent years, new things have been learned about the health benefits of bathing.
People who bathe daily have higher levels of happiness
The relationship between bathing ( soaking in the bathtub) and happiness was studied among 6,000 residents of Shizuoka Prefecture. Happiness is an internationally used measure of how an individual feels about his or her life. It does not necessarily correspond to income; some people may have high incomes but low levels of happiness.
The study found that the percentage of people in the group who soaked in the bathtub daily had a high level of happiness (54%), compared to 44% in the group who did not soak in the tub daily. Those who soak in the bathtub every day are 10% more likely to be happy than those who do not.
Reference：https://www.jstage.jst.go.jp/article/onki/77/2/77_171/_pdf
Reduce the risk of needing nursing care
A three-year follow-up study was conducted on approximately 14,000 elderly residents in 18 municipalities across Japan. The study examined the relationship between the frequency of soaking in the bathtub and subsequent new certification of need for nursing care. The results showed that the elderly who bathed seven or more times a week had a 30% reduced risk of needing nursing care compared to those who bathed 0 to 2 times a week.
Reference：https://www.jstage.jst.go.jp/article/jea/29/12/29_JE20180123/_pdf
Reduce risk of cerebro-cardiovascular disease
A 19-year follow-up survey was conducted on approximately 30,000 men and women living in Akita, Iwate, Tokyo, Nagano, and Okinawa prefectures. The survey asked about the frequency of soaking in the bathtub and clarified the relationship with the development of cerebrovascular disease. The group that soaked in the bathtub 5 to 7 times a week had about a 30% lower risk of myocardial infarction and stroke than the group that soaked in the tub less than twice a week.
Reference：https://pubmed.ncbi.nlm.nih.gov/32209614/
Points to keep in mind when bathing
Bath Temperature
The ideal water temperature for thermal effects is 38-40°C. Since deep body temperature is approximately 37°C, soaking in slightly higher temperature water will increase deep body temperature. The appropriate water temperature depends on the purpose of bathing. High water temperature tends to activate the sympathetic nervous system, which excites the body and mind and does not lead to relaxation.
Time spent soaking in a bath
It is recommended to soak in a bathtub for 10 to 15 minutes. 10 to 15 minutes of shoulder-deep soaking in 38 to 40°C water is said to raise body temperature by approximately 1°C. If you take a long soak because it feels good, your skin will be deprived of moisture unnecessarily, leading to dryness. This is especially important for people who are concerned about rough or itchy skin.
Not good after drinking
Alcohol is a diuretic. Bathing in a water-deprived state after drinking can be very dangerous because more water is lost, increasing the risk of dehydration. In addition, alcohol disrupts blood circulation, which can cause a drop in blood pressure and an increase in heart rate. This can lead to cerebral anemia and arrhythmias.
You have found that Japanese people not only enjoy taking a bath, but also get health benefits from bathing on a daily basis. There are also many public bathhouses and hot springs in Japan, each with its own detailed rules. We will introduce how to enjoy onsen in Japan in a separate article. We hope you will take a visit to a public bath or hot spring on your next trip to Japan and refresh your body and soul.
Reference：https://we-xpats.com/ja/guide/as/jp/detail/10219/
