When you soak in a hot spring, your body feels lighter, your mind calms, and fatigue fades away. This sensation is not just psychological. Hot springs have many scientifically proven health benefits.

In Japan, hot springs have long been used for medical purposes, known as 'Toji'. In modern times, research in hot spring medicine has scientifically clarified these benefits.

This article provides a detailed explanation of the health benefits of hot springs based on scientific evidence. We will comprehensively cover the three effects of hot springs, the benefits by spring quality, and specific health benefits.

The Three Effects of Hot Springs

The reason hot springs are good for health is due to three effects.

1. Thermal Effect: The Warming Effect on the Body

Mechanism Soaking in warm water raises your body temperature.

Effects

Vasodilation

• Blood vessels expand, increasing blood flow
• Oxygen and nutrients are distributed throughout the body
• Promotes the elimination of waste products

Muscle Relaxation

• Heat loosens muscles
• Relieves shoulder stiffness and lower back pain
• Improves joint mobility

Activation of Internal Organ Functions

• Stimulates gastrointestinal activity
• Improves digestion and absorption
• Relieves constipation

Boosting Immunity

• Increased body temperature activates immune cells
• Enhances the function of white blood cells
• Improves resistance to infections

2. Hydrostatic Pressure Effect: The Effect of Water Pressure

Mechanism When you soak in a bath, water pressure is applied to your entire body.

Effects

Massage Effect

• Even pressure on the entire body
• Reduces swelling
• Improves blood and lymph flow

Strengthening Respiratory Muscles

• Water pressure on the chest makes breathing slightly difficult
• Strengthens respiratory muscles (such as the diaphragm)
• Increases lung capacity

Promotion of Venous Return

• Blood accumulated in the legs returns more easily to the heart
• Reduces the burden on the heart
• Improves overall blood circulation

3. Component Effect: The Effect of Hot Spring Components

Mechanism Various mineral components in hot springs are absorbed through the skin and inhaled into the body.

Absorption Routes

Transdermal Absorption

• Trace components are absorbed through the skin
• Easily absorbed through pores
• Local effects (such as skin diseases)

Inhalation

• Inhaling hot spring steam absorbs components
• Effects on the respiratory system
• Notable in sulfur springs

Drinking Hot Spring Water

• Directly absorbed into the body by drinking
• Direct effects on the stomach and intestines
• Only possible with drinkable hot springs

Health Benefits by Spring Quality

Simple Hot Springs

Benefits

• Fatigue recovery
• Stress relief
• Improvement of insomnia
• Autonomic nerve regulation

Characteristics Mild stimulation, safe for anyone to enter.

Chloride Springs

Benefits

• Improvement of cold sensitivity
• Peripheral circulation disorders
• Cuts and burns (after bathing)
• Joint and muscle pain

Mechanism Salt forms a film on the skin, enhancing the warming effect.

Bicarbonate Springs

Benefits

• Skin beautification
• Cuts
• Burns
• Chronic skin diseases

Mechanism Softens the skin's keratin, making it easier to remove old keratin.

Sulfate Springs

Benefits

• Arteriosclerosis
• High blood pressure
• Cuts and burns
• Chronic skin diseases

Mechanism Dilates blood vessels and improves blood flow.

Carbon Dioxide Springs

Benefits

• High blood pressure
• Arteriosclerosis
• Heart disease
• Cold sensitivity

Mechanism Carbon dioxide gas is absorbed through the skin, dilating blood vessels.

Sulfur Springs

Benefits

• Chronic skin diseases
• Chronic gynecological diseases
• Diabetes
• High blood pressure

Mechanism Strong antibacterial effect and vasodilation.

Acidic Springs

Benefits

• Chronic skin diseases
• Athlete's foot
• Atopic dermatitis

Mechanism Strong antibacterial effect due to high acidity.

Proof by Scientific Research

Immunity Boosting Effect

Research Results Regular hot spring bathing has been confirmed to increase the secretion of Immunoglobulin A (IgA).

Stress Reduction Effect

Research Results Hot spring bathing reduces stress hormones (cortisol) and increases happiness hormones (serotonin).

Blood Pressure Improvement Effect

Research Results Continuous hot spring therapy has been reported to significantly lower blood pressure in hypertensive patients.

Pain Relief Effect

Research Results Hot spring therapy has been shown in numerous studies to alleviate chronic pain (such as back pain and joint pain).

What is Hot Spring Therapy (Toji)?

Medically Recognized Treatment

Hot spring therapy is one of the officially recognized treatments in Japanese medicine.

Insurance Coverage At some hot spring therapy facilities, insurance coverage is possible with a doctor's instruction.

Method of Toji

Duration Stay for at least one week, ideally 2 to 3 weeks.

Number of Baths 2 to 3 baths per day.

Effects

• Improvement of chronic diseases
• Improvement of constitution
• Stress relief

Specific Health Benefits

1. Fatigue Recovery

Mechanism

• Promotes blood circulation to eliminate fatigue substances
• Relaxes muscle tension
• Deep relaxation

2. Skin Beautification

Mechanism

• Opens pores, making it easier to remove dirt
• Promotes metabolism
• Bicarbonate springs remove keratin

3. Improvement of Cold Sensitivity

Mechanism

• Improves overall blood circulation
• Dilates peripheral blood vessels
• Warms the body from the core

4. Improvement of Insomnia

Mechanism

• Dominance of the parasympathetic nervous system
• Relaxation effect
• Quality sleep through body temperature regulation

5. Regulation of Autonomic Nervous System

Mechanism

• Autonomic nerves are regulated by thermal stimulation
• Improves the balance of sympathetic and parasympathetic nerves

6. Detoxification Effect

Mechanism

• Elimination of waste products through sweating
• Promotes metabolism
• Reduces the burden on the kidneys

Proper Bathing Methods

Bathing Time

Recommended Time One bath: 5 to 15 minutes

Risks of Long Baths Prolonged bathing can strain the body.

Number of Baths

2 to 3 times a day Bath in the morning, afternoon, and evening.

Leave intervals Leave at least 2 hours between baths.

Hydration Before and After Bathing

Essential Drink a glass (200ml) of water before and after bathing.

Prevention of Dehydration You lose more water than expected in hot springs.

Conclusion: The Power of Hot Springs Proven by Science

The health benefits of hot springs are not just folk remedies. Through the three scientific mechanisms of thermal effect, hydrostatic pressure effect, and component effect, various health benefits are provided.

Fatigue recovery, stress relief, immunity boosting, skin beautification, improvement of cold sensitivity. All of these have been proven by scientific research.

Hot springs are the best health method nature has given us. When you visit Japan, be sure to experience these scientifically proven health benefits.

Hot springs are nature's medicine.