Hot Water and Healthy Living

By Jonathan B. Smith

Indian University of Pennsylvania

Disclaimer: Safe Soaking

The information contained in this book, Hot Water & Healthy Living, represents the findings of the author. The use of hot water may carry certain risks and may not be suitable for every person. Therefore, readers are strongly urged to consult with their physician before soaking in hot water. The use of hot water may carry certain unavoidable risks, including(but not limited to) physical and medical effects of prolonged exposure to hot water, risks to pregnant women from soaking in temperatures above 102 degrees, overheating, scalding, adverse effects when combines with alcohol or other drugs, physical injury, drowning and death. Readers should follow all manufacturer’s guidelines, recommendations and warnings in connection with the use of hot water, and follow all applicable laws, regulations, and codes.

Preface

Startling research shows that both the body and mind benefit from the simple act of immersion in warm water. We live in a world where many people are facing serious health issues, including loss of mobility, chronic disease, depression, and premature death. Movement in water, even simple immersion in water, is an ideal way to improve our health and the quality of our lives. Regular soaking in warm water, whether it is a bath, natural hot spring, or portable spa/hot tub, shouldn’t be considered an extravagance. The reality is, as you will discover in this book, soaking in warm or hot water can make a big difference in your health and daily living. The benefits are broad, and the science is exciting. The National Swimming Pool Foundation (NSPF) invited Dr. Jonathan B. Smith to research existing science and to share with you how hot water helps to create healthier lives. We hope that you enjoy reading about how “getting in hot water” can lead to happier, more active lives for you, your family, and your friends. Proceeds from the book are used to fund aquatic health benefit research. – Thomas M. Lachocki, Ph.D.

Introduction

Picture a recent stressful day. Perhaps you worked all day, had a disagreement, fought traffic for 30 minutes or more, and came home either tired or not prepared to shift to the demands and rewards of home life.

Now, imagine a different start to the evening. You arrive home eagerly, shed your day’s worries, and slip into your personal hot tub. After lingering a few minutes in the warm water, having your muscles and joints massaged with water jets – physical, mental, and emotional relaxation takes hold. In fact, as you climb out and dry off, you feel calm and energized for the evening ahead. Sure, life at home has its demands and stresses, but you know from experience that your evening soak can help you feel better for up to four hours. Can you see it? This is a brief picture of how regular soaking in hot water can provide a relaxing oasis in our stressful daily lives. It is like taking a little vacation every day. Of course, no amount of scientific explanation can equal what 15 minutes soaking in hot water several times a week can mean for you. We encourage you to do more than read. Explore improving the quality of your life by trying a hot water soak yourself. You can visit a professional hot tub retailer; many have programs to give you a private “test drive” of a hot tub.

The Potential of Warm Water Immersion

For thousands of years, civilizations have been born, developed, and prospered beside water. Throughout history, people have used water to maintain their health and to recover from injuries. We need only watch children play in puddles after a summer shower to confirm our instinctive attraction to water. Today, water activities remain very popular. The United States has over 400 million annual visits to aquatic venues such as pools, hot tubs, fresh water outlets, and beaches. In fact, there are over 5 million hot tubs in the United States.

Many books, magazines, news stories, and government reports alarm us that Social Security, Medicare, secure retirement, pensions, insurance, and our average life span are all in jeopardy due to our poor health. We hear media stories every day about problems like obesity, heart disease, diabetes, cancer, and an aging population. Yet, the general public and health-care providers are often unaware of the science that demonstrates how hot-water immersion can ease these problems.

The question many of us have is, “How can immersion in hot water benefit my health?” Our bodies make adjustments when we are immersed in hot water. These changes are similar to those that occur when we exercise. The changes include increased circulation, more efficient breathing, and improvements in mood. It is well known that when a person’s body is immersed in water, the water’s pressure affects almost every part of the body. When immersed, the body must adjust to the pressure from the surrounding warm water. The result is greater cardiac output and lower resting pulse rate. Also, the water pressure and hot temperature help the body to release chemicals (hormones) that help us relax and improve our mood.

This book summarizes the present knowledge about many health benefits that result from immersion in hot water. Specifically, the book highlights how hot-water immersion can help to heal our injuries, exercise our heart, and improve our mental health.

Hot Water & Healing

As we experience life, we often feel pain and sore muscles and joints. Healing happens faster as blood flow to the injured location increases. When we perform light exercise, our muscles are less sore. This is because exercise increases blood flow, thus improving the healing. Immersion in all temperatures of water has been used extensively for years to promote the healing of wounds and injuries. The success and positive results associated with water immersion have been noted in the healing of wounds. More specifically, water immersion helps in the healing of muscles and/or joint injuries.

There are several ways in which hot-water immersion improves healing:

1.  Immersion increases circulation. When muscles are warmed and the body is immersed, the blood supply to the area increases. More blood flow means more nutrients are available to help cells regenerate in order to speed the healing process. Also, the increase in blood circulation helps remove pain-causing chemicals that build up in tissues. As a result, muscle pain goes away faster.

2.  When our bodies are immersed, water exerts pressure on our body. This increased pressure tends to reduce swelling. For example, our ankles and feet are less likely to swell in water than on land.

3.  The buoyancy of the water provides unique benefits that are significant. Immersion in water reduces the amount of weight we bear on our joints due to gravity. The result is we feel lighter in water. Activities we may find painful on land are easier in water. Water is thicker than air and provides resistance to movements. The resistance increases depending on how fast we move against the water. This is called graded resistance, which is helpful when we exercise in water to help recover from injuries. Numerous studies demonstrate the increased range of motion and decreased pain when therapeutic exercise is performed under water.

4.  Being able to “get around” is very important to most people. Water plays a useful role for people who suffer from arthritis, knee, hip, or other joint problems. Immersion in warm water tends to increase joint mobility, reduce joint stiffness, and increase flexibility and range of motion. For example, people with arthritis and lower back pain experience greater flexibility and less pain with regular use of warm water immersion.

 

Therapy can be painful. Performing therapy in water is often less painful. Professionals who provide therapy recognize that immersion can lead to a faster and a longer-lasting recovery. As a result, water is commonly used in physical therapy and rehabilitation. An environment which is less prone to cause pain, and is even pleasurable, makes immersion in warm water a unique healing environment.

 

Hot Water & Heart Health

 

Our hearts pump blood through the circulatory system (arteries and veins) to all parts of the body. The veins and arteries expand and contract depending on the volume of blood being pumped. Blood circulates oxygen and nutrients throughout the body and carries waste away from cells. When we exert ourselves or when we exercise, our hearts pump faster and stretch to pump more blood per stroke in order to transport needed oxygen and nutrients throughout the body. When we exercise, our hearts adjust in two ways to make sure we get enough oxygen and nutrients to wherever they are needed. First, the heart beats faster; this is called our heart rate or pulse rate. Second, the heart stretches to pump more blood with every stroke; the amount of blood that the heart pumps in each beat, or stroke, is called our “stroke volume.”

 

Since we have a maximum pulse rate dictated by our age, we cannot increase it. Your maximum pulse rate is about 220 minus your age. See chart.

 

 

However, when we exercise regularly, we can improve our stroke volume. Thus, stroke volume is a key measure about our heart’s health.

 

When we get in the water, our heart stretches as it does during exercise, even if we are just soaking in the water. Here is how that happens: During immersion, the water exerts pressure on all parts of the body, including the arteries and veins that carry blood throughout the body. The water’s pressure on our legs and arms pushes blood toward the chest cavity, increasing blood flow to the heart by about one third (33%). Since more blood is being pushed to our heart, it adjusts by stretching.

 

When we are in the water, our heart pumps more blood per beat. So, our pulse rate may increase or decrease depending on the temperature of the water and if we are exerting ourselves or not. Although the arteries and veins, which circulate blood, are being compressed from the water pressure, they must also adjust to the higher output from the heart. The arteries expand (dilate), working against the water pressure to allow higher blood volume to move throughout the body.

 

Therefore, when a person is immersed in warm water, the heart is working harder and more efficiently, like it does when we exercise. The arteries and veins dilate to carry more blood. Blood moves more easily through the body and circulation may be improved.

 

Studies show that younger people see an average increase in blood flow of 59%, while older people still experience a 22% increase in blood flow when immersed in shoulder depth water. Studies also show that blood flow increases in people as water temperature increases for people who are immersed up to their shoulders. Immersion in water above 104°F is not recommended. Research sponsored by the National Swimming Pool Foundation® (NSPF®) is underway to verify how blood flow changes at the shallow depths and higher temperatures present in hot tubs. Initial test show at 91°F an average increase of blood flow is 30%. While immersed in temperatures of 104°F the body averages a 121% increase of blood flow. Most people see their blood pressure go down when they are immersed in warm water for a period of time. A recent study found that people being treated for high blood pressure used a hot tub with no ill effects. In fact, their blood pressure went down temporarily and their heart rate increased, just as it did with the non-hypertensive control group. People with high blood pressure may wish to consult their physician to determine whether hot tub immersion may help them.

 

Hot Water & Relaxation

 

It is widely accepted that soaking in hot water is relaxing. Each of us normally feels refreshed when we emerge from a shower or bath. The effects of warm water are enhanced by water pressure when we are immersed in deeper water. The available scientific research explains the impact hot-water immersion has on the body. The body’s nervous system is designed to respond to physical or emotional threats or “stresses” as part of our survival instinct. The nervous system helps us relax after the threat has passed. Long-term stress is unhealthy and has been linked to many causes of disease and death. When we are threatened or “stressed,” our body creates hormones that trigger an increased blood flow:

·  Our hearts beat faster

·  Our heart stroke volume increase

·  We breathe faster to oxygenate the higher blood volume

·  Other coping responses occur

This increase in blood flow prepares our body for a fight so we can protect ourselves from a threat. Similarly, the body has to be prepared to flee if needed. These natural responses prepare us for “fight or flight.”

 

The part of our nervous system that prepares us to deal with stress is called the sympathetic branch. The sympathetic branch is important in the human’s survival instincts. However, if we are stressed too much and too often, our long-term health suffers. Fortunately, the body has a system (the parasympathetic branch) to create hormones that cause the body to relax after the stress has passed.

 

Physicians agree that managing stress will increase our chances for healthier and happier lives. Scientific evidence shows that immersion in water helps us reduce the effects of stress. Immersion in hot water helps our body relax by allowing the parasympathetic branch to reverse the effects of the sympathetic branch. Dopamine, a hormone that causes relaxation, is released when a person is immersed in hot water; the formation of this hormone shows an increased parasympathetic response.

 

Hot Water & Mental Health

 

Everyday life can provide many stresses. These include anxiety, stress, pain, fatigue, addiction, poor energy levels, range of motion problems, and lack of sleep, just a name few. Anxiety is a particular,

More to come...