These principles of hydration, which are based on modern knowledge of anatomy and physiology, scientific research on hydration, are relevant to gaining a comprehensive understanding of the principles of hydration. Knowledge of hydration can benefit every client, can be used immediately, and requires no investment in equipment or products, other than a few simple items for teaching demonstrations.

Why is Hydration Important?
Hydration is fundamental to health and wellness because the human body is mostly water and also a dynamic, fluid, cellular system. The human body is approximately 60 percent water and this water is the main component of the body’s 100 trillion living cells, the blood, and the interstitial fluid that surrounds the body’s cells. All the water in the body, which is approximately 10 gallons, is constantly circulating as part of the blood, the interstitial fluid, lymphatic fluid, and the fluid inside the cells. The body needs to maintain a precise volume of water not only in the blood plasma, interstitial fluid, lymphatic fluid and within each cell, but also in the cerebral spinal fluid, aqueous humor (eyes), and other fluids. Maintaining these precise volumes depends on ensuring that the body has adequate levels of hydration. However, maintaining adequate levels of hydration is complicated by the fact that each day, we naturally and automatically lose approximately two and a half quarts of water, which represents six and a quarter percent of the total amount of water in the body. Proper hydration prevents dehydration, which has been associated with decreased physical and mental performance, as well as with more serious health problems and skin conditions.

Amount of Daily Water Loss
Using precise measuring techniques, scientific studies have determined that each day, an average-size person weighing about 140 pounds naturally loses about two and a half quarts of water. This represents an average loss of about three and a half ounces each hour, although the loss is somewhat less during sleep. Obviously, the amount of daily water loss is relative to body size—that is, a smaller person will, on average, lose less water than will a larger person. Any water loss through sweating due to exercise or heat will add anywhere from a small amount to several quarts to a person’s total daily water loss. Sweating is one of the body’s main cooling mechanisms—as sweat evaporates from the skin, heat is lost and the body is cooled. A significant amount of heat is removed from the body for every ounce of sweat. As with normal daily water loss, the loss of water through sweating must be completely replaced to maintain balanced hydration. The timing of normal water replacement should be at regular intervals throughout the day to prevent dehydration; water loss from sweating should be replaced as quickly as possible, as sweating produces rapid water loss over a short period of time.

How the Body Loses Water
In addition to knowing how much water the body loses, it is also important to know how the body loses that water. Each day, the human body naturally and automatically loses water in five ways. Our bodies lose approximately .5 quarts in the form of urine, .4 quarts in the form of evaporation from the skin, .2 quarts in the form of sweat from the skin, .3 quarts in the form of evaporation from the lungs, and .1 quarts in the form of fecal moisture from the gastrointestinal (GI) tract. We lose some water in the form of sweat, even if we don’t exercise or are not in a hot environment. During strenuous physical activity or in hot weather, the rate of sweating can increase from a small amount up to one quart per hour or greater. This means the rate of water loss can go from an average of about three and a half ounces per hour to more than 1.1 quart per hour or greater, representing more than a 10-fold increase in water loss due to sweating. During certain spa and wellness treatments that increase the body’s core temperature, sweating is produced at levels of one quart per hour or greater. These treatments include full-body steam treatments, saunas, and immersion in hot-water hydrotubs. It is important that clients rehydrate following these treatments so that they can receive maximum benefits from the treatment without any of the negative side effects of dehydration. It can also be of value for clients to drink some water before the treatment, knowing that water is going to be rapidly lost due to sweating.

Water Loss And Gain: Every 20 Days
Over a period of 20 days, a person’s average total water intake is more than 12 gallons (or about 100 pounds) of water. Over those same 20 days, a person will naturally lose more than 12 gallons of water. This intake and loss of water is greater than the entire amount of water in the human body, which averages 84 pounds (10 gallons). Because of the large amount of water we take into our bodies each day, month, and year, it is essential to not only balance water loss and water gain for normal hydration, but also to choose the highest-quality sources of water intake in the form of drinking water, beverages, and food. It is also important to have a healthy balance between the amount of water intake from plain drinking water versus that from beverages. Many people prefer beverages over drinking water for staying hydrated. However, many of these beverages, especially soft drinks, contain high amounts of calories and are also sources of potentially harmful (toxic) substances.

Areas of the Body Affected by Dehydration
Scientific research has shown that as the body becomes dehydrated, the levels of dehydration are greater in some organs of the body than in others. Muscles will show a level of dehydration of 40 percent, the skin of 30 percent, and both the viscera and the bones of 14 percent. This shows that all the systems of the body do not become equally depleted as dehydration develops and the skin is more affected by dehydration than most other body organs. Aestheticians have long known that good hydration is essential for the healthy appearance and aging of the skin.

Hydration Guidelines
Amount: Based on evaluation of the client’s daily total water intake relative to his or her size, recommendations are made for increasing (or decreasing) the amount, if necessary. In general, the recommendation to increase water intake would be to consume more drinking water either at meals or during intervals between meals. The amount of additional drinking water depends on the amount estimated to be lacking. When clients are met during follow-up meetings, their  feedback can be used to evaluate whether the recommendation appear to be producing the desired effect and further adjustments can then be made as needed.
Timing: If the evaluation shows that there are long intervals between the client’s water intake, recommend drinking water at regular intervals to balance continual water loss. Because time spent sleeping is the longest interval between water intakes, there should be adequate water intake after waking to balance water lost during sleep.
Percentage of Drinking Water to Beverages: For some clients, it will be obvious that they are drinking mostly beverages during the day and very little water. Gradual changes are recommended, for example, by having the client substitute one beverage with the same amount of water. Over several months, a client could significantly improve this ratio of plain water to beverages, which could have very positive health and wellness benefits. A higher ratio of drinking water to beverages means that a person is consuming fewer calories and the numerous additives in many beverages. Remember that most patterns of daily consumption of beverages is learned behavior that is repeated automatically (unconsciously) each day and take time to change. A ratio of 50 percent plain water to 50 percent beverages would be a good initial goal for people drinking mostly beverages and then the ratio of plain water could be increased over time.
Source and Quality: There are a wide range of sources for drinking water, beverages, and food. From all these possible options, your client has developed a regular, learned pattern of total daily water intake. Recommendations should mainly be to see that your client uses quality sources of drinking water, beverages, and food. Drinking water should be as pure as possible, which normally requires some level of purification. Beverages, that are high in additives such as artificial sweeteners, food colors, and preservatives, should be gradually reduced. This can also apply to beverages with high amounts of substances such as sugar, salt, and caffeine. As mentioned, the fact that people naturally prefer to drink something that “tastes good” is one of the greatest challenges to normal balanced hydration. Research has shown that drinks that have a sweet taste are generally preferred. Thus, virtually all beverages sold today are sweetened in some way. Getting people to change their patterns of beverage and consumption can be very difficult, even if they know it is better for them.

Richard Eidson is the author of Hydrotherapy for Health & Wellness: Theory, Treatments & Programs, Milady Publishing, 2009. This book was written with education and treatments for both aestheticians and massage therapists. Richard is a hydrotherapy educator, has traveled extensively both nationally and internationally and is also an inventor of hydrotherapy equipment. www.studyhydrotherapy.com, This email address is being protected from spambots. You need JavaScript enabled to view it.