So it’s a matter of some interest that sleepy Aliso Viejo managed to make the world news in March 2004. What attracted the media were reports that the good people on the city council were going to ban an extremely dangerous environmental contaminant. Somehow, dihydrogen monoxide had reached startling levels in Aliso Viejo. In its crude form, this critical ingredient in many common chemical compounds often spilled onto the city’s otherwise pristine streets. Investigation revealed that it showed up even in Styrofoam cups.
The serious effects of dihydrogen monoxide were presented by a paralegal who’d obtained the information from an official-looking, seemingly authoritative Web site. The report noted that dihydrogen monoxide was lethal if inhaled, that it could cause severe burns in its gaseous state and that it was the major component of acid rain. In short, the report concluded, dihydrogen monoxide posed a “threat to human health and safety.”
The Web site also noted that dihydrogen monoxide was particularly insidious, being odorless, tasteless and colorless. The symptoms of excessive dihydrogen monoxide intake included sweating and urination, a possible bloated feeling and an electrolyte or mineral imbalance. In large print, the site proclaimed, “This horror must be stopped!”
Is it any wonder the city fathers of Aliso Viejo were concerned? With most of the population in the 25-to-35-year-old age group, they had to consider the impact of dihydrogen monoxide on children and future generations. Something had to be done, and quickly.
Aliso Viejo’s alarm is replicated daily because other Internet sites proclaim the toxicity of everything from protein to artificial sweeteners. The well-meaning but seriously uninformed paralegal who prepared the report for the city council had fallen for a put-on: Dihydrogen monoxide is the chemical name for water. (Nobody caught the joke in time for Aliso Viejo’s plan not to hit humor-hungry wire services.)
Eliminating water would prove disastrous to life on Earth. A human being can live without oxygen for four to six minutes. You can survive without eating anything for up to 60 days, but you may have noticed that even those whose hunger strikes make the news never stop drinking water. No water almost certainly means death within five days. The immediate cause of death for Terry Schiavo, a medically brain-dead Florida woman whose feeding tube was disconnected after more than a decade, was dehydration. Fluids had been withdrawn less than a week earlier. Grotesque as it may sound, she died right on schedule from lack of water.
Water intake is no less important for bodybuilders. While many look at it merely as the source of a refreshing interlude between sets or something they shower in after a workout, water has much more critical uses. From an aesthetic viewpoint, the amount of water the body retains can determine the winner in a close bodybuilding contest. Being bloated, or having accumulated too much water, is among most competitors’ greatest fears, for it can obscure muscular definition honed by weeks or even months of hard training and dieting.
Some bodybuilders, especially on the professional level, circumvent the water retention that inevitably results from using drugs such as anabolic steroids and growth hormone by using other drugs, such as diuretics. That can create another whole new set of problems, however, such as an electrolyte imbalance that results in embarrassing muscle cramps onstage. Since muscle itself is 72 percent water, injudicious use of diuretics can lead to a flat appearance, especially after a low-carb diet has eliminated the glycogen that holds water in muscles.
The problem with diuretics and other drugs that induce rapid water loss is that they have an overkill effect. Water is key both inside and outside the body’s cells. Intracellular water accounts for two-thirds of the body’s water, and the other third is extracellular. When a bodybuilder uses diuretics, he intends to eliminate extracellular water, but the drugs are so potent that they also reduce intracellular water. That leads to an electrolyte imbalance.
Research has illuminated some fascinating effects of water that are directly relevant to anybody who wants added muscle and vibrant health. An example is the cellular hydration theory, which deals with the status of water contained in a cell.1 Hydration of a muscle cell sets off an anabolic cascade that results in upgraded muscle protein synthesis. The reverse is true. When a cell is dehydrated, it becomes catabolic, prone to breakdown. Dehydrated cells characterize many diseases, such as cancer, and they include a catabolic component.
Water: The Facts
The human body is 60 percent water; babies are about 70 percent water. Men have more water in their bodies than women because men usually have more muscle, which is 72 percent water. By contrast, fat contains about 10 percent water, which makes it an ideal storage fuel. The structures of protein contain water, as does glycogen, the stored form of carbohydrate in the human body. Each gram of glycogen is stored with three grams of water. That explains the high initial weight loss that occurs with many diets, especially low-carb plans. Without carbs, glycogen rapidly degrades, eliminating the water stored with it.
Muscle contains more water because such elements as protein, glycogen, creatine and amino acids pull water into the tissue. Because fat doesn’t contain those elements, there’s no osmosis, which makes fat a drier tissue than muscle.
Water is the primary solvent, dissolving various nutrients, including minerals, vitamins, amino acids and glucose. Water is also involved in the digestion and absorption of those nutrients, as well as their transport, via blood, into tissues and cells; blood is also largely water.
Water is an excellent solvent because it’s a polar molecule. It has no electrical charge of its own, but its molecular structure fosters partial negative and positive charges on its oxygen and hydrogen atoms. Thus water interacts with other water molecules and partially charged substances, such as electrolytes, glucose and amino acids.
Dehydration is usually defined as a 1 to 2 percent loss of bodyweight resulting from fluid losses.2 Rat-based studies found that 28 hours after rodents were deprived of water, the solid elements of their blood increased and that the liquid portion, or volume, declined. Thickening of blood, associated with blood clotting and slowed blood flow, is also associated with strokes and heart attacks.
A study of Seventh-Day Adventists—8,280 men and 12,017 women—examined the relationship between heart disease and water intake.3 Those who drank five or more glasses of water daily were less likely to die of a heart attack than those who drank two or fewer. Of the subjects who drank five or more glasses daily, the women were 41 percent and the men 54 percent less likely to die from a heart attack.
Drinking other fluids, however, such as coffee, tea, juice, milk and alcohol, reversed the benefits of water and led to a greater mortality rate. Blood thinning was water’s key protective property; decreased blood thickness, or viscosity, meant less chance of fatal blood clots. Fluids like coffee have the opposite effect because to be digested they need to be diluted, which draws water from the blood, making it temporarily thicker. Coffee is a mild diuretic, causing some water loss, which can also lead to blood thickening. On the other hand, in those who regularly drink coffee, the diuretic action is lost, which makes a cup of coffee equivalent to two-thirds of a cup of water.
The Importance of Water During a Diet
Fat is a storage base for various toxins, and as it degrades through diet and exercise, you need to take in enough water to flush out the toxins released from stored fat. Water is also a natural diuretic, flushing out such elements as sodium, which can lead to water retention and a bloated appearance.
Bodybuilders who restrict water shortly before a contest are likely working against themselves, depending on how limited their intake is. As you restrict fluid intake, blood volume declines. When the brain detects that, the posterior pituitary gland secretes antidiuretic hormone. As the name implies, ADH works to retain water so the body can maintain the right blood volume. In other words, you wind up retaining more water when you restrict water. Conversely, drinking water inhibits ADH release. So does alcohol, which explains why you need to pee not long after you have an alcoholic drink.
People who diet often complain that they can’t concentrate, but the cause may be less the lack of calories than a mild form of dehydration. Studies of animals have shown that dehydration impairs brain function. It damages the mitochondria of neurons, or brain cells—and mitochondria are the source of the energy that maintains cellular function. The level of glutamate, an amino acid that stimulates neuron activity, can increase too fast and possibly kill neurons; excess glutamate activity is a primary cause of stroke-related neuron death.
In human studies dehydrated subjects show impaired math ability, memory and reaction time.4 That happens after only a 2 percent body-fluid loss—which is considered the point where dehydration side effects appear. Nitric oxide, also produced in the brain, is involved in learning and memory. Normally dehydration increases nitric oxide in the brain, but that effect is lost in older people, which may help explain memory defects.
Studies show that drinking water with meals results in eating less food, in turn leading to weight losses. An old dieting trick is to drink a glass of water shortly before eating a meal. The water makes you feel full and decreases your appetite and food intake.
A surprising property of water is its thermogenic aspect.5 One experiment measured the effects on seven men and seven women who drank 500 milliliters, or just over a pint, of water. That amount resulted in a 30 percent increase in resting metabolic rate within 10 minutes of drinking and reached maximum effects in 30 to 40 minutes. The increased metabolic rate was fueled by fat in men and by carbs in women. This is related to a release of catecholamine hormones, such as epinephrine. The release of catecholamines usually leads to a rise in blood pressure, but not when you drink water. That’s because water also elicits increased activity of the vagal nerve, which works against blood pressure increase caused by sympathetic hormones.6
Anabolic Water?
Cellular hydration is considered a potent anabolic stimulus. Conversely, when a cell is dry, catabolic effects dominate, often leading to cell death. Most studies showing the effect of cellular hydration have used cells extracted from liver. One such study showed that perfusing liver cells with the amino acid glutamine makes the size of the cell swell by 12 percent. It happens in minutes and lasts as long as the perfusion continues.
Glutamine swells cells because it promotes the entry of sodium into the cell. Inside the cell the sodium exchanges with potassium, which then exits the cell to prevent excess swelling. That mechanism is known as the sodium-potassium pump. Other substances also promote cellular hydration—various amino acids, bile acids, insulin and possibly creatine. Researchers think that most of insulin’s anabolic effects come about because it promotes cellular hydration. Some substances—glucagon, cyclic AMP, serotonin and urea—promote cellular dehydration, which has catabolic consequences.
Hydration-related cellular swelling is anabolic because hydration inhibits protein breakdown. Other effects include an increase in glycogen synthesis and a decrease in glutamine synthesis, as well as uptake of lactate and amino acids. The effects of cellular hydration on isolated liver cells are replicated in muscle, bone and other cells and tissues of the body.
The effects of cellular hydration on an intact human body have been noted in clinical settings. For example, burn patients are notably dehydrated and also show huge nitrogen or protein losses. Various types of cancer marked by relative dehydration also show a high nitrogen loss. While there is a dearth of studies to back up clinical observations, one experiment did attempt to show the effect of cellular swelling in humans.7 Ten men were artificially dehydrated or hydrated. When they were hydrated, protein breakdown significantly decreased, and they showed decreased peripheral insulin sensitivity. The net effect appeared similar to that of fasting—protein sparing, increased fat oxidation, increased ketone release and impaired glucose metabolism.
Does Water Help Prevent Cancer?
A 10-year study featuring 48,000 men linked a lower incidence of bladder cancer to a high intake of fluids that dilute and eliminate carcinogens. The researchers calculated that bladder cancer decreased by 7 percent for every eight ounces of water the men drank.
Other studies have demonstrated water’s salutary impact against colorectal cancer and premalignant polyps, finding an inverse relationship between drinking as few as five glasses daily and cancer. Evidently drinking lots of water speeds passage of food through the gastrointestinal tract, thereby limiting cellular exposure to carcinogens.
Water and Training
Whether dehydration adversely affects your workouts depends on such factors as the temperature and the type of training you’re doing. Individual response also enters the picture; some people appear to tolerate dehydration better than others. The tipping point is usually a loss of 2 percent of bodyweight in fluid over the course of an exercise session or athletic event, though that applies mainly to endurance exercise under warm or hot conditions. In colder temperatures, dehydration is less likely to manifest. Other studies show that dehydration doesn’t seem to affect strength training until you lose 7 percent or more in fluid.
Some studies show that upper-body muscles are more vulnerable than lower-body muscles to mild dehydration. In one study, however, 10 experienced powerlifters became dehydrated after sitting in a hot sauna for two hours.8 They lost 1.5 percent of body mass, primarily as water. Tests of their maximum bench press strength showed a 5.6 percent decrease. Full strength returned after two hours of rest and fluid intake.
Dehydration may adversely affect exercise for several reasons. When your body’s water content goes down, your heart must work harder to pump the blood that supplies working muscles and that cools the skin. Straining your heart by not getting enough fluids in the heat may lead to fatigue and loss of intensity. You can tell that from a higher heart rate during exercise, as the heart attempts to compensate. Whatever you’re doing will seem considerably harder when you’re dehydrated.
Core body temperature rises, which leads to exhaustion and the end of the session. As temperature increases, it’s detected by the central nervous system, which responds by reducing the drive to exercise; a big spike in body temperature can damage the brain.
When the body overheats from lack of fluid intake, it accelerates use of muscle glycogen, the primary fuel that powers anaerobic exercise. Rapid glycogen use is linked to increased catecholamine release, a stress reaction, and higher body temperature. The reduced cardiac response that occurs during dehydration inhibits blood flow to muscles, which results in less oxygen delivery and greater fatigue. Dehydration also promotes a stress response due to lower blood volume, and that promotes the release of cortisol, the body’s primary catabolic hormone. Too much of it can lead to muscle loss.
You can prevent dehydration during athletic activity if you do the following:
•Before exercise: Drink about 20 ounces of water two hours before training.
•During exercise: Drink up to a quart of water. You get better water uptake by drinking a cold sports drink that contains small amounts of minerals and no more than 7 percent carbs.
•After exercise: Drink 150 percent to 200 percent of total fluids lost.
Water Requirements and Myths
In an article published three years ago, a physiology professor questioned the frequent advice to drink at least eight glasses of water a day.9 He noted that there was no scientific evidence to confirm the recommendation, just as there’s no scientific rationale for eating no more than 30 grams of protein at each meal. The idea that by the time you experience thirst you’re likely already dehydrated was also pronounced a myth by the professor, who noted that the human sense of thirst is remarkably accurate and usually in concert with fluid needs.
The notion that dark urine means you’re dehydrated is also false. Many nutrients, as most bodybuilders know, lead to darker urine, but it has nothing to do with being dehydrated.
Another myth is that you must drink a copious amount of water to maintain kidney function. True, drinking clean, pure water is one of the best things you can do to protect your kidneys, but the kidneys aren’t adversely affected unless severe dehydration, or a bodyweight fluid decline of 5 percent or more, occurs. Researchers who study kidney function say that in a normal-sized adult in a temperate climate, one liter or four eight-ounce glasses of water are enough to meet all of the body’s water needs.
Drinking too much water can be just as hazardous as drinking too little. Too much water can dilute the electrolytes you need for brain function and can lead to convulsions—even death. Loss of sodium leads to potentially fatal edema, or swelling, of the brain.
Teenage deaths at rave parties have been connected to use of the drug Ecstasy. One of its effects is the intense thirst that results from an increase in body temperature. Ecstasy also promotes the release of vasopressin, an antidiuretic hormone. Continued water intake when the body is already retaining water leads to hyponatremia, or low sodium, and that leads to death.
Safe water intake means drinking one milliliter (an ounce contains 30 milliliters) per calorie per day. So if you’re eating 3,000 calories, drink 3,000 milliliters, or about three quarts, per day. Factors that may require increased water intake include exercise under hot conditions, a high-fiber diet and the increased fluid loss that comes with drinking a lot of alcohol. Keep in mind that your body’s metabolism generates nearly a pint of water and that the water content of foods such as fruits and vegetables can be more than 90 percent.
References
1 Ritz, P., et al. (2001). Effects of changes in water compartments on physiology and metabolism. Eur J Clin Nutr, 57:S2-S5.
2 Shirrefs, S. (2005). The importance of good hydration for work and exercise performance. Nut Reviews, 63:S14-S21.
3 Chan, J., et al. (2002). Water, other fluids, and fatal coronary heart disease. Am J Epidemiol, 155:827-33.
4 Wilson, M., et al. (2001). Impaired cognitive function and mental performance in mild dehydration. Eur J Clin Res, 57:S24-S29.
5 Boshmann, M., et al. (2003). Water-induced thermogenesis. J Clin Endocrinl Metab, 88:6015-6019.
6 Brown, C.M., et al. (2005). Cardiovascular responses to water drinking—does osmolality play a role? Am J Physiol. In press.
7 Keller, U., et al. (2001). Effects of changes in hydration on protein, glucose, and lipid metabolism in man: impact on health. Eur J Clin Nutr, 57:S69-S74.
8 Schoffstall, J.E., et al. (2001). Effects of dehydration and rehydration on the one-repetition-maximum bench press of weight-trained males. J Strength Cond Res, 15:102-108.
9 Valtin, H. (2002). “Drink at least eight glasses of water a day.” Really? Is there scientific evidence for “8x8”? J Applied Physiol, 283:R993-R1004.
