The Body is Water

Dr. Laura Roxann Alexander
5 min readNov 4, 2019


How important is water to the body?

Water is so important that a 3% loss means you are already dehydrated, and a 10% loss causes severe disorders. Water is so vital that an adult cannot survive more than ten days and a child for more than five days without it. Water is so essential to maintaining a healthy body. Yet, most people never even drink water regularly and instead gulp down liters of soda and sugary concoctions. When people think of nutrition and health, they often forget about water, but water is just as important as the calories you consume and should be part of a balanced nutrition plan.

What role does water play in maintaining a healthy body?

Water is the most significant component of the human body and makes up about 50 to 70% of an individual’s weight. Water has many essential physiological functions. Water regulates body temperature, protects and cushions organs, and provides a driving force for nutrient absorption. It carries nutrients to cells and carries waste products away from cells. Water makes up about 70% of lean tissue (muscles and organs). Water leaves the body through urine production, breathing, and sweat. Sweat is especially crucial during exercising because it acts as a cooling mechanism to decrease body temperature. Water aides in the whole digestive pathway from forming saliva, converting food to components needed to survive, and flushing waste. It lubricates joints and acts as a shock absorber for the brain and spinal cord.

Hydration and just how important is it?

Staying hydrated through the day has multiple benefits to your health. Improvement in skin blood flow, improving glycogen usage, which in turn enhances endurance; and a less pronounced increase in heart rate and core body temperature when exercising. Like with most biological processes, there is a balance when it comes to hydration. Too much can lead to hyponatremia, and too little can lead to severe dehydration and death. In typical day to day activities, the key to staying adequately hydrated is simple, drink water. Keep a bottle with you at all times and sip away. Current recommendations are to drink half your body weight in ounces. For example, a 120-pound woman would need about 60 ounces of fluid per day. The easiest way to get in all that water through the day is to buy a large stainless steel or glass bottle that measures about 30 ounces and try to drink two of those per day.

You DON’T need SPORTS DRINKS or Juices!

In the ’60s, before the invention of sports drinks, athletes used thirst as a guide and in most cases, did not even drink during exercise. Even long-distance runners and elite marathoners did not drink during long runs. Marathons in the 1960s had no official water stations, and most competitors ran the full marathon without drinking anything. Since the 70' and ’80s, the sports drink phenomena have convinced athletes and even non-athletes to believe that dehydration is so common that they need to drink high-calorie sports drinks to combat the loss of fluid. In almost every case, a sports drink is not a requirement for dehydration prevention.

Matt Fitzgerald, author of Diet Cults: The Surprising Fallacy at the Core of Nutrition Fads and a Guide to Healthy Eating for the Rest of Us, wrote, “Simply stated, sugar is the primary reason that sports drinks like Gatorade enhance athletic performance. Their hydrating effect is secondary.”

I don’t recommend chugging these high-calorie drinks during routine exercise. Keep water with you and sip between sets.

Juices are just processed food in liquid form. They contain added sugars and leave out the nutritious part of the fruit, which is fiber!

How much water is too much during exercise?

The body can withstand dramatic variations in fluid intake during exercise and at rest, so the risk of dehydration is low in most exercisers. On the other hand, hyponatremia cases have seen a rise in recent years. Hyponatremia occurs when people ingest excessive amounts of fluid to compensate for minimal losses, and they become overloaded. The New England Journal of Medicine found that 13% of Boston Marathon runners had hyponatremia, and 0.6% had critical hyponatremia at the end of the race. In 2002, a twenty-eight-year-old woman died after running the Boston Marathon. The cause was hyponatremia. She had followed the advice of many to “drink as much as possible” while running. Between 2000 and 2003, one study reported the average participant in the Houston Marathon drank 20 cups of water and Gatorade during the event. Many drank so much they gained weight while running.

“Gatorade’s marketing system was so successful that it changed the behavior of athletes, …but it also changed how the public thought about dehydration. Before Gatorade, a person was either thirsty or not thirsty. Thirst was no big deal — drinking took care of it…But as Gatorade gained influence, dehydration came to be seen as a sort of disease…Athletes were convinced that they couldn’t trust their thirst to tell them when to drink….”–Matt Fitzgerald.

Sports drinks: What a load of extra calories!

This sports drink craze has lead America to overhydrate in some endurance sports and to even use the sugary sports drinks in place of water during everyday activities. Children are especially susceptible to the sports drink craze, and unfortunately, the average child is not active enough to warrant them drinking two or three Gatorades per day. Some children even drink these instead of water. Instead of getting adequately hydrated, these kids are just adding excessive calories to an already sugar-filled diet. The same goes for almost every adult that drinks a sports drink. Most adults do not exercise to the intensity of needing any electrolyte replacement, and plain water will keep you hydrated and take care of the thirst. The latest recommendations are to let thirst be your guide during exercising and sports activities, if thirsty, then drink water!

Are you a soda drinker?

If you are a soda drinker, then stop now. Soda has no nutritional benefit, and no one needs the extra calories found in sodas. Diet soda is no better. Fake sugar and chemicals are things your body does not need and cannot use. Enough has been said on this subject by many experts, so I’ll keep it simple, stay away from soda and reach for that water bottle.

Water, Water, Water

There is only one thing you should be drinking to keep your body going like a well-oiled machine. Your body does not run on soda or Gatorade. Keep your body adequately hydrated by carrying water with you and sipping all day long. You’ll be amazed at how much better you feel when you are in a hydration balance! Water is just as important as the calories you consume and should be part of a balanced nutrition plan.


1. Muth, Natalie Digate. Ace Fitness Nutrition Manual. San Diego, CA: American Council of Exercise, 2013.

2. Bushman, Barbara. ACSM’s Resources for the Personal Trainer, 4th Edition. Associate Editors Rebecca Battista, Pamela Swan, Lynda Ransdell, Walter Thompson. China: Lippincott Williams & Wilkins, 2014.

3. Perlman, Howard. The Water in You, U.S. Department of the Interior.

4. Fitzgerald, Matt. Diet Cults: The Surprising Fallacy at the Core of Nutrition Fads and a Guide to Healthy Eating for the Rest of Us. New York, NY: Pegasus Books LLC, 2014.



Dr. Laura Roxann Alexander

Pharmacist.Personal Trainer.Lift heavy, skip the run.Let food by thy medicine and medicine be thy food.