We are mostly water!  

It is true that we are mostly water, about 10 gallons on average. That is about 84 lbs of water, and all of it is constantly circulating. Also amazing, is that every 20 days, you will have naturally lost about 100 lbs of water (12.5 gallons) and replaced that will 100 lbs (12.5 gallons) of water flowing from the hydrosphere.
One of the main principles of optimal hydration is that is very important what sources of water you use to replace the water that you naturally lose. Normally, about 20% of this water comes as part of the solid food we eat and the rest comes form the beverages and plain water that we drink. Depending on the ratio of plain water to beverages, it is possible to be consuming considerable amounts of calories, glucose (sugar) and man-made chemicals. Getting sufficient water to maintain balanced hydration is very important, but is also very important to manage the amount and quality of beverages consumed that contribute towards our hydration.

Review of Key Elements of Anatomy and Physiology

The following is a brief summary of the dynamic cellular nature of the human body that gives an insight into why maintaining normal hydration levels in the human body is so essential to health and wellness. The following is a summary of the dynamic cellular fluid nature of the human body:

Dynamic Fluid Elements of the Human Body

• 60% water - average 10 gallons of water. 10 gallons of water weighs 84 lbs.

• 66% of the water is in the 100 trillion cells of the body, 27% is in the interstitial fluid that surrounds the cells and 7% is in the blood plasma. The volume of water in the cells, interstitial fluid and blood plasma must be maintained at very precise levels.

• Heat pumps 1,800 gallons of blood per day, actually 3,600 gallons a day if you consider the heat as 2 pumps, left and right sides.

• Total amount of blood in the body is  5 qt/5 L, which re-circulates 1,440 time per day through a vascular system that is greater than 60,000 miles long.

• 5 gallons a day flows through the capillaries from the blood plasma to the interstitial fluid bringing nutrients, oxygen and hormones to the cells. There more than 10 billion capillary beds in the human body and most cells are no more than 5 cells distance from a capillary.

• 4.25 gallons a day returns to the blood plasma through the capillaries from the interstitial fluid bringing by-products of cellular metabolism that must be removed from the body or converted to non-toxic substances, such as carbon dioxide, lactic acid and urea.

•  .75 gallons (3 qt/L) returns via the lymphatic system removing proteins in the interstitial fluid and also allows for purification of the lymphatic fluid in the lymph nodes.

• The kidneys process more than 45 gallons of blood plasma a day and produce about 1.5 qt/L of urine which is eliminated from the body.

• The digestive system produces about 1.8 gallons of digestive fluids (juices) a day, mostly made up of water, which are reabsorbed after being used.

• The body naturally, automatically loses approximately 2.5 qt/L of water per day which represents 6.25% of the total amount of water in the body. This is what must be replaced each day and at regular intervals during the day to maintain a balanced level of hydration.