Water schedule and water balance in the body
Water schedule means a reasonable schedule of water consumption. The right water schedule ensures a good fluid-and-electrolyte balance and creates favourable conditions for your body’s activity.
Water balance means that the amount of liquid that human body obtains and excretes in the process of its activity is the same.Water imbalance may cause changes till serious disorders in the body’s functioning.
At a negative balance, i.e. inadequate hydration of the body, you lose weight and your blood viscosity increases, at the same time, oxygen and energy supply to tissues is disturbed, consequently, body temperature increases, pulse and breath quicken, you develop sense of thirst and nausea and your work efficiency reduces.
On the other hand, overdrinking can cause poor digestion (because gastric juice is too much diluted), as a result, load on heart increases (because of excessive blood rarefaction). The body tries to equilibrate the amount of water it obtains inside by increasing of sweat secretion; load on kidneys surges too. At the same time, the body begins to excrete valuable mineral substances with the sweat and through the kidneys (in particular, common salt) that results in salt imbalance. Even a short-term water overload may lead to fast fatigability of muscles and even to convulsions. For that reason, by the way, sportsmen never drink during competitions but they just rinse their mouth with water.
It has been established that a daily water requirement of an adult person is equal to 30 or 40 g for a kilogram of body weight. It is commonly supposed that in total a person consumes about 2.5 l of water a day, and the same amount is removed from the body.
Generally, the body obtains water in the following ways:
- 1.2 liter in the form of liquid
- 1 liter in the form of food
- 0.3 liter is produced by the body itself
It is necessary to mention an important thing: on average, an adult person consumes daily in the form of free liquid (various beverages and liquid food) about 1.2 l of water (48 % of the daily scale). The rest is water consumed in the form of food – about 1 l (40% of the daily scale). We never think about it, though porridges contain up to 80% of water, bread – about 50%, meat – 58 to 67%, fish – almost 70%, fruits and vegetables – up to 90% of water. In whole, our “dry” food consists by 50 to 60% of water.
Finally, a small amount of water, about 0.3l (3%) is produced by our body as a result of biochemical processes.
The ways of water removal are given below:
- 1.2 liter – via the kidneys
- 0.85 liter – by sweat secretion
- 0.32 liter – by breathing
- 0.13 liter – via the intestine
Water is mostly removed via the kidneys, about 1.2 l a day, or 48% of the total volume, and by sweet secretion (0,85 l – 34%). A certain amount of water is removed during breathing (0.32 l a day – about 13%) and via the intestine (0.13 l – 5%). The mentioned figures are average and depend much on a number of factors including climatic conditions and degree of physical activity. Thus, general water requirement during hard physical labour in hot conditions may achieve 4.5 to 5 l a day.
Under normal conditions, human body adapts to the environment and the water balance is maintained “by itself”. To put is simply, if you are thirsty, drink something. “Failures” in a regular schedule may occur at a rapid temperature change (for example, when you go to bath), or at increasing of physical activity (for example, when you do sports). Besides, daily water requirement of the body may be influenced by temperature and humidity of the air, consumption of coffee and alcoholic beverages, the body’s condition (for example, a disease), nursing time for women, etc.
The website of the IBWA (International Bottled Water Association) contains interesting information about dependence of water intake on weight and activity level. There is even a calculator that enables you to calculate more accurately your water requirement based on duration of your physical exercise. Based on the data of the IBWA, we took the liberty to prepare a table that presents in a convenient way the information about average amount of water a person consumes.
However, we deem it duty to warn about the following. On the IBWA website data are provided as a water amount that you “need to consume”. Figures given by the IBWA have more the semblance of a daily total water intake and here a “drinking” share must be about 50% (at least, during low physical activity). To be fair, we need to add that the main increase in water intake during increase of physical activity will be provided mostly due to “drinking” water.
|Your weight (kg)||Daily water requirement, l|
|Low physical activity||Moderate physical activity||High physical activity|
|50||1.55 l||2.00 l||2.30 l|
|60||1.85 l||2.30 l||2.65 l|
|70||2.20 l||2.55 l||3.00 l|
|80||2.50 l||2.95 l||3.30 l|
|90||2.80 l||3.30 l||3.60 l|
|100||3.10 l||3.60 l||3.90 l|
Of course, these figures can only serve as a reference and are not at all a strict guide for action.