For the human body, water is a vital resource. We know it is indispensable for life itself, and it provides a host of essential functions for good health. There is no more important nutrient in our bodies than water. It is the most widely used nutrient at work within the body’s functions and processes as well as constituting a huge part of its physical makeup.
The typical man is made up of around 60% water, a woman around 50% and our brains around 75%. We can only survive a small number of days without water, yet can survive weeks without food.
Daily water intake is extremely important in helping to replenish the water lost through our bodily processes including urination, sweating and breathing.
When the water is not replaced, we become dehydrated:
1 % dehydration - we become thirsty with reduced concentration
5% dehydration - we become hot and tired with decreased performance
10% dehydration - delirium and blurred vision
20% dehydration - may result in death.
Water leaves the body through several routes - the evaporation of sweat, in the moisture of exhaled breath, in the urine and in the faeces. It is also used to facilitate all the previously mentioned functions in the body.
This amount equals between 1.4-2.8 litres per day.
There is another key reason why remaining hydrated is so important. When we lose fluid from the body, we also lose electrolytes. Maintaining healthy concentrations of electrolytes (Sodium, calcium, potassium, chloride, phosphate, and magnesium ) is critical in supporting the important activities of the vital organs.
The key role of electrolytes is to balance the fluids inside and outside of the cells, so they can function properly and allow body fluids to bring cells the necessary nutrients while removing waste products.
Electrolytes also help create the environment in which the cells work takes place e.g. nerve-nerve communication, heartbeats and contraction of muscles.
The Functions of Water In The Body
• Transports nutrients through the body • Moistens eyes, mouth and nose • Can help maintain pH and electrolyte balance • Participates in many chemical reactions • May reduce constipation • Ensures adequate blood volume • Forms main components of body fluids
Adults are advised to consume 1-1.5 ml of water for each calorie-expended daily.
For example: if your daily energy expenditure (BMR x activity level) is 2000kcal per day, then you would require 2-3 litres of water per day. It does not mean that you have to drink the whole 2 - 3L water bottle in a day. Water intake recommendation includes tea/ coffee/soups and other liquids. Fruits & vegetables are also great sources of water.
Water consumption throughout training should be a given, and it is suggested for every pound in bodyweight lost between the start and finish of training, 500ml of water per pound should be replaced. How to check how much weight you lost? Weigh yourself before & after the training. Oh, by the way, don’t get too excited... the number on the scale will not tell you how much fat you burnt but how much water you lost, disappointed? That’s the fact, accept it:-)
The general guidelines I give my clients are:
• When thirsty, drink.
• When not thirsty anymore, stop.
• During high heat and exercise, drink enough to compensate for the lost fluids.