The document summarizes key points about body water balance: - Body water accounts for 60-70% of total body weight in adults, with distribution varying between tissues. Muscle contains 70% water while fat contains 30%. - Water intake and output is usually balanced at around 2.8 L/day through drinking, food, and metabolic water production versus urine, feces, breathing, and sweat. More sweat is lost in hot climates. - The hypothalamus and pituitary gland regulate water balance through thirst and antidiuretic hormone signals in response to plasma osmolality changes of even 1-2%. This maintains water balance and a urine output of at least 500 ml/day to excrete

1. •Body is composed of about 60-70% water.
• Distribution of water in body compartments =
solute content of each compartment.
• In adults, water accounts for: 70% of the total body
weight in males and 60% of the total body weight in
females
• Water content differs in different tissues:
Muscles- 70%, Adipose tissue-30% ,Bones-10%
•Water content is more in muscular persons than in
obese persons

4. •Water balance of the body depends upon
the relative intake and output of water
•Water is taken in as drinking water and in
the form of food and beverages
•Some water is formed in the body during
oxidative reactions (metabolic water)

7. In a temperate climate, intake of water is:
Source Volume
Drinking water about 1.5 L /day
Water in food and beverages about 1.0 L /day
Metabolic water about 0.3 L /day
Total intake about 2.8 L /day

9. Water is lost from the body in the form of:
Route Volume
Urine about 1.5 L /day
Faeces about 0.1 L /day
Water vapour in expired air about 0.4 L /day
Water loss in the form of sweat about 0.8 L /day
Total output about 2.8 L /day
In hot climates, sweat loss is much more .This is compensated
by increased intake of drinking water .If it is not compensated,
urine output will decrease. However, urine output cannot
decrease below a certain level.
Normal excretion of solutes by the kidneys is about 600
milliosmol/day .Minimum water required to dissolve 600
milliosmol solutes is 500 ml .If urine output is below 500
ml/day, excretion of metabolic waste decreases .A urine output
below 500 ml/day is called oliguria.

11. Regulation of water balance
Water balance is maintained by:
The thirst centre in hypothalamus .
Antiduretic hormone of posterior pituitary.
These two receive signals about osmolality of plasma from
osmoreceptors located in the hypothalamus
Osmo-receptors can perceive a change of even 1-2% in the
osmolality of plasma
If there is an increase in the osmolality of plasma:
 Thirst centre is stimulated which increases water intake
Posterior pituitary secretes anti- diuretic hormone which
decreases urine output

14. •Euhydration is the state or situation of being in
water balance.
•Normal state of body water content; absence of a
bsolute or relative hydration or dehydration.
•Euhydration is the state of optimal total body
water content as regulated by the brain.
Intracellular and extracellular fluid volumes are
maintained with minimal physiological
adjustment. The body's systems function most
efficiently in this state.

15. IMPORTANCE OF EUHYDRATION
Being well hydrated is an important consideration for optimal
exercise performance. Because dehydration increases the risk of
potentially life-threatening heat injury such as heat stroke, athletes
should strive for euhydration before, during, and after exercise.
Importance of Maintaining Euhydration:
•Physiological Implications of Hypohydration
•Physiological Implications of Hyperhydration
•Performance Implications of Hydration During Exercise
•Endurance Performance
•Anaerobic Performance
•Cognitive Performance

17. PRESENTED BY
SOUNDARYA VIJAYAKUMAR
17ufno54