Water - Fluids

Objectives After reading Chapter 7 and class discussion, you will be able to: Describe the functions of water Describe the fluid composition of the body Describe water balance Identify sources of water and % of water in selected foods

Objectives Discuss symptoms of dehydration Provide recommendations for fluid replacement Define hyponatremia Discuss fluid replace beverages

Body Fluids Intracellular Extracellular –Interstitial –Intravascular

Body Water of body weight Brain- 75% water Blood- 85%water Skeletal muscle- 75% water Adipose- 10% water Bones- 22% water

Body Composition 60%

Functions of Water Body temperature regulation Water absorbs excess heat Body releases fluid/heat via perspiration Skin cools as perspiration evaporates Key transportor and solvent Blood, lymphatics, urine, digestive fluids Nutrients, oxygen; removes waste Maintain blood volume

How much??? 8x8 rule RDI’s Adequate Intakes 15 cups men, 11 cups women Institute of Medicine Thirst be guide Healthcare 1 – 1.5 ml per calorie 1800 calories = ml 240 ml/cc = 1 cup

Dehydration Fluid loss greater than intake Compounds over time Risk Athletes, GI illness, older adults, reduced calorie intake Contributes to Poor performance, constipation, urinary tract infections, prolonged labor

Body Conserves Fluids Thirst signal Vasopressin (antidiuretic hormone) Forces the kidney to reduce urine flow Alcohol inhibits Aldosterone hormone Signals the kidney to retain sodium, other electrolytes

Monitor Sweat Rate Weigh before and after Goal to replace 100% What’s lost = how much to replace National Athletic Training Association oz of fluid per pound lost 2-3 cups per pound

Hydration Calculator es/tools-hydration-calculator.html es/tools-hydration-calculator.html Factors that affect… Gender Age Exercise Type Intensity Length of time Temperature (humidity)

Whats In Sweat? Electrolytes Lost in Sweat Sodium920–1,840 mg/l Chloride 1,062–2,478 mg/l Potassium156–312 mg/l Magnesium24–96 mg/l 17

Sodium Most Important 1 pound sweat 500 mg sodium Hyponatremia Low blood sodium Symptoms Muscle cramps, nausea Decreases thirst before adequate hydration Causes Hydrating without sodium (plain water) Overhydration

Add Sodium Fluids with sodium Most clear colored sports drinks Gatorade Powerade Foods with sodium

College of Sports Medicine Recommends….. Water is fine when exercising for less than 1 hour in moderate temperature conditions. A sports drink is recommended for exercise of 1 hour or longer, and anytime conditions are hot or humid.

Sports Drink Benefits Flavor encourages greater fluid intake Sodium Encourages fluid intake Helps retain fluids consumed Most contain carbohydrates Energy Quick absorption

Hydrators Besides Water, Clear Sports Drinks…. Juice Milk Diet, caffeine free pop Caffeinated beverages Any beverage…….except alcohol Food