WATERWATER

WATERWATER

Essential nutrient – NO caloriesEssential nutrient – NO calories Part of every cellPart of every cell

muscle muscle 75% 75%

bones bones 25% 25%

teeth teeth 10% 10%

fat tissue fat tissue 20-33%20-33%

Higher body fat = Less H2OHigher body fat = Less H2O

Higher lean = Higher H2OHigher lean = Higher H2O

WATER COMPARTMENTSWATER COMPARTMENTS

WATERWATER Do not store waterDo not store water How long can we survive without water?How long can we survive without water? Water varies by:Water varies by: Age – caused by loss of extracellular fluidAge – caused by loss of extracellular fluid embryo = ~97% embryo = ~97% newborn = ~75%newborn = ~75% adult = ~60%adult = ~60% elderly = ~<60% (~50%)elderly = ~<60% (~50%) Gender- because of LBM relationshipGender- because of LBM relationship Men = 60% of body weightMen = 60% of body weight Women = 50% of body weightWomen = 50% of body weight

WATER WATER ESTIMATESESTIMATES

FUNCTIONSFUNCTIONS Building material – part of every cellBuilding material – part of every cell Medium for chemical reactions – chemicals (enzymes, Medium for chemical reactions – chemicals (enzymes,

hormones, coenzymes) dissolve and act on metaboliteshormones, coenzymes) dissolve and act on metabolites Hydolysis – digestionHydolysis – digestion Transport medium – solvent for waste productsTransport medium – solvent for waste products Lubricant – water filled sacs around jointsLubricant – water filled sacs around joints Shock absorber – around brain and spinal cordShock absorber – around brain and spinal cord Temperature control – cools skin, excess heat from Temperature control – cools skin, excess heat from

metabolic reactionsmetabolic reactions Blood volume Blood volume

FLUID BALANCEFLUID BALANCE

Fluid lossFluid loss Concentration of electrolytesConcentration of electrolytes Water absorbed from salivaWater absorbed from saliva Dry mouth, thirst stimulatedDry mouth, thirst stimulated Children, elderly, athletesChildren, elderly, athletes

WATER REGULATIONWATER REGULATION

WATER LOSSESWATER LOSSES

Normal 2-3 liters/dayNormal 2-3 liters/day Urine = 500-1400 mlUrine = 500-1400 ml Skin = 450-900 mlSkin = 450-900 ml Lungs = 350 mlLungs = 350 ml Feces = 150 mlFeces = 150 ml Insensible losses (skin, lungs, feces)Insensible losses (skin, lungs, feces) GI tract 8 liters/day secreted as GI tract 8 liters/day secreted as

digestive juices digestive juices reabsorbed in colon reabsorbed in colon

WATER OUTPUTWATER OUTPUT

LOSSES INCREASEDLOSSES INCREASED

AlcoholAlcohol CaffeineCaffeine Diuretics Diuretics

OUTPUT DEPENDS ONOUTPUT DEPENDS ON

Total intakeTotal intake Metabolic disturbancesMetabolic disturbances Altered dietary intake: protein, Altered dietary intake: protein,

NaCl, CHO increase urine output NaCl, CHO increase urine output for urea, ketones, and Nafor urea, ketones, and Na

Output of 1 liter/day = Output of 1 liter/day = concentrated urine concentrated urine increased increased risk of stones in susceptible peoplerisk of stones in susceptible people

WATER SOURCESWATER SOURCES

Fluids = 550-1500 mlFluids = 550-1500 ml Solid food = 700-1000 mlSolid food = 700-1000 ml Metabolic water = 200-300 mlMetabolic water = 200-300 ml Needs = lossesNeeds = losses Input and output normally in equilibriumInput and output normally in equilibrium Obligatory waste excretion – need at Obligatory waste excretion – need at

least 500 ml to excrete metabolic least 500 ml to excrete metabolic wasteswastes

WATER INPUTWATER INPUT

DEHYDRATION – LOW WATER DEHYDRATION – LOW WATER LEVELSLEVELS

Physical causes:Physical causes: VomitingVomiting DiarrheaDiarrhea Blood lossBlood loss FeverFever Weight lossWeight loss Work in high temperatures/hot climatesWork in high temperatures/hot climates Strenuous physical exerciseStrenuous physical exercise

SYMPTOMSSYMPTOMS

Thirst – not always reliableThirst – not always reliable Loss of appetite Loss of appetite Decreased blood volumeDecreased blood volume Impaired physical performanceImpaired physical performance Impaired temperature regulationImpaired temperature regulation Muscle spasmsMuscle spasms General debilitationGeneral debilitation

LAB TESTS TO DIAGNOSELAB TESTS TO DIAGNOSE

Increased hematocritIncreased hematocrit Increased serum sodiumIncreased serum sodium Increased albuminIncreased albumin Increased BUNIncreased BUN

WATER LOSSESWATER LOSSES

3% of body weight 3% of body weight decreased decreased physical performancephysical performance

4-5% body weight 4-5% body weight impaired impaired mental functionmental function

10% of body weight 10% of body weight life life threateningthreatening

20% body weight 20% body weight fatal fatal

DEHYDRATION CHARTDEHYDRATION CHART

REHYDRATIONREHYDRATION Drinking enough fluid?Drinking enough fluid? color of urinecolor of urine volume of urinevolume of urine weight lossweight loss For every pound lost drink 2 cups of fluidFor every pound lost drink 2 cups of fluid During exercise – 1 quart fluid for every 1000 cal During exercise – 1 quart fluid for every 1000 cal

spentspent drink 8-10 ounces every 15-20 min. of strenuous drink 8-10 ounces every 15-20 min. of strenuous

exercise – may sweat 3 times that much exercise – may sweat 3 times that much At risk for Na depletion if longer than 4 hour At risk for Na depletion if longer than 4 hour

workout – athletes acclimate, sweat less salty as workout – athletes acclimate, sweat less salty as become more conditionedbecome more conditioned

WHAT TO DRINKWHAT TO DRINK

? Caffeine - increases urination? Caffeine - increases urination ? Soft drinks - empty calories? Soft drinks - empty calories ? Gatorade, Allsport, Powerade - little nutritional ? Gatorade, Allsport, Powerade - little nutritional

valuevalue ? Beer - ETOH dehydrating effect, increase ? Beer - ETOH dehydrating effect, increase

urinationurination ? Juice? Juice

Vit C and KVit C and K ? Water? Water ? Glucose polymers & CHO powders – can ? Glucose polymers & CHO powders – can

provide energy value with less sweetnessprovide energy value with less sweetness ? Salt tablets – increase dehydration? Salt tablets – increase dehydration

WATER INTOXICATIONWATER INTOXICATION

Kidneys are overwhelmed – can’t excrete fast Kidneys are overwhelmed – can’t excrete fast enoughenough

Caused byCaused by

Greatly increased water intakeGreatly increased water intake

Increased secretion of antidiuretic hormoneIncreased secretion of antidiuretic hormone

Acute weight gainAcute weight gain Physical symptomsPhysical symptoms

HeadachesHeadaches

Blurred visionBlurred vision

CrampsCramps

Eventually convulsionsEventually convulsions

LABORATORY SIGNSLABORATORY SIGNS

Decreased hematocritDecreased hematocrit Decreased serum sodiumDecreased serum sodium Decreased albuminDecreased albumin Decreased BUNDecreased BUN Excess water dilutes Na Excess water dilutes Na

decreases Na concentration in ECF decreases Na concentration in ECF water enters cells and upsets water enters cells and upsets balancebalance