Hydration and Sports Drinks

7/26/2019 Hydration and Sports Drinks

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Water Requirements and

Fluid Balance

Dr. Jay A. Campbell



Heat Production DuringEercise

• For e!ery liter o" #$ consumed during eercise%cycling or running&' ( )cals o" *eat areproduced

– +ost o" t*is *eat is passed to t*e core t*roug*con!ecti!e ,o- o" !enous blood returning to t*e *eart

• emperature can increase in t*e belly o" amuscle at a rate o" /0 C1min -it* eerciseintensity o" 203405 6#$ ma

– Wit*out an e7cient means o" remo!ing t*is *eat'muscle contractile proteins and en8ymes -ould bedenatured in about /0 minutes

• *ese c*anges in temperature are sensed by

t*ermoreceptors in t*e *ypot*alamus



Heat 9torage DuringEercise

• Heat production is directly proportional toeercise intensity

– 9torage rates in t*e body goes up -it* *ot and*umid eercise en!ironments

• W*en body temperature reac*es about :4.;0 C %/0:0 F& central fatigue %"atigueeperienced in t*e brain !s. t*e tissues& -illensue

– A body temperature o" :<3:20 C is normal "or rest'-*ile :23(00 C is normal "or intense eercise oreercise in t*e *eat



•Heat storage increases our coretemperature= – >ncreases blood ,o- to t*e s?in – >nitiates s-eating

• En!ironmental *eat stress is relatedto= – ambient temperature – relati!e *umidity

– -ind !elocity – solar radiation

• #ur ability to lose *eat comes in t*e "ormo" e!aporation' con!ection' and conduction

Heat 9torage During Eercise



Wet Bulb @lobe emperature%WB@&

• se"ul inde o" en!ironmental *eatstress

• WB@ 0. -b 0.$ bg 0./ db

– -b -et bulb t*ermometer temperature

– bg blac? globe t*ermometer

temperature – db dry bulb t*ermometer temperature







Heat @ain and Heat oss

Key Slide



9-eating and Fluid oss

• +ild to moderate -or? and routinep*ysical training typically result in -*ole3body s-eat losses o" about 0.23/.( 1*.

• E!aporation o" / o" -ater "rom t*e s?in-ill remo!e ;: ?cal o" *eat "rom t*ebody. – Heat loss !ia e!aporation o" s-eat is largely

dependent on t*e *umidity %proimate to t*es?in& in -*ic* t*e at*lete is -or?ing.

• >ndi!idual s-eat rates and ,uid losses !ary-idely bet-een at*letes and across sports.





De*ydration andPer"ormance

• >" s-eating is not compensated "or -it* ,uidinta?e per"ormance is aGected.

– De*ydration may eplain some o" t*e "atigueat t*e end o" a long sporting e!ent.

• Eercise per"ormance is impaired by a ,uid losso" $5 %t*is is /.; in a /;;lb male at*lete&

• osses in ecess o" ;5 can decrease -or?capacity by :05 %-ater -eig*t loss o" 2lbs&

Key Slide



Body weight loss (%)

E

x e r c i s e C a p a c i t y

0 21 3 !

"0%

#0%

100%

$ the heat& sweat rates icrease e'e ore sch that *lidita+e st ,e e'e ore closely oitored-



De*ydration andPer"ormance

• *e main reasons de*ydration *as anad!erse eGect on eercise per"ormance=

– Reduction in blood !olume

– Decreased s?in blood ,o- – Decreased s-eat rate

– Decreased *eat dissipation

– >ncreased core temperature

– >ncreased rate o" muscle glycogen use

• direct result o" increased intensity o"-or? at any gi!en absolute -or?load

Key Slide



+odi"ying Factors

• Women generally *a!e lo-er s-eating ratest*an men.

– Women are at greater ris? t*an men to de!elopeercise3associated symptomatic *yponatremia.

• #lder adults *a!e age related decreasedt*irst sensiti!ity -*en de*ydrated

– ma?es t*em slo-er to !oluntarilyreestablis* eu*ydration.

– #lder adults *a!e age related slo-er renalresponses to -ater and may be at greater ris? "or*yponatremia.

Key Slide



+odi"ying Factors• C*ildren *a!e lo-er s-eating rates t*an adults.

• +eal consumption promotes eu*ydration.

• 9-eat electrolyte %sodium and potassium& losses

s*ould be "ully replaced to reestablis* eu*ydration.

• CaGeine consumption -ill not mar?edly alter dailyurine output or *ydration status.

• Alco*ol consumption can increase urine output anddelay "ull re*ydration.

Key Slide



.ow does sweatig (*lid loss) wor+ to decrease per*orace/

icrease i plasa osolarity (highercocetratio o* solte i soltio)

release o* 'asopressi (.) *ro theposterior pititary glad-

. cases the +idey to rea,sor, water

rie 'ole goes 456 draatically to preser'e,lood osolarity& 'ole ad pressre

s exercise progresses& the tras*er o* ,odywater ito the plasa caot +eep p withsweat losses so---per*orace decreases-



How can I tell how much I’m sweating?

7re exercise weight !! +g

7ostexercise weight !3-! +g

8ole o* *lid cosed drig exercise 1 +g

Exercise dratio 2 h

Calclatios

• 9lid de*icit (:) ; !! +g – !3-!+g ; 1-! +g

• <otal sweat loss (:) ; 1-! +g = 1 +g ; 2-! +g

• Sweat rate (:>h) ; 2-! +g > 2hr ; 1-2! :>h

Key Slide



rine 9peciIc @ra!ity• rine speciIc gra!ity is a scientiIc measure o"

*ydration by measuring t*e density %concentration&o" a urine sample.

• Equipment required=

• a re"ractometer %a simple *and3*eld !ersion is illustrated*ere&

• urine specimen containers "or urine collection

• distilled -ater

• cleaning clot* 1 disposable tissues

• "ridge or ice cooler "or urine storage• glo!es.

• ormal 9@ "rom /.00:3/.0:0

– /.0$0 is -*ere per"ormance decrements seem to begin



11

22

33

44

55

66

77

88

• rie Color Chartrie Color Chart

• ssess .ydratio ssess .ydratio

• 1& 2& or 3? 5ell1& 2& or 3? 5ell.ydrated.ydrated

• @ or ar+er?@ or ar+er?

ehydratedehydrated

.ydratio A ehydratio.ydratio A ehydratio

Key Slide





Daily Water Balance

At*letes need to be "ully *ydrated be"oretraining1competition

*e a!erage sedentary person ecretes about$00 milliliters o" -ater1day %/(00 "rom urine' //00

s-eat1breat*&

o replace t*at $00 ml' get=

• :003(00 ml "rom metabolism'• /000 ml "rom "ood and• /:003/(00 ml "rom be!erages

$00 ml



At*letes and Daily Water BalanceAt*letes and Daily Water Balance

Key Slide



At*letes and Fluid >nta?e

• At*letes *a!e to consider t*eir daily-ater balance and s-eat loss duringeercise -*en t*ey construct a

*ydration plan. – C*oices to maintain1increase ,uid inta?e=

• Water

• CH# drin?s• C*oc +il?

• Coca3Cola



• *e maimum amount o" ,uid t*atempties "rom t*e stomac* duringeercise is 0.23/.$ 1*. – Remember' s-eating during eercise can

cause ,uid losses o" 0.23/.( 1*

•p to /05 CH# solution empties "romt*e stomac* at t*e same rate as pure-ater %Co?e is //5&

• @lucose and sodium bot* stimulate t*eabsorption o" ,uid across t*emembrane o" t*e small intestine.• in ot*er -ords' adding eit*er or bot* can

*elp -it* ,uid absorption Key Slide



• At*letes s*ould consume enoug*

-ater t*roug*out eercise t*at t*eir-eig*t remains constant %i" possible&

• @uidelines "or ,uid inta?e are 6ERKgeneral due to t*e !ariability o"s-eat rates among indi!iduals.

– @ood rule o" t*umb is to consumesomet*ing e!ery I"teen minutes %23/$o8.&



ACSM NATA AIS Gatorade NCAA

Before !00 l ? 2 hors !00"00 l ? 23 hors $d 1@ 20 o ? 2 to 3 hors 1@ 1# o ? 2 hors

200300 l ? 1020 i @10 o ? 10 1! pre warp

During eglar $ter'als 200300 e'ery 1020 i $d @10 o e'ery 101! i # o e'ery 101! i

After EDal to loss 1!0% o* weight lost $d 202 o > l, 202 o > l,

Tem !o @2o 9 !0o !o 9 $d Cooled !0o !o 9

Contents C.4 ad Sodi C.4 ad Electrolytres $d C.4 ("@%) ad Sodi



A"ter Eercise

• Drin? /;05 o" -ater -eig*t loss to ac*ie!enormal *ydration <*rs post3eercise

%t*is accounts "or reduced urine output&

• Pure -ater may not be t*e ideal reco!erydrin?=

– Causes rapid "all in plasma sodium and t*usplasma osmolarity -*ic* reduce t*e stimulationto drin? and also increases urine output.

– *is can delay t*e re3*ydration process



W*at to drin? t*enL

Plasma !olume is rapidly restored i" somesodium c*loride is added %mol or 0.(;g1&

9odium=• Helps maintain t*irst' delays urine production

Potassium=• *oug*t to promote intracellular *ydration %little e!idence tosupport t*is' but it sounds good&

CH# %glucose' glucose polymers&• +ore li?ely to continue drin?ing ,uid i" be!erage is s-eetened

%taste& !s. pure -ater• Presence o" glucose stimulates ,uid absorption

• We ?no- it *elps -it* muscle glycogen re3synt*esis

Key Slide



CH# 9ports Drin?s

*e goal o" t*e carbo*ydrate content is to pro!ide t*eappropriate CH# concentration -*ile pre!entinggastrointestinal disturbances.

– At <325 carbo*ydrate concentration' sports drin?s

can be absorbed :05 "aster t*an -ater.

*e : t*ings a sports drin? s*ould

accomplis*=/. Hydrate eGecti!ely.

$. Replenis* electrolytes.

:. Pro!ide energy "or -or?ing muscles to en*ance

per"ormance and speed reco!ery.

Key Slide



@atorade

• Fatorade – !0 calories per # *l o-

– "% Car,ohydrate

electrolyte soltio- – 1 g o* C.4 (sgar) i # *l

o-

– 110 g o* 6a= i # *l o-

– 30 g o* K= i # *l o-

– 0 g o* Cl2 i # *l o-

– etail 7rice G12-



7owerade

• 7owerde – !0 +cals per # *l- o

– @% Car,ohydrateelectrolyte dri+-

– 1# g o* C.4 i # *l o with1! g as sgar-

– !3 g o* 6a= i # *l o-

– 3 g o* K= i # *l o-

– etail 7rice G12-



• 7ropel 9itess 5ater – Calories 10 i # *l o-

– Sodi 3! g

– 7otassi 0 g

– <otal Car,ohydrate 3 g

– Sgars 2 g

– 8itai C 10%

– 8itai E 10% 6iaci 2!%

– 7atotheic cid 2!%

– 8itai B12 %

– 8itai B" – etail 7rice G1-2! per ,ottle-

Fla!ored Water



• From t*e tetboo? to t*e trac?=/. DonHt -ait until t*irsty... *irst signal is

t*e result o" being slig*tly de*ydrated.$. +onitor urine output and -eig*t be"ore

and a"ter eercise %approimate ,uid loss&

:. >n *ot -eat*er at*letes need to consume

more ,uid during1a"ter eercise comparedto colder -eat*er.

(. For reco!ery' supplement -it* acarbo*ydrate drin? t*at contains somesodium to aid in replenis*ment o"glycogen stores and electrolytes.%remember t*e protein&... @atorade' C*ocmil? or co?eL

Key Slide



Eercise and Fluid

Replacement/. Eat a balanced diet and drin? plenty o" ,uids in

t*e $( *ours prior to competition

$. Drin? <32 m o" ,uid1?g o" b- about $ *oursbe"ore eercise

– allo-s "or ,uid absorption and ecretion o"ecess -ater

:. During eercise drin? early and regularly

– t*is s*ould be customi8ed based on pre and

post eercise -eig*t c*anges

(. >ngested ,uids s*ould be cool %;43$0F&

– ,a!oring increases palatability

Key Slide

os t on tan =



;. Add carbo*ydrate1electrolytes "or eercise /*our

– :03<0 g1* o" CH# %maintains oidation M delays"atigue&

– (32 5 CH# per /00 m o" ,uid -it* glucose'sucrose' or starc* %maltodetrins&

<. >nclude sodium %;00300 mg1 o" -ater&

–less needed i" a sodium su7cient meal -asconsumed

. >" rapid replenis*ment is needed' /.; 1)g o"body -eig*t lost

os t on tan =Eercise and Fluid

Replacement

Key Slide



HE ED

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Hydration and Sports Drinks