Energy Systems Powerpoint

7/23/2019 Energy Systems Powerpoint

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FACTORS AFFECTING

PERFORMANCEENERGY SYSTEMS

HSC CORE 2



ENERGY SYSTEMS

The human body requires a continuous supply oener!y both to meet the needs o its systems andor!ans and to po"er muscular contraction or

mo#ement$%nli&e a car "hich carries its ener!y supply in a uel

tan&' body ener!y is stored in the chemical bondsthat (oin atoms and is released only as needed$ The

transormation o ood )chemical ener!y* to ener!ythat the muscles can use )mechanical ener!y* is therole o ener!y systems$



ENERGY SYSTEMS

Ener!y pro#ided by ood is measured in &ilo(oules )&+*$

,oods ha#e dierent amounts o ener!y "hich they supply-

.Carbohydrate /0 &ilo(oules o ener!y per !ram

. 1rotein / &ilo(oules o ener!y per !ram

. at yields 3 &ilo(oules per !ram$ ,oods "ith relati#ely hi!h le#els o at yield a lar!er numbero &ilo(oules and thereore a lot more ener!y$

,ood is di!ested and brea&s do"n to su!ars' amino acids and atty acids4 usable orm oener!y$

,rom these' 5T1 or adenosine triphosphate is produced and represents the most importantsubstance in ener!y production$

5T1 can be li&ened to a spar& plu! in an en!ine$ 6t enables the release o ener!y rom thesesubstances "here it can be used or muscular contraction and essential body processes suchas di!estion' blood circulation and tissue buildin!$



,unctions o 5T1



5T1 STR%CT%RE

The 5T1 compound consists o a lar!e moleculecalled adenosine )5* and three smaller moleculescalled phosphates )1*$ Each o the phosphates is held

to!ether by hi!h ener!y bonds$ The chemicalstructure o 5T1 is sho"n belo"$



5T1

7hen the last )terminal* phosphate is detached' ener!y stored in bonds bet"een the phosphates becomes a#ailable and this is transerred to thecells$ This process is li&e lic&in! on a li!ht s"itch$ The li!ht "ill not "or& until the current lo"s and pro#ides ener!y to li!ht the !lobe$ 6nthe muscle cells' the ener!y rom 5T1 allo"s the ibres to contract and

ma&es mo#ement possible$ This is represented as ollo"s$



5T18591

Ho"e#er' 5T1 no" has only t"o phosphatesattached$ 6n this state it is reerred to as 591)adenosine diphosphate* and is po"erless to pro#ide

ener!y$ 6t is represented as ollo"s$



,unctions o 5T1

%sed 5T1 does not become a "aste product$

6t can be quic&ly rebuilt or resynthesised' allo"in! us to continue to unction$

The bodies demand or 5T1 #aries throu!hout the day dependin! on ener!y requirements$ ,or e:amplee:ercisin! as compared to restin! or sleepin!$

5T1 needs to be continually rebuilt to enable an ener!y lo"$

%nder normal conditions such as sittin!' lyin! or readin!' only suicient is produced to enable basicunctions to be sustained$

%nder intense physical demands such as cyclin!' s"immin! or runnin! are placed on the body' the systemsrespond by producin! much hi!her le#els o 5T1 to ensure that our immediate ener!y needs are met$

The three systems that ma&e 5T1 a#ailable are-

the alactacid system )commonly called the 5T181C system*

the lactic acid system )!lycolytic system*

the aerobic system )o:y!en system*$



Ener!y Systems O#er#ie"



Ener!y Systems O#er#ie"

The alactacid and lactic acid systems are both calledanaerobic path"ays because they do not require oxygen or the resynthesis o 5T1$

Ho"e#er' the aerobic system is o:y!en dependent; that is'

5T1 produced usin! this system relies on the aaila!ilityo" su""i#ient oxygen in the cells$

The systems are commonly called ener!y path"ays becausethey each supply 5T1 but use dierent processes to do so$

Each system has a "ay o resynthesisin! )rebuildin!* thepartly destroyed 5T1 molecule$ Ho" "ell each systemresynthesises 5T1 determines its eiciency in ener!yproduction$



Ala#ta#id syste$ %ATP&PC'

Supplies o 5T1 in the body are #ery limited$

Only ha#e suicient or one e:plosi#e muscular contraction' or e:ample' a standin! lon! (ump or sprint start lastin! one to t"o seconds$

5n e:plosi#e mo#ement causes the 5T1 molecule to <split=' pro#idin! ener!y or muscular

contraction$

6n order to continue e:ercisin! at a hi!h intensity past this time the body must replenish 5T1stores and thereore it uses the creatine phosphate )C1* stored in the muscle to achie#e this$

This process occurs by brea&in! do"n the creatine and phosphate' and releasin! ener!y in the

process$ The ener!y is used to dri#e ree phosphate bac& to 591 so it can once a!ain become atriple phosphate$

Once reormed' 5T1 can brea& do"n a!ain > and so the process !oes on$

C1 supplies are e:hausted "ithin /?@/2 seconds and ta&e t"o minutes to be restored$



Ala#ta#id syste$ %ATP&PC'Energy Path(ay



5lactacid System )5T181C* O#er#ie"

Sour#e o" "uel

7e ha#e about A? !rams o 5T1 in our body$ This is suicient to po"er the musclesrequired in one e:plosi#e mo#ement such as a (ump' start or thro"$ That equates toone to t"o seconds o hard "or&$ ,ollo"in! that' "e rely on the /2? !rams oreser#e uel' C1' stored in our cells$ Creatine phosphate' then' is the uel o the 5T181C system$

E""i#ien#y o" ATP )rodu#tion

The alactacid system unctions to ma&e 5T1 rapidly a#ailable$

Occurs "hether or not o:y!en is a#ailable$

This rapid supply is enabled primarily by a concentration o C1 "ithin muscle cells$

The supply o 5T1 is #ery limited' ho"e#er' i the demand is hi!h as a result osustained' ma:imal or near ma:imal "or&$

System is able to reco#er quic&ly$ Hence' the importance o this system to short'e:plosi#e mo#ements in acti#ities such as "ei!ht.litin!' discus thro"in! and startsin athletics is paramount$



5lactacid System )5T181C* O#er#ie"

*uration o" the syste$6n the alactacid system' 5T1 supplies are e:hausted ater t"o seconds o hard "or& and C1

supplies are e:hausted in a urther /? to /B seconds$ Ho"e#er' at rest' C1 supplies are almostully restored "ithin t"o minutes$

Cause o" "atigue

5t ma:imal or near ma:imal eort' ati!ue is caused by the inability o the system to continuallyresynthesise 591 rom C1 because C1 supplies are quic&ly e:hausted$ This is "hy "e are unable

to run at ma:imal eort or distances lon!er than /?? metres$ 6t is particularly e#ident in an all.out sprint o#er /B? metres' "here the "inner "ill not be the athlete that accelerates most to theinish' but the one "ho slo"s do"n the least in the inal metres o the race$

+y,)rodu#ts o" energy )rodu#tion

7hile there are no ati!uin! by.products o this system' heat is produced durin! the process omuscular contraction$

Rate o" re#oery The 5T181C system reco#ers quic&ly rom e:ercise$ 7ithin t"o minutes' most o the 5T1 and

C1 supplies ha#e been ully restored' "ith B? per cent o creatine phosphate replenishmentoccurrin! in the irst 3? seconds o rest reco#ery$ This is "hy hi!h (umpers' "ei!ht liters anddiscus thro"ers can <bac& up= almost immediately ater their irst and second attempts$



-a#ti# a#id syste$ %anaerobic !lycolysis*

,ollo"in! /?@/2 seconds o ma:imal e:ercise' C1 supplies are e:hausted$ 5T1 still needs to beproduced to pro#ide ener!y' assumin! that the acti#ity requires eort or lon!er than this' such as ina ?? metre race$ Suicient o:y!en is not a#ailable e#en thou!h the breathin! rate has increased

because o eort$ This is because it ta&es some time or the blood to mo#e rom the lun!s around the body and then to the "or&in! muscles "here o:y!en is in hi!h demand$

The body needs to ind a dierent uel because C1 supplies are at a lo" le#el$ 6t does this by usin! theimmediate su!ar supplies circulatin! in the blood )blood su!ar*' as "ell as our su!ar stora!e suppliesin the muscle and li#er$ 7e reer to our blood su!ar as !lucose$ 6t circulates reely in the bloodstreamand its le#el is constantly re!ulated by the pancreas$ 7hen "e accumulate too much' the body storesthe e:cess in the li#er and muscle$ Stored !lucose is called !lyco!en$

The process o usin! !lyco!en or !lucose as uel is called !lycolysis$ Glyco!en is much moreabundant than C1 and can be used "hether o:y!en is a#ailable or not$ The lactic acid system isanaerobic and' because !lyco!en is the only uel' the de!radation process is called anaerobic!lycolysis$ 5s suicient o:y!en is not a#ailable durin! intense e:ercise' lactic acid le#els rise andcontinue to rise as intensity increases$

Dactic acid is produced because insuicient o:y!en results in the partial brea&do"n o !lucose'pro#idin! quic& but limited 5T1 production' as "ell as the by.product' lactic acid$




Sour#e o" "uel

The only uel that can be used by the lactic acid system is carbohydrate$ This e:istsin t"o orms-

as !lucose in the blood

in the stora!e orm called !lyco!en$

Glyco!en is bro&en do"n' producin! 5T1 and ener!y or muscular contraction$


The lactic acid system pro#ides 5T1 quic&ly' but this requires lar!e quantities o!lucose$ 6n other "ords' 5T1 is rapidly a#ailable but at considerable cost$ ,or

e:ample' three moles o 5T1 is the most that can be manuactured rom the brea&do"n o /? !rams o !lyco!en durin! anaerobic !lycolysis$




*uration o" the syste$

The duration )"or& span* o the system depends on the intensity o the acti#ity$ 7hereas a near ma:imaleort causes e:haustion in 3? seconds' an eort o ?@? per cent "ill not cause e:haustion or three toour minutes and much lon!er or moderate intensity acti#ity$

Generally spea&in!' the lactic acid system produces ener!y or hi!h intensity acti#ities lastin! rom /?seconds to one minute or more dependin! on the eort in#ol#ed$ 6t is the dominant system or all ma:imalacti#ity perormed bet"een 3? seconds and t"o minutes > or e:ample' 2?? metre sprint' ?? metrerunnin!' ?? metre runnin!' 2?? metre reestyle and !ymnastic routines$

Cause o" "atigue

,ati!ue occurs "hen lactic acid le#els build up "ithin the muscle cells$

1re#iously thou!ht that lactic acid impeded perormance' recent research su!!ests that it can be beneicial$

Researchers ha#e sho"n that ati!ue is not caused directly by lactic acid but rather by its rate o remo#al$

Dactic acid is produced "hene#er the body uses carbohydrate as uel' and this occurs most o the time$ E#en

at rest' some lactic acid is produced because some carbohydrate is bein! metabolised' e#en thou!h the bodyFs predominant uel source is at$ The speed o lactic acid production depends on e:ercise intensity$ Theaster you "or&' the more rapidly lactic acid accumulates$ E:cessi#ely hi!h le#els o lactic acid pre#ent themuscle ibres rom contractin! and result in a rapid deterioration in perormance$

Ho"e#er' "hile hi!h lactic acid le#els cause ati!ue' tolerable le#els can' in act' enhance perormance' because lactate is a uel source$ ,indin! the balance bet"een the le#els comes "ith trainin!' to!ether "iththe indi#idualFs a"areness o the presence o lactic acid accumulation$ Dactic acid tolerance impro#es "ithtrainin!' as do remo#al rates$ E#en thou!h production rates may be hi!h durin! intense e:ercise' hi!h

remo#al rates may ensure that perormance is not aected$




.hat is the relationshi) !et(een la#ti# a#id and "atigue/ 7hen lactic acid is ormed' itimmediately separates into the lactate ion )lactate* and a hydro!en ion )H *$ The hydro!en ion is theacid part o lactic acid and impairs perormance$ 6n contrast' the lactate ion is a ast uel' and isactually preerred by the muscle' e#en o#er !lucose' because o its easy remo#al rom the blood$Dactate is readily processed in the mitochondria or <ood actories= in the muscle cells and' "hile mostis con#erted to carbon dio:ide and "ater )0B per cent*' some is con#erted to uel$ ,rom here it istransported to other tissues such as the heart and brain and is used or ener!y$ 6n act' about 2? per

cent o the li#erFs !lyco!en supplies are produced rom lactic acid$

The cause o ati!ue in this system is predominantly the accumulation o lactic acid in quantities aster thanit can be remo#ed$ Ho"e#er' other actors' such as the demandin! nature o muscular eort' also need to beconsidered$ Hi!h le#els o lactic acid in isolation may not be the cause o ati!ue' as some "ell.trainedathletes can tolerate hi!h le#els' pro#idin! the remo#al rate is equally hi!h$ ,or e:ample' "hile the lactatethreshold or untrained people is around mmol8D' trained athletes ha#e been &no"n to continue aerobic "or& "ith blood lactate le#els abo#e 2? mmol8D$ 1roper trainin! positi#ely aects the rate o remo#al olactic acid rom the body$

Elite athletes train "ith the intent o producin! lactic acid by "or&in! abo#e the lactic acid threshold or aslon! as they can sustain output$ The response to this intense trainin! is that the body produces enymes thathasten the use o lactic acid as a uel$ The ability to use lactate as a uel thereore #aries rom one athlete toanother because o the trained characteristics o muscle ibres and' particularly in the case o endurance

athletes' red muscle ibres$




Rate o" re#oery

9urin! the post.e:ercise period' lactic acid diuses rom the muscle andinto the bloodstream "here its use as a by.product is important$ 6n theli#er' lactic acid is recon#erted to !lyco!en and can once a!ain be used as asource o uel )see i!ure belo"*$ The process ta&es about 3? minutes to an

hour$ This urther contributes to the bodyFs eiciency by resynthesisin! "aste or use at a later sta!e$



Aero!i# syste$

1hysical acti#ity lastin! more than a e" minutes requires the presenceo o:y!en to ensure the continuation o muscular contraction$

O:y!en is not immediately abundant to the muscles "hen "e be!ine:ercise; rather' it !radually becomes a#ailable as the o:y!en.rich blood ills the muscle cells$

This allo"s the third ener!y path"ay' called the aerobic path"ay oro:idati#e system to become the predominant supplier o 5T1$

This process o uel de!radation is sometimes called aerobicmetabolism because !lucose and at )and sometimes protein* are bro&en do"n in the presence o o:y!en to produce 5T1$

Dactic acid does not accumulate durin! aerobic metabolism becauseo:y!en is present$ This is in contrast to anaerobic !lycolysis$



Sour#e o" "uel

7hereas the lactic acid system can use only !lucose as uel' the aerobicsystem can use carbohydrate' at and e#en protein )i!ure B$/3*$ 9urin!the early sta!es o endurance "or&' carbohydrate is the preerred uel$Ho"e#er' i e:ercise continues beyond an hour or so' at becomesincreasin!ly important as a uel and rei!ns as the dominant ener!y

source i !lyco!en supplies become e:hausted$




The aerobic system is e:tremely eicient in the metabolism o uel andpro#ision o ener!y$ 7hereas the lactic acid system is able to !enerateonly three moles o 5T1 rom /? !rams o !lyco!en' the aerobicsystem is able to !enerate 3A moles o 5T1 rom /? !rams o !lyco!en$6n eect' it enables the production o much more ener!y rom !lyco!en'

enablin! us to continue sustained "or& or lon!er periods o time$



*uration o" the syste$

The total amount o !lyco!en in the body is appro:imately 3B? !rams$ Thisis suicient or /2 hours o rest or one hour o hard "or&$ 6n intermittente:ercise' such as ootball or netball' !lyco!en supplies last orappro:imately our to si: hours$ Ho"e#er' in the case o marathon runners'supplies could be e:hausted in about t"o hours$

The body has #irtually unlimited supplies o at and this is used as a uelsource as !lyco!en supplies are depleted$ 6n "ell.trained athletes' the bodymi:es carbohydrate and at in endurance e#ents$ This process' calledglycogen sparing' results in some at uel bein! used earlier so that!lyco!en can be a#ailable at a later sta!e' such as or a sprint inish$ Theseuels used (ointly' yet sparin!ly' ensure that the body can operate usin! thissystem or lon! periods o time$ The aerobic system is the predominantsystem or use durin! e:tended endurance e#ents such as marathons andlo" demand acti#ities such as "al&in!' sittin! and readin!$



Cause o" "atigue

Iecause the aerobic system is so #ersatile in uel usa!e )remember it can usecarbohydrate' at and e#en protein to produce ener!y*' it is not a lac& o uel butother actors that contribute to ati!ue "hile this system predominates$ 9urin!endurance "or&' slo".t"itch muscle ibres "ill do most o the "or&$ Theseibres ha#e many capillaries and a rich o:y!en supply$ Ieore a run' these ibresmay be saturated "ith !lucose$ Ho"e#er' acti#ity beyond an hour or so results indepletion o uel and' althou!h some is replaced rom the li#er' !lyco!en ise:hausted$ Glyco!en is premium uel or muscles$ 7hen it runs out' the bodytires$

5 second cause o ati!ue is the e:haustion o carbohydrate and subsequentreliance on the secondary uel' at$ 5lthou!h at is much hi!her in ener!y than

carbohydrate' its use as a sole uel can cause problems$ The point at "hich the body chan!es its main uel supply rom !lyco!en to at is called <hittin! the "all=$,ati!ue occurs because at requires more o:y!en or metabolism than doescarbohydrate$ This increases the runnerFs body temperature and rate orespiration$



Iy.products 8Rate o reco#ery

+y,)rodu#ts o" energy )rodu#tion

9urin! aerobic acti#ity' o:y!en is required to burn the uels in the body )carbohydrate and at*$ 5s "ith most uels that are burnt' by.products are produced' in this case' carbon dio:ide and "ater$ The

carbon dio:ide is breathed out throu!h the process o respirationand the "ater is a#ailable to the cells$ These by.products are notharmul to perormance$

Rate o" re#oery

The reco#ery rate o the aerobic system depends on the duration

o use$ 6 used or a short period o time' the system reco#ersquic&ly because !lyco!en stores ha#e not been depleted$ Ho"e#er'i used or hours' !lyco!en stora!e areas could "ell be e:hausted$6n this case' it may ta&e days to ully replenish !lyco!en reser#es$



ENERGY SYSTEMS COMI6NE9

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