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PhysiologicalCapacityand PhysiologicalCapacityand PerformanceAcrosstheLifespan Metabolicdifferencesbetween Metabolic children&adults 1. 2. 3. 4. Lowerglycogenstores LowerATPstores Fewerglycolyticenzymes Fewermitochondrial enzymes Why? LESSMUSCLEMASS! Cardiovasculardifferences betweenchildren&adults 1. 1. 2. 1. 2. HigherHR Lowerstrokevolume Lowercardiacoutput Morebloodflowto workingmuscles Lesshemoglobinin blood 2 1. avO differenceis aboutequal Respiratorydifferencesbetween children&adults 1. 2. 1. Higherminute ventilation Higherrespiratory musclefatigue Smallerlungvolumes Why? Childrenaresmallerpeople. Thermoregulatorydifferences betweenchildren&adults 1. 1. 1. Greatermetabolic heatduringexercise. Lateronsetof increasedsweat productionathigher relativeworkloads. Lessresponsive thirstmechanism. 1. DifferencesinVO2max: Increasesuntilage1618in males&untilage1214 infemales VO2maxishigherinboys thangirlsafterage9. 2max FemaleVO =8590%of malesbeforepuberty& 70%ofmalesafterpuberty AerobicExerciseCapacityin AerobicExerciseCapacityin Children ChangesinVO2maxaredue tochangesinsize&body composition AerobicTraininginChildren AerobicTraininginChildren Whatendurancetrainingadaptationsdoweobservein children? DecreasedrestingHR IncreasedSv+Q(cardiacoutput) IncreaseinVO2max(525%) Increasedlactatethreshold AerobicperformanceincreasedmorethanVO2max. Howisthispossible? AnaerobicExerciseCapacityin AnaerobicExerciseCapacityin Children Childrenhavealoweranaerobiccapacitythanadults evenwhenadjustedforleanbodymass. Howisthispossible? Lowerglycogenstores Lowerglycolyticenzymeactivity Lowerbufferingcapacity Theyrecoverfasterthanadultsafterintenseboutsof physicalactivity. Howisthispossible? Oxygendoesnthavetotravelasfar AnaerobicExerciseCapacityin Children Anaerobiccapacityrises duringchildhood& adolescencebetween ages915 Anaerobiccapacitypeaks afterpuberty&into earlyadulthood: 1416infemales Atleast20inmales MuscularStrengthinChildren MuscularStrengthinChildren Thereisalinearrelationshipbetweenstrengthandage untilage1314inmales&1416infemales. Afterpubertymuscularstrengthisrelatedto: 1. Bodymassweight 2. Bodycomposition%massvs.musclevs.bone 3. Testosteronemalesexhormoneisasteroid hormone 4. Maturationofneuralpathways StrengthTraininginChildren StrengthTraininginChildren Shouldchildrenstrengthtrain? Recommendationsforstrengthtrainingandchildren: Supervisionwhenliftingweightsabovetheirheads and/orusingfreeweights Emphasisshouldbeonform&technique,not competition 30minutesessions!! DecreasesinExerciseCapacity DecreasesinExerciseCapacity DuringAging Aerobic&Anaerobiccapacitiesdecreasewithage. Cardiacoutput(Q) Whatfactorscausethisdecline? Aerobicpower(VO2max) Musclemass Muscularstrength Aerobiccapacitydecreaesabout 1%peryear. HRmaxdecreasesabout1 beat/year. SVmaxdecreases,thoughitcan bewellmaintainedwith training. Qmaxdecrease AerobicPower(VO2max) AerobicPower(VO Withaerobictraining VO2maxcanincrease Increasedmitochondrialand capillarydensitygreat oxidativecapacityandO2 extraction MuscularStrength MuscularStrength Whyisitimportantforadultsto maintainmuscularstrength? posture balance coordination dailyactivities Howdoesmuscularstrength Howdoesmuscularstrength changeasweage? decreaseby24%peryear Between2080yrs.welose40% ofourmusclemass. Gradualdeclinebetween 3050yrs. Accelerateddeclineafter50 yrs. Whatcausesthesechanges? inactivity Muscleatrophydecreasein musclesize Neuralinput ExercisePrescriptionforOlder ExercisePrescriptionforOlder Adults Thegoalofprogramdesignforolderadultsis toimproveormaintain: 1) 1) 2) 1) 1) 2) 3) Functionalcapacity Muscularstrength Muscularendurance Qualityoflife Flexibility Coordination Balance GenderDifferencesinAerobic GenderDifferencesinAerobic ExerciseCapacity Differencesinperformance cantbeexplainedby differenceinVO2max alone. 40%differencein absoluteVO2max 20%differencein relativeVO2max 10%differencewhen adjustedforleanbody mass Leanbodymassbody massminusfatmass GenderDifferencesinAerobic GenderDifferencesinAerobic ExerciseCapacity WhatcanaccountforthedifferenceinVO2maxbetween malesandfemaleswhenadjustedforleanbody mass? RBCcount Hemoglobin Heartsize Lungcapacity ADAPTIONSARETOAEROBICTRAININGARESIMILAR BETWEENMALESANDFEMALESALTHOUGHTHE MAGNITUDEISGREATERINMALES! Totalworkandpoweroutputis greaterinmalesthanfemales Differencesstillremainwhen adjustedforleanbodymass. Causesofdifferences? Bodycomposition Limblength(maleshave largerandlongerlimbs) ADAPTIONSARETOANAEROBIC TRAININGARESIMILAR BETWEENMALESAND FEMALESALTHOUGHTHE MAGNITUDEISGREATERIN MALES! GenderDifferencesinAnaerobic GenderDifferencesinAnaerobic Capacity Physiologicaldifferencein Effectonperformance females Smallerbodiesie:shorterlimbs Lessleanmusclemassinrelationtofat mass GenderDifferencesinSport GenderDifferencesinSport Performance Lowermuscularstrengthandpower LoweroxidativecapacitylowerVO2max (aerobicpower);fewerTypeII fibers loweranaerobicpower Lowerforceproductionlower muscularpower&strength Lowerstrokevolumelowercardiac outputlowerVO2max LessO2carryingcapacityloweravO2 difflowerVO2max Lowersweatingrateduringexercise Smallermusclefiberdiameter Smallerheart Lowerhemoglobin Greaterrelianceoncirculatory adjustmentsthansweatingfor thermoregulation TABLE12.2YOUNEEDTOKNOWTHISTABLE! ... View Full Document

Exercise Physiology Chapter 6

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