Development Issues in Exercise Development Issues in Exercise ScienceScience

IntroductionIntroduction

Developmental Issues in Developmental Issues in Exercise ScienceExercise Science

Physical Responses on Exercise Physical Responses on Exercise Conditioning in AdolescenceConditioning in Adolescence

Developmental ContinuumDevelopmental ContinuumPrenatalPrenatal– EmbryoEmbryo 2-8 weeks2-8 weeks– FetusFetus 8weeks-birth8weeks-birth

NeonateNeonate birth-4 weeksbirth-4 weeks

InfancyInfancy– EarlyEarly birth-12 monthsbirth-12 months– LaterLater 12-24 months12-24 months

ChildhoodChildhood– ToddlerhoodToddlerhood 24-36 months24-36 months– Early Childhood (Preschool)Early Childhood (Preschool) 3-5 yrs3-5 yrs– Late ChildhoodLate Childhood 6-10 yrs6-10 yrs

AdolescenceAdolescence– Pre-pubescencePre-pubescence

FemalesFemales 10-12 yrs10-12 yrsMalesMales 11-13 yrs11-13 yrs

– Post-pubescencePost-pubescenceFemalesFemales 12-18 yrs12-18 yrsMalesMales 14-20 yrs14-20 yrs

AdulthoodAdulthood– Young adulthoodYoung adulthood 18-40 yrs18-40 yrs– Middle adulthoodMiddle adulthood 40-60 yrs40-60 yrs– Older adulthoodOlder adulthood

Young oldYoung old 60-70 yrs60-70 yrsMiddle oldMiddle old 70-80 yrs70-80 yrsFrail oldFrail old 8080++ yrs yrs

Motor DevelopmentMotor Development

Described as “Progressive change in Motor Described as “Progressive change in Motor behavior throughout the life cycle”behavior throughout the life cycle”

1.1. Physical ChangesPhysical Changes

2.2. Biomechanical ChangesBiomechanical Changes

Developmental Changes in Youth Developmental Changes in Youth FitnessFitness

Female 9-11, Male 11-13 children’s bodies Female 9-11, Male 11-13 children’s bodies begin to changes due to hormonal change with begin to changes due to hormonal change with pubertypubertyThese change influence by health-related These change influence by health-related physical fitnessphysical fitness– Muscular strength/enduranceMuscular strength/endurance– Aerobic enduranceAerobic endurance– Joint flexibilityJoint flexibility– Body compositionBody composition

Field based researchField based research– Know about the motor performance of youth is Know about the motor performance of youth is

derivedderived– Conducted in school, play grounds…Conducted in school, play grounds…– Realistic motor performance situations Realistic motor performance situations – More relaxed atmosphere than a formal LabMore relaxed atmosphere than a formal Lab

Muscular Strength and EnduranceMuscular Strength and Endurance

Key components of Health-related physical Key components of Health-related physical fitness.fitness.Measurement: bent knee sits-ups, hand grip…Measurement: bent knee sits-ups, hand grip…Pre-pubertal growth spurt, girls and boys Pre-pubertal growth spurt, girls and boys follow a same pattern until male growth spurt.follow a same pattern until male growth spurt.Obvious gender differences are muscle mass Obvious gender differences are muscle mass increases of maleincreases of male

Aerobic EnduranceAerobic EnduranceCan use treadmill test to measure maximal; oxCan use treadmill test to measure maximal; oxygen capacity in childrenygen capacity in children

Lab tests Lab tests v.s.v.s. Field tests Field tests

Female improve their running time until 14 yrs Female improve their running time until 14 yrs of ageof age

Male show improvement across age groups untMale show improvement across age groups until age 16il age 16

Can be due to increase muscle mass in male anCan be due to increase muscle mass in male and limit physical activity as acquisition of a drivd limit physical activity as acquisition of a driver license in femaleer license in female

Performance-Related Fitness Performance-Related Fitness ComponentsComponents

Exercise Scientist’s InterestsExercise Scientist’s Interests

Biomechanist: an increase length accompanyiBiomechanist: an increase length accompanying growing bodiesng growing bodies

Physiologist:an increase in body fat on the perfPhysiologist:an increase in body fat on the performance of a prepubescent girlormance of a prepubescent girl

Joint FlexibilityJoint Flexibility

Sit and reach is the test most use in determine Sit and reach is the test most use in determine flexibilityflexibility

Generally increases until about age of 16Generally increases until about age of 16

A reduction in joint flexibility may occur until A reduction in joint flexibility may occur until the muscles and tendons growththe muscles and tendons growth

Body CompositionBody Composition

From age of 10 to 15 yrs, females experience From age of 10 to 15 yrs, females experience an increase in body fatan increase in body fatMale undergo an increase in muscle mass and Male undergo an increase in muscle mass and consistent body fat percentageconsistent body fat percentageMay throughout adolescence and subject to May throughout adolescence and subject to lifestyle behaviors as physical activity levels lifestyle behaviors as physical activity levels and nutritional patternsand nutritional patternsCan help researchers establishing weight Can help researchers establishing weight reduction strategies and so on.reduction strategies and so on.

Youth SportsYouth Sports

American children in 1999 are 13 pound American children in 1999 are 13 pound heavier than same age group were in 1983heavier than same age group were in 1983

10 yrs old required longer time to run a mile in 10 yrs old required longer time to run a mile in 1989 than those measure in 19801989 than those measure in 1980

Modern children may be fatter, less fit, more Modern children may be fatter, less fit, more susceptible to chronic diseasesusceptible to chronic disease

School system tried to solve budgetary School system tried to solve budgetary problem by decreasing physical education problem by decreasing physical education classes of eliminating them entirelyclasses of eliminating them entirely

After school youth sport program like After school youth sport program like community soccer and Little League baseballcommunity soccer and Little League baseball

Those program can serve to develop skills for Those program can serve to develop skills for enjoyable fitness activities enjoyable fitness activities

Considerations of Athletic Training Considerations of Athletic Training

Training principles and injury susceptibility Training principles and injury susceptibility and preventionand prevention

SpeedSpeed

While pre-puberty, boy’s and girl’s are similar While pre-puberty, boy’s and girl’s are similar in their average running velocity and pattern of in their average running velocity and pattern of speed improvementspeed improvement

While pubertal change begin, male continue tWhile pubertal change begin, male continue to improve in speed and female begin to plateao improve in speed and female begin to plateauu

Muscular strength is a major component of runMuscular strength is a major component of running speeds in male ning speeds in male

Girl tends to plateau in speed at about age 11 Girl tends to plateau in speed at about age 11 and may due to puberty-related gain in body and may due to puberty-related gain in body fatfat

Speed also largely related to genetically Speed also largely related to genetically determined muscle fibers type of young determined muscle fibers type of young athletes, but improved with trainingathletes, but improved with training

Muscular PowerMuscular Power

The result of a forceful muscular contraction The result of a forceful muscular contraction performed rapidlyperformed rapidly

Most adolescents participate require muscular Most adolescents participate require muscular power to successful skill performancepower to successful skill performance

Performance patterns are similar to the patterns Performance patterns are similar to the patterns observed in other fitness characteristicsobserved in other fitness characteristics

Increases in muscle mass in male and body fat Increases in muscle mass in male and body fat in female are major contributors to the in female are major contributors to the performance patterns following the onset of performance patterns following the onset of pubertypuberty

Muscle power is highly individual’s Muscle power is highly individual’s genetically determined muscle fiber genetically determined muscle fiber characteristics characteristics

Scientist may help determine an athlete’s Scientist may help determine an athlete’s potential in a power-oriented skillspotential in a power-oriented skills

Measurement of musculMeasurement of muscular power have a skill coar power have a skill component that may reducmponent that may reduce their validitye their validity

Reaction TimeReaction Time

Time interval from the onset of a signal to the Time interval from the onset of a signal to the initiation of the appropriate movement initiation of the appropriate movement responseresponse

Ability to process movement-oriented Ability to process movement-oriented information rapidlyinformation rapidly

Can improve their reaction time throughout Can improve their reaction time throughout adolescence and then begin to plateauadolescence and then begin to plateau

Factors Influence Reaction TimeFactors Influence Reaction Time

The familiarity of the The familiarity of the skill to be performedskill to be performed

The opportunity to The opportunity to practice the required practice the required skillskill

The number of The number of movement choices from movement choices from which the performer which the performer must selectmust select

Intensive Training and Health Intensive Training and Health Considerations for the Young Considerations for the Young

AthletesAthletes

High-intensity Training ConsiderationsHigh-intensity Training Considerations

Children are not miniature adultsChildren are not miniature adults

Young athletes differ from adult athletesYoung athletes differ from adult athletes– Cognitively: conceptualize and strategize in sport Cognitively: conceptualize and strategize in sport

situationssituations– Psychologically: motivated differ from parents and Psychologically: motivated differ from parents and

coachcoach– Physically:Physically:– Physiologically: immature bodies response to Physiologically: immature bodies response to

intense trainingintense training

Degree o f Skeletal MaturityDegree o f Skeletal MaturityBone growth take place at the epiphyseal growBone growth take place at the epiphyseal growth plateth plateExcessive weight bearing or shearing forces caExcessive weight bearing or shearing forces can result in fractures of the platen result in fractures of the plateA reduction in blood flow to the growing bone A reduction in blood flow to the growing bone and subsequent premature cessation of bone grand subsequent premature cessation of bone growth owth Growth plate remain a concern for prepubesceGrowth plate remain a concern for prepubescent and adolescent population until the ages of 1nt and adolescent population until the ages of 18 to 20 yrs.8 to 20 yrs.

Epiphyseal Growth Plate DamageEpiphyseal Growth Plate Damage

Overuse injuries due to the repeated Overuse injuries due to the repeated application of many small stresses that by application of many small stresses that by themselves create no apparent injury as stress themselves create no apparent injury as stress fractures and tendinitisfractures and tendinitis

May have originated before an athlete reached May have originated before an athlete reached puberty but cumulative effect may reveal until puberty but cumulative effect may reveal until adolescenceadolescence

Thermoregulation in the Young AthleteThermoregulation in the Young Athlete

Children loss heat rapidly, due to small body Children loss heat rapidly, due to small body surface area to mass ratiosurface area to mass ratioChildren tend to perspire less than adultsChildren tend to perspire less than adultsWhen training in warm or hot temp.When training in warm or hot temp.– Training lighter than normalTraining lighter than normal– Session should shorter than normalSession should shorter than normal– Frequent rest in the shadeFrequent rest in the shade– Drink fluids before thirst levelsDrink fluids before thirst levels– Training time and intensity should be increased Training time and intensity should be increased

gradually until athlete become acclimatedgradually until athlete become acclimated

When training in cool or cold temp.When training in cool or cold temp.– Out of water when not training or competingOut of water when not training or competing– When water below 22 , stay in the water a ℃When water below 22 , stay in the water a ℃

maximum of 15 min maximum of 15 min

Exercise scientist need to educate about Exercise scientist need to educate about developmental differences in thermoregulation developmental differences in thermoregulation and take step to prevent the athlete’s healthand take step to prevent the athlete’s health

Nutritional ConcernsNutritional Concerns

Growing bodies of young athletes require a Growing bodies of young athletes require a healthy diethealthy dietExcessive caloric restrictions can result in loss Excessive caloric restrictions can result in loss of bone mineral densityof bone mineral densityYoung athletes have either intrinsic or Young athletes have either intrinsic or extrinsic pressure to obtain a leaner body build extrinsic pressure to obtain a leaner body build may attempt rapid weight loss by unhealthy may attempt rapid weight loss by unhealthy behaviorsbehaviorsYo-Yo dieting as gain weight after meet and Yo-Yo dieting as gain weight after meet and loss before meetloss before meet

Resistance Training with the Resistance Training with the Prepubescent AthletePrepubescent Athlete

Two concernsTwo concerns

1.1. Potential damagePotential damage of epiphyseal plate as a r of epiphyseal plate as a result of excessive weight bearing on growiesult of excessive weight bearing on growing bonesng bones

2.2. Prepubescent resistance training is its Prepubescent resistance training is its efficefficacyacy

Safety Guidelines for Prepubescent Safety Guidelines for Prepubescent Strength Training ProgramStrength Training Program

Neural EfficacyNeural Efficacy

Levels of testosterone are need for muscle hypLevels of testosterone are need for muscle hypertrophy to occur and then strength increaseertrophy to occur and then strength increase

Short-term weight training in prepubescents reShort-term weight training in prepubescents reveal a strength gains occur without changes in veal a strength gains occur without changes in muscle size without hypertrophy may concern muscle size without hypertrophy may concern neural efficiencyneural efficiency

Adult Development and AgingAdult Development and Aging

Aging is the accumulation of changes in a Aging is the accumulation of changes in a person over timeperson over time– Juvenile [via infancy, childhood, preadolescence, Juvenile [via infancy, childhood, preadolescence,

adolescence (teenager)]: 0-19adolescence (teenager)]: 0-19– Early adulthood: 20-39Early adulthood: 20-39– Adulthood (20 to 40 yrs)Adulthood (20 to 40 yrs)– Middle adulthood (40-60 yrs)Middle adulthood (40-60 yrs)– Old adulthood (60Old adulthood (60++ yrs) yrs)

The Demographics of AgingThe Demographics of Aging

Many factor Many factor contributing to this contributing to this trend toward a greater trend toward a greater proportion of older proportion of older adultsadults– Health careHealth care

– Proper dietProper diet

– Physical activityPhysical activity

– Smoking Smoking

The Physiology of AgingThe Physiology of AgingAging in humans refers to a multidimensional Aging in humans refers to a multidimensional process of physical, psychological, and social process of physical, psychological, and social changechange

Understanding the effects aging has on specifiUnderstanding the effects aging has on specific physiologic systems assists the professional c physiologic systems assists the professional working upon principles of working upon principles of – Task specificityTask specificity– Interindividual / intraindividual variabilityInterindividual / intraindividual variability

Nervous and muscular systems are of particulNervous and muscular systems are of particular importance when motor performance of oldar importance when motor performance of older adults is examineder adults is examined

Muscle in AgingMuscle in Aging

With increasing ageWith increasing age– Slow-twitch fiber increaseSlow-twitch fiber increase– Fast-twitch fiber decreaseFast-twitch fiber decrease– May represent a model of disuseMay represent a model of disuse– Total muscle size and muscle strength decreaseTotal muscle size and muscle strength decrease

Can be test by measuring tape and MRICan be test by measuring tape and MRI

– The relationship between muscle size and muscle The relationship between muscle size and muscle strength is not perfect in older adultsstrength is not perfect in older adults

The Central Nervous SystemThe Central Nervous SystemSome evidence that the number of brain cells Some evidence that the number of brain cells decreases with advancing agedecreases with advancing age

The numbers of connections or synapses The numbers of connections or synapses between brain neurons decrease with agebetween brain neurons decrease with age

Motor behavior in older adult may be altered Motor behavior in older adult may be altered because of deteriorated neural pathwaysbecause of deteriorated neural pathways

Aging brain also susceptible to the reception Aging brain also susceptible to the reception of an inadequate amount of oxygen, hypoxiaof an inadequate amount of oxygen, hypoxia– The nerve cells’ function and longevity are The nerve cells’ function and longevity are

affectedaffected

Reaction time and AgingReaction time and Aging

The ability of react quickly to certain The ability of react quickly to certain situations may diminishedsituations may diminishedRT demonstrate a tendency to ward slowing RT demonstrate a tendency to ward slowing with age.with age.Age-related structural changes in the brain are Age-related structural changes in the brain are inevitable, older adults can moderate the inevitable, older adults can moderate the influence of aging on brain functioninfluence of aging on brain function– Physical activityPhysical activity

Maintenance or enhancement RT ability in older adult Maintenance or enhancement RT ability in older adult may stem from an increase in cerebral blood flow and may stem from an increase in cerebral blood flow and increase oxygen to brain cellincrease oxygen to brain cell

BalanceBalance

Involves many variables (vestibular system, soInvolves many variables (vestibular system, somatosnesory system…)that interacts to control matosnesory system…)that interacts to control an individual’s posture and prevent fallsan individual’s posture and prevent falls

Seniors may use different methods to recover fSeniors may use different methods to recover from loss of balance (older adults tend to activarom loss of balance (older adults tend to activate muscle groups of the lower body of a differete muscle groups of the lower body of a different pattern) nt pattern)

Compensatory mechanism to prevent fallsCompensatory mechanism to prevent falls– Environmental considerationsEnvironmental considerations

Firm surface underfootFirm surface underfoot

Improving room lightingImproving room lighting

– Muscle fitnessMuscle fitnessIncreasing the muscular strength of the ankle, knee, and Increasing the muscular strength of the ankle, knee, and hiphip

Skeletal SystemSkeletal System

Following skeletal maturity, age-related changes in bFollowing skeletal maturity, age-related changes in bone characteristics are generally not noticeable until one characteristics are generally not noticeable until old adulthoodold adulthoodIn older adults, reduction in the water content of interIn older adults, reduction in the water content of intervertebral discs, spinal misalignment, and loss of bone vertebral discs, spinal misalignment, and loss of bone mineral densitymineral densityLoss of water in the discs of the spinal column, reducLoss of water in the discs of the spinal column, reduces their shock absorption and capacities, and discs coes their shock absorption and capacities, and discs compression may reduces the length of spinal columnmpression may reduces the length of spinal column

OsteoporosisOsteoporosisBone mineral production and absorptioBone mineral production and absorption are ongoing processesn are ongoing processesWhen absorption becomes more acceleWhen absorption becomes more accelerated than what is accounted for by the rated than what is accounted for by the normal aging, it is known as osteoporonormal aging, it is known as osteoporosissisTwo major concerns become apparentTwo major concerns become apparent– Brittle bones may experience fracturBrittle bones may experience fractur

es form withines form withinUsual seen in vertebae of the spinUsual seen in vertebae of the spinal columnal column

– The potential for bone fractures follThe potential for bone fractures following event minimal traumaowing event minimal trauma

Sensory SystemsSensory Systems

Visual systemVisual system– Many changes adversely affect the quality of Many changes adversely affect the quality of

vision (fig.)vision (fig.)– Functional changesFunctional changes

Decrease in visual clarityDecrease in visual clarity

Reduction in the constricting and dilating properties of Reduction in the constricting and dilating properties of the eye musclethe eye muscle

Decline I n the ability to adapt to dim light settingsDecline I n the ability to adapt to dim light settings

– ImprovementImprovementSurgical procedure for cataractsSurgical procedure for cataracts

Increasing room illuminationIncreasing room illumination

Wearing corrective eye wearWearing corrective eye wear

Auditory SystemAuditory System– Presbycusis, or age-related hearing loss, is the cumPresbycusis, or age-related hearing loss, is the cum

ulative effect of aging on hearing. Also known as pulative effect of aging on hearing. Also known as presbyacusis, it is defined as a progressive bilateral resbyacusis, it is defined as a progressive bilateral symmetrical age-related sensorineural hearing loss symmetrical age-related sensorineural hearing loss (fig.)(fig.)

– Can be result from a loss of nerve cells in the inner Can be result from a loss of nerve cells in the inner ear, a decreased in the flexibility of the bones and ear, a decreased in the flexibility of the bones and membranes of the middle ear, and the increased semembranes of the middle ear, and the increased secretion of cerumen (earwax)cretion of cerumen (earwax)

– Older adults experience tinnitus, which is a constaOlder adults experience tinnitus, which is a constant ringing or buzzing noise in the earsnt ringing or buzzing noise in the ears

Longitudinal Versus Cross-Sectional Aging Longitudinal Versus Cross-Sectional Aging researchresearch– Longitudinal research involves observation of the Longitudinal research involves observation of the

dame individuals for an extended duration dame individuals for an extended duration – Cross-Sectional research might study a group with Cross-Sectional research might study a group with

similar similar aged aged

GeneticsGenetics

Lifetime physical activityLifetime physical activity

Nutritional historyNutritional history

General socioeconomicGeneral socioeconomic

Medical backgroundMedical background

Intervention Strategies Intervention Strategies

Compensatory techniques for offsetting these aCompensatory techniques for offsetting these age-related declined using principles of task spege-related declined using principles of task specificity, interindividual and intraindividual varicificity, interindividual and intraindividual variabilitiesabilities

Altering environmental conditionsAltering environmental conditions

Use medical advancesUse medical advances

Increasing muscular strengthIncreasing muscular strength

Practice postural stability taskPractice postural stability task

Risk Factors for Falling and Possible Risk Factors for Falling and Possible Intervention StrategiesIntervention Strategies

Possible Risk FactorsPossible Risk Factors

Of the Older AdultOf the Older Adult

Possible Intervention StrategiesPossible Intervention Strategies

Decrease in muscular strengthDecrease in muscular strength Strength training exerciseStrength training exercise

Assistance device (cones, walkers, handrails)Assistance device (cones, walkers, handrails)

Decrease in joint flexibilityDecrease in joint flexibility Active lifestylesActive lifestyles

Stretching exerciseStretching exercise

Decrease in visual abilitiesDecrease in visual abilities Increased room lightingIncreased room lighting

Reduced glareReduced glare

Eye glassesEye glasses

Surgical treatmentSurgical treatment

Decrease in auditory abilitiesDecrease in auditory abilities Removal of cerumenRemoval of cerumen

Hearing assistance devicesHearing assistance devices

Decrease in proprioceptionDecrease in proprioception Firm walking surfaceFirm walking surface

Focused attention on taskFocused attention on task

Allowance for practice of taskAllowance for practice of task

Increased motivationIncreased motivation

MedicineMedicine Awareness of drug side effectsAwareness of drug side effects

Awareness of drug interaction side effectsAwareness of drug interaction side effects

Adapted from Gallahue & Ozmun, 1995Adapted from Gallahue & Ozmun, 1995

Elite Motor Performance in Older Elite Motor Performance in Older AdulthoodAdulthood

Gerontology is the scientific study of Gerontology is the scientific study of the aging processthe aging processChronologic age v.s. biologic ageChronologic age v.s. biologic ageMotor performance in adulthood is hiMotor performance in adulthood is highly variableghly variableSome older individuals may be come Some older individuals may be come to frail and suffer serious health probto frail and suffer serious health problems at a early older agelems at a early older ageContinue to excel in their performancContinue to excel in their performance throughout adulthood and appear to e throughout adulthood and appear to be minimally affected by the aging prbe minimally affected by the aging processocess