Correlation between BMI and motor coordination in children

(1)

JournalofScienceandMedicineinSportxxx(2011)xxx–xxx

Original

research

Correlation

between

BMI

and

motor

coordination

in

children

Vítor

P. Lopes

a,∗

,

David

F. Stodden

b

,

Mafalda

M. Bianchi

c

,

Jose

A.R.

Maia

c

,

Luis

P. Rodrigues

d

a_Research_Centre_in_Sports_Sciences,_Health_Sciences_and_Human_Development_(CIDESD)_and_Department_of_Sports_Science_of_Polytechnic_Institute_of

Bragan¸ca,Portugal

b_Department_of_Health,_Exercise,_and_Sports_Sciences,_Texas_Tech_University,_USA c_Faculty_of_Sports_Sciences_of_Porto_University,_Portugal

d_Research_Centre_in_Sports_Sciences,_Health_Sciences_and_Human_Development_(CIDESD)_and_Department_of_Human_Kinetics_of_Polytechnic_Institute_of

VianadoCastelo,Portugal

Received21March2011;receivedinrevisedform6July2011;accepted11July2011

Abstract

Objectives:Toanalyzetheassociationbetweenmotorcoordination(MC)andbodymassindex(BMI)acrosschildhoodandearlyadolescence.

Design:Thisstudyiscross-sectional.Methods:Datawerecollectedin7175children(boysn=3616,girlsn=3559),ages6–14years.BMIwas

calculatedfrommeasuredheightandweight[bodymass(kg)/height(m2_)]._Motor_coordination_was_evaluated_using_{Kiphard-Schilling’s}_body coordinationtest(KTK).Spearman’srankcorrelationwasusedtostudytheassociationbetweenBMIandMC.AKruskal–Wallistestwasused toanalyzethedifferencesinMCbetweenchildrenofnormalweight,overweightandobesechildren.Results:CorrelationsbetweenMCand BMIwerenegativeandvariedbetween0.05and0.49.Thehighestnegativecorrelationsforbothboysandgirlswasat11yearsofage.There wasageneralpatternofincreasingnegativecorrelationsinbothgendersfrom6to11yearsofageandthenadecreaseincorrelationstrengths through14yearsofage.Inbothboys(χ2

(2)=324.01;p<0.001)andgirls(χ2(2)=291.20;p<0.001)thereweresignificantdifferencesinMC betweenthethreegroups’weightstatus.NormalweightchildrenofbothsexesdemonstratedsignificantlyhigherMCscoresthanoverweight. ObesechildreninbothsexeshadthelowestMCscoresamongallthreegroups.Conclusion:Motorcoordinationdemonstratedaninverse relationshipwithBMIacrosschildhoodandintoearlyadolescence.Thestrength oftheinverserelationincreasedduringchildhood,but decreasedthroughearlyadolescence.OverweightandobesechildrenofbothsexesdemonstratedsignificantlylowerMCthannormalweight children.

Keywords:Physicalactivity;Obesity;Motorproficiency;Children;Cross-sectional;Motorskills

1. Introduction

Theprevalenceofchildhoodobesityisincreasing world-wide.InEurope,thepercentageofoverweightandobesityin adolescentsrangesfrom3%toalmost35%in13-year-olds andfrom5% to28% in15-year-olds. In Portugal32% of childrenbetweenseventonineyearsofageareoverweight orobese.1

Althoughseveralstudieshaveshownthatobesechildren and adolescents are less physically active than their non-obese peers, relationships between physical activity (PA),

∗_{Corresponding}_author.

E-mailaddress:vplopes@ipb.pt(V.P.Lopes).

sedentary activity, andobesityinchildren andadolescents has not been clearly established.2 Overall, many studies examiningPAand/orweightstatusinchildrenhaveonly pro-videddataonpsychologicalandenvironmentalcorrelates.3 Recentstudieshavefocusedonunderstandingthe relation-ships among motor coordination (MC) and health-related behaviorsandattributes.Arecentreviewontherelationships amongMCandhealthbenefitsinchildrenandadolescents4 indicatedMClevelsareinverselycorrelatedwithweight sta-tus,butpositivelycorrelatedwithPA,andperceivedphysical competenceincross-sectionalandlongitudinaldata.Weight statuswasnegativelycorrelatedwithMCinsixofnine stud-ies,withtheremainingthreedemonstratingnorelationship. ThisreviewofassociationsofMCandaspectsofphysicaland

(2)

psychologicalattributesprovidesindirectevidencethatMC maybeanimportantantecedent/consequentmechanismfor promotingtohealthylifestylesrelatedbehaviors,including weightstatus.

Despite the fact that a large number of children do not achieve PA recommendations5 children are naturally drawn tobe active and, if provided the opportunity,often engage in active play6 Inherent pleasure associated with movement,7 as well as the psychological benefits associ-atedwithMC8maybeimportantcontributorstochildren’s PA.

Stoddenetal.9 proposedadevelopmental andrecursive modelsuggestingthatobesitytrajectoriesmaybetriggered by the cumulative effects that lower levels of MC has on reducingmovementopportunities(PA),physicalfitness,and perceived physical competence during childhood.Overall, lowMC will result inunsuccessful participationin move-mentplayactivitiesand/orsportsinmiddletolatechildhood, thusleadingtoanegativespiralofdisengagementfroman active lifestyle. Accordingly, the model predicts that MC levels will eventually lead to positive or negative obesity trajectories overtimeas the recursive nature ofthe model effectscompoundovertime.To ourknowledge,nostudies havespecificallyexaminedtherelationshipbetweenMCand weightstatusovertime.

It is important to note that the term “motor coordina-tion,”usedinthisstudyisageneraltermthatencompasses variousaspectsof movementcompetency.Thereare many different test batteries that assess movement in a vari-ety of ways using different movement tests. Specifically, process and product oriented movement assessments are used to examine differences in levels of MC. For exam-ple,the aforementionedreviewarticle4 reporteddatafrom manystudiesthatassessed“fundamentalmovementskills” (i.e., object control and locomotor skills) from a subjec-tive,process-orientedperspective.Thatis,actualmovements, and not the product of the movements, were subjectively assessed to differentiate skill levels. Alternatively, other studies not used in the Lubans et al. review have used product-orientedmovement assessments.10–12 These types

of assessmentsexamine objectiveoutcomes of movements (e.g., distance,speed).Whileitisoutsidethescopeofthis studytoexplainthedifferencesandlimitationsinhow move-mentand/ormovementoutcomesareassessed,9weusedthe term “motor coordination” in this study as it specifically alignswiththelanguageusedintheassessmentimplemented for this study (Kiphard-Schilling body coordination test) andwithpreviousliteraturethathasused thesame assess-ment.

The purpose of this study was to examine the associ-ation between MC (as defined by the Kiphard-Schilling body coordination test) and weight status (BMI) across childhood and early adolescence. This is the first study to specifically address the possible changing relationships between weight status and MC across a wide range of ages.

2. Methods

Datawerecollectedfrom7175children(boysn=3616– girlsn=3,559),between6and14yearsofage(seeTable1 insupplementarymaterial).Thesedatawerecombinedfrom several researchprojects13–15 conducted by the authorsin four regionsof Portugal(AzoresIslands, MadeiraIslands, northeast andcentralregions of continental area)between 2003and2009.Allchildrenwereattendingpublicschools selected according to the general characteristics of each region. Despite the fact that Madeira andAzores are two archipelagos in Atlantic Ocean, thereare not marked dif-ferences between the regionsin terms of social economic development.Parentsandchildrengavetheirinformed con-sent.Theresultsofchildrenwithanydiagnosedphysicalor mentaldisabilitywereexcludedfromthedata.Thisstudywas approvedbytheethicscommitteeofPolytechnicInstituteof Braganc¸a.

Statureandbodymassweremeasuredusinga stadiome-terandascaleaccordingtostandardizedprocedures.Values were recorded to the nearest 0.1cm and 100g, respec-tively.Bodymassindex(BMI)wascalculated[BMI=weight

Table1

Descriptivestatistic(mean±standarddeviation)fortheassessedvariablesbysexandage.

Age(y) Girls Boys

BMI(kgm−1) Weight(kg) Height(cm) MC(#points) BMI(kgm−1) Weight(kg) Height(cm) MC(#points) 6 17.0±2.6 24.6±5.0 119.7±5.6 78.8±13.9 17.0±2.5 24.9±4.9 120.6±6.1 87.8±13.5* 7 17.4±3.1 27.4±6.6 124.7±6.2 81.1±15.1 17.4±2.8 27.6±6.1 125.5±6.4 88.0±15.3* 8 17.9±3.0 30.7±6.9 130.6±6.7 81.9±15.8 18.0±3.4 31.4±8.0 131.1±6.7 86.5±16.3* 9 18.6±3.3 34.5±8.3 135.5±8.3 77.4±15.4 18.5±3.5 34.3±8.6 135.6±6.6 85.3±15.2* 10 18.7±3.5 36.7±9.0 139.4±7.6 78.4±15.1 18.7±3.5 36.7±9.2 139.1±7.5 87.5±15.1* 11 19.7±3.8 42.9±10.0 147.2±7.8 82.7±14.4 19.4±3.7 41.7±10.6 145.9±7.8 88.3±17.3* 12 19.4±3.5 46.3±10.2 153.8±6.5 82.9±15.9 20.6±3.9 48.8±12.3 153.3±8.4 91.2±14.8* 13 21.1±3.5 52.4±9.9 157.5±6.2 78.5±15.6 20.2±3.8 52.2±11.9 160.3±9.5 94.5±16.3* 14 21.3±2.7 54.7±8.0 160.3±6.6 83.5±16.6 20.5±3.2 57.4±11.3 166.7±9.4 100.8±11.8* BMI:bodymassíndex;MC:motorcoordination[MCcategories:‘notpossible’(MQ<56),‘severemotordisorder’(MQ56–70),‘moderatemotordisorder’ (MQ71–85),‘normal’(MQ86–115),‘good’(MQ116–130)and‘high’(MQ131–145)].

(3)

(kg)/height (m2)]. Weight status was classified according toInternational Obesity Task Force(IOTF) cut-values for BMI.16

Motor coordination was evaluated with the Kiphard-Schillingbodycoordinationtest, Körperkoordination-Test-für-Kinder (KTK), developed and validated on German children17TheKTKincludestheassessmentofthefollowing items:

• Balance–childwalksbackwardonabalancebeam3min length,butofdecreasingwidths:6cm,4.5cm,3cm. • Jumpinglaterally– childmakesconsecutivejumpsfrom

sidetosideoverasmallbeam (60cm×4cm×2cm)as fastaspossiblefor15s.

• Hopping on one leg over an obstacle – the child is instructedtohopononefootatatimeoverastackoffoam squares.Afterasuccessfulhopwitheachfoot,theheight isincreasedbyaddingasquare(50cm×20cm×5cm). • Shiftingplatforms – childbeginsby standingwithboth

feetononeplatform(25cm× 25cm×2cmsupportedon fourlegs3.7cmhigh);placesthesecondplatform along-sidethefirstandstepsontoit;thefirstplatform isthen placedalongsidethesecondandthechildstepsontoit; thesequencecontinuesfor20s.

The “motor quotient” (MQ), a global indicator of MC adjustedforageandgender,wascalculatedusingthefour items and used as indicator of MC. The MQ allows an assessmentofthegrossmotordevelopmentinthefollowing categories:‘notpossible’(MQ<56),‘severemotordisorder’ (MQ56–70,percentile0–2),‘moderatemotordisorder’(MQ 71–85,percentile3–16),‘normal’(MQ 86–115,percentile 17–84),‘good’(MQ116–130,percentile85–98)and‘high’ (MQ131–145,percentile99–100).

Thepsychometriccharacteristics oftheKTKhavebeen documented17withatest–retestreliabilitycoefficientforthe rawscoreonthetotaltestbatteryof0.97,while correspond-ingcoefficientsforindividualtestsrangefrom0.80to0.96. Validity was further determined through differentiation of “normal”and“disabled”children.TheKTKtest differenti-ated91%ofchildrenwithbraindamagecomparedtonormal children.It is important tonote that the KTKitems mea-suredinthisstudy representmovementproductscoresthat generallyassesslocomotorandbalanceoutcomes.

Thesample was splitbygenderandage andall analy-seswereconductedaccordingly.Descriptivestatistics(mean andstandarddeviation)werecalculatedforheight,weight, BMIandMCvariables.Kolmogorov-SmirnovwithLilliefors significancecorrectionwasusedtotestBMIandMC vari-ablesfornormality.SinceBMIinallagegroupsandgender andMC insomeof theage groupsdid notdemonstrate a normaldistribution,Spearman’srankcorrelationcoefficient wasusedtoexaminetheassociationbetweenBMIandMC. AKruskal–Wallistestwasused toanalyzethedifferences inMCbetweenchildrenamongthethreeweightstatus cat-egories (i.e., normal weight, overweight and obese). The

Table2

Spearman’srankcorrelationbetweenBMIandMCinboysandgirlsbyage.

Age(years) Girls Boys

6 −0.16** _−0.18** 7 −0.28** _−0.23** 8 −0.26** _−0.26** 9 −0.29** _−0.20** 10 −0.30** _−0.28** 11 −0.44** _−0.49** 12 −0.29** _−0.43** 13 −0.26* _−0.19 14 −0.20 −0.05

* _Correlation_is_significant_at_the_0.05_level_(2-tailed). **_Correlation_is_significant_at_the_0.01_level_(2-tailed).

Mann–WhitneyTestwasusedtotestthedifferencesbetween boysandgirlsinMC.

3. Results

Table1providesdescriptivestatisticsforweight,height, BMIandMQforboysandgirlsofdifferentagegroups.

MotorcoordinationresultsshowclearMCgender differ-enceswithboysoutperforminggirlsateveryage.According tonormativevaluesofKTKtestbattery,17 resultsindicated lowtomoderateMC,especiallyforgirls,acrossallages.The resultsforgirlswereindicativeof“moderatemotordisorder”. Forboystheresultswereatthelowerrangesof“normal coor-dination”,exceptfor9yearsolds,whichindicated“moderate motordisorder”.

Table3(insupplementarymaterial)providesdataonthe percentageofboys andgirlsinnormal weight,overweight andobesitycategoriesbyage.Theprevalenceofoverweight andobesity,respectively,fortheentiresamplewas22%and 11%forgirlsand18%and10%forboys,whichisconsistent withrecentdataonPortuguesechildrenofthesameage.1

Spearman’s rankcorrelationsbetweenBMI andMC in boysandgirlsbyageareshowninTable2.Allcorrelations betweenBMIandMCwerenegativeandvariedbetween0.05 and0.49.Thatis,higherMCwasassociatedwithlowerBMI. Correlationvaluesweresimilarinboysandgirls,exceptat 14yearsofage,whereboysdemonstratedalowercorrelation thangirls.Overall,therewasageneralpatternofcorrelation strengthsincreasingacrosstimefrom6 to11yearsofage. The highest correlation for both boys andgirlswas at 11 yearsof age. Onlyeight yearold girls’andnineyear old boys’correlationsdid notfollowthispattern. Therewasa decreaseincorrelationstrengthsfrom12through14yearsof agewithcorrelationstrengthsinboysdecreasingmorethan girls.Specifically,correlationswerenotsignificantineither boysorgirlsatage14.

In both boys (χ2(2)=324.01; p<0.001) and girls

(χ2(2)=291.20;p<0.001)thereweresignificantdifferences

inMCbetweenthethreegroupsweightstatus.Normalweight childrenhadsignificantlyhigherMCscoresthanoverweight children,andobesechildrenhadsignificantlylowerscores

(4)

Fig.1.Motorcoordinationlevels(mean±standarddeviation)byweight statusinboysandgirls[*indicatessignificantdifferences(p<0.05)between boysandgirls].

thanoverweightchildren. Boyssignificantlyoutperformed girlsinMCinallweightcategories(Fig.1).

4. Discussion

Thepurposeofthisstudywastoanalyzetheassociation betweenBMIandMC(asmeasuredbytheKTKassessment) inchildren,ages6–14years.Thepresentstudydemonstrated lowtomoderatenegativecorrelationsbetweenMCandBMI acrossage.DataalsoindicatemarkedlypoorerMCfor over-weightandobesechildrenofbothsexescomparedtonormal weightchildren.Overall, thesedataagree withmost other datathatdemonstrateaninverserelationshipbetween child-hoodbodyweightstatusandvariousmeasuresofMC(i.e., process and product movement assessments).4,18,19 Most studiesthathavedemonstratedarelationshipbetweenBMI andMChaveexamineditwithinasmallagerange(i.e.,1–3 yrs).Onlyonestudyhasexaminedtherelationshipbetween measuresofbodycompositionandMCacrossmultipleages. Okelyetal.19examinedbothBMIandwaistcircumference andtheirassociationstoobjectcontrolandlocomotorMC inlatechildhood/adolescence across fouragegroups (i.e., approximately10,12,14and16yrs).Theirresultsindicated that, despite a general inverse relationship between body compositionandoverallMC,therewerevirtuallyno associa-tionswithobject-controlcoordination.Thatis,thecorrelation occurredonlywithlocomotor coordination. Thus,theMC testsassessedinthisstudygenerallyalignwiththetypesof locomotortestsusedinOkelyetal.19study.Inaddition,the strongestinverse relationships werefound inthe youngest

agegroups(i.e.,10and12yrs),whichgenerallyagreeswith thedatareportedinthisstudy.

ThestrengthsofthenegativecorrelationsbetweenMCand BMIforbothboysandgirlsinthisstudygenerallyincreased uptoage11,andthenbegantodecline.D’Hondtetal.20also found aninverse correlationbetween MC(i.e., Movement ABCtest)andBMIinchildrenof5–10yearsbetween bal-ance(r=0.20)(staticanddynamic)andballskills(r=0.46) with BMI z-score adjusted for age and sex. These corre-lation strengths are in line with the correlations found in thepresentstudy.AlthoughHumeetal.21 foundaverylow correlation(r=0.01–0.08)betweenMC(objectcontroland locomotor) andBMIin9–12yearoldboysandgirls, their datawasnotanalyzedbyage.Thus,itisratherdifficultto compare and contrast the data from the Hume et al.data to our study as the onsetof puberty may occur for many children,particularlyforgirls,duringthistimeframe.This shouldbe consideredinastatisticalanalysis acrosssucha wide agerange, specificallyinthis timeof developmental transition.

Thecleartendencyforstrengthening oftheinverse cor-relations betweenMC andBMI uptoage11,presumably resultfromthereciprocaleffectsbetweenthetwovariables.9 ThesedataindirectlysupporttheStoddenetal.9hypothesis that children’sweightstatusacross timemaybe indirectly affected(fromthedirectresultofPAandfitnesslevels)via thedevelopmentofMCthroughoutchildhood.Childrenwho continue todevelophigher levelsofMC throughout child-hoodwillbeabletosuccessfullyengageinandenjoymore movementopportunities.Thus,thiswillreinforcethe devel-opmentofMC,perceivedphysicalcompetence,PA,physical fitness, and consequentlypromote a healthyweight status (i.e., lowerBMI).The oppositeistobe expectedfor chil-drenwithlowinitialMCandwhodonotcontinuetodevelop MC.AdditiveeffectsofincreasedweightonMCmayalso affect the relationship between MC and BMI at any age, but this hypothesis needs to be adequately tested. These hypothesizedpositiveornegativespiralsofreinforcementof MC,whichmayindirectlyleadtolong-termadaptationsin body composition,parallelsthe increased strength of neg-ative correlation values across childhood observed in our data.

OtherlongitudinalstudiesexaminingMC,PA, cardiores-piratoryfitnessandperceivedphysicalcompetenceprovide furthersupportforthesehypothesizedreciprocalpathwaysas theyindicateMCisbothapredictorofPAand/or cardiores-piratoryfitness10,22andaproductofcontinueddevelopment of PAandfitness.23 Overall, these factorsmayhave been associatedtolong-termchangesinbodycompositionstatus. Unfortunately,bodycompositionwasnotassessed.

In general, there are consistent negative correlations amongweightstatusandMC.18,20,24However,decreasesin negativecorrelationstrengthsbetweenBMIandMCoccurred (moremarkedlyonboys)from12to14yearsofage. Dur-ingthe beginningyearsofadolescence,inversecorrelation strengths tended to decrease, which may be explained by

(5)

theappearanceofrapidanddifferentiatedindividualgrowth (i.e., differential growth spurt and growth intensity) typi-calduringthisperiod.25 Infact,duringpubertalyearsitis expectedthattherelationshipbetweenMCandBMIcanbe dramaticallyalteredbytherapidandindividualizedchanges insomaticgrowththatresultinchangesinmusclemass(boys) andadipose tissue (girls).25–27 The occurrenceof puberty mayexplainnotonlythe decreaseinthe negative correla-tion values,but also the sex biased heterocronicity of the event.2Accordingly,girlshaveanearlierdecreaseof corre-lationstrengthsat12yearsofage,withboysfollowingayear later.Furthermore,boysshowamoredramaticdecrease in negativecorrelationstrengthsfrom12to14years,perhaps relatedtothemoremeaningfulchangesinmusclemassover thegrowthspurt.Inordertofullyclarifythisphenomenon, longitudinal dataand post-pubertalinformation isneeded. Inaddition,thedocumenteddifferencesinhowobject con-trol and locomotor MC levels relate to weight status are ratherperplexingandmayberelatedtospecificculturaland environmental differences among the populations studied. Futureresearchisneededtobetterunderstandthepossible differingmovementconstructsthatvarioustestingbatteries measureand how they may relate toweight status across age.

Thestrengthofthisstudyliesinthelargeage-span distri-butionofBMIandMCdatathatallowscomparisonacross time.However,thecross-sectionalnatureofthedatadoesnot allowustomakecausalinferencesregardingtherelationships betweenBMIandMC.Inaddition,BMIisnotthemost accu-ratepredictorofbodyfatpercentages.Furthermore,amore comprehensiveMCassessment(e.g.,developmentallyvalid productandprocessMCassessments)mayprovideaclearer pictureoftherelationshipbetweenMCandbody composi-tiontrajectoriesacrosstime.Examiningothervariables(e.g., energybalance,fitness,socialandpsychologicalvariables) thatinfluenceweightstatusacrosstimealsoisnecessaryto fully understand the nature of this relationship. Although oursample sizesweresmaller inolderagegroups(12–14 years)(Table1 insupplementary material),thedecreasing negativecorrelationstrengthsfromages12to14dofitwith traditionalviewsofpubertaltransitionsofadiposeand mus-cle mass ingirls andboys respectively. In addition, these datacomparefavorablywiththedatafromOkelyetal.19 in thatinverse relationshipstrengthsseemtodecreaseduring adolescence.

5. Conclusion

Thesedata supportthe majority of cross-sectionaldata thatindicateMCisinverselyassociatedwithBMI,andthat the strengthof the inverse relationincreases during child-hoodinbothgenders.Overweightandobesechildrenshowed markedly worse MC levels. Despite the limitation of the cross-sectionaldesign,MCshowedtobeanimportant,yet dynamic,correlateofweightstatus.

6. Practicalimplications

• Observationsfromthisstudyhighlightthepotential impor-tance of promoting motor coordination in children to alleviateincreasingobesitytrajectoriesacrosschildhood. • Theincreasingnegativecorrelationsbetweenmotor coor-dinationandbodymassindexacrosschildhoodsuggests there is a need to allocate appropriate time for play anddirectedlearningexperiences thatwillallowfor the development of motorcoordination. Providingadequate directedlearningexperiences,timeforplayanda develop-mentallyappropriateenvironmentforchildrenmayassist inpromotingahealthyweightstatusacrosschildhood. • Thesedata alsosuggestthat it maybebeneficialto

tar-getyoungchildrenwithlowmotorcoordinationforearly screeningandintervention.

• Thedevelopmentofmotorcoordinationshouldbeakey strategy in childhood interventions aiming to promote long-termobesitypreventionandphysicalactivity promo-tion.

Acknowledgments

Partofthedataofthepresentstudywascollectedwiththe financialsupportoftheDepartmentofPhysicalEducational and Sports and the Department of Science and Technol-ogyofAutonomicGovernmentofAzoresRegion(Direc¸cão

RegionaldeEduca¸cãoFísicaeDesportoeDirec¸cãoRegional daCiênciaeTecnologiadaRegiãoAutónomadosA¸cores),

Portugal.

AppendixA. Supplementarydata

Supplementary data associated with this article can be found, in the online version, at doi:10.1016/ j.jsams.2011.07.005.

References

1.PadezC,FernandesT,MourãoI,etal.Prevalenceofoverweightand obesityin7–9yearoldportuguesechildren:trendsinbodymassindex from1970–2002.AmJHumBiol2004;16:670–8.

2.MalinaRM,BouchardC,Bar-OrO.Growth,maturationandphysical activity.2nded.Champaign:HumanKintetics;2004.

3.HorstKVD,PawMJCA,TwiskJWR,etal.Abriefreviewoncorrelates ofphysicalactivityandsedentarinessinyouth.MedSciSportsExerc

2007;39(8),1241’–1250.

4.LubansDR,MorganPJ,CliffDP,etal.Fundamentalmovementskills inchildrenandadolescents:reviewofassociatedhealthbenefits.Sports Med2010;40(12):1019–35.

5. NilssonA,AnderssenSA,AndersenLB,etal.Between-and within-dayvariabilityinphysicalactivityandinactivityin9-and15-year-old europeanchildren.ScandJMedSciSports2009;19(1):10–8.

(6)

6.BurdetteHL,WhitakerRC.Resurrectingfreeplayinyoungchildren: lookingbeyondfitnessandfatnesstoattention,affiliation,andaffect.

ArchPediatrAdolescMed2005;159(1):46–50.

7. Keitz M, Martin-Soelch C, Leenders KL. Reward processing in the brain: a prerequisite for movement preparation? Neural Plast

2003;10(1–2):121–8.

8.Wrotniak BH, Epstein LH, Dorn JM, et al. The relationship betweenmotorproficiencyandphysicalactivityinchildren.Pediatrics

2006;118(6):e1758–65.

9.StoddenDF,GoodwayJD,LangendorferSJ,etal.Adevelopmental perspectiveontheroleofmotorskillcompetenceinphysicalactivity: anemergentrelationship.Quest2008;60:290–306.

10.LopesVP,RodriguesLP,MaiaJAR,etal.Motorcoordinationas pre-dictorofphysicalactivityinchildhood.ScandJMedSciSports2010.

DOI:10.1111/j.1600-0838.2009.01027.x.

11.StoddenD,LangendorferS,RobertonMA.Theassociationbetween motorskillcompetenceandphysicalfitnessinyoungadults.ResQ ExercSport2009;80(2):223–9.

12.GrafC,KochB,Kretschmann-KandelE,etal.Correlationbetween BMI,leisurehabitsandmotorabilitiesinchildhood(chilt-project).Int JObesRelatMetabDisord2004;28(1):22–6.

13.RodriguesL,SáC,BezerraP,etal.Estudomorfofuncionaldacrian¸ca vianense.VianadoCastelo:CâmaraMunicipaldeVianadoCastelo; 2006.

14.MaiaJA,R., Lopes VP, MoraisFP, etal.Estudo do crescimento somático,aptidãofísica,actividadefísicaecapacidadedecoordenação corporaldecriançasdo1◦ciclodoensinobásicodaregiãoautónoma dosaçores.Porto,FaculdadedeCiênciasdoDesportoedeEducação FísicadaUniversidadedoPorto,DirecçãoRegionaldeEducaçãoFísica eDesportodaRegiãoAutónomadosAçores,DirecçãoRegionalde CiênciaeTecnologiadaRegiãoAutónomadosAçores;2002. 15. FerreiraJCV,MarquesAT,MaiaJ.Aptidãofísica,actividadefísicae

saúdedapopulac¸ãoescolardocentrodaáreaeducativadeviseu.Um estudoemcrianc¸asejovensdeambosossexosdos10aos18anosde idade.Viseu,InstitutoPolitécnicodeViseu;2002.

16.ColeTJ,BellizziMC,FlegalKM,etal.Establishingastandard defini-tionforchildoverweightandobesityworldwide:internationalsurvey.

BMJ2000;320(7244):1240–3.

17. KiphardEJ, SchillingF. Korper-koordinations-testfur kinder.Ktk. Manual.Weiheim:BeltzTestGmbH;1974.

18. JonesRA,OkelyAD,CaputiP,etal.Perceivedandactual compe-tenceamongoverweightandnon-overweightchildren.JSciMedSport

2010;13(6):589–96.

19.OkelyAD,BoothML,CheyT.Relationshipsbetweenbody composi-tionandfundamentalmovementskillsamongchildrenandadolescents.

ResQExercSport2004;75(3):238–47.

20.DˇıHondtE,DeforcheB,BourdeaudhuijID,etal.Relationshipbetween motorskillandbodymasindexin5-to10-year-oldchildren.AdaptPhys ActQ2009;26:21–37.

21. HumeC,OkelyA,BagleyS,etal.Doesweightstatusinfluence asso-ciationsbetweenchildren’sfundamentalmovementskillsandphysical activity?ResQExercSport2008;79(2):158–65.

22.BarnettLM,BeurdenEv,MorganPJ,etal.Childhoodmotorskill pro-ficiencyasapredictorofadolescentphysicalactivity.JAdolescHealth

2009;44(3):252–9.

23.BarnettLM,MorganPJ,vBE,etal.Areversepathway?Actualand perceivedskillproficiencyandphysicalactivity.MedSciSportsExerc

2010;43(5):898–904.

24.BarnettLM,BeurdenEV, MorganPJ,etal.Doeschildhoodmotor skillproficiencypredict adolescent fitness? Med SciSports Exerc

2008;40(12):2137–44.

25.Tanner JM, Davies PSW. Clinical longitudinal standards for heightand heightvelocity for north american children. J Pediatr

1985;107(3):317–29.

26.AndersonSE,DallalGE,MustA.Relativeweightandraceinfluence averageageatmenarche:resultsfromtwonationallyrepresentative surveysofusgirls studied25 yearsapart.Pediatrics 2003;111(4): 844–50.

27. KaplowitzPB.Linkbetweenbodyfatandthetimingofpuberty. Pedi-atrics2008;121(Suppl.3):S208–17.