Mediators of the association between physical activity and executive functions in primary school children

This is a sel -a chi ed e sion o an o iginal a icle. This e sion may di e om he o iginal in pagina ion and ypog aphic de ails. Au ho (s): Ti le: Yea : Ve sion: Copy igh : Righ s: Righ s u l: Please ci e he o iginal e sion: CC BY-NC-ND 4.0 h ps://c ea i ecommons.o g/licenses/by-nc-nd/4.0/ Media o s o he associa ion be ween physical ac i i y and execu i e unc ions in p ima y school child en © 2024 The Au ho (s). Published by In o ma UK Limi ed, ading as Taylo & F ancis G oup Published e sion Bao, Ran; Leahy, Angus A.; Lubans, Da id R.; Diallo, Thie no M.O.; Beauchamp, Ma k R.; Smi h, Jo dan J.; Hillman, Cha les H.; Wade, Le i Bao, R., Leahy, A. A., Lubans, D. R., Diallo, T. M., Beauchamp, M. R., Smi h, J. J., Hillman, C. H., & Wade, L. (2024). Media o s o he associa ion be ween physical ac i i y and execu i e unc ions in p ima y school child en. Jou nal o Spo s Sciences, Ea ly online. h ps://doi.o g/10.1080/02640414.2024.2422203 2024 Jou nal o Spo s Sciences ISSN: (P in ) (Online) Jou nal homepage: www. and online.com/jou nals/ jsp20 Media o s o he associa ion be ween physical ac i i y and execu i e unc ions in p ima y school child en Ran Bao, Angus A. Leahy, Da id R. Lubans, Thie no M.O. Diallo, Ma k R. Beauchamp, Jo dan J. Smi h, Cha les H. Hillman & Le i Wade To ci e his a icle: Ran Bao, Angus A. Leahy, Da id R. Lubans, Thie no M.O. Diallo, Ma k R. Beauchamp, Jo dan J. Smi h, Cha les H. Hillman & Le i Wade (28 Oc 2024): Media o s o he associa ion be ween physical ac i i y and execu i e unc ions in p ima y school child en, Jou nal o Spo s Sciences, DOI: 10.1080/02640414.2024.2422203 To link o his a icle: h ps://doi.o g/10.1080/02640414.2024.2422203 © 2024 The Au ho (s). Published by In o ma UK Limi ed, ading as Taylo & F ancis G oup. Published online: 28 Oc 2024. Submi you a icle o his jou nal View ela ed a icles View C ossma k da a Full Te ms & Condi ions o access and use can be ound a h ps://www. and online.com/ac ion/jou nalIn o ma ion?jou nalCode= jsp20 PHYSICAL ACTIVITY, HEALTH AND EXERCISE Media o s o he associa ion be ween physical ac i i y and execu i e unc ions in p ima y school child en Ran Bao a,b , Angus A. Leahy a,b , Da id R. Lubans a,b,c , Thie no M.O. Diallo d , Ma k R. Beauchamp e , Jo dan J. Smi h a,b , Cha les H. Hillman and Le i Wade a,b a Cen e o Ac i e Li ing and Lea ning, Uni e si y o Newcas le, Callaghan, New Sou h Wales, Aus alia; b Ac i e Li ing Resea ch P og am, Hun e Medical Resea ch Ins i u e, New Lamb on Heigh s, New Sou h Wales, Aus alia; c Facul y o Spo and Heal h Sciences, Uni e si y o Jy äskylä, Jy äskylä, Finland; d School o Social Sciences, Wes e n Sydney Uni e si y, Pen i h, New Sou h Wales, Aus alia; e School o Kinesiology, Uni e si y o B i ish Columbia, Vancou e , BC, Canada; Cen e o Cogni i e & B ain Heal h, Depa men o Psychology, Depa men o Physical The apy, Mo emen & Rehabili a ion Sciences, Cen e o Cogni i e and B ain Heal h, No heas e n Uni e si y, Bos on, MA, USA ABSTRACT The e is g owing in e es in iden i ying he mechanisms unde pinning he e ec s o physical ac i i y on execu i e unc ions (e.g. inhibi o y con ol, cogni i e lexibili y) in child en. Ou s udy examined ca dio - espi a o y i ness, muscula i ness, and mo o compe ence as po en ial media o s o his ela ionship. The s udy used baseline da a om he Lea ning o Lead (L2L) clus e andomised con olled ial. In o al, 675 child en (7–11 yea s, 49.5% gi ls) comple ed measu es o mode a e- o- igo ous physical ac i i y (MVPA), ca dio espi a o y i ness, muscula i ness, mo o compe ence, and execu i e unc ions. S uc u al equa ion modelling was used o examine he po en ial media ing oles o ca dio espi a o y i ness, muscula i ness, and mo o compe ence in he c oss-sec ional associa ion be ween MVPA and execu i e unc ions. Ca dio espi a o y i ness (β = 0.06, SE = 0.021, p = 0.004) pa ially media ed he associa ion be ween MVPA and cogni i e lexibili y. Muscula i ness was a signi ican media o o he associa ion be ween MVPA and bo h inhibi o y con ol (β = 0.03, SE = 0.014, p = 0.027) and cogni i e lexibili y (β = 0.06, SE = 0.021, p = 0.005). No signi ican media ed e ec s we e ound o mo o compe- ence. Ou indings sugges ca dio espi a o y and muscula i ness (bu no mo o compe ence) media e he associa ion be ween physical ac i i y and execu i e unc ions in child en. ARTICLE HISTORY Recei ed 18 May 2024 Accep ed 20 Oc obe 2024 KEYWORDS Mode a e- o- igo ous physical ac i i y; ca dio espi a o y i ness; muscula i ness; mo o compe ence; execu i e unc ions; child en In oduc ion The heal h bene i s o physical ac i i y o young people a e well documen ed and include a ange o physical (e.g., enhanced physical i ness) and psychological (e.g., dec eased dep essi e symp oms) bene i s (Biddle e al., 2019; Chapu e al., 2020). The e is also e idence ha physical ac i i y is bene icial o child and adolescen execu i e unc ioning (Biddle e al., 2019). Execu i e unc ions encompass he abili y o selec , schedule, coo dina e, and moni o complex, goal-di ec ed cogni i e ac i - i ies (Diamond, 2013). They include inhibi o y con ol, which is he abili y o main ain ocus and supp ess p epo en o au oma- ised esponses (such as a oiding dis ac ions in he class oom), wo king memo y, which is he abili y o e ain and upda e in o ma ion when pe o ming asks ( o ins ance, emembe ing mul iple s eps in sol ing a ma hs p oblem), and cogni i e lex- ibili y, which is he abili y o shi men al esou ces be ween asks (like when we need o adjus s a egies in esponse o new ules in a game). Execu i e unc ions suppo highe -o de p ocesses such as p oblem sol ing, easoning, and planning (Diamond, 2013; Willoughby & Hudson, 2023). In child en, be e execu i e unc ions a e ela ed o posi i e physical, psychological, and social-emo ional heal h (Diamond, 2013; Riggs e al., 2006; Yang e al., 2022), whe eas impai ed execu i e unc ions may ha e de imen al e ec s on physical (e.g., a isk o obesi y (Mam o & Hanć, 2019)) and men al (e.g., dep ession (Ga dine & Ia occi, 2018; Hollocks e al., 2014)) heal h. De iciencies in execu i e unc ions a e also associa ed wi h subop imal aca- demic pe o mance (Co és Pascual e al., 2019; Jacob & Pa kinson, 2015) and inc eased social-emo ional challenges (e.g., poo social adap a ion (Ga dine & Ia occi, 2018; Riggs e al., 2006)). P e ious s udies ha e shown ha , al hough he e ec s a e ypically small, physical ac i i y in e en ions a e gene ally bene icial o child en and adolescen s’ execu i e unc ions (Ci ia e al., 2023; Ga cía-He moso e al., 2021; Singh e al., 2019; Xue e al., 2019). Gi en ha child en spend a subs an ial amoun o ime a school, i is impo an o explo e how physical ac i i y du ing school hou s con ibu es o hese cog- ni i e bene i s. The e is also g owing acknowledgemen o he impo ance o iden i ying he mechanisms esponsible o he e ec o physical ac i i y on execu i e unc ions. A deepe unde s anding o hese mechanisms may help o in o m he design and implemen a ion o u u e physical ac i i y p o- g ammes. The exis ing e idence sugges s ha his ela ionship is likely in luenced by bo h he quali a i e (e.g., ype, le el o CONTACT Le i Wade [email p o ec ed] Cen e o Ac i e Li ing and Lea ning, Uni e si y o Newcas le, Uni e si y D i e, Callaghan, New Sou h Wale 2308, Aus alia JOURNAL OF SPORTS SCIENCES h ps://doi.o g/10.1080/02640414.2024.2422203 © 2024 The Au ho (s). Published by In o ma UK Limi ed, ading as Taylo & F ancis G oup. This is an Open Access a icle dis ibu ed unde he e ms o he C ea i e Commons A ibu ion-NonComme cial-NoDe i a i es License (h p://c ea i ecommons.o g/licenses/by-nc-nd/4.0/), which pe mi s non-comme cial e-use, dis ibu ion, and ep oduc ion in any medium, p o ided he o iginal wo k is p ope ly ci ed, and is no al e ed, ans o med, o buil upon in any way. The e ms on which his a icle has been published allow he pos ing o he Accep ed Manusc ip in a eposi o y by he au ho (s) o wi h hei consen . cogni i e demand) and quan i a i e (e.g., in ensi y) cha ac e - is ics o he physical ac i i y (Bes , 2010; Hill e al., 2023; D. R. Lubans e al., 2021; Willoughby & Hudson, 2023). Howe e , he e is no consensus on he ela i e con ibu ions o hese cha ac e is ics (Diamond & Ling, 2019; Hillman e al., 2019). Wo k in his a ea has esul ed in he p oposi ion o wo ela ed hypo heses: he “ i ness” and he “skill acquisi ion” hypo heses (Pe uzzello e al., 1997; Tompo owski & Pesce, 2019). The “ i ness” hypo hesis sugges s ha pa icipa ion in physical ac i i y o su icien du a ion and in ensi y o imp o e i ness (e.g., ca dio espi a o y i ness, muscula i ness) may enhance cogni ion ia changes in he s uc u e and unc ion o he b ain (Pe uzzello e al., 1997; Tompo owski & Pesce, 2019). The “skill acquisi ion” hypo hesis sugges s ha physical ac i i y p o ides oppo uni ies o skill acquisi ion, and subse- quen imp o emen s in cogni ion a e d i en by he in luence o skill acquisi ion on changes o ela ed neu al pa hways (Tompo owski & Pesce, 2019). Mo e speci ically, i is engage- men in cogni i e complex and/o no el mo emen s ha likely lead o imp o emen s in execu i e unc ions. The e is e idence om c oss-sec ional and expe imen al s udies in suppo o he “ i ness” hypo hesis. Re iews o he li e a u e sugges ha ca dio espi a o y i ness is posi i ely associa ed wi h execu i e unc ions in child en and adolescen s (Bes , 2010; De G ee e al., 2018; Hillman e al., 2008). Changes in execu i e unc ions may be a ibu able, a leas in pa , o exe cise-induced inc eases in neu o ophins (including b ain- de i ed neu o ophic ac o and insulin-like g ow h ac o ) ha subsequen ly in luence b ain s uc u e and unc ion (Khan & Hillman, 2014; S illman e al., 2016). The e is also e idence ha changes in muscula i ness (i.e., muscle s eng h, endu ance, and powe ) may p o ide some explana ion o he ela ionship be ween physical ac i i y and execu i e unc ions (Robinson e al., 2023; Soga e al., 2018). A ecen me a-analysis ound ha muscula i ness was posi i ely associa ed wi h cogni i e lex- ibili y (Cohen’s d = 0.18) and wo king memo y (Cohen’s d = 0.14) in child en and adolescen s (Robinson e al., 2023). Simila o ca dio espi a o y i ness, he associa ion be ween muscula i ness and execu i e unc ions may be explained by changes in b ain s uc u e and unc ion (e.g., whi e ma e olume, b ain-de i ed neu o ophic ac o ) (Es eban-Co nejo e al., 2019; Isaac e al., 2021). Muscula i ness is associa ed wi h no able heal h imp o emen s in child en and adolescen s, including educ ions in me abolic isk ac o s and imp o e- men s in psychological ou comes (J. Smi h e al., 2014), each o which may imp o e execu i e unc ions (Kamijo e al., 2012; D. Lubans e al., 2016). While p omising, limi ed s udies ha e examined he media ing e ec s o i ness (pa icula ly muscula i ness) in he ela ionship wi h execu i e unc ions in child en. The “skill acquisi ion” hypo hesis sugges s ha he p ocess o lea ning new skills migh explain he bene i s o physical ac i i y o cogni ion. In suppo o his idea, e iews om he pas ew yea s no e a posi i e associa ion be ween mo o skill compe ency and execu i e unc ions in child en and adoles- cen s (Gando a e al., 2022; Hill e al., 2023; Willoughby & Hudson, 2023), wi h a ecen me a-analysis indica ing a small consis en associa ion ( = 0.18) (Bao e al., 2024). The heo y is ha cogni i ely complex ac i i y (including he acquisi ion o new skills) elies on sha ed unc ional egions wi hin he b ain, no ably he p e on al co ex, he ce ebellum, and he basal ganglia, which a e belie ed o unde pin he associa ion be ween physical ac i i y and execu i e unc ions (Diamond, 2000; Leisman e al., 2016; Pangelinan e al., 2011). Despi e ew expe imen al s udies, he exis ing e idence sugges s ha phy- sical ac i i y p og ammes may bene i he de elopmen o execu i e unc ions in child en by imp o ing hei mo o com- pe ence (MC) (Mul ey e al., 2018; Vazou e al., 2020). As ou lined, eme ging e idence sugges s ca dio espi a o y i ness, muscula i ness and mo o compe ence may media e he ela ionship be ween physical ac i i y and execu i e unc- ions in child en. Howe e , only a ew s udies ha e o mally es ed he i ness and skill acquisi ion hypo heses ia media ion analyses (Mun ane -Mas e al., 2022; Spanou e al., 2022). While hese s udies ha e p o ided aluable indings, hey did no es he ela i e con ibu ions o ca dio espi a o y i ness, muscula i ness, and mo o compe ence o execu i e unc ions. To Figu e 1. Hypo hesized associa ions be ween mode a e- o- igo ous physical ac i i y, ca dio espi a o y i ness, muscula i ness, mo o compe ence and execu i e unc ions. 2R. BAO ET AL. add ess hese esea ch gaps, ou s udy aimed o explo e he media ing oles o hese h ee componen s in he associa ion be ween school-hou mode a e- o- igo ous physical ac i i y (MVPA) and execu i e unc ions in child en (Figu e 1). Ou esea ch ques ions we e as ollows: (1) Is physical ac i i y posi i ely associa ed wi h ca dio e- spi a o y i ness, muscula i ness, and mo o compe- ence (a pa hway)? (2) Is ca dio espi a o y i ness, muscula i ness, and mo o compe ence posi i ely associa ed wi h execu i e unc- ions (b pa hway)? (3) Is physical ac i i y posi i ely associa ed wi h execu i e unc ions (c`pa hway)? (4) Will ca dio espi a o y i ness, muscula i ness, and mo o compe ence media e he c oss-sec ional associa- ions be ween physical ac i i y and execu i e unc ions? We hypo hesized ha ca dio espi a o y i ness, muscula i - ness, and mo o compe ence would be posi i ely associa ed wi h physical ac i i y and media e he c oss-sec ional ela ion- ship wi h execu i e unc ions. Me hods S udy design and pa icipan s We used baseline da a om he Lea ning o Lead (L2L) clus e andomised con olled ial. De ailed in o ma ion abou his p og amme is a ailable in ou published p o ocol pape (Wade e al., 2023). Da a we e collec ed by ained esea che s be ween 2022 (coho 1) and 2023 (coho 2) ac oss 20 p ima y schools in he s a e o New Sou h Wales (NSW), Aus alia. In o al, 675 child en (7–11 yea s, 49.5% gi ls) who we e in G ades 3 and 4 we e eligible and included in he cu en c oss-sec ional s udy. We ob ained w i en in o med assen om s uden s and w i en consen om hei pa en s o legal gua dians. The s udy was app o ed by he human esea ch e hics commi ee o he Uni e si y o Newcas le (app o al numbe : H-2020–0109) and he NSW Depa men o Educa ion ( e e ence numbe : 2020143). The L2L ial was p ospec i ely egis e ed wi h he Aus alian New Zealand Clinical T ials Regis y ( e e ence num- be : ACTRN12621000376842). Measu emen Baseline da a ega ding pa icipan s’ demog aphic in o ma ion (e.g., age, socioeconomic s a us) we e collec ed ia an online su ey using elec onic able s. Physical ac i i y Child en’s physical ac i i y le els we e assessed by w is - wo n accele ome e s (Ac iG aph GT9X). Pa icipan s wo e he de ice on hei non-dominan w is and we e asked o wea hem du ing he school day o i e school days (app oxima ely be ween he hou s o 9:00 am and 3:00 pm). Physical ac i i y in ensi y was ca ego ised as ligh , mode a e, and igo ous using alida ed cu poin s (Chandle e al., 2016). Physical i ness Ca dio espi a o y i ness was e alua ed using he 20 m Mul is age Fi ness Tes . This es has shown mode a e- o-high alidi y o es ima e maximum oxygen up ake in child en (Mayo ga-Vega e al., 2015). The child en we e equi ed o un be ween wo lines se up 20 m apa . The o al sco e was he numbe o comple ed laps. Muscula i ness was assessed by he s anding long jump, which has shown good alidi y and eliabili y o assess muscu- la i ness in child en and adolescen s (Cas o-Piñe o e al., 2010; Ruiz e al., 2011). Pa icipan s pe o med wo jumps, wi h he u hes jump eco ded in cen ime es as hei inal sco e. Mo o compe ence Mo o compe ence was assessed using a subse o objec con ol skills ( h owing, ca ching, and kicking) om he Tes o G oss Mo o De elopmen 3 (TGMD-3) (Webs e & Ul ich, 2017). Child en we e ilmed pe o ming h ee ials o each o he h ee skills (including an ini ial p ac ice ial ha was no assessed). These skills we e selec ed based on hei ans e abili y in o a a ie y o di e en spo s ha a e pop- ula among Aus alian child en. Each skill in he eco ding was assessed acco ding o skill-speci ic pe o mance c i e ia by ained esea ch assis an s. Each skill componen was sco ed a “1” i pe o med co ec ly, o “0” i pe o med inco ec ly. This p ocedu e was comple ed o each o he wo p ima y ials, and ial sco es we e summed o calcula e a o al sco e o each skill. An o e all objec con ol mo e- men skills sco e was calcula ed by summing he sco es om all h ee skills. Execu i e unc ions Inhibi o y con ol and cogni i e lexibili y we e measu ed using wo assessmen s om he Na ional Ins i u e o Heal h Toolbox o he Assessmen o Neu ological and Beha iou al Func ion. Pa icipan s comple ed bo h es s on an iPad app in a quie oom alongside a maximum o 20 o he s uden s comple ing he es s a he same ime. Ins uc ions o bo h es s we e explained by a membe o he esea ch eam and we e also shown on he sc een. All pa icipan s wo e headphones o he du a ion o he es ba e y, which ook app oxima ely 10 min o comple e. Inhibi o y con ol was assessed using he “Flanke Inhibi o y Con ol and A en ion Tes ” ( e sion o child en be ween 8 and 11 yea s). In his popula ion, sco es de i ed om his es ha e shown con e gen alidi y and good es – e es eliabili y (ICC = 0.95, 95% CI = 0.92–0.97) (Wein aub e al., 2013). Inhibi ion pe o mance was calcula ed as a combina ion o speed and accu acy and p oduced a sco e be ween 0 and 10, wi h a highe sco e indica ing g ea e pe - o mance. Cogni i e lexibili y was assessed by he Dimensional Change Ca d So Tes ( e sion o child en be ween 8 and 11 yea s). Sco es de i ed om his es ha e also shown good es – e es eliabili y (ICC = 0.94, 95% CI = 0.92–0.96), and alidi y when used wi h child en and adolescen s (Wein aub e al., 2013). Based on a combina ion o es accu acy and speed, JOURNAL OF SPORTS SCIENCES 3 he es p o ides a sco e be ween 0 and 10, wi h highe sco es indica ing supe io pe o mance. S a is ical analysis To maximise he numbe o s uden s in he cu en s udy whils p ese ing he alidi y o he measu emen , we conduc ed ICC analyses compa ing wo o mo e and h ee o mo e days o alid accele ome y. The alues we e as ollows: wo o mo e, ICC = 0.75, and h ee o mo e, ICC = 0.83. Acco ding o p e ious s udies, an ICC o 0.75, calcula ed om wo o mo e days, is conside ed accep able o accele ome y (An czak e al., 2021; Ba boza e al., 2021; Ridley e al., 2009), acco dingly, we used da a wi h wo o mo e days o alid wea ime. Desc ip i e analyses ( he Chi-squa e and independen - es ) and bi a ia e co ela ions be ween physical ac i i y, mo o compe ence, ca - dio espi a o y i ness, muscula i ness, and execu i e unc ions (alpha le els se a p < 0.05) we e conduc ed in IBM SPSS S a is ics o Windows, V.28.0 (IBM, A monk, New Yo k, USA) and a e p esen ed in Table 1. We used mul i-le el s uc u al equa ion modelling in Mplus e sion 8.10 o in es iga e whe he ca dio espi a o y i ness, muscula i ness, o mo o compe ence media e he c oss- sec ional associa ions be ween MVPA and execu i e unc ions (indi ec e ec ). These ques ions we e in es iga ed using he models shown in Figu es 2 and 3. To add ess missing da a and Table 1. Cha ac e is ics o he s udy sample. O e all (n = 675 a ) Boys (n = 336, 50.5%) Gi ls (n = 329, 49.5%) S a is ic (χ 2 / ) P aluen (%) Mean (SD) n (%) Mean (SD) n (%) Mean (SD) Cul u al backg ound, n (%) Aus alian 606 (90.2%) 300 (89.3%) 302 (91.8%) 1.22 0.270 O he 66 (9.8%) 36 (10.7%) 27 (8.2%) Socioeconomic s a us, n (%) Low 66 (9.9%) 32 (9.6%) 33 (10.1%) 0.83 0.659 Medium 512 (76.4%) 253 (75.5%) 254 (77.4%) High 92 (13.7%) 50 (14.9%) 41 (12.5%) Age 672 8.7 (0.7) 336 8.7 (0.7) 329 8.6 (0.7) 1.87 0.062 MVPA (minu es) 675 34.3 (14.1) 336 39.6 (14.8) 329 29.0 (10.8) 10.52 <0.001 MC (sco es) 643 14.4 (3.5) 316 15.9 (3.2) 320 12.9 (3.2) 11.74 <0.001 Ca dio espi a o y i ness (laps) 653 26.2 (15.4) 327 29.6 (17.6) 318 22.7 (12.0) 5.80 <0.001 Muscula i ness (cm) 662 119.7 (22. 6) 329 125.6 (23.5) 325 114.0 (19.9) 6.78 <0.001 Inhibi o y con ol (sco es) 666 7.4 (1.1) 331 7.5 (1.1) 327 7.4 (1.0) 1.28 0.202 Cogni i e lexibili y (sco es) 666 6.9 (1.1) 331 6.9 (1.1) 327 6.8 (1.1) 0.63 0.532 a = he e was missing da a o he sex o 10 pa icipan s. Figu e 2. The media ing associa ion be ween MVPA and inhibi o y con ol in o e all sample (n = 664). (No e: adjus ed o socioeconomic s a us and sex, he numbe s in he b acke s e e o SE, solid lines ep esen signi ican β coe icien s and dashed lines indica e non-signi ican β coe icien s) 4R. BAO ET AL. he non-independence o s uden s clus e ing wi hin schools, we applied obus maximum likelihood es ima ion by adjus ing s anda d e o s using a sandwich es ima o . Each ou come was s anda dised by con e ing hem in o z-sco es be o e analysis. Two mul iple media o models we e used o es ima e he indi ec e ec s o physical ac i i y on inhibi o y con ol and cogni i e lexibili y. The goodness o model i s we e e alua ed using χ 2 (Chi-squa e s a is ics), he Compa a i e Fi Index (CFI) (Ben le , 1990), he Tucke -Lewis Index (TLI) (Tucke & Lewis, 1973), he Roo Mean Squa e E o o App oxima ion (RMSEA) (B owne & Cudeck, 1992) and hei 90% con idence in e al (90% CI). A alue o TLI and CFI g ea e han 0.95 and an RMSEA less han 0.05 indica e an adequa e model i o he obse ed da a (Hu & Ben le , 1999). Each model adjus ed o socioeconomic s a us and sex. Each model es ed he ela ion- ship be ween he independen a iable and he hypo hesised media o s (a pa h); he media o s and he dependen a iables (b pa h). Then, a se ies o p oduc o coe icien s (a pa h × b pa h) we e es ed o calcula e he media ed es ima es o each hypo hesised media o (ca dio espi a o y i ness, muscula i - ness, and mo o compe ence). The indi ec es ima es we e conside ed signi ican whe e p < 0.05. The magni ude o he associa ions can be desc ibed as small (0.10–0.29), mode a e (0.30–0.49), and s ong (≥0.50) (Cohen, 2013). Resul s The sample cha ac e is ics a e displayed in Table 1. Among 675 child en (wi h a mean o 8.67 ± 0.67 yea s), 49.5% we e emale, and 90.2% o hem we e bo n in Aus alia. Table 2 ou lines he bi a ia e co ela ions among all measu es. Figu e 2 p esen s he esul s o di ec es ima es o MVPA and media o s on inhibi o y con ol in child en. The media ion model o inhibi o y con ol p o ided an adequa e i o he da a wi h χ 2 (18) = 8.126, CFI = 0.994, TLI = 0.979, RMSEA = 0.031 and 90% CI = 0.000–- 0.067. Figu e 3 shows he esul s o di ec es ima es o MVPA and media o s on cogni i e lexibili y in child en. The media ion Figu e 3. The media ing associa ion be ween MVPA and cogni i e lexibili y in o e all sample (n = 664). (No e: adjus ed o socioeconomic s a us and sex, he numbe s in he b acke s e e o SE, solid lines ep esen signi ican β coe icien s and dashed lines indica e non-signi ican β coe icien s) Table 2. Pea son’s bi a ia e co ela ions among a iables in child en. Coe icien s (sample size) 1 2 3 4 5 6 1. MVPA 1 2. CRF 0.462** (653) 1 3. MF 0.387** (662) 0.590** (649) 1 4. MC 0.389** (643) 0.363** (627) 0.413** (636) 1 5. Inhibi o y con ol 0.012 (666) 0.093* (647) 0.122** (656) 0.084* (637) 1 6. Cogni i e lexibili y 0.039 (666) 0.197** (647) 0.218** (656) 0.109** (637) 0.332** (666) 1 MVPA = mode a e- o- igo ous physical ac i i y; CRF = ca dio espi a o y i ness; MF = muscula i ness; MC = mo o compe ence. *. Co ela ion is signi ican a he 0.05 le el (2- ailed); **. Co ela ion is signi ican a he 0.01 le el (2- ailed). JOURNAL OF SPORTS SCIENCES 5 model o cogni i e lexibili y also p o ided an adequa e i o he da a, χ 2 (18) = 605.754, CFI = 0.994, TLI = 0.979, RMSEA = 0.032 and 90% CI = 0.000–0.069. MVPA on hypo hesised media o s (a pa hway – ac ion heo y es s) MVPA was associa ed wi h ca dio espi a o y i ness (β = 0.46, SE = 0.049, p < 0.001), muscula i ness (β = 0.35, SE = 0.055, p < 0.001) and mo o compe ence (β = 0.27, SE = 0.049, p < 0.001). Hypo hesised media o s on execu i e unc ions (b pa hway – concep ual heo y es s) Muscula i ness was associa ed wi h inhibi o y con ol (β = 0.09, SE = 0.043, p = 0.045) and cogni i e lexibili y (β = 0.16, SE = 0.053, p = 0.002), while ca dio espi a o y i ness was only associa ed wi h cogni i e lexibili y (β = 0.13, SE = 0.044, p = 0.003). No signi ican associa ions we e obse ed be ween mo o compe ence and measu es o execu i e unc ion. MVPA on execu i e unc ions (c` pa hway – including media o s) MVPA was nega i ely associa ed wi h cogni i e lexibili y (β = −0.10, SE = 0.043, p = 0.016), while no associa ion was obse ed be ween MVPA and inhibi o y con ol. Signi icance o he indi ec e ec s (ab pa hway – media ion es s) Table 3 displays he indi ec es ima es o MVPA on inhibi o y con ol and cogni i e lexibili y. Ca dio espi a o y i ness media ed he associa ion be ween MVPA and cogni i e lexibili y in he o e all sample (β = 0.06, SE = 0.021, p = 0.004). Muscula i ness media ed he ela ionship be ween MVPA and inhibi o y con ol in he o e all sample (β = 0.03, SE = 0.014, p = 0.027). Muscula i ness was also a signi ican media o o he e ec o MVPA on cogni i e lexibili y (β = 0.06, SE = 0.021, p = 0.005) in he o e all sample. We did no obse e indi ec e ec s o mo o compe ence in he ela ionship be ween MVPA and execu i e unc ions in child en. Discussion The aim o ou s udy was o examine whe he ca dio espi a o y i ness, muscula i ness, o mo o compe ence media ed he c oss-sec ional associa ion be ween MVPA and execu i e unc- ions in child en. The indings indica ed ha ca dio espi a o y i ness media ed he associa ion be ween MVPA and cogni i e lexibili y, while muscula i ness media ed he ela ionship be ween MVPA and bo h inhibi o y con ol and cogni i e lex- ibili y. Con e sely, we did no ind a media ing ole o mo o compe ence on ei he ou come. The “ i ness” hypo hesis pos ula es ha pa icipa ion in physical ac i i y o su icien du a ion and in ensi y can p o- duce ca dio espi a o y i ness gains, which may subsequen ly enhance cogni ion (Pe uzzello e al., 1997; Tompo owski & Pesce, 2019). In line wi h his hypo hesis, ou indings sug- ges ed ha ca dio espi a o y i ness was posi i ely associa ed wi h execu i e unc ions in child en, which is consis en wi h e iews on he opic (De G ee e al., 2018; Hillman e al., 2008; Van Wael elde e al., 2020). No ably, ew s udies ha e o mally examined he media ion o ca dio espi a o y i ness in child en (Visie -Al onso e al., 2021; Yangüez e al., 2021). Speci ically, we ound ha ca dio espi a o y i ness media ed he ela ionship be ween MVPA and cogni i e lexibili y bu no o inhibi o y con ol. Resea ch on he media ing e ec s o ca dio espi a o y i ness, as assessed by he 20-m shu le un es , has yielded mixed esul s. Some s udies ha e epo ed simila indings o he cu en s udy (Yangüez e al., 2021), while o he s ha e ound ha ca dio espi a o y i ness media es inhibi o y con ol bu no cogni i e lexibili y (Visie -Al onso e al., 2021). These disc epancies may be pa ly due o me hodological di e ences in how ca dio espi a o y i ness is measu ed. Fo ins ance, while some s udies ha e used di ec measu es o maximal oxygen consump ion, in he cu en s udy, ca dio espi a o y i ness was assessed based on he numbe o comple ed laps in he shu le un. The inding ha ca dio espi a o y i ness media ed he ela ionship be ween MVPA and cogni i e lexibili y may be explained by se e al hypo heses. Ca dio espi a o y i ness can con ibu e o g ea e ce eb al ci cula ion, and an up egula ion o neu o ophins (e.g., b ain- de i ed neu o ophic ac o ) ha con ibu e o execu i e unc- ion pe o mance (S impson e al., 2018). Al e na i ely, he e is a beha iou al explana ion o ca dio espi a o y i ness as a media o o execu i e unc ions. Ae obic exe cises demand a ying le els o cogni i e engagemen , which may pose chal- lenges o child en’s execu i e unc ions (Bes , 2010; Tompo owski & Pesce, 2019). In pa icula , con ex ual in e e - ence a ises du ing pa icipa ion in ae obic exe cises, compel- ling child en’s need o c ea e, moni o and modi y hei ac ions o accomplish di e se and complex exe cise asks (Bes , 2010; Tompo owski & Pesce, 2019). This p ocess necessi a es he in ol emen o execu i e p ocesses, and he cogni i e skills essen ial o engaging in ae obic exe cises may ans e o pe o mance on execu i e unc ion asks (Bes , 2010). We ound ha muscula i ness was a media o be ween MVPA and bo h o ou execu i e unc ioning ou comes. The Table 3. The indi ec es ima es o MVPA on execu i e unc ions h ough media o s. Pa hways O e all (n = 675) βSE p MVPA o inhibi o y con ol ia CRF 0.02 0.027 0.404 MVPA o inhibi o y con ol ia MF 0.03 0.014 0.027 MVPA o inhibi o y con ol ia MC 0.02 0.012 0.185 MVPA o cogni i e lexibili y ia CRF 0.06 0.021 0.004 MVPA o cogni i e lexibili y ia MF 0.06 0.021 0.005 MVPA o cogni i e lexibili y ia MC 0.01 0.010 0.435 MVPA, mode a e- o- igo ous physical ac i i y; CRF, ca dio espi a o y i ness; MF, muscula i ness; MC, mo o compe ence; β, s anda dised coe icien s; SE, s anda d e o . 6R. BAO ET AL. ela ionship be ween muscula i ness and execu i e unc ions in child en is s ill an eme ging ield o esea ch, bu ou indings a e consis en wi h he exis ing li e a u e (Robinson e al., 2023; J. J. Smi h e al., 2014). A ecen e iew ound ha muscula i ness is posi i ely associa ed wi h cogni i e lexibili y (Cohen’s d = 0.18) and wo king memo y (Cohen’s d = 0.14) in child en and adolescen s (Robinson e al., 2023). Fu he , he e is e i- dence ha highe le els o muscula i ness a e associa ed wi h g ea e inhibi o y con ol and cogni i e lexibili y (Solis‐U a e al., 2021; Zeng e al., 2023). The e is also e idence o a posi i e associa ion be ween muscula i ness and whi e ma e olume in child en (Es eban-Co nejo e al., 2019). Howe e , i is impo an o acknowledge he di e ences in how muscula i ness was assessed ac oss s udies. Fo example, se e al s udies ha e used composi e measu es, such as he combina ion o handg ip s eng h and he s anding long jump (Es eban-Co nejo e al., 2019; Solis‐U a e al., 2021), o a b oade ba e y o es s, including he assessmen o g ip s eng h, pull ups (boys), si -ups (gi ls) and s anding long jump (Zeng e al., 2023). In con as , ou s udy assessed mus- cula i ness solely using he s anding long jump es . These me hodological di e ences in how muscula i ness is assessed mus be conside ed when compa ing ou esul s wi h hose o o he s udies. In e es ingly, ou s udy has shown ha muscula i ness was a p edic o o execu i e unc ioning, independen ly o ca dio - espi a o y i ness. This ela ionship may be explained, a leas in pa , by he ela ionship o muscula i ness o b ain s uc u e and unc ions. The ac i a ion o skele al muscle may s imula e he elease o neu o ophins (such as i isin and b ain-de i ed neu o ophic ac o ), which may acili a e execu i e unc ions (Isaac e al., 2021). The e o e, i may be he case ha ac i i ies ha a e pa icula ly axing on skele al muscle (e.g., esis ance exe cise), and hus con ibu e o muscula i ness, may be especially e ec i e on execu i e unc ions. Clea ly, he e is a need o u he esea ch on he ela ionship be ween mus- cula i ness and execu i e unc ions. The “skill” hypo hesis p oposed ha physical ac i i y pa i- cipa ion can acili a e he acquisi ion o mo o skill compe- ency, which subsequen ly imp o es cogni i e unc ion. Engagemen in cogni i ely complex and/o no el mo o skill asks may lead o imp o emen s in execu i e unc ions. The e is e idence ha mo o compe ence is posi i ely associa ed wi h execu i e unc ions in child en and adolescen s (Gando a e al., 2022; Hill e al., 2023; Willoughby & Hudson, 2023). Recen ly, indings om a me a-analysis sugges ha mo o compe ence ( = 0.18) is associa ed wi h execu i e unc ions in child en and adolescen s (Bao e al., 2024). Fu he , eme ging e idence sugges s ha mo o compe ence may in luence he ela ionship be ween physical ac i i y and execu i e unc ions (Hill e al., 2023; Willoughby & Hudson, 2023). The unde lying mechanisms may be ela ed o he use o unc ional egions wi hin he b ain, such as p e on al co ex, he ce ebellum, and he basal ganglia ha a e common o bo h mo o and cogni- i e ac i i ies (Diamond, 2000; Leisman e al., 2016). Con a y o ou hypo hesis, we did no ind ha mo o compe ence media ed he associa ion be ween MVPA and execu i e unc- ions. No ably, ew s udies ha e o mally in es iga ed he po en ial media ing ole o mo o compe ence in his ela ionship. Among hem, Spanou e al. (2022), ound ha mo o compe ence, assessed using he B uininks – Ose e sky Tes o Mo o P o iciency-Second Edi ion (BOT-2), media ed he associa ion be ween physical ac i i y and execu i e unc ions in child en. Gi en he limi ed esea ch on he po en ially med- ia ing ole o mo o compe ence, u u e longi udinal and expe imen al esea ch is needed o be e unde s and he em- po ali y o his ela ionship and he causal pa hways linking mo o compe ence, physical ac i i y, and execu i e unc ions. To da e, much o he exis ing esea ch has ocused on he ela ionship be ween ca dio espi a o y i ness and execu i e unc ioning, wi h subs an ially less a en ion gi en o he po en ial con ibu ions o muscula i ness and mo o compe- ence (De G ee e al., 2018; Xue e al., 2019). This imbalance lea es a gap in ou unde s anding o he speci ic aspec s o physical ac i i y ha may in luence cogni i e de elopmen in child en. The cu en s udy add esses his gap by es ing he ela i e con ibu ions o ca dio espi a o y i ness, muscula i - ness, and mo o compe ence o child en’s execu i e unc ions. Ou indings lend suppo o he “ i ness hypo hesis”, sugges - ing ha physical ac i i y-induced imp o emen s in bo h ca di- o espi a o y and muscula i ness a e signi ican ly associa ed wi h enhanced execu i e unc ioning pe o mance. Impo an ly, his is one o he ew s udies o o mally es and compa e he ela i e impac o hese dis inc aspec s o physi- cal i ness and compe ence on execu i e unc ions, he eby p o iding a mo e comp ehensi e unde s anding o he in i- ca e ela ionships be ween physical ac i i y and cogni i e de elopmen . S eng hs and limi a ions To ou knowledge, his is he i s s udy o o mally es ca dio - espi a o y i ness, mo o compe ence, and muscula i ness as media o s in he ela ionship be ween de ice-assessed physical ac i i y and execu i e unc ions in child en. We used a mul i- le el modelling app oach, which is conside ed bes p ac ice o analysing clus e ed da a. Howe e , se e al limi a ions should be conside ed. Fi s , ou indings a e based on a c oss-sec ional s udy design, p e en ing he analysis o a causal ela ionship be ween MVPA and execu i e unc ions in child en. The e a e po en ial bi-di ec ional associa ions be ween physical ac i i y and mo o compe ence, as well as ca dio espi a o y and mus- cula i ness in child en and adolescen s (Ba ne e al., 2022). Fo example, imp o emen s in mo o compe ence may lead o inc eased physical ac i i y among you h. Con e sely, inc easing physical ac i i y could also enhance mo o compe ence. Fu u e expe imen al esea ch is needed o es ablish he empo al o de o hese ela ionships. Second, al hough inhibi ion, cogni i e lexibili y, and wo king memo y a e conside ed he h ee co e execu i e unc ions (Zelazo, 2020), we did no measu e wo king memo y due o logis ical cons ain s. We used he NIH oolbox ha includes a measu e o wo king memo y ha equi es one- on-one adminis a ion. This was no easible, as we needed o es se e al s uden s simul aneously. Fu u e esea ch should include wo king memo y o p o ide a mo e comp ehensi e accoun o he ela ionship be ween physical ac i i y and execu i e unc ions. Thi d, ou assessmen o mo o compe- ence was limi ed o h ee objec con ol skills. I is possible JOURNAL OF SPORTS SCIENCES 7