In . J. En i on. Res. Public Heal h 2015, 12, 10362-10373; doi:10.3390/ije ph120910362
In e na ional Jou nal o
En i onmen al Resea ch and
Public Heal h
ISSN 1660-4601
www.mdpi.com/jou nal/ije ph
A icle
Associa ions be ween Ac i e Commu ing o School and
Heal h-Rela ed Physical Fi ness in Spanish School-Aged
Child en: A C oss-Sec ional S udy
Emilio Villa-González 1,2,*, Jona an R. Ruiz 2 and Palma Chillón 2
1 Depa men o Physical Cul u e, School o Heal h Sciences, Na ional Uni e si y o Chimbo azo,
A da. An onio José de Suc e, Km. 1 1/2 ía a Guano, 060150 Riobamba, Ecuado
2 P o i h “PROmo ing FITness and Heal h h ough physical ac i i y” Resea ch G oup, Depa men o
Physical Educa ion and Spo , School o Spo Science, Uni e si y o G anada, Spain C a. Al aca , s/n,
18011 G anada, Spain; E-Mails: uizj@ug .es (J.R.R.); [email p o ec ed] (P.C.)
* Au ho o whom co espondence should be add essed; E-Mail: e [email p o ec ed];
Tel.: +593-033-730-880 (ex . 3000); Fax: +593-033-730-880 (ex . 117).
Academic Edi o : Paul B. Tchounwou
Recei ed: 13 June 2015 / Accep ed: 18 Augus 2015 / Published: 26 Augus 2015
Abs ac : Ac i e commu ing (walking o cycling) o school has been posi i ely associa ed wi h
imp o ed i ness among adolescen s. Howe e , cu en e idence lacks in o ma ion on whe he
his associa ion pe sis s in child en. The aim o his s udy was o examine he associa ion o
ac i e commu ing o school wi h di e en i ness pa ame e s in Spanish school-aged child en.
A o al o 494 child en (229 gi ls) om i e p ima y schools in G anada and Jaén (Spain),
aged be ween eigh and 11 yea s, pa icipa ed in his c oss-sec ional s udy. Pa icipan s
comple ed he Assessing Le els o Physical Ac i i y (ALPHA) i ness es ba e y and answe ed
a sel - epo ed ques ionnai e ega ding he weekly a el mode o school. Ac i e commu ing o
school was signi ican ly associa ed wi h highe le els o speed-agili y in boys (p = 0.048) and
muscle s eng h o he lowe body muscula i ness in gi ls (p = 0.016). Howe e , he e we e no
signi ican associa ions be ween ac i e commu ing o school and ca dio espi a o y i ness and
uppe body muscula i ness. Ou indings sugges ha ac i e commu ing o school was
associa ed wi h highe le els o bo h speed-agili y and lowe body muscula i ness in boys and
gi ls, espec i ely. Fu u e s udies should con i m whe he inc easing ac i e commu ing o school
inc eases speed-agili y and muscle s eng h o he lowe body.
OPEN ACCESS
In . J. En i on. Res. Public Heal h 2015, 12 10363
Keywo ds: physical ac i i y; ac i e anspo a ion; public heal h; s eng h
1. Backg ound
Physical i ness, mainly ca dio espi a o y i ness, muscula i ness, and mo o i ness, has shown o be a
powe ul ma ke o heal h in young people [1]. Low i ness has been associa ed wi h clus e ing o me abolic
isk ac o s in young people ha may pe sis in o adul hood [2,3]. Modi ying isk ac o le els in child en
may hus be o c i ical impo ance o amelio a ing u u e ca dio ascula disease (CVD) isk [4,5].
Obse a ional s udies ha e shown ha young people who ac i ely commu e o school (de ined as he use
o ac i e means, such as walking and bicycling, o and om school) end o be mo e physically ac i e han
passi e commu e s [6,7], al hough he con ibu ion o ac i e commu ing o you hs’ physical i ness le els
(beyond ae obic i ness) is s ill unclea [8,9]. The associa ion be ween ac i e commu ing o school and
heal h- ela ed physical i ness has been s udied in adolescen s [10–12] as well as in child en [7,13–15].
These s udies di e ed in he i ness componen s measu ed. All he p e ious s udies measu ed
ca dio espi a o y i ness and a ew o hem measu ed muscula i ness [13,15] and speed-agili y [13].
Ac i e commu ing by cycling has been associa ed wi h a highe ca dio espi a o y i ness le el compa ed
o non-cyclis and walke adolescen s [7,10,13]. Longi udinal s udies ha e also shown ha ae obic
i ness imp o ed om childhood o adolescence when pa icipan s swi ched om passi e commu e s o
cycling as he dominan mode o a el o school [10,14].
Mos o he s udies ha epo ed associa ions be ween ac i e commu ing o school and heal h- ela ed
physical i ness we e a ge ed a adolescen s and hey ocused mainly on ca dio espi a o y i ness ou comes.
Howe e , ew s udies o da e ha e explo ed he ela ionship be ween ac i e commu ing and heal h- ela ed
physical i ness in school-aged child en (8–11 yea olds), al hough he e is p e ious e idence ha
ecommends disease p e en ion should begin om childhood [16]. Thus, he cu en s udy aims o examine
he associa ion be ween ac i e commu ing o school and heal h- ela ed physical i ness as measu ed by he
Assessing Le els o Physical Ac i i y (ALPHA) i ness es ba e y [17] in Spanish school-age child en.
The e o e, ou hypo hesis is ha ac i e commu e s could show g ea e heal h- ela ed physical i ness han
passi e commu e s.
2. Me hods
2.1. Pa icipan s and S udy Design
A o al o 494 child en (229 gi ls) aged be ween 8 and 11 yea s (mean = 9.2 and SD = 0.6) pa icipa ed
in he s udy. Pa icipan s we e ec ui ed om i e schools in he p o inces o G anada (Salob eña,
N = 125; Hué o Vega, N = 95; San a Fe, N =96; he ci y o G anada, N = 128) and Jaén (Cas illo de Locubin,
N = 50). Those pa icipan s who had alid da a on commu ing o school we e included (N = 469).
The s udy was conduc ed wi hin a public heal h ini ia i e lead by Dipu ación de G anada
(Á ea de Medio Ambien e). The pu pose o his p og am was o p omo e sa e and heal hy ways o
commu ing om home o school. An ag eemen was signed by he school boa d, Dipu ación de G anada,
and he municipali ies. The school boa d, pa en s, and s uden s we e in o med abou he s udy and hey
In . J. En i on. Res. Public Heal h 2015, 12 10364
ag eed o pa icipa e. W i en consen om pa en s was ob ained. The measu emen s we e aken a each
o he schools du ing school hou s in he mon h o Janua y, in he academic yea 2011/2012. The Medical
E hics Commi ee o Hospi al Vi gen de las Nie es (G anada, Spain) app o ed he s udy design, s udy
p o ocols, and in o med consen p ocedu e (case numbe 817).
2.2. Mode o Commu ing o School
Pa icipan s comple ed a sel - epo ques ionnai e ega ding he la es weekly pa e ns o commu ing
o and om school (Monday o F iday). The modes o commu ing we e: walk, bike, ca , mo o cycle,
and bus. Walking and biking we e ca ego ized as ac i e commu ing, whe eas a eling by ca ,
mo o cycle, and bus was ca ego ized as passi e commu ing. This ques ionnai e has been p oposed as
he mos app op ia e measu emen o asking abou mode o commu ing o school a e e iewing 158
s udies wi hin he scien i ic li e a u e [18]. Child en comple ed he ques ionnai e wi h he help o he
eache and he esea ch eam. The weekly equency o commu ing o school was exp essed as numbe s
o ac i e a els pe week o and om school ( ange: 0 o 10). One a iable o h ee ca ego ies
(0–2 ac i e a els s. 3–7 ac i e a els s. 8–10 ac i e a els) was c ea ed.
2.3. Heal h-Rela ed Physical Fi ness
Physical i ness, an h opome ic a iables, and sexual ma u a ion s a us we e assessed by he ALPHA
i ness es ba e y o high p io i y, p e iously desc ibed in de ail and alida ed in child en and
adolescen s [17]. All pa icipan s comple ed he es du ing hei physical educa ion class.
The same esea che s pe o med all he measu emen s. Measu emen s we e o ganized in a ci cui ,
and pa icipan s pe o med each es consecu i ely, excep o he ca dio espi a o y i ness es ,
whe e se e al pa icipan s pe o med i a he same ime. Comple ion o he physical measu emen s ook
one hou pe school g oup. Se e al physical i ness es s we e pe o med.
Ca dio ascula i ness was assessed by means o he 20-m shu le un es , as desc ibed in de ail by Lege
e al. [19]. In b ie , he pa icipan s we e equi ed o un be ween wo lines 20 me e s (m) apa while keeping
pace wi h audio signals emi ed om a p e eco ded CD. The ini ial speed was 8.5 km/h, and he speed was
inc eased by 0.5 km/h pe minu e. The es was comple ed when he pa icipan s ailed o each he end lines
concu en wi h he audio signals on wo consecu i e occasions, o when he pa icipan s s opped because o
a igue. The equa ions o Lege e al. [19], p e iously alida ed in child en and adolescen s, we e used o
es ima e he maximum oxygen consump ion (VO2max) om he es sco es.
Lowe body muscula i ness was assessed by means o he s anding long jump. The pa icipan s ood
behind he s a ing line, wi h ee oge he , and pushed o igo ously and jumped o wa d as a as
possible. The dis ance was measu ed om he ake-o line o he poin whe e he back o he heel nea es
o he ake-o line lands on he ma o non-slippe y loo . The es was epea ed wice,
and he bes sco e was e ained (in cm).
Uppe body muscle s eng h was assessed by means o handg ip s eng h using a hand dynamome e
wi h adjus able g ip (TKK 5401 G ip D; Takey, Tokyo, Japan). Child en we e gi en a b ie
demons a ion and e bal ins uc ion o he es and, i necessa y, he dynamome e was adjus ed
acco ding o he child’s hand size as ecommended [20]. The es was done in he s anding posi ion wi h
he w is in he neu al posi ion and he elbow ex ended; child en we e gi en e bal encou agemen o
In . J. En i on. Res. Public Heal h 2015, 12 10365
“squeeze as ha d as possible” and apply maximal e o o a leas wo seconds (s). Two a emp s pe
hand we e pe o med, and he bes sco e was used. The a e age o he bes sco es achie ed by each hand
was used in he analysis.
Speed-agili y was measu ed by he 4 × 10 shu le un es . Two lines, a a dis ance o 10 m, and wo
cones d awn we e placed a he dis an line. The pa icipan s an as as as possible om he s a ing line,
picked up one sponge a he dis an line, e u ned o he s a ing line, and placed he cone on his line
be o e epea ing he same un and e ie ing he second sponge. Two a emp s we e pe o med, and he
bes sco e was e ained (in seconds). The agili y measu e was he ime o comple e his 40-m un wi h
co ec placemen o he cones.
2.4. Co a ia es
The dis ance om home o school was es ima ed using he In e ne p og am Google Maps V.6, simila
o he p e ious s udy [21]. The sho es ne wo k pa h be ween each s uden 's home add ess and he school
measu ed in me e s was used.
The an h opome ic a iables measu ed we e weigh and heigh . Body mass index (BMI) was
calcula ed as weigh (in kilog ams)/heigh (in m2) by s anda d p ocedu es. Wais ci cum e ence (WC)
was measu ed in cm, using an inelas ic ape. Sexual ma u a ion s a us was assessed acco ding o he
me hod desc ibed by he scien i ic li e a u e [22] in a b ie examina ion by a ained esea che . P i acy
was main ained a all imes.
2.5. S a is ical Analyses
Di e ences in socio-demog aphic cha ac e is ics (sex, age, and dis ance) be ween pa icipan s who
p o ided i ness da a and hose who did no we e es ed using chi-squa e o ca ego ical a iables and
Mann-Whi ney U es o non-no mal con inuous a iables. The no mali y o he i ness es a iables
was s udied using he Kolmogo o -Smi no es . Since hey we e no no mal, a log ans o ma ion was
conduc ed o each i ness es . Linea eg ession analysis wi h obus s anda d e o s was used o
in es iga e he associa ions o ac i e commu ing o school (numbe o ac i e a els pe week) wi h
i ness es s (20-m shu le un, s anding long jump, handg ip s eng h, and 4 × 10 shu le un) adjus ing
o age, BMI, and dis ance om home o school.
We ca ego ized he ac i e commu ing a iable (numbe o ac i e a els) in h ee ca ego ies
(0–2 ac i e a els s. 3–7 ac i e a els s. 8–10 ac i e a els). These cu o poin s p o ided
homogeneous sample sizes in e e y ca ego y. In o de o know he impac o he numbe o ac i e a els
in he i ness es s, di e ences be ween ac i e commu ing o school (ca ego ical a iable wi h h ee
ca ego ies) and i ness es s we e examined by one-way analysis o co a iance (ANCOVA) adjus ing
o age, BMI, and dis ance. Pos hoc Bon e oni es s we e conduc ed when he a iable o he h ee
ca ego ies was included. All he analyses we e pe o med sepa a ely o boys and gi ls. Analyses we e
pe o med using he S a is ical Package o he Social Sciences (SPSS) ( . 18.0 o Windows, Chicago,
IL, USA), and he le el o signi icance was se o 0.05.
In . J. En i on. Res. Public Heal h 2015, 12 10366
3. Resul s
D op-ou analyses did no ind di e ences be ween hose who p o ided i ness da a and hose who
did no . Cha ac e is ics o he s udy sample by sex a e shown in Table 1. The a e age numbe o ac i e
a els (mainly walking) pe week was 4.4, and he e we e no sex di e ences.
Table 1. Desc ip i e cha ac e is ics o he s udy sample s a i ied by sex.
Va iables N
All
Mean (SD) N Boys
Mean (SD) N Gi ls
Mean (SD)
Age (yea s) 469 9.2 (0.6) 251 9.3 (0.6) 218 9.2 (0.6)
Weigh (kg) 424 37.3 (10.1) 235 37.7 (10.3) 187 37.0 (9.8)
Heigh (cm)
BMI (kg/m2)
410
410
140.5
18.6
(8.8)
(3.7)
226
226
140.9
18.6
(8.7)
(3.7)
182
184
140.2
18.5
(8.8)
(3.7)
WC (cm) 423 67.2 (10.0) 235 67.7 (10.5) 188 66.7 (9.2)
Sexual ma u a ion s a us (%)
S age 1
S age 2
S age 3
S age 4
420
26.7
60.5
12.1
0.7
233
4.3
84.5
10.3
0.9
187
54.5
30.5
14.4
0.5
Ca dio espi a o y i ness
VO2max
(mL/kg pe min)
413 41.5 (4.3) 229 42.6 (4.6) 184 40.2 (3.6)
20-m shu le un (s age) 413 1.9 (1.3) 229 2.3 (1.5) 184 1.5 (1.0)
Muscula i ness
S anding long
jump (cm)
Handg ip s eng h (kg)
420
423
114.1
14.4
(22.4)
(6.7)
233
234
119.0
14.4
(20.3)
(3.0)
187
189
109.8
14.3
(19.1)
(9.5)
Speed-agili y
4x10 shu le un (s) 419 14.8 (2.3) 232 13.7 (1.4) 187 14.2 (1.3)
F equency o ac i e a el
(nº/week) * 469 4 (0,9) 251 4 (0,9) 218 4 (0,9)
Mode o commu ing º/week) *
Walk
Bike
Ca
Mo o cycle
Bus
O he s
469
4 (0,9)
0 (0,0)
4 (0,9)
0 (0,0)
0 (0,0)
0 (0,0)
251
3(0,9)
0(0,0)
4(0,8)
0(0,0)
0(0,0)
0(0,0)
218
4 (0,9)
0 (0,0)
5 (0,9)
0 (0,0)
0 (0,0)
0 (0,0)
Dis ance o
school (m) * 324 600 (412,1000) 163 650 (450,1000) 161 600 (400,1000)
Da a a e shown as mean and s anda d de ia ion, unless o he wise s a ed; BMI, Body mass index WC,
Wais ci cum e ence; * Numbe o ac i e a els o and om school pe week ( ange: 0–10) and dis ance (m)
exp essed as Median (25 h, 75 h) pe cen ile.
The associa ions be ween ac i e commu ing o school (mainly walking) and heal h- ela ed physical
i ness a e shown in Table 2. Ac i e commu ing o school was associa ed wi h highe sco es in he
speed-agili y es o boys (ß = 0.062, 95% CI: 0.001 o 0.122, p = 0.048) and wi h highe sco es in he
s anding long jump es o gi ls (ß = 1.009, 95% CI: 0.125 o 1.866, p = 0.016). The associa ion be ween
ac i e commu ing ( h ee ca ego ies) o school and i ness es s is g aphically shown in Figu e 1.

In . J. En i on. Res. Public Heal h 2015, 12 10367
Ac i e commu ing o school was associa ed wi h highe le els in he 4 × 10 shu le un es only in boys
(p = 0.04) and in he s anding long jump only in gi ls (p = 0.01).
Table 2. Reg ession analysis ( alue o he uns anda dized be a and s anda d e o (SE)) o
ac i e commu ing o school (exp essed in o al numbe o ac i e a els o and om school
pe week) and i ness es s, adjus ing o age, BMI, and dis ance.
Fi ness es s * Ac i e Commu ing
Boys Gi ls
ß SE p ß SE p
Ca dio espi a o y i ness
20-m shu le un (s age) −0.024 0.036 0.488 −0.005 0.018 0.786
Muscula i ness
S anding long jump (cm) −0.495 0.297 0.435 1.009 0.433 0.016
Handg ip s eng h (kg) −0.117 0.068 0.121 0.331 0.208 0.168
Speed-agili y
4 × 10 shu le un (s) 0.062 0.031 0.048 −0.046 0.031 0.127
* Log- ans o med da a we e used in he analysis o e e y i ness es ,
bu aw da a a e shown in he able, o ß (be a) and SE (s anda d e o ).
The e was an in e g oup associa ion (p = 0.01) when compa ing mo e ac i e commu e s
(8–10 ac i e a els/week) wi h less ac i e commu e s (0–2 ac i e a els/week) o he s anding long
jump in gi ls. The esul s emained consis en when using o he ca ego ical a iables o ac i e
commu ing using di e en cu -o poin s (da a no shown). Fo he o e all p e ious analyses,
he esul s emained consis en when adjus ing o sexual ma u a ion s a us ins ead o age and when
including sexual ma u a ion s a us oge he wi h age, BMI, and dis ance. The esul s emained consis en
when pe o ming he analysis wi hou including BMI.
4. Discussion
The main inding o his s udy was ha boys and gi ls who we e mo e ac i e school commu e s
(mainly walking) had a g ea e speed-agili y (al hough a sligh di e ence) and muscle s eng h o he
lowe body, espec i ely, han hose boys and gi ls who we e less ac i e school commu e s.
The e we e no signi ican associa ions be ween ac i e commu ing o school and o he i ness a iables
such as ca dio espi a o y i ness and uppe body muscula i ness.
4.1. Ca dio ascula Fi ness
The esul s om he cu en s udy sugges ed ha he e we e no associa ions be ween ac i e
commu ing o school and ca dio espi a o y i ness le els in child en.
In . J. En i on. Res. Public Heal h 2015, 12 10368
Figu e 1. Associa ion be ween ac i e commu ing o school and i ness es s, adjus ing o
age, BMI, and dis ance, om home o school o boys and gi ls.
In . J. En i on. Res. Public Heal h 2015, 12 10369
Se e al s udies ha e epo ed a posi i e associa ion be ween ac i e commu ing o school and
ca dio espi a o y i ness le els in young people [7,11–15,23,24]. Howe e , only h ee o hese s udies
epo ed his posi i e associa ion speci ically o child en [7,14,15]. In Danish child en aged 9.7 ± 0.5 yea s
old, cycling o school was signi ican ly associa ed wi h highe ca dio espi a o y i ness in child en o
bo h sexes. Mo eo e , cyclis s we e signi ican ly i e han hose who walked o school o used passi e
anspo a ion [7,14], possibly due o he ac ha hey pe o med a g ea e a e age ip dis ance o and
om school han walke s. The same esul was ound among No wegian child en aged 9 yea s old [15].
I mus be highligh ed ha in he wo c oss-sec ional s udies, he pe cen age o cyclis s in he samples
was 38.3% and 5.5%, espec i ely, because hey belong o coun ies wi h a long p e ious cycling
adi ion. In he cu en s udy, only 0.1% o he pa icipan s cycled o school, which is no an la ge
enough sample size o s udy i s e ec s.
On he o he hand, o he bes o ou knowledge, he e is no e idence o he associa ion be ween walking
o school and ca dio espi a o y i ness among child en. E en he h ee p e ious s udies [7,14,15] did no
epo associa ions be ween walke s and hose who used passi e anspo a ion o ca dio espi a o y
i ness, since he e is e idence ha walking as a mode o commu ing seems o no be enough s imula ion
o modi y heal h- ela ed i ness [23]. Fu u e s udies should add ess his issue.
The cu en s udy assessed ca dio espi a o y i ness using he 20-m shu le un es . The es uses unning,
which is an exe cise modali y o which all child en and adolescen s a e accus omed. The es is a
alid [19,24–26] and easily adminis e ed ield es ha p o okes maximal e o in schoolchild en [27].
I has been used ex ensi ely o assess he ae obic i ness o child en and adolescen s [28]. The majo i y
o s udies ha we e iewed assessed ca dio espi a o y i ness using he cycle e gome y es ,
while we used he 20-m shu le un es . This may be aken in o accoun when compa ing di e en s udies.
4.2. Muscula Fi ness
Gi ls who we e mo e ac i e commu e s had highe le els o lowe body muscula i ness han hose
who we e less ac i e commu e s. The e we e no associa ions be ween ac i e commu ing o school and
uppe body muscula i ness in boys and gi ls.
The e is li le e idence on he associa ion be ween ac i e commu ing o school and lowe body
muscula i ness in child en and adolescen s [9,13,15]. The e we e no associa ions be ween ac i e
commu ing o school and muscula i ness in Danish adolescen s aged 15 o 19 yea s old [13].
In he Danish s udy, he unc ional s eng h o he leg ex enso s was measu ed by he Sa gen jump es ,
and he unc ional s eng h in he dominan a m was measu ed by he i on ball h ow es . Mo eo e ,
he e we e no di e ences in he esul s be ween gi ls and boys. In No wegian child en and adolescen s
aged 9 o 15 yea s old, he e was an associa ion be ween ac i e commu ing o school and muscula
i ness [15]. In he No wegian s udy, he lowe body muscula i ness was assessed by he s anding long
jump es , he same es used in he cu en s udy, conside ed a gene al index o bo h lowe body and
uppe body muscula i ness in child en and adolescen s [29]. The s a is ical analyses included bo h
child en and adolescen s and hey ound a sex s. anspo in e ac ion. The esul s showed a signi ican
associa ion among walke s and passi e emales (p < 0.001), simila o he esul s in he cu en s udy.
In he s anding long jump es , No wegian walke s and passi e gi ls sco ed a 117 cm and 115 cm,
espec i ely. In he cu en s udy, Spanish gi ls who we e mo e ac i e (8–10 ac i e a els/week) sco ed
In . J. En i on. Res. Public Heal h 2015, 12 10370
118 cm and had g ea e lowe body muscula i ness compa ed o he less ac i e (3–7 and 0–2 ac i e
a els/week) ha sco ed 109 cm and 106 cm, espec i ely. Resul s om he s anding i ness es showed
a simila endency in bo h s udies, al hough he di e ence in cm was much highe in he cu en s udy.
Mo e esea ch is needed o explain why his associa ion was only ound in gi ls and no in boys.
4.3. Speed-Agili y
Boys who we e mo e ac i e commu e s had g ea e speed-agili y sco es han hose who we e less
ac i e commu e s. To he bes o ou knowledge, he e is li le e idence on he associa ion be ween ac i e
commu ing o school and speed-agili y. The e we e no associa ions be ween ac i e commu ing o school
and speed-agili y among Danish adolescen s aged 15 o 19 yea s old [13]. In his s udy, he speed-agili y
was assessed wi h he 4 × 10 shu le un es , he same es used in he cu en s udy. In he 4 × 10 shu le
un es , Danish passi e and ac i e boys sco ed a 10.8 s and 10.6 s, espec i ely. In he cu en s udy,
Spanish boys who we e mo e ac i e commu e s (8–10 ac i e a els/week) sco ed 14.0 s and had g ea e
speed-agili y compa ed o he less ac i e commu e s (3–7 and 0–2 ac i e a els/week) who sco ed
14.2 s and 14.3 s, espec i ely.
The posi i e associa ion be ween ac i e commu ing and speed-agili y was only epo ed in boys and
no in gi ls. Since he e is no a clea explana ion o i , we migh specula e ha boys a e o en mo e
compe i i e han gi ls a his age. Howe e , mo e esea ch is necessa y o explain why his associa ion
was only ound in boys and no in gi ls. This es is a ma ke o speed and agili y and has been associa ed
wi h bone mass in young people [1]. Ex a gains in bone mass du ing g ow h could be c ucial o
achie ing a high peak bone mass and o p e en ing os eopo o ic ac u es la e in li e [1].
The p esen obse a ional s udy has some limi a ions, such as he s udy design. The ques ionnai e
used o assess he mode and equency o commu ing o school has no been alida ed. Howe e ,
he alidi y and eliabili y o he ques ionnai e is being s udied. The e we e no da a o pa icipa ion in
physical ac i i y and/o spo s; howe e , all s uden s pe o med wo weekly hou s o physical educa ion.
Addi ionally, he e was no in o ma ion on pa icipan s’ socio-economic s a us (SES). Fu he , he cu en
c oss-sec ional design does no allow us o explain he di ec ion o he ela ionship be ween physical
i ness and he mode o commu ing o school. The s udy was conduc ed in Janua y and his may
unde es ima e he ac i e commu ing o school due o wea he condi ions (cold and/o ain). On he o he
hand, he me hod used o es ima e home- o-school dis ance (i.e., Google Maps) may no ep esen he
ac ual ou e aken, as well as he sho dis ances in home- o-school ips, bu i could be ecommended
in o de o minimize cos . Un o una ely, we we e no able o measu e o al daily physical ac i i y o
eeding habi s, which may ha e in luenced ou esul s.
A majo s eng h o he s udy is he use o se e al physical i ness es s o measu ing di e en
componen s o i ness and he a ge ing o he associa ion be ween ac i e commu ing and physical i ness
among schoolchild en.
5. Conclusions
The p esen s udy showed ha boys and gi ls who we e mo e ac i e commu e s had g ea e
speed-agili y and lowe body muscula i ness, espec i ely, han hose boys and gi ls who we e less
ac i e commu e s. Mo e s udies a e needed o u he elucida e he complex ela ionships be ween ac i e