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Thisistheauthors’finalpeeredreviewed(postprint)versionoftheitempublishedas: Ridgers,NicolaD.,Timperio,Anna,Crawford,DavidandSalmon,Jo2012,Five‐yearchangesinschoolrecessandlunchtimeandthecontributiontochildren’sdailyphysicalactivity,Britishjournalofsportsmedicine,vol.46,no.10,pp.741‐746.
Available from Deakin Research Online: http://hdl.handle.net/10536/DRO/DU:30047133Reproducedwiththekindpermissionofthecopyrightowner.Copyright:2012,BMJGroup
1
Five-year changes in school recess and lunchtime and the contribution to children’s daily
physical activity
Nicola D. Ridgers, Anna Timperio, David Crawford, Jo Salmon
Centre for Physical Activity and Nutrition Research, Deakin University, Melbourne, Australia
Corresponding Author:
Dr Nicola Ridgers
Centre for Physical Activity and Nutrition Research
Deakin University, 221 Burwood Hwy
Burwood, 3125, Australia
Fax: 61-3-9244-6017
Email: [email protected]
2
ABSTRACT
Objective: To investigate longitudinal changes in children’s recess and lunchtime physical
activity levels and in the contribution of recess and lunchtime to daily physical activity levels
over 5-years amongst 5-6 and 10-12 year olds.
Methods: Data were drawn from two longitudinal studies that were conducted in
metropolitan Melbourne, Australia. Boys and girls (n=2782) aged 5-6 years and 11-12 years
participated in baseline (T0) measures. Physical activity (n=2490) was measured every 60-
secconds for 8 consecutive days using hip mounted accelerometry. Subsequent
measurements were taken at 3-years (T1; n=773) and 5-years (T2; n=634) follow-up.
Physical activity intensities were derived using age-adjusted cut-points. Sedentary time was
defined as 100 counts/min. Longitudinal data were analysed using 3-level (time, child,
school) multilevel analyses, stratified by sex and cohort, and adjusted for potential
confounding variables.
Results: Significant decreases in recess and lunchtime moderate and vigorous physical
activity were observed (p<0.001), with larger decreases occurring in the older cohort.
Associated increases were observed in sedentary time over time (p<0.01). While the
contribution of recess to daily moderate intensity physical activity increased in the younger
cohort over time (p<0.001), significant decreases were observed in the older cohort
(p<0.001).
Conclusion: Physical activity levels during recess and lunchtime decreased in both cohorts
over time. Decreases in the contribution of recess and lunchtime to older children’s daily
physical activity were also observed. Interventions are needed in both primary and
secondary schools to promote physical activity levels during recess and lunchtime,
particularly during the early years of secondary school.
3
INTRODUCTION
Physical activity in childhood is associated with physical and mental health.[1-2] There is
increasing concern that children are not engaging in sufficient physical activity to benefit
health[1] and that increased sedentary recreation outside of school may be a contributing
factor to obesity risk profiles, independent of physical activity levels.[3] Moreover, while
light intensity physical activity (LPA) has negative associations with metabolic risk factors,[4]
little is known how physical activity accrual changes over time. Understanding physical
activity and patterns over time is important for the design of interventions in children that
aim to benefit overall physical activity and health.
Children spend a significant proportion of their waking time in the school environment,
which explains a significant amount of variance in youth physical activity.[5] At school,
opportunities to be active are afforded by physical education classes and recess and
lunchtime breaks.[6] Of these, recess and lunchtime provide opportunities for discretionary
physical activity,[7] where children have some choice about their activities.[6, 8] Boys often
engage in more moderate-to-vigorous (MVPA) and vigorous (VPA) physical activity than girls
during recess and lunchtime,[6, 9-11] although differences between age groups and grades
are inconsistent.[9, 12] However, no studies have examined longitudinal changes in
children’s physical activity during recess and lunchtime, or whether these changes vary by
sex and age of the child. Furthermore, while recess and lunchtime can contribute up to 40%
towards daily physical activity recommendations,[12-13] little research has investigated the
overall contribution of recess and lunchtime to daily physical activity or how this may
change as children age. This is of interest, especially in light of age-related declines in daily
physical activity engagement.[14-15]
4
No research has investigated how recess and lunchtime physical activity levels and the
contribution of these periods to overall daily physical activity change during adolescence or
over the transition from primary (elementary) to secondary (high) school. Moreover, few
studies have investigated recess and lunchtime activity intensities lower than moderate
intensity (MPA).[16] Examining patterns of change over time will help understand the
interplay between the different physical activity intensities, identify potential intervention
points and inform public policy and the debate concerning the importance of recess and
lunchtime in schools.[8]
The purpose of this study is to investigate longitudinal changes in children’s recess and
lunchtime physical activity levels and the contribution of recess and lunchtime to daily
physical activity levels over 5-years amongst 5-6 and 10-12 year olds, and how these vary by
age and sex.
METHOD
Procedure
Data were drawn from two longitudinal studies of Australian school children; the Children
Living in Active Neighbourhoods Study (CLAN)[17] and the Health, Eating and Play Study
(HEAPS).[18] Ethical approval for both studies was provided by the Deakin University Human
Research Ethics Committee, the Department of Education and Training Victoria, and the
Victorian Catholic Education Office. Informed written consent was obtained from parents
and secondary school children at each wave of data collection.
5
Sample
Stratified random sampling proportionate to school size (enrolment greater than 200 pupils)
was employed to recruit schools from metropolitan Melbourne, Australia, into both studies.
Nineteen (10 low socioeconomic status [SES], 9 high SES) and 24 (9 high SES, 7 middle SES, 8
low SES) elementary schools selected agreed to participate in the CLAN and HEAPS studies,
respectively. In both studies, all children in Grade Prep (5-6 years) and Grades 5-6 (10-12
years) were invited to participate. In CLAN, 1220 children (38.3% response rate) provided
active consent to participate at baseline (2001; T0). In HEAPS, 1562 children (42% response
rate) provided consent to participate in baseline measures (2002/2003; T0). Families who
were willing to be contacted about future research were invited to participate in follow-up
measures in 2004 and 2006 for CLAN (T1 and T2), and in 2006 and 2008 for HEAPS (T1 and
T2).
Measures
In both studies, questions about demographic characteristics were included in a survey sent
home with the child and were completed by 2689 parents. In addition, 2490 children had
their physical activity measured by accelerometry. At baseline, complete accelerometer
data (based on the inclusion criteria) were collected from 2075 children. At T1 and T2
complete accelerometer were collected from 773 children (88.9% children monitored at T1)
and 634 children (90.2% children monitored at T2), respectively.
6
Physical activity
Children’s physical activity levels were measured for eight consecutive days at each time
point using hip-mounted uni-axial accelerometers (Actigraph model 7164, Fort Walton
Beach, Florida, USA). The epoch length was 60 seconds. Children were instructed to wear
the accelerometer during all waking hours except during water-based activities (e.g.
swimming, bathing). Accelerometers have been validated for use in paediatric populations
and are accepted as an effective objective field-based measurement tool for physical
activity.[19-20]
Break period duration
School bell times were recorded by the schools and used to determine recess and lunchtime
breaks.
Demographic data
At baseline, a questionnaire was completed by the children’s parents that collected
demographic information about the child (e.g. sex, age, date of birth) and the family as a
whole (e.g. maternal education, employment status, marital status). The self-reported
highest level of maternal education was used as a proxy-measure of SES, consistent with
previous studies,[21-22] and was classed as low (some high school attendance or less),
medium (high school or trade certificate completed) and high (tertiary education).
7
Data management
Accelerometer data were downloaded and data recorded on the first day discarded. Only
weekday data were examined here. Non-wear time was defined as sustained 20-minutes
periods of zero counts, and total duration of these periods represented the duration the
total non-wear duration.[23] For a day to be considered valid, children were required to
have produced counts for 610 minutes (T0), 646 minutes (T1) and 633 minutes (T2),
representing non-missing counts for at least 80% of a standard measurement day, defined
as the length of time that at least 70% of the sample wore the monitor,[23] and to have
produced counts for at least 50% of both recess and lunchtime. Children who provided valid
recess, lunchtime and daily physical activity data on at least three weekdays were retained
for further analysis.
Age-specific cut-points [24] determined durations of light activity (LPA; 1.5 -3.99 METS),
MPA (4-5.99 METS),[25] and VPA (>6.0 METS). Sedentary time was defined as <100
counts/minute.[26] The average duration (minutes) of sedentary, LPA, MPA and VPA per
valid day was determined. The average accelerometer wear time per valid day was also
calculated. The percentage of time children engaged in sedentary, LPA, MPA and VPA during
recess and lunchtime were determined for days that met inclusion criteria. The relative
contribution of recess and lunchtime to daily weekday physical activity was calculated as a
proportion using ((time in activity intensity/total time in activity intensity during the school
day)*100), and averaged over valid days.
Statistical analysis
8
Descriptive analyses were initially calculated for all measured variables. Initial analyses were
conducted to investigate whether differences occurred between children who provided 3, 4
and 5 days of data for use in the analyses. As children with five valid days engaged in more
sedentary activity and less MPA and VPA than children with 3 or 4 days of data at each time
point, analyses adjusted for number of valid days.
Multilevel analyses were used to examine changes in children’s recess and lunchtime
physical activity over time, and the contribution of recess and lunchtime to daily physical
activity. Multilevel models are the most appropriate technique for analysing nested data
that are not independent of each other (e.g. time points within children) and violate the
assumption of independent observations.[27-28] Multilevel modelling is robust against
missing data points, and can estimate effects over time using incomplete data sets.[29] As
such, all data collected were included in the analyses.
A three-level model was used in the analyses, namely the measurement time point (T0, T1,
T2; Level 1), children (Level 2) and baseline school (Level 3). To estimate changes in activity,
and the contribution of recess and lunchtime to daily physical activity, two dummy predictor
variables were generated. These were for physical activity levels at T1 and T2 compared to
T0. The random structure considered random intercepts and random slopes on T1 and T2.
Potential confounding variables were also added to the model as these may influence the
magnitude of any differences observed.[28] These variables included sex, maternal
education, study, number of valid days of accelerometry, daily accelerometer wear time and
the break period duration (recess or lunchtime). Analyses were stratified by cohort,
9
therefore the younger cohort analyses indicate changes across primary school, while the
older cohort analyses document the transition from primary school into secondary school.
Analyses were conducted with the percentage of recess and lunchtime spent in sedentary,
LPA, MPA and VPA, and the contribution of break periods to daily MPA and VPA as the
dependent variables. Separate analyses were conducted for recess and lunchtime.
To examine differences between boys and girls on the dependent variables, potential effect
modification was assessed by constructing interaction terms between sex and the T1 and T2
dummy variables. Subgroup analyses were conducted in the event of significant
interactions. The Wald Statistic was used to assess the significance of the regression
coefficients.[28] Statistical significance was set at p<0.05 and p<0.1 for interaction
terms.[28] Data were analysed using MLwiN 1.10 software (Institute of Education,
University of London, UK).
RESULTS
At T0, most families reported speaking English at home (89.3%). Approximately a third
(38.9%) of mothers reported full-time employment, while 19.7% reported being employed
part-time. Based on maternal education, 37.1% were of medium SES and 34.6% were of high
SES. Average recess and lunchtime durations were 27.2 ± 5.5 and 55.9 ± 6.7 minutes (T0),
25.1 ± 6.3 and 53.4 ± 8.2 minutes (T1), and 24.8 ± 6.2 and 56.4 ± 13.9 minutes (T2),
respectively. There were no differences in physical activity between those with follow-up
data and those without, although those followed up had significantly higher maternal
10
education (43% vs. 32%) and higher proportions were employed part-time employment
(26% vs. 17%), and spoke English at home (96 % vs. 4%).
The physical activity levels of the children at baseline (mean, SD) are displayed in Table 1.
The proportion of time spent sedentary or engaged in physical activity were similar across
recess and lunchtime for all groups.
Table 1: Children's physical activity levels at baseline by age group and sex (T0)
Younger Girls(a)
(n = 300)
Younger Boys(a)
(n = 315)
Older Girls(b)
(n = 796)
Older Boys(b)
(n = 664)
Recess
%Sedentary 16.7 (12.7) 13.8 (13.5) 25.0 (14.4) 19.8 (15.0)
%LPA 47.1 (11.3) 40.3 (14.3) 51.2 (12.5) 49.8 (14.1)
%MPA 23.8 (10.6) 26.0 (10.9) 14.0 (8.5) 19.7 (10.2)
%VPA 12.3 (10.3) 19.9 (14.6) 9.8 (6.9) 10.7 (10.9)
Lunchtime
%Sedentary 14.9 (11.1) 13.3 (10.2) 23.2 (13.3) 18.4 (13.9)
%LPA 46.5 (10.5) 41.2 (11.4) 52.2 (10.4) 48.9 (11.9)
%MPA 26.3 (9.9) 27.5 (9.3) 15.4 (7.9) 21.5 (10.3)
%VPA 12.3 (8.6) 18.0 (11.5) 9.2 (6.1) 11.2 (9.8)
Daily MPA (min) 97.7 (22.3) 106.6 (22.1) 47.9 (16.1) 62.6 (17.7)
Daily VPA (min) 39.7 (16.9) 52.9 (22.9) 18.8 (13.6) 28.9 (17.1)
Daily MVPA (min) 137.4 (34.7) 159.5 (37.9) 66.7 (26.2) 91.5 (30.7)
11
Daily wear time (min) 751.9 (77.5) 754.0 (65.5) 806.9 (79.7) 813.2 (84.0)
a5-6 years at baseline; b10-12 years at baseline
12
Changes in recess and lunchtime physical activity over time
Potential effect modification analyses revealed significant interaction terms between sex
and the time variables for all physical activity intensities for recess and lunchtime, and for
the relative contribution of recess and lunchtime to daily physical activity levels. The results
presented in Tables 2 and 3, therefore, are stratified by gender.
Statistically significant T1 effects were found for boys and girls in both the younger and
older cohorts for all recess and lunchtime physical activity intensities, with the exception of
girls’ LPA (younger and older cohort) during recess and lunchtime and MPA (younger cohort)
during recess and lunchtime (Table 2; p>0.05). For example, the proportion of time spent
sedentary during recess between T0 and T1 increased between 5.6-7.1% for younger
children and 22.6-25.2% for older children, with similar increases observed during
lunchtime. In contrast, recess VPA decreased 5.4-5.9% for younger children and 4.2-8% for
older children between T0 and T1, with similar decreases observed during lunchtime.
Significant decreases in LPA, MPA and VPA between T0 and T1 were observed for both boys
and girls in older cohort.
A similar pattern was observed for the T2 analyses. In the younger cohort, significant
increases in sedentary time and LPA and significant decreases in MPA and VPA were found
for boys and girls during recess and lunchtime, with the exception of boys’ LPA during
recess. For the older cohort, significant increases in sedentary time and significant decreases
in LPA, MPA and VPA were found between T0 and T2 (Table 2).
13
Tabl
e 2:
Ave
rage
cha
nges
in re
cess
and
lunc
htim
e ph
ysic
al a
ctiv
ity o
ver 3
yea
rs (T
0 to
T1)
and
5 y
ears
(T0
to T
2) b
y se
x an
d ag
e gr
oup.
Yo
unge
r Coh
ort
Old
er C
ohor
t
Boys
Rece
ss
%Se
dent
ary
7.05
(2.9
2 to
12.
09)*
* 18
.60
(13.
25 to
23.
68)*
**
25.2
3 (1
9.83
to 3
0.63
)***
27
.58
(24.
17 to
30.
99)*
**
%LP
A 5.
57 (2
.57
to 8
.57)
***
3.07
(-0.
35 to
6.5
0)
-11.
22 (-
15.0
4 to
-7.4
0)**
* -1
2.65
(-15
.42
to -9
.88)
***
%M
PA
-6.1
1 (-8
.97
to -3
.24)
***
-12.
47 (-
15.6
8 to
-9.2
8)**
* -8
.49
(-10.
47 to
-6.5
2)**
* -1
0.35
(-12
.04
to -8
.65)
***
%VP
A -5
.93
(-8.8
8 to
-2.9
8)**
* -9
.08
(-11.
84 to
-6.3
2)**
* -4
.19
(-5.0
8 to
-3.2
9)**
* -4
.49
(-5.4
9 to
-3.4
8)**
*
Lunc
htim
e
%Se
dent
ary
7.64
(3.9
3 to
11.
34)*
**
16.0
5 (1
2.21
to 1
9.88
)***
23
.14
(19.
09 to
27.
14)*
**
32.1
6 (2
8.98
to 3
5.33
)***
%LP
A 5.
29 (2
.65
to 7
.94)
***
5.75
(2.6
6 to
8.8
3)**
* -9
.24
(-11.
72 to
-6.7
6)**
* -1
5.88
(-18
.08
to -1
3.69
)***
%M
PA
-7.2
9 (-9
.64
to -4
.94)
***
-12.
74 (-
15.5
8 to
-9.9
0)**
* -8
.50
(-9.6
3 to
-7.3
6)**
* -1
0.96
(-12
.21
to -9
.70)
***
%VP
A -5
.35
(-7.7
9 to
-2.9
1)**
* -9
.04
(-11.
19 to
-6.8
9)**
* -4
.53
(-5.4
1 to
-3.6
4)**
* -5
.24
(-6.2
2 to
-4.2
6)**
*
Girl
s
14
Rece
ss
%Se
dent
ary
5.64
(1.1
2 to
10.
15)*
8.
30 (3
.22
to 1
3.37
)**
22.6
1 (1
7.14
to 2
8.08
)***
26
.61
(22.
98 to
30.
23)*
**
%LP
A 1.
35 (-
1.56
to 4
.26)
9.
86 (6
.44
to 1
3.29
)***
-1
.85
(-5.7
7 to
2.0
7)
-4.6
5 (-7
.67
to -1
.64)
**
%M
PA
-1.4
1 (-4
.22
to 1
.41)
-5
.16
(-8.3
5 to
-1.9
8)**
-1
0.63
(-12
.68
to -8
.58)
***
-12.
44 (-
14.2
8 to
-10.
59)*
**
%VP
A -5
.36
(-8.2
6 to
-2.4
6)**
* -1
2.20
(-15
.73
to -1
0.21
)***
-7
.96
(-8.9
7 to
-6.9
6)**
* -9
.31
(-10.
47 to
-8.1
5)**
*
Lunc
htim
e
%Se
dent
ary
4.09
(0.4
4 to
7.3
3)*
8.27
(4.5
9 to
12.
24)*
**
17.6
3 (1
3.52
to 2
1.72
)***
23
.97
(20.
62 to
27.
32)*
**
%LP
A 0.
93 (-
1.64
to 3
.51)
7.
58 (4
.50
to 1
0.66
)***
-0
.19
(-2.7
7 to
2.3
9)
-2.6
3 (-5
.03
to -0
.23)
*
%M
PA
-1.7
8 (-4
.08
to 0
.52)
-4
.88
(-7.7
1 to
-2.0
5)**
* -9
.66
(-10.
91 to
-8.4
0)**
* -1
1.76
(-13
.20
to -1
0.31
)**
%VP
A -3
.02
(-5.4
1 to
-0.6
3)*
-11.
10 (-
13.2
3 to
-8.9
8)**
* -6
.36
(-7.3
5 to
-5.3
8)**
* -9
.03
(-10.
16 to
-7.9
6)**
*
***p
< 0
.001
, **p
< 0
.01,
*p<
0.05
. CI =
Con
fiden
ce in
terv
als.
The
val
ue re
flect
s the
per
cent
age
chan
ge in
chi
ldre
n’s a
ctiv
ity le
vels
durin
g re
cess
and
lunc
h be
twee
n Ye
ar 1
(T0)
and
Yea
r 3 (T
1) a
nd Y
ear 1
(T0)
and
Yea
r
5 (T
2). A
pos
itive
v
alue
refle
cts a
n in
crea
se in
chi
ldre
n’s p
hysic
al a
ctiv
ity le
vels
durin
g re
cess
or l
unch
time
at e
ither
T1
or T
2 co
mpa
red
to T
0, w
hilst
a
nega
tive
val
ue re
flect
s a d
ecre
ase
rece
ss o
r lun
chtim
e ph
ysic
al a
ctiv
ity. A
ll m
odel
s are
adj
uste
d fo
r sex
, stu
dy, m
ater
nal e
duca
tion,
num
ber o
f val
id d
ays,
daily
wea
r tim
e an
d br
eak
perio
d du
ratio
n.
15
Tabl
e 3:
Ave
rage
cha
nge
in th
e co
ntrib
utio
n of
rece
ss a
nd lu
ncht
ime
to d
aily
phy
sica
l act
ivity
ove
r 3 y
ears
(T0
to T
1) a
nd 5
yea
rs (T
0 to
T2)
by
sex
and
age
grou
p.
Yo
unge
r Coh
ort
Old
er C
ohor
t
Rece
ss
Ove
rall
%M
PA
2.36
(1.3
8 to
3.3
3)**
* 2.
54 (1
.24
to 3
.84)
***
-3.5
3 (-4
.57
to -2
.45)
***
-2.8
2 (-3
.86
to -1
.78)
***
%VP
A 0.
83 (-
0.92
to 2
.59)
-0
.05
(-2.4
1 to
2.3
2)
-5.4
6 (-6
.79
to -4
.13)
***
-6.6
8 (-8
.03
to -5
.32)
***
Boys
%M
PA
1.97
(0.8
8 to
3.0
7)**
* 1.
57 (0
.20
to 2
.94)
* -3
.47
(-4.5
9 to
-2.3
4)**
* -3
.15
(-4.2
8 to
-2.0
2)**
*
%VP
A -0
.07
(-2.0
5 to
1.9
1)
-0.9
3 (-3
.13
to 1
.27)
-4
.68
(-6.1
5 to
-3.2
2)**
* -5
.93
(-7.4
4 to
-4.4
2)**
*
Girl
s
%M
PA
2.70
(1.6
3 to
3.7
8)**
* 3.
50 (2
.13
to 4
.87)
***
-3.6
1 (-4
.76
to -2
.45)
***
-2.4
3 (-3
.61
to -1
.25)
***
%VP
A 1.
53 (-
0.42
to 3
.46)
0.
80 (-
1.40
to 3
.01)
-6
.42
(-7.9
6 to
-4.8
7)**
* -7
.70
(-9.3
4 to
-6.0
5)**
*
Lunc
htim
e
16
Ove
rall
%M
PA
3.97
(2.5
6 to
5.3
8)**
* 3.
82 (1
.86
to 5
.78)
***
-6.7
6 (-8
.68
to -4
.84)
***
-7.5
8 (-9
.57
to -5
.58)
***
%VP
A 2.
19 (-
0.05
to 4
.43)
0.
14 (-
2.38
to 2
.66)
-9
.13
(-11.
71 to
-6.5
4)**
* -1
3.00
(-15
.67
to -1
0.33
)***
Boys
%M
PA
2.83
(1.1
3 to
4.4
2)**
* 1.
97 (-
0.11
to 4
.05)
-7
.39
(-9.4
6 to
-5.3
3)**
* -8
.95
(-11.
07 to
-6.8
2)**
*
%VP
A 1.
11 (-
1.44
to 3
.66)
-0
.38
(-3.2
4 to
2.4
9)
-9.8
2 (-1
2.66
to -6
.99)
***
-14.
23 (-
17.2
0 to
-11.
26)*
**
Girl
s
%M
PA
4.98
(3.2
6 to
6.7
1)**
* 5.
60 (3
.52
to 7
.67)
***
-6.0
2 (-8
.14
to -3
.91)
***
-5.8
8(-8
.09
to -3
.66)
***
%VP
A 4.
20 (1
.71
to 6
.70)
***
1.45
(-1.
39 to
4.3
0)
-8.2
8 (-1
1.22
to 5
.33)
***
-11.
43 (-
14.5
8 to
-8.2
7)**
*
***p
< 0
.001
, **p
< 0
.01,
*p<
0.05
. CI =
Con
fiden
ce in
terv
als.
The
val
ue re
flect
s the
per
cent
age
chan
ge in
the
cont
ribut
ion
of re
cess
and
lunc
htim
e to
chi
ldre
n’s d
aily
phy
sical
act
ivity
leve
ls be
twee
n Ye
ar 1
(T0)
and
Year
3 (T
1) a
nd Y
ear 1
(T0)
and
Yea
r 5 (T
2). A
pos
itive
v
alue
refle
cts a
n in
crea
se in
the
cont
ribut
ion
of re
cess
or l
unch
time
to c
hild
ren’
s dai
ly p
hysic
al
activ
ity a
t eith
er T
1 or
T2
com
pare
d to
T0,
whi
lst a
neg
ativ
e v
alue
refle
cts a
dec
reas
e in
the
cont
ribut
ion
of re
cess
or l
unch
time
to c
hild
ren’
s dai
ly p
hysic
al
activ
ity. A
ll m
odel
s are
adj
uste
d fo
r sex
, stu
dy, m
ater
nal e
duca
tion,
num
ber o
f val
id d
ays,
dai
ly w
ear t
ime
and
brea
k pe
riod
dura
tion.
17
Contribution of recess and lunchtime to daily physical activity
Younger children engaged in 68.4 (± 18.4) minutes and 31.0 (± 19.9) minutes of daily MPA
and VPA at T1, and in 51.4 (± 19.1) minutes and 17.1 (13.9) minutes of daily MPA and VPA at
T2, respectively. Older children engaged in 37.8 (± 16.3) minutes and 12.8 (± 11.5) minutes
of daily MPA and VPA at T1, and in 28.1 (± 14.5) minutes and 6.3 (± 6.1) minutes of daily
MPA and VPA at T2, respectively. The relative contribution of recess and lunchtime to
children’s weekday physical activity levels are shown in Figure 1. The results of the
multilevel analysis are shown in Table 3. In the younger cohort, the multilevel analyses
revealed significant increases in the contribution of recess and lunchtime to boys’ and girls’
daily MPA between T0 and T1 and between T0 and T2. A significant increase in the
contribution of lunchtime to girls’ daily VPA was also observed between T0 and T1. In the
older cohort, significant decreases were observed in the contribution of recess and
lunchtime to boys’ and girls’ daily MPA and VPA between T0 and T1 and T0 to T2.
[Insert Figure 1 here]
DISCUSSION
This study examined changes in children’s recess and lunchtime physical activity levels and
the contribution of recess and lunchtime to children’s daily physical activity levels in two age
groups over a 5-year period. There were increases in boys’ and girls’ sedentary time and
decreases in MPA and VPA in recess and lunchtime in both cohorts, supporting previous
studies that reported age-related declines in daily physical activity levels[14, 30] and the
notion that declines in daily physical activity start at a young age.[14]
18
The decreases in MPA and VPA observed after 3 years (T1) in the younger cohort are, in
general, lower than short-term observations in control children in European-based
intervention studies. For example, after a 3-month period in Belgium, girls’ MPA and VPA
decreased by 11.5% and 7.1% during recess and 9.9% and 5.3% during lunchtime,
respectively, while decreases were observed in boys’ recess MPA (1%) and VPA (2.6%) and
lunchtime VPA (5.6%).[16] Similarly, in the UK, decreases of 6.5% in control children’s
MVPA two months after baseline measures were reported,[31] which coincided with the
sample moving up one school year. Collectively, these findings suggest that physical activity
levels during recess and lunchtime decrease in both the short- and long-term. As such,
research is needed to identify factors that explain these decreases.
Despite declines in the younger children’s activity levels during recess and lunchtime over
time, the contribution of recess and lunchtime to daily physical activity generally increased
over 3 years (T1), and decreases were mainly observed in VPA after 5 years (T2).
Interestingly, while physical activity decreased during recess and lunchtime, overall daily
physical activity also decreased, but at a greater magnitude, during other parts of the day.
Notably, the contribution to recess and lunchtime to daily physical activity in the younger
cohort at each time point was greater than in previous studies that used objective
measures.[12, 32-33] The present data suggest that recess and lunchtime provide an
important and salient contribution to daily activity levels for Australian primary school
children.
The largest decreases in MPA and VPA and increases in sedentary time were observed in the
older cohort between baseline (T0) and 3 years (T1), coinciding with the transition between
19
primary and secondary school. Early adolescence marks a shift from active play behaviours
to social behaviours,[30] characterised by low physical activity levels. The present study
somewhat supports this, particularly as sedentary time increased between baseline and the
5-year follow-up. This may be explained further by the secondary school physical
environment and the availability of different spaces and equipment for use during recess
and lunch. However, there is currently a dearth of literature that investigates the activity
preferences and behaviours of adolescents during recess and lunchtime. A recent review
stated that research into adolescents’ physical activity levels and behaviour during recess
and lunchtime is needed.[8] While that review excluded intervention studies that specially
targeted MVPA and mainly focusing on the developmental value of recess, no
developmental and health benefits of recess on adolescents was reported suggesting a lack
of data in this area.
Large decreases in the contribution of recess and lunchtime to daily physical activity were
noted over time in the older cohort. However, after 5 years (T2), lunchtime still contributed
10.7% and 6.6% towards daily MPA and VPA, respectively. These data suggest that recess
and lunchtime do contribute a small amount to adolescents’ daily physical activity levels,
and that interventions to increase physical activity and decrease sedentary behaviour during
recess and lunchtime at secondary schools are warranted. To date, there has been no such
published intervention studies in secondary schools. While research is needed to examine
what types of recess (e.g. structured versus unstructured) would be beneficial,[8] such
school-based interventions would be attractive from a public health perspective, particularly
as they would not be competing with screen-based sedentary leisure time activities that
become increasing prevalent in older adolescents outside the school environment.[30, 34]
20
Research is needed to identify what activities adolescents enjoy participating in during
recess and lunchtime, and whether these can be incorporated into the design of
interventions that aim to increase physical activity during these time periods.[35] Based on
the current results, researchers and practitioners should consider using sex and age-
appropriate activities if these discrete periods are to provide opportunities to engage in
physical activity at school.
To the best of our knowledge, this is the first study to investigate changes in recess and
lunchtime physical activity and the contribution of these discrete time periods to daily
physical activity levels as children age. Strengths of this study include measuring a large
population of children over a substantial length of time in two age groups. There are,
however, several limitations. Firstly, data were collected using 60-s epochs, which may
underestimate VPA in children due to the sporadic nature of their physical activity
behaviours.[36] Second, it is not known whether different year groups had their recess and
lunchtime periods together or separately in the different schools. It is possible that this may
influence activity due to the number of children on the playground at one time, which
affects the amount of space children have to engage in different activities. Lastly,
accelerometers do not provide behavioural information, so it is not known what activities
the children engaged in, which could be important for informing the development of future
interventions.
CONCLUSION
21
Understanding patterns of physical activity in discrete time periods of the day provides an
opportunity to inform future intervention development. In this study, physical activity levels
during recess and lunchtime decreased in both groups over time, particularly during the
transition from primary to secondary school. Interventions are needed in both primary and
secondary schools to contribute to overall physical activity levels. Further research is
needed to examine behaviours during recess and lunchtime, and determine how these
change and influence physical activity over time.
WHAT IS KNOWN ON THIS TOPIC
School recess and lunchtime provide daily opportunities for children to engage in physical
activity. Boys engage in more physical activity during recess and lunchtime than girls. Little is
known concerning how children’s recess and lunchtime and their contribution to daily
physical activity change longitudinally.
WHAT THIS STUDY ADDS
Physical activity levels during recess and lunchtime and their contribution to daily physical
activity decrease over time, with larger decreases associated with the transition from
primary to secondary school. Strategies for increasing recess and lunchtime physical activity,
particularly in adolescents, warrant attention.
ACKNOWLEDGEMENTS
22
We gratefully acknowledge the contribution of all project staff, especially Dr. Michelle
Jackson, Dr. Amanda Telford, Sophie Thal-Janssen and Anna Stzendur for the collection of
data in both studies, and Eoin O’Connell for the analysis of the raw data.
COMPETING INTERESTS
The authors declare that they have no competing interests.
FUNDING
NR is supported by an Alfred Deakin Postdoctoral Research Fellowship. AT and DC are
supported by VicHealth Public Health Research Fellowships. JS is supported by a National
Heart Foundation of Australia and sanofi-aventis Career Development Award. Data
collection for HEAPS was funded by the Victorian Health Promotion Foundation (baseline)
and Australian Research Council (follow-ups; ID DP 0664206) and for CLAN by the Financial
Markets Foundation for Children (baseline) and the National Health and Medical Research
Council (follow-ups; ID 274309).
COPYRIGHT STATEMENT
The Corresponding Author has the right to grant on behalf of all authors and does grant on
behalf of all authors, an exclusive licence (or non-exclusive for government employees) on a
worldwide basis to the BMJ Publishing Group Ltd and its Licensees to permit this article (if
accepted) to be published in British Journal of Sports Medicine and any other BMJPGL
products to exploit all subsidiary rights, as set out in our licence
(http://group.bmj.com/products/journals/instructions-for-authors/co_owned_licence.pdf).
23
FIGURE CAPTION
Figure 1: Contribution of recess and lunch to children’s school day physical activity at (a)
baseline (T0), (b) follow-up 1 (T1) and (c) follow-up 2 (T2). Data are unadjusted means.
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