Interventions to Increase Physical Activity in Middle-Age Women at the Workplace

“Interventions to Increase Physical Activity in Children Aged 2-5 Years: A Systematic Review”

by Ling J, Robbins LB, Wen F, Peng W

Pediatric Exercise Science

© 2015 Human Kinetics, Inc.

Note. This article will be published in a forthcoming issue of the

Pediatric Exercise Science. The article appears here in its accepted,

peer-reviewed form, as it was provided by the submitting author. It has

not been copyedited, proofread, or formatted by the publisher.

Section: Review

Article Title: Interventions to Increase Physical Activity in Children Aged 2-5 Years: A

Systematic Review

Authors: Jiying Ling1, Lorraine B. Robbins1, Fujun Wen2, and Wei Peng3

Affiliations: 1College of Nursing; 2Department of Kinesiology; 3Department of

Telecommunication, Information Studies, and Media; Michigan State University, East Lansing,

MI.

Journal: Pediatric Exercise Science

Acceptance Date: February 2, 2015

©2015 Human Kinetics, Inc.

DOI: http://dx.doi.org/10.1123/pes.2014-0148

http://dx.doi.org/10.1123/pes.2014-0148





Interventions to Increase Physical Activity in Children Aged 2-5 Years:

A Systematic Review

Jiying Ling

Michigan State University College of Nursing

Lorraine B. Robbins

Michigan State University College of Nursing

Fujun Wen

Michigan State University Department of Kinesiology

Wei Peng

Michigan State University Department of Telecommunication, Information Studies, and Media

Ling and Robbins are with the College of Nursing, Wen is with the Department of Kinesiology,

and Peng is with the Department of Media and Information, Michigan State University, East

Lansing, MI. Address author correspondence to Jiying Ling at [email protected].

mailto:[email protected]





Abstract

Comprehensive evaluation of prior interventions designed to increase preschoolers’ physical

activity is lacking. This systematic review aimed to examine the effect of interventions on

objectively measured physical activity in children aged 2-5 years. We followed the Preferred

Reporting Items for Systematic Reviews and Meta-Analyses statement. In May 2014, we

searched PubMed, CINAHL, PsycINFO, ERIC, SPORTDiscus, Cochrane, and Embase. Two

reviewers independently identified and appraised the studies. Twenty-four articles describing 23

independent studies and 20 unique interventions met inclusion criteria. Of the eight interventions

resulting in a significant effect in objectively measured physical activity, all were center-based

and included a structured physical activity component, six included multiple components, five

integrated theories or models, and four actively involved parents. Seven of the eight were

randomized controlled trials. Due to the heterogeneity of the study designs, physical activity

measures, and interventions, drawing definitive conclusions was difficult. Although the overall

intervention effect was less than optimal, the review indicated that theory-driven, multi-

component interventions including a structured physical activity component and targeting both

parents and their children may be a promising approach for increasing preschoolers’ physical

activity and warrant continued investigation using rigorous designs to identify those that are

most effective.

Keywords: review, exercise, preschool, program evaluation





From 1990 to 2010, the worldwide prevalence of overweight and obesity among

preschool children has increased from 4.2% to 6.7%, and is expected to reach 9.1% by 2020 (20).

In the U.S., 22.8% of children, aged 2-5 years, are overweight or obese (50). Children who are

overweight at age 5 are 4 times as likely as those of the same age with a healthy weight to

become obese in either later childhood or adolescence (17). These alarming findings indicate that

excess body weight early in a child’s life may be strongly correlated with subsequent obesity

risks. Children who participate in a physical activity (PA) and nutrition intervention at an earlier

age (< 5 years) have greater weight loss over 2 years than those who participate in the same

intervention at an older age (> 5 years) (15). Therefore, intervening before the start of elementary

school holds promise in reversing the current epidemic of childhood obesity.

PA is protective against obesity during the preschool years (57) and is essential for

children’s physical, cognitive, social, and emotional development at all ages (28). Children aged

3-5 years who are inactive are 3.8 times more likely to gain subcutaneous fat than those who are

active (43). Preschoolers’ accelerometer-measured vigorous PA is significantly associated with

their lower odds of being overweight (40). A recently conducted systematic review indicates that

a high level of PA not only reduces adiposity, but also improves motor skill development and

psychosocial and cardiovascular health in children aged 0-4 years (68). These studies support

that important health benefits are accrued from PA.

Although PA guidelines have been developed in several countries, the amount of daily

PA recommended is inconsistent. Recommendations in Australia and the United Kingdom

indicate that preschool children should participate in at least 3 hours of PA every day, including

light, moderate, and vigorous PA (62). The U.S. National Association for Sport and Physical

Education (NASPE) (45) guidelines call for 120 minutes of daily PA. Moreover, the U.S.





Institute of Medicine (IOM) (35) recommends that preschool children should participate in 15 or

more minutes of PA per hour, approximately 3 hours per day. Based on accelerometer data,

preschool children actually participate in an average of 43 minutes of moderate to vigorous PA

(MVPA) daily (13). Regardless of the guideline discrepancies, the majority of preschool children

worldwide do not meet current PA recommendations (58, 62, 69).

Conducting interventions during early childhood may be a promising approach for

assisting children to establish a positive behavioral pattern that has the potential to continue into

adulthood (66). Although many interventions have been conducted to increase PA in preschool

children, current information on their overall impact, especially factors influencing the

intervention effect, is lacking. Two systematic reviews only focus on PA interventions conducted

in childcare center-based settings including daycare or childcare center, preschool, and nursery

(39, 70). One meta-analysis, including studies conducted before 2012, examined the effect of PA

interventions in preschool children (30). Although childcare center-based settings provide an

excellent location for PA interventions, examining interventions conducted at home or other

community settings (e.g., church, park, outpatient clinic, or hospital) is also essential to acquire

information for targeting children’s home and community environment. In all three reviews, PA

was operationally defined and measured in a variety of ways including proxy reports. Due to the

limited reliability and validity of proxy reports of PA (54), results of the three reviews may be

questionable.

Previous reviews focusing on identifying factors influencing the intervention effect have

yielded somewhat contradictory findings. One review of 19 studies conducted in childcare

center-based settings indicated that regular structured PA programs had a beneficial effect in

increasing PA among preschoolers (70). In contrary, a meta-analysis of 15 studies showed that





short-term (< 4 weeks), teacher-led PA programs including outdoor activity and unstructured PA

were most effective (30). Finally, another review that included 23 studies conducted in childcare

center-based settings noted no effect of theory-based, multi-component interventions (39). The

inconsistent findings, possibly due to the heterogeneity of the included studies, limit the ability to

draw conclusions regarding factors that influence the intervention effect.

This paper adds to the existing body of knowledge by conducting a systematic review of

all relevant PA intervention studies up to May 2014 that involve preschool-age children and

include an objective measure of PA, such as pedometers and accelerometers. To efficiently

inform future research efforts directed toward preventing obesity among older children and

adolescents, effective and sustainable interventions and strategies targeting PA in preschool-age

children need to be identified. Less biased than a narrative review, a systematic review can assist

with achieving this objective by offering a rigorous and comprehensive examination of all

studies addressing a specific topic (26), such as PA interventions among preschoolers.

Objective

The aim was to examine the effect of interventions on objectively measured PA in

children of preschool age. In this study, preschoolers represent children aged 2-5 years. Research

questions were:

(a) What types of interventions have been conducted to increase objectively measured PA

in preschoolers?

(b) What is the overall effect of previously conducted interventions on objectively

measured PA?

(c) What factors may influence the effect of interventions on objectively measured PA?





Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA)

statement guided the literature search, conduct of the systematic review, and report of the

findings (42). The PRISMA statement, including a 27-item checklist and a 4-phase flow diagram,

specifies ways to ensure transparent and complete reporting of a review. The checklist addresses

the content to be included in each section of the review, including title, abstract, introduction,

methods, results, discussion, and funding. The flow diagram helps depict the number of records

identified, included, and excluded; and reasons for exclusion. Due to the need for a

comprehensive representation of evidence in the review, both randomized and non-randomized

quantitative studies incorporating a control or comparison group were analyzed (16).

Data Sources and Search Strategy

Assisted by a master-prepared university health science librarian, the first author

developed the initial search strategy to determine the general quantity and quality of published

studies testing PA interventions in children aged 2-5 years old in the PubMed database (from

1969). The following search terms and strategy were used: (("Motor Activity"[Mesh]) OR

("Exercise"[Mesh]) OR ("Play and Playthings"[Mesh]) OR "physical activity" OR "exercise*"

OR play*) AND (("Intervention Studies"[Mesh]) OR intervention* OR program*) Filters:

Humans; English; Preschool Child: 2-5 years. The procedure used for the PubMed database was

adapted to create a database-specific search strategy for CINAHL (from 1978), PsycINFO (from

1889), ERIC (from 1966), SPORTDiscus (from 1976), Cochrane database of systematic reviews

(from 1996), and Embase (from 1960). Because no filter or limit for age group existed in

databases of ERIC, SPORTDiscus, and Cochrane database of systematic reviews, (preschool*

OR toddler* OR child) was used to limit searching citations to children only. In May 2014, we





carried out the full electronic search for published studies dating from their inception to 2014 in

these seven databases. To identify additional studies, we also reviewed reference lists of any

relevant reviews and original studies. The objective was to ensure an exhaustive search for all

international evidence associated with all disciplines and published in English.

Eligibility Criteria

Studies were included in the review if they: (a) primarily targeted children of preschool

age (2-5 years); (b) were original studies testing an intervention to increase PA or decrease

sedentary activity in any setting; (c) included a control or comparison group; and (d) reported

objectively measured PA as an outcome variable at baseline and post-intervention. In this study,

setting referred to the location where the intervention had been implemented. Exclusion criteria

were: (a) secondary analysis; (b) abstract only; (c) protocol only; (d) review study; (e) entire

population defined by a disease or a chronic condition such as autism, asthma, or obesity; and (f)

sample size less than 30 participants.

Study Selection

After exporting citations into the Endnote reference manager software, two authors (JL

and FW) independently screened all titles and abstracts against the inclusion and exclusion

criteria. After excluding citations that did not meet the inclusion criteria, they retrieved the full

text of the retained citations. They independently conducted a second screening by reading the

full version of each article and assessing whether or not the retained articles met the inclusion

criteria. They compared their findings and resolved any disagreement through discussion or, if

necessary, consultation with the second author (LR).





Data Extraction

To simplify the analysis of each study, the first author developed a data extraction form

based on the Consolidated Standards of Reporting Trials (CONSORT) checklist (61). Details

about each study’s sample and setting, design, intervention, PA measure, and results were

extracted by the first author. All authors independently checked the extractions against the full

text for accuracy. Any discrepancies were discussed until all authors reached agreement.

Quality Appraisal and Risk of Bias

Each study was appraised based on the criteria adapted from the Cochrane Handbook for

Systematic Reviews of Interventions (33). Two authors (JL and LR) independently evaluated

each study and discussed any discrepancies until they agreed regarding the outcome. Risk of bias

(yes: low risk of bias, no: high risk of bias, and unclear: insufficient information) was evaluated

based on the following four quality indicators: (a) random sequence generation; (b) blinding of

PA outcome assessment; (c) valid PA measure (≥ 3 days of data) (1); and (d) clear explanation of

withdrawal. Only studies with no high risk of bias for all four indicators were considered low

risk of bias.

Data Synthesis

Examination of the included studies indicated substantial heterogeneity of the designs,

outcome measures, and intervention components. Therefore, a narrative summary technique

rather than a meta-analysis was used to report the findings according to the three research

questions.





Results

Study Selection

A total of 11,559 citations were identified from the database searches and reference lists.

After screening titles and abstracts and removing duplicates, 191 articles were retained. The

second screening based on reading the full text yielded 24 articles focusing on increasing

objectively measured PA in children aged 2-5 years old. Two articles described the same study,

resulting in 23 independent studies; and four articles described one intervention but different

studies, resulting in 20 unique interventions. Figure 1 presents the flow diagram depicting study

selection results. Table 1 summarizes the 23 independent studies included in the review.

Risk of Bias

Table 2 presents the assessment of risk of bias for the 23 independent studies based on

the four quality indicators: random sequence generation, blinding of PA outcome assessment,

valid PA measure, and clear explanation of withdrawal. Several studies failed to provide details

to allow us to assess risk of bias, particularly concerning the random sequence generation

method (n = 16) and blinding of outcome assessment (n = 9). Only six studies clearly reported

the random sequence generation method including shuffling envelopes, using a computer random

number generator, or drawing of lots (18, 24, 36, 49, 52, 55); and one study did not use random

assignment (72). Seven studies reported taking measures to blind PA outcome assessment. Nine

studies did not use a valid PA measure (≥ 3 days of data). Most studies (n = 21) clearly explained

the reasons for missing PA data, but no study imputed missing data. Overall, based on the four

quality indicators, eight studies had low risk of bias.





Study Characteristics

Publication dates for the 23 studies ranged from 2003 to 2014. As noted in Table 1,

studies were conducted in the U.S. (n = 11), United Kingdom (n = 2), Australia (n = 2), Belgium

(n = 2), Switzerland (n = 2), Canada (n = 1), Germany (n = 1), Scotland (n = 1), and Israel (n =

1). Eighteen studies were cluster RCTs, with clusters being preschools or childcare centers in 11

studies or classes in seven studies. Four studies were RCTs, and one study used quasi-

experimental non-equivalent group design. The sample size ranged from 32 (4) to 1,154 (6), with

a total sample size of 8,448 (mean age = 4.08). Eighteen studies enrolled children only aged 2-5

years, and one study involved children aged 1-3 (n = 40, M = 1.75; 32). In addition to including

children aged 2-5, four studies also involved children aged 6 (n = 2,034, M = 4.94; 18, 19, 23,

55). Details on children’s age were included in Table 1.

Physical Activity Measure. The most commonly used device for assessing PA was the

ActiGraph accelerometer: GT1M (n = 7), GT3X (n = 4), and CSA/MTI WAM-7164 (n = 3).

Four studies used pedometers to assess PA, with one study including Walk4Life (10), another

using Yamax (24), and two not reporting any particular model (23, 72). The remaining studies

used other types of accelerometers, including Actical (n = 1), Actiwatch (n = 1), TriTrac (n = 1),

and Actiheart (n = 1). The length of time for monitoring ranged from minutes (86-149 min.) to

seven days. The reported PA outcome variables included minutes or % of sedentary activity,

light PA (LPA), moderate PA (MPA), vigorous PA (VPA), MVPA, or overall PA.

Research Question 1: What types of interventions have been conducted to increase

objectively measured PA in preschoolers?

Among the 20 unique interventions, two interventions were home-based (32, 52), with

the remaining being center-based. Center-based interventions include interventions that were





implemented in daycare or childcare centers, preschools, or nurseries. Intervention duration

ranged from 6 weeks (49) to 12 months (19, 63), with a mean duration of six months. Nine

interventions targeted both parents and children, with two having an environmental component

(19, 55). One intervention targeted only the preschools’ environment (14). Only two

interventions collected long-term follow-up data at either six months (49) or six and twelve

months after the intervention had ended (64).

Theoretical Framework. Of the 20 interventions, a single theory or model was used in

six; and two models or theories were integrated in three. Bandura’s (9) social cognitive theory

was integrated with self-efficacy theory in one intervention (7) and with self-determination

theory in another (25). One intervention was based on early childhood development theory and

general system theory (72). The socio-ecological model provided the theoretical foundation for

four interventions (12, 24, 48, 49). Other theories or models used alone included PRECEDE-

PROCEED model (19) and general system theory (18).

Research Question 2: What is the overall effect of previously conducted interventions on

objectively measured PA?

When compared to their respective control groups, eight of the 20 interventions

significantly increased PA or decreased sedentary activity at post-intervention (2, 5-8, 18-19, 23,

25, 63-64, 72). Among the eight interventions having a significant effect, two decreased

sedentary activity only (2, 18), three increased overall PA (23, 63-64, 72), and the remaining

three increased MVPA. One of the two interventions with long-term follow-up assessments

sustained the effect on PA six months, but not 12 months, after the intervention had ended (63-

64).

https://www.researchgate.net/publication/7335500_Randomized_Trial_of_Physical_Activity_and_Calcium_Supplementation_on_Bone_Mineral_Content_in_3-_to_5-Year-Old_Children?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==

https://www.researchgate.net/publication/8139248_Increased_periosteal_circumference_remains_present_12_months_after_an_exercise_intervention_in_preschool_children?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==





Research Question 3: What factors may influence the effect of interventions on objectively

measured PA?

Risk of bias. Only three of the eight interventions with low risk of bias had a significant

effect (2, 18, 23). Two of the three decreased only accelerometer-measured sedentary activity (2,

18), and the remaining one increased overall pedometer-measured PA (23).

Study design. Seven of the 19 RCT interventions, including four RCTs and 15 cluster

RCTs, and one quasi-experimental study intervention had a significant intervention effect. Of the

eight interventions with a significant effect, two RCT interventions decreased only sedentary

activity (2, 18), whereas five RCT and one quasi-experimental interventions resulted in increased

MVPA or overall PA. One RCT, including 178 preschoolers offering 30 minutes of PA daily for

twelve months, had a significant intervention effect at 6-month, but not 12-month, follow-up (64).

Intervention Setting. Eight of the 18 center-based, teacher-delivered interventions had a

significant effect, while the two home-based interventions had no effect on PA. One 16-week

home-based intervention focusing on obesity prevention included 11 parenting lessons with 40

parent-child dyads (32). The other occurred across eight months and included monthly

interactive kits and a motivational interviewing session for parents among 400 parent-child dyads

(52).

Theoretical framework. Of the nine theory-based interventions, five had a significant

effect on sedentary activity, MVPA, or overall PA. Grounded in social cognitive theory and self-

efficacy theory, a 9-month Start For Life intervention, including 30 minutes of structured PA

daily, teacher training, and progress monitoring, resulted in a 2% increase in MVPA, compared

to a 1% decrease in the control group (5-8). Based on social cognitive theory and self-

determination theory, a 14-week teacher-delivered weight control intervention, including 20





minutes of structured PA twice a week and weekly homework assignments for parents, increased

MVPA by 11 minutes/day, as compared to 4 minutes/day for the control group (25). Compared

to a state-sponsored PA program that decreased sedentary activity by 3 minutes/day, a 9-month

participatory PA intervention based on general system theory that involved parents through

parent-teacher meetings and a website decreased sedentary activity by 7 minutes/day (18). A 12-

month PRECEDE-PROCEED model-based ToyBox intervention including PA sessions for

children, newsletters for parents, and an environmental change increased MVPA by 1.2%,

compared to a 0.6% increase in the control group (19). Another study compared an 18-week

center-based with a home- and center-based intervention with both being grounded in early

childhood development theory and general system theory (72). Findings showed a significant

increase in PA assessed by pedometers in both intervention groups, but no between-group

differences.

Physical activity measure. Of the 11 interventions using 3-7 day accelerometer data to

assess PA, four had a significant effect. One non-theory-based structured PA program conducted

with 71 preschoolers decreased their sedentary activity by 3%, compared to a 4% increase in the

control group (2). The remaining three were theory-based, including Fitzgibbon’s (25) Weight

Control Intervention, De Bock’s (18) Participatory Physical Activity Intervention, and De

Craemer’s (19) ToyBox Intervention.

Significant difference between the intervention and control groups occurred in two of

three interventions measuring children’s PA using pedometers for at least three days (23, 72).

Yin’s (72) 18-week PA intervention increased PA by approximate 18 steps/minute in 252

preschoolers. Eliskim and colleagues’ (23) 4-month, center-based nutrition and PA intervention

with 101 children, ages 5-6, increased PA by 1,438 steps/day.





Length of intervention. Of the eight interventions having a significant effect, one was

implemented for either 8 weeks or 9 months (due to heterogeneous reporting of findings,

intervention effect was not able to be compared) (5-8). The duration of the remaining seven

interventions were: 14 weeks (25), 4 months (23), 18 weeks (72), 6 months (2), 9 months (18),

and 12 months (n = 2) (19, 63). The average duration for the interventions with a significant

effect was 6.55 months, compared to 6 months for the 20 included unique interventions.

Parental involvement. Five of nine interventions including a child component and a

parental component had a significant effect, with four of five actively involving parents through

goal setting, lecturing, group discussion, or homework assignment (18, 23, 25, 72), and one of

four passively involving parents through sending home handouts, CD/DVDs, flyers, leaflets,

books, or text messages (19). Two interventions that targeted only parents through motivational

interviewing, monthly newsletter, or educational lessons, had no beneficial effect (32, 52). One

intervention significantly increased PA when targeting both children and parents, compared to

only targeting parents through lectures (23). Two interventions evaluated the unique contribution

of involving parents to children’s PA (18, 72). One 9-month intervention adding a parental

component through a parent-teacher meeting and website resulted in a significant greater

decrease in children’s accelerometer-measured sedentary activity than a state-sponsored PA

program (18). The other intervention involving parents through peer-education and posters did

not change children’s PA, when compared to a regular center-based PA program (72).

Intervention components. Six of 12 multi-component interventions and two of eight

single-component interventions had a significant effect. Of the six multi-component

interventions, five involved both children and parents (18-19, 23, 25, 72), and one targeted only

children (8). The intervention components for children included: (a) structured PA (8, 18-19, 23,






25, 72); (b) PA education (25); and (c) recess (72). The two effective single-component

interventions provided 30-60 minutes of structured PA daily for six or twelve months (3, 63).

Summary. Eight of the 20 unique interventions significantly decreased sedentary activity

or increased PA at post-intervention compared to a control group, and one of the two with

follow-up assessments sustained the effect six months after intervention had ended. Of the eight

interventions with a significant effect, all were center-based and included a structured PA

component, seven were RCTs including one RCT and six cluster RCTs, six used accelerometers

to assess PA, six involved more than one component, five integrated theories or models, four

actively involved parents, and three had low risk of bias. In summary, compared to other

approaches, center-based, theory-driven, multi-component interventions that include a structured

PA component and target both parents and their children hold a promise for increasing PA.

Discussion

This systematic review, which provided a critical synthesis and evaluation of 20 unique

interventions described in 23 independent studies targeting preschoolers to increase their PA, had

both strengths and limitations. All studies assessed PA objectively, and 19 were RCTs. The

majority (n = 16) had sample sizes greater than 200. Participants included diverse ethnic and

racial groups from several countries. Despite strengths, drawing conclusions from the review by

comparing the interventions was challenging due to some methodological limitations and

heterogeneity of the included studies, including varied wear time for pedometers and

accelerometers, and intervention durations ranging from six weeks to twelve months. Only two

studies had long-term (≥ 6 months) follow-up data, precluding any comprehensive synthesis of

results on whether or not an intervention effect can be sustained after an intervention has ended.

Overall, the review indicated that the effect of interventions conducted to date on objectively





measured PA in preschoolers is not nil, as evidenced by significant improvement in the behavior

resulting from eight of 20 interventions. Additionally, four (n = 2,034) of the 20 interventions (N

= 8,448) enrolled children up to 6 years old with three reporting a significant effect, so results

from this review may be applicable to this age group of preschool children. However, of the

eight interventions with significant findings on PA, risk of bias was low for only three. Therefore,

continued investigation involving rigorous study designs is needed to accurately determine the

effect of interventions on preschoolers’ PA.

Study Design

Only one quasi-experimental intervention and seven of 19 RCT interventions had a

significant effect. Even though the preferred design of RCT was used, intervention effect can be

influenced by outcome measures (60) and implementation fidelity (21). Because only one of two

studies employing long-term follow-up measures had a sustained intervention effect in this

review, no definitive conclusion can be drawn about sustainability. Some researchers propose

that an intervention effect is delayed in health-promotion studies. An 8-week PA intervention

with 50 preschoolers did not increase MVPA after intervention, but did so at 4-month follow-up

(56). Another intervention did not show a significant effect until 12-month follow-up, and the

effect was sustained for 36 months (27).

Employing long-term follow-up measurements is not only essential in evaluating the

sustainability of an intervention effect, but also necessary in determining the duration of an effect

and identifying a delayed intervention effect. We found several studies involving adults only that

explored strategies or influencing factors for sustaining the behavioral intervention effect. One

study with 1,032 overweight or obese adults showed monthly personal contact had a modest

benefit in sustaining the effect, while an interactive technology-based intervention had an early





but transient benefit (65). A systematic review concluded that maintenance in adults is

influenced by their internal motivation, social support, coping strategies, self-efficacy, and

autonomy (22). To better understand intervention sustainability and strategies for promoting it in

preschoolers, follow-up efforts for a minimum of 6-12 months after the last intervention contact

is essential (29).

Intervention Setting

Consistent with reports from other researchers (30), the review indicated that

interventions for preschoolers are mostly center-based and teacher-delivered. This approach

makes sense for the following reasons: (a) worldwide, about 33% of children aged 0-3 and 70%

of children aged 3-5 attend an organized childcare program (67); (b) the majority of children’s

waking hours are spent in the setting; (c) conducting an intervention can be cost-effective when

delivered by teachers in a school (71); and (d) sustaining an intervention effect needs

implementation of the intervention under real-world conditions that can be continued after the

researchers remove the resources (31). This information indicates that preschool teachers are

ideal interventionists for delivering center-based healthy lifestyle programs. Unfortunately, the

influence of interventionist and intervention setting on the intervention effect cannot be fully

evaluated due to the limited number of home-based interventions for comparison. With

approximately 67% of children aged 0-3 and 30% of children aged 3-5 not attending an

organized childcare program (67), family- and community-based interventions are essential to

target this group of children.





Theoretical Framework

The majority of theory- or model-based interventions and less than one-third of the non-

theory-based interventions resulted in a beneficial effect. Although theory-based interventions

have been recommended for preventing obesity in children, a recent systematic review concludes

that use of appropriate behavioral change strategies (e.g., develop skills and behavioral capacity,

increase self-efficacy, educate parents and children, and model healthful behaviors) rather than

theoretical models is the key for managing obesity in preschoolers (46). Although tailoring a

theory or model to a specific population and behavior is important for enhancing intervention

effect, few theories or models have been developed for or tested in preschoolers (29). To capture

the variance of a behavior, the theory or model should be applied in a manner that is

developmentally appropriate for children’s age (11). Studies are needed to examine ways to

appropriately apply theories or models in interventions for preschoolers so that any benefit

concerning their use with this young population can be identified.

Physical Activity Measure

The most commonly used devices were ActiGraph GT1M or GT3X accelerometer,

consistent with other study findings (69). However, only 11 of 16 interventions met the

minimum requirement for assessing PA via accelerometers with four having a significant effect.

To obtain a reliability of .75 when estimating preschoolers’ PA via accelerometers, 5.5 days of

monitoring are needed (1). In this review, only nine used 5-days as a cut point, and four of them

had a significant effect on PA.

Although two of four interventions that included pedometers to assess PA showed a

significant effect, the reliability and validity of using pedometers to estimate preschoolers’ PA

are problematic (44, 51). Pagels and colleagues (53) reported a weak correlation (r = .19)





between pedometer steps and MVPA assessed by accelerometer. One plausible explanation is

that preschoolers’ intensity of steps taken can be detected only by the more sensitive

accelerometer and are not strong enough for detection by pedometer. In addition, the types of PA

behaviors young children engage in may also not be detected by conventional pedometers.

Therefore, to accurately assess PA in preschoolers and compare the effect of different

interventions, researchers need to use standardized measurement protocols and accelerometers,

as opposed to pedometers.

Length of Intervention

Based on this review, the average duration for effective interventions on PA is 6.55

months, much longer than the four weeks reported by Gordon and colleagues (30). Little

evidence exists regarding the influence of intervention duration on intervention effect among

preschoolers. A meta-analysis of 32 studies involving individuals aged 7 or older showed that the

mean effect sizes of pedometer-based PA interventions differed according to intervention

duration (< 8 weeks: .68, 8-15 weeks: .65, >15 weeks: .76; 37). Another review including 31

studies noted no influence of intervention duration on intervention effect on objectively

measured PA among children (41). As can be determined from this information, the evidence on

the intervention duration effect is limited and inconsistent.

Parental Involvement

Although evidence on the effect of parental involvement in increasing children’s PA is

inconsistent, actively involving parents through goal setting, lecturing, group discussion, or

homework assignment may hold some promise. Research suggests that involving parents through

a family visit or via a phone to provide training, counseling, or preventive messages offers some





promise in increasing the PA of children (47). Similarly, interventions that engage parents

directly in activities, such as family counseling or training, have more positive effects on

children’s healthy eating behaviors than indirect methods, such as inviting parents to a healthy

behavior activity or providing messages without requesting a response (34). Therefore, actively

engaging parents in behavioral interventions with their children may be a fruitful approach for

promoting positive changes.

Intervention Components

A structured PA component ranging from 20 to 45 minutes/session was included in all

the interventions with a significant effect. Alhassan and colleagues (3) found that a structured PA

program significantly decreased sedentary activity more than an unstructured free-play program,

consistent with the finding from a systematic review (70). This information indicates that

providing structured PA may be an important strategy for increasing PA in preschoolers.

However, because free play is vital for child’s motor, emotional, and cognitive development (38),

interventions to increase PA should not be implemented at the cost of children’s free play time.

Therefore, opportunities for both structured (e.g., physical education) and non-structured (e.g.,

recess) PA are needed during a child’s school day. One possible approach is simply integrating

structured PA into a child’s daily routine or existing curriculum.

Conclusion

This review indicates that theory-driven, multi-component interventions including a

structured PA component and targeting both parents and preschoolers may be promising for

promoting positive behavior changes in this young age group, although definitive conclusions

regarding the overall effect of interventions conducted to date to increase preschoolers’ PA are





difficult to draw due to varied settings, designs, outcome measures, and interventions. To reduce

the current childhood overweight and obesity problem, continuing investigation with well-

designed RCTs that incorporate long-term follow-up procedures and reliable measures is

warranted to identify the most effective approaches for increasing the PA of preschoolers.

Acknowledgment

The authors thank Ms. Heidi M. Schroeder for her consultation and assistance on developing the

search strategies.





References

1. Addy CL, Trilk JL, Dowda M, Byun W, Pate RR. Assessing preschool children's

physical activity: How many days of accelerometry measurement. Pediatr Exerc Sci.

2014;26(1):103-109. doi:10.1123/pes.2013-0021

2. Alhassan S, Nwaokelemeh O, Ghazarian M, Roberts J, Mendoza A, Shitole S. Effects of

locomotor skill program on minority preschoolers' physical activity levels. Pediatr Exerc

Sci. 2012;24(3):435-449.

3. Alhassan S, Nwaokelemeh O, Lyden K, Goldsby T, Mendoza A. A pilot study to

examine the effect of additional structured outdoor playtime on preschoolers' physical

activity levels. Child Care in Practice. 2013;19(1):23-35.

doi:10.1080/13575279.2012.712034

4. Alhassan S, Sirard JR, Robinson TN. The effects of increasing outdoor play time on

physical activity in Latino preschool children. Int J Pediatr Obes. 2007;2(3):153-158.

doi:10.1080/17477160701520108

5. Annesi JJ, Smith AE, Tennant GA. Cognitive-behavioural physical activity treatment in

African-American pre-schoolers: Effects of age, sex, and BMI. J Paediatr Child Health.

2013;49(2):E128-E132. doi:10.1111/jpc.12082

6. Annesi JJ, Smith AE, Tennant GA. Effects of a cognitive-behaviorally based physical

activity treatment for 4- and 5-year-old children attending US preschools. Int J Behav

Med. 2013;20(4):562-566. doi:10.1007/s12529-013-9361-7

7. Annesi JJ, Smith AE, Tennant GA. Effects of the Start For Life treatment on physical

activity in primarily African American preschool children of ages 3-5 years. Psychol

Health Med. 2013;18(3):300-309. doi:10.1080/13548506.2012.712704

8. Annesi JJ, Smith AE, Tennant GA. Reducing high BMI in African American

preschoolers: effects of a behavior-based physical activity intervention on caloric

expenditure. South Med J. 2013;106(8):456-459. doi:10.1097/SMJ.0b013e3182a05bef

9. Bandura A. Social cognitive theory: An agentic perspective. Annu Rev Psychol.

2001;52:1-26. doi:10.1146/annurev.psych.52.1.1

10. Bellows LL, Davies PL, Anderson J, Kennedy C. Effectiveness of a physical activity

intervention for head start preschoolers: A randomized intervention study. Am J Occup

Ther. 2013;67(1):28-36. doi:10.5014/ajot.2013.005777

11. Bluford DA, Sherry B, Scanlon KS. Interventions to prevent or treat obesity in preschool

children: A review of evaluated programs. Obesity. 2007;15(6):1356-1372.

doi:10.1038/oby.2007.163

12. Bonvin A, Barral J, Kakebeeke TH, Kriemler S, Longchamp A, Schindler C, et al. Effect

of a governmentally-led physical activity program on motor skills in young children





attending child care centers: A cluster randomized controlled trial. Int J Behav Nutr Phys

Act. 2013;10(1):90-101. doi:10.1186/1479-5868-10-90

13. Bornstein DB, Beets MW, Byun W, McIver K. Accelerometer-derived physical activity

levels of preschoolers: A meta-analysis. J Sci Med Sport. 2011;14(6):504-511.

doi:10.1016/j.jsams.2011.05.007

14. Cardon G, Labarque V, Smits D, De Bourdeaudhuij I. Promoting physical activity at the

pre-school playground: The effects of providing markings and play equipment. Prev Med.

2009;48(4):335-340. doi:10.1016/j.ypmed.2009.02.013

15. Cheng JK, Wen X, Coletti KD, Cox JE, Taveras EM. 2-year BMI changes of children

referred for multidisciplinary weight management. Int J Pediatr. 2014;152586.

doi:10.1155/2014/152586

16. Cochrane Effective Practice and Organisation of Care Group. EPOC Resources for

review authors [Internet]. 2013 [cited 2014 Jun]. Available from

http://epocoslo.cochrane.org/epoc-specific-resources-review-authors

17. Cunningham SA, Kramer MR, Narayan KM. Incidence of childhood obesity in the

United States. N Engl J Med. 2014;370(5):403-411. doi:10.1056/NEJMoa1309753

18. De Bock F, Genser B, Raat H, Fischer JE, Renz-Polster H. A participatory physical

activity intervention in preschools: A cluster randomized controlled trial. Am J Prev Med.

2013;45(1):64-74. doi:10.1016/j.amepre.2013.01.032

19. De Craemer M, De Decker E, Verloigne M, De Bourdeaudhuij I, Manios Y, Cardon G, et

al. The effect of a kindergarten-based, family-involved intervention on objectively

measured physical activity in Belgian preschool boys and girls of high and low SES: The

ToyBox-study. Int J Behav Nutr Phys Act. 2014;11:38. doi:10.1186/1479-5868-11-38

20. de Onis M, Blossner M, Borghi E. Global prevalence and trends of overweight and

obesity among preschool children. Am J Clin Nutr. 2010;92(5):1257-1264.

doi:10.3945/ajcn.2010.29786

21. Durlak JA, DuPre EP. Implementation matters: A review of research on the influence of

implementation on program outcomes and the factors affecting implementation. Am J

Community Psychol. 2008;41(3-4):327-350. doi:10.1007/s10464-008-9165-0

22. Elfhag K, Rossner S. Who succeeds in maintaining weight loss? A conceptual review of

factors associated with weight loss maintenance and weight regain. Obes Rev.

2005;6(1):67-85. doi:10.1111/j.1467-789X.2005.00170.x

23. Eliakim A, Nemet D, Balakirski Y, Epstein Y. The effects of nutritional-physical activity

school-based intervention on fatness and fitness in preschool children. J Pediatr

Endocrinol Metab. 2007;20(6):711-718. doi: 10.1515/JPEM.2007.20.6.711





24. Finch M, Wolfenden L, Morgan PJ, Freund M, Jones J, Wiggers J. A cluster randomized

trial of a multi-level intervention, delivered by service staff, to increase physical activity

of children attending center-based childcare. Prev Med. 2014;58(1):9-16.

doi:10.1016/j.ypmed.2013.10.004

25. Fitzgibbon ML, Stolley MR, Schiffer LA, Braunschweig CL, Gomez SL, Van Horn L, et

al. Hip-hop to Health Jr. obesity prevention effectiveness trial: Postintervention results.

Obesity. 2011;19(5):994-1003. doi:10.1038/oby.2010.314

26. Garg AX, Hackam D, Tonelli M. Systematic review and meta-analysis: When one study

is just not enough. Clin J Am Soc Nephrol. 2008;3:253-260. doi: 10.2215/CJN.01430307

27. Gillham JE, Reivich KJ, Freres DR, Chaplin TM, Shatte AJ, Samuels B, et al. School-

based prevention of depressive symptoms: A randomized controlled study of the

effectiveness and specificity of the Penn Resiliency Program. J Consult Clin Psychol.

2007;75(1);9-19. doi:10.1037/0022-006x.75.1.9

28. Ginsburg KR. The importance of play in promoting healthy child development and

maintaining strong parent-child bonds. Pediatrics. 2007;119(1):182-191.

doi:10.1542/peds.2006-2697

29. Glanz K, Rimer BK, Viswanath K. Health behavior and health education: Theory,

research, and practice (4th ed.). San Francisco, CA: John Wiley & Sons, Inc., 2008.

30. Gordon ES, Tucker P, Burke SM, Carron AV. Effectiveness of physical activity

interventions for preschoolers: A meta-analysis. Res Q Exerc Sport. 2013;84(3):287-294.

doi:10.1080/02701367.2013.813894

31. Han SS, Weiss B. Sustainability of teacher implementation of school-based mental health

programs. J Abnorm Child Psychol. 2005;33(6):665-679. doi:10.1007/s10802-005-7646-

2

32. Harvey-Berino J, Rourke J. Obesity prevention in preschool Native-American children: A

pilot study using home visiting. Obes Res. 2003;11(5):606-611. doi:10.1016/S0749-

3797(99)00117-8

33. Higgins JP, Green A. Cochrane handbook for systematic reviews of interventions.

Chichester: Wiley-Blackwell, 2011.

34. Hingle MD, O'Connor TM, Dave JM, Baranowski T. Parental involvement in

interventions to improve child dietary intake: A systematic review. Prev Med.

2010;51(2):103-111. doi:10.1016/j.ypmed.2010.04.014

35. Institute of Medicine. Early childhood obesity prevention policies. Washington, DC: The

National Academies Press, 2011.





36. Jones RA, Riethmuller A, Hesketh K, Trezise J, Batterham M, Okely AD. Promoting

fundamental movement skill development and physical activity in early childhood

settings: A cluster randomized controlled trial. Pediatr Exerc Sci. 2011;23(4):600-615.

37. Kang M, Marshall SJ, Barreira TV, Lee JO. Effect of pedometer-based physical activity

interventions: A meta-analysis. Res Q Exerc Sport. 2009;80(3):648-655.

doi:10.1080/02701367.2009.10599604

38. Kreichauf S, Wildgruber A, Krombholz H, Gibson EL, Vogele C, Nixon CA, et al.

Critical narrative review to identify educational strategies promoting physical activity in

preschool. Obesity Reviews. 2012;13:96-105. doi:10.1111/j.1467-789X.2011.00973.x

39. Mehtala MAK, Saakslahti AK, Inkinen ME, Poskiparta MEH. A socio-ecological

approach to physical activity interventions in childcare: A systematic review. Int J Behav

Nutr Phys Act. 2014;11. doi:10.1186/1479-5868-11-22

40. Metallinos-Katsaras ES, Freedson PS, Fulton JE, Sherry B. The association between an

objective measure of physical activity and weight status in preschoolers. Obesity.

2007;15(3):686-694. doi:10.1038/Oby.2007.571

41. Metcalf B, Henley W, Wilkin T. Effectiveness of intervention on physical activity of

children: Systematic review and meta-analysis of controlled trials with objectively

measured outcomes (EarlyBird 54). BMJ. 2012;345:e5888. doi:10.1136/bmj.e5888

42. Moher D, Liberati A, Tetzlaff J, Altman DG, Group P. Preferred reporting items for

systematic reviews and meta-analyses: The PRISMA statement. PLoS Med.

2009;6(7):e1000097. doi:10.1371/journal.pmed.1000097

43. Moore LL, Nguyen US, Rothman KJ, Cupples LA, Ellison RC. Preschool physical

activity level and change in body fatness in young children: The Framingham Children's

Study. Am J Epidemiol. 1995;142(9):982-988.

44. Murray ME. Validity and reliability of using MVP 4 Function Walk4Life digital

pedometers to assess physical activity levels among preschool-aged Head Start children

[thesis]. Houston, TX: The University of Texas Health Science Center at Houston; 2009.

45. National Association for Sport and Physical Education. Active start: A statement of

physical activity guidelines for children from birth to age 5 (2nd ed.). Sewickley, PA:

American Alliance for Health, Physical Education, Recreation, and Dance, 2009.

46. Nixon CA, Moore HJ, Douthwaite W, Gibson EL, Vogele C, Kreichauf S, et al.

Identifying effective behavioural models and behaviour change strategies underpinning

preschool- and school-based obesity prevention interventions aimed at 4-6-year-olds: A

systematic review. Obes Rev. 2012;13(Suppl 1):106-117. doi:10.1111/j.1467-

789X.2011.00962.x

https://www.researchgate.net/publication/221694687_Critical_narrative_review_to_identify_educational_strategies_promoting_physical_activity_in_preschool?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==







https://www.researchgate.net/publication/6435704_The_Association_Between_an_Objective_Measure_of_Physical_Activity_and_Weight_Status_in_Preschoolers?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==



https://www.researchgate.net/publication/15626098_Preschool_physical_activity_level_and_change_in_body_fatness_in_young_children_The_Framingham_Children's_Study?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==



https://www.researchgate.net/publication/26805686_Preferred_Reporting_Items_for_Systematic_Reviews_and_Meta-Analyses_the_PRISMA_Statement?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==



https://www.researchgate.net/publication/232223197_Effectiveness_of_intervention_on_physical_activity_of_children_Systematic_review_and_meta-analysis_of_controlled_trials_with_objectively_measured_outcomes_EarlyBird_54?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==








47. O'Connor TM, Jago R, Baranowski T. Engaging parents to increase youth physical

activity: A systematic review. Am J Prev Med. 2009;37(2):141-149.

doi:10.1016/j.amepre.2009.04.020

48. O'Dwyer MV, Fairclough SJ, Knowles Z, Stratton G. Effect of a family focused active

play intervention on sedentary time and physical activity in preschool children. Int J

Behav Nutr Phys Act. 2012;9:117. doi:10.1186/1479-5868-9-117

49. O’Dwyer MV, Fairclough SJ, Ridgers ND, Knowles ZR, Foweather L, Stratton G. Effect

of a school-based active play intervention on sedentary time and physical activity in

preschool children. Health Educ Res, 2013;28(6):931-942. doi:10.1093/her/cyt097

50. Ogden CL, Carroll MD, Kit BK, Flegal KM. Prevalence of childhood and adult obesity in

the United States, 2011-2012. JAMA. 2014;311(8):806-814. doi:10.1001/jama.2014.732

51. Oliver M, Schofield GM, Kolt GS, Schluter PJ. Pedometer accuracy in physical activity

assessment of preschool children. J Sci Med Sport. 2007;10(5):303-310.

doi:10.1016/j.jsams.2006.07.004

52. Ostbye T, Krause KM, Stroo M, Lovelady CA, Evenson KR, Peterson BL, et al. Parent-

focused change to prevent obesity in preschoolers: Results from the KAN-DO study.

Prev Med. 2012;55(3):188-195. doi:10.1016/j.ypmed.2012.06.005

53. Pagels P, Boldemann C, Raustorp A. Comparison of pedometer and accelerometer

measures of physical activity during preschool time on 3- to 5-year-old children. Acta

Paediatr. 2011;100(1):116-120. doi:10.1111/j.1651-2227.2010.01962.x

54. Pate RR, O'Neill JR, Mitchell J. Measurement of physical activity in preschool children.

Med Sci Sports Exerc. 2010;42(3);508-512. doi:10.1249/MSS.0b013e3181cea116

55. Puder JJ, Marques-Vidal P, Schindler C, Zahner L, Niederer I, Burqi F, et al. Effect of

multidimensional lifestyle intervention on fitness and adiposity in predominantly migrant

preschool children (Ballabeina): Cluster randomised controlled trial. BMJ.

2011;343:d6195. doi:10.1136/bmj.d6195

56. Qiu W. Physical activity intervention in early care and education settings [dissertation].

Newark, DE: University of Delaware; 2008.

57. Reilly JJ. Physical activity, sedentary behaviour and energy balance in the preschool

child: Opportunities for early obesity prevention. ProcNutr Soc. 2008;67(3):317-325.

doi:10.1017/S0029665108008604

58. Reilly JJ. Low levels of objectively measured physical activity in preschoolers in child

care. Med Sci Sports Exerc. 2010;42(3):502-507. doi:10.1249/MSS.0b013e3181cea100

59. Reilly JJ, Kelly L, Montgomery C, Willianson A, Fisher A, McColl JH, et al. Physical

activity to prevent obesity in young children: Cluster randomised controlled trial. BMJ.

2006;333(7577):1041. doi:10.1136/bmj.38979.623773.55

http://dx.doi.org/10.1016/j.amepre.2009.04.020

http://dx.doi.org/10.1016/j.ypmed.2012.06.005

https://www.researchgate.net/publication/6875488_Pedometer_accuracy_in_physical_activity_assessment_of_preschool_children?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==



https://www.researchgate.net/publication/23165016_Physical_activity_sedentary_behaviour_and_energy_balance_in_the_preschool_child_Opportunities_for_early_obesity_prevention?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==




https://www.researchgate.net/publication/45460341_Comparison_of_pedometer_and_accelerometer_measures_of_physical_activity_during_preschool_time_on_3_to_5-year_old_children?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==




https://www.researchgate.net/publication/284030758_Effect_of_a_family_focused_active_play_intervention_on_sedentary_time_and_physical_activity_in_preschool_children?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==







60. Savovic J, Jones H, Altman D, Harris R, Juni P, Pildal J, et al. Influence of reported study

design characteristics on intervention effect estimates from randomised controlled trials:

Combined analysis of meta-epidemiological studies. Health Technol Assess.

2012;16(35):1-82. doi:10.3310/hta16350

61. Schulz KF, Altman DG, Moher D, Consort Group. CONSORT 2010 Statement: Updated

guidelines for reporting parallel group randomised trials. J Clin Epidemiol.

2010;63(8):834-840. doi:10.1016/j.jclinepi.2010.02.005

62. Skouteris H, Dell'Aquila D, Baur LA, Dwyer GM, McCabe MP, Ricciardelli LA, et al.

Physical activity guidelines for preschoolers: A call for research to inform public health

policy. Med J Aust. 2012;196(3):174-177.

63. Specker B, Binkley T. Randomized trial of physical activity and calcium supplementation

on bone mineral content in 3- to 5-year-old children. J Bone Miner Res. 2003;18(5):885-

892. doi:10.1359/jbmr.2003.18.5.885

64. Specker B, Binkley T, Fahrenwald N. Increased periosteal circumference remains present

12 months after an exercise intervention in preschool children. Bone. 2004;35(6):1383-

1388. doi:10.1016/j.bone.2004.08.012

65. Svetkey LP, Collaborat WLM. Comparison of strategies for sustaining weight loss: The

weight loss maintenance randomized controlled trial. Am J Health Promot.

2008;23(2):152-153. doi:10.1001/jama.299.10.1139

66. Telama R, Yang X, Leskinen E, Kankaanpaa A, Hirvensalo M, Tammelin T, et al.

Tracking of physical activity from early childhood through youth into adulthood. Med

Sci Sports Exerc. 2014;46(5):955-962. doi:10.1249/Mss.0000000000000181

67. The Convention on the Organisation for Economic Co-operation and Development.

PF3.2: Enrolment in childcare and pre-schools. 2014 [cited 2015 Jan.]. Available from

www.oecd.org/social/family/database

68. Timmons BW, Leblanc AG, Carson V, Connor GB, Dillman C, Janssen I, et al.

Systematic review of physical activity and health in the early years (aged 0-4 years).

Appl Physiol Nutr Metab. 2012;37(4):773-792. doi:10.1139/h2012-070

69. Tucker P. The physical activity levels of preschool-aged children: A systematic review.

Early Child Res Q. 2008;3(4):547-558. doi:10.1016/j.ecresq.2008.08.005

70. Ward DS, Vaughn A, McWilliams C, Hales D. Interventions for Increasing Physical

Activity at Child Care. Med Sci Sports Exerc. 2010;42(3):526-534.

doi:10.1249/Mss.0b013e3181cea406

71. Wu S, Cohen D, Shi Y, Pearson M, Sturm R. Economic analysis of physical activity

interventions. Am J Prev Med. 2011;40(2):149-158. doi:10.1016/j.amepre.2010.10.029







https://www.researchgate.net/publication/41001152_Interventions_for_Increasing_Physical_Activity_at_Child_Care?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==




https://www.researchgate.net/publication/221837156_Physical_activity_guidelines_for_preschoolers_A_call_for_research_to_inform_public_health_policy?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==



https://www.researchgate.net/publication/257754111_Tracking_of_Physical_Activity_from_Early_Childhood_through_Youth_into_Adulthood?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==



https://www.researchgate.net/publication/248544761_The_physical_activity_levels_of_preschool-aged_children_A_systemic_review?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==

https://www.researchgate.net/publication/248544761_The_physical_activity_levels_of_preschool-aged_children_A_systemic_review?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==

https://www.researchgate.net/publication/49759219_Economic_Analysis_of_Physical_Activity_Interventions?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==

https://www.researchgate.net/publication/49759219_Economic_Analysis_of_Physical_Activity_Interventions?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==

https://www.researchgate.net/publication/275045983_Interventions_to_Increase_Physical_Activity_in_Children_Aged_2-5_Years_A_Systematic_Review?el=1_x_8&enrichId=rgreq-7650b8ef-54ce-428d-adbc-5d505e816262&enrichSource=Y292ZXJQYWdlOzI3NTA0NTk4MztBUzoyMjQwMTU2MjYwNTE1ODRAMTQzMDQyMDg5NTE4Nw==








72. Yin Z, Parra-Medina D, Cordova A, He M, Trummer V, Sosa E, et al. Miranos! Look at

us, we are healthy! An environmental approach to early childhood obesity prevention.

Child Obes. 2012;8(5):429-439. doi:10.1089/chi.2012.0125





Figure 1 ─ Flow of literature search on physical activity interventions among children aged 2-5





Table 1 Study Summary: Sample, Design, Intervention, Measure, and Results (N = 23)

Study* Sample Design Intervention Measure Results

Randomized Controlled Trial (RCT)

4 Country: Western U.S.

Setting: 1 Head Start center

Sample: 32 children aged 3-5

Intervention: 17 Latino children,

mean age 3.8 (.5), 41.2% female.

Control: 15 Latino children, mean

age 3.5 (.5), 33.3% female.

RCT

Duration: 3

months

Recess Intervention

60 minutes unstructured recess/day at playground: 30

minutes morning, 30 minutes afternoon.

Control

Usual care.

ActiGraph

accelerometer

4 days

% of time

MVPA: ≥1594

counts/min

Non-significant

change in sedentary

activity, % of LPA,

and % of MVPA.

32 Country: Canada

Setting: home

Sample: 40 parent-child dyads;

children aged 1-3, mean age 1.8;

46% female; mothers mean age

26.5.

OPPS Group: 20 parent-child

dyads.

PS Group: 20 parent-child dyads.

RCT

Duration:

16 weeks

Obesity Prevention and Parenting Support (OPPS)

Group

11 parenting lesson topics focusing on eating and

exercise behaviors.

Peer educators received 120-hour training.

Monthly staff development sessions.

Parenting Support (PS) Group

11 parenting lesson topics focusing on child’s

psychological and behavioral goals, logical and

natural consequences, mutual respect, and

encouragement techniques.

Peer educators received 120-hour training.

Monthly staff development sessions.

TriTrac R3D

accelerometer

3 days

Vector

magnitude/

hour

Non-significant

change in PA at

both groups.

52 Country: Southern U.S.

Setting: home

Sample: 400 parents with 2-5 year-

old child

Intervention: 200 parent-child

dyads, 43.5% female.

Control: 200 parent-child dyads,

45% female.

RCT

Duration: 8

months

Intervention

Parents received monthly interactive kits.

20-30 minutes MI coaching session/month.

Control

Parents received monthly newsletters emphasizing

pre-reading skills.

Actical

accelerometer

(Mini Mitter)

7 days

minutes/day

MVPA: ≥715

counts/15

second epoch

Non-significant

change in PA and

sedentary activity.

63,64 Country: Midwestern U.S.

Setting: 11 childcare centers


RCT

Duration:

12 months

Fine motor + Calcium (Group 1)

30 minutes/day sitting quietly.

Two 500mg calcium tablets/day, 5 days/week.

Actiwatch

Model AW16

activity

Gross Motor Group

vs. Fine Motor

Group






Group 1: 45 children, mean age 4.0

(.6), 48.9% female, 2.2% Black.


(.6), 46.7% female, 11.1% Black.


(.6), 44.2% female, 7.0% Black.

Groups 4: 45 children, mean age

3.8 (.5), 48.9% female, 4.4% Black.

Follow-up:

6, 12

months

Fine motor + Placebo (Group 2)

30 minutes/day sitting quietly.

Cross motor + Calcium (Group 3)

30 minutes PA/day, 5 days/week; 5 minutes warm-up,

20 minutes jumping, hopping, and skipping activities,

5 minutes cool-down.

Two 500mg calcium tablets/day, 5 days/week.

Cross motor + Placebo (Group 4)

30 minutes PA/day, 5 days/week; 5 minutes warm-up,

20 minutes jumping, hopping, and skipping activities,

5 minutes cool-down.

monitor

2 days

% of time, and

counts/day

Significant increase

in % of VPA, and

counts/day after

intervention, and at

6-month follow-up.

Non-significant

change at 12-month

follow-up.

Cluster RCT

2 Country: Northeastern U.S.

Setting: 2 preschool centers

Sample: 71 children aged 2.9-5

Intervention: 4 classrooms, 43

children, mean age 4.5 (.6), 49%

female, 65% Hispanic, 35% Black.

Control: 4 classrooms, 28 children,

mean age 4.1 (.6), 54% female, 54%

Hispanic, 46% Black.

Cluster RCT

Duration: 6

months

Locomotor Skills-based Structured PA Program

30 minutes structured PA/day, 5 days/week.

Teachers received 8 hours training on structured PA.

Control: Unstructured free playtime

30 minutes free play PA/day, 5 days/week.

Teachers received 2 hours training on free play.

ActiGraph

GT1M

accelerometer

7 days

% of time

MVPA: ≥615

counts/ 15

second epoch

Significant

decrease in % of

sedentary activity,

76.2 (5.5) to 73.7

(8.0) vs. 70.6 (7.0)

to 74.7 (6.0), p=.01.

Non-significant

change in % of

LPA.


Setting: 32 YMCA preschool

classes

Sample: 275 Black children aged

3.5-5.6, mean age 4.6 (.5), 55.6%

female.

Intervention: 21 classes, 154

children.

Control: 11 classes, 121 children.

Cluster RCT

Duration: 8

weeks

Start For Life Intervention

Self-efficacy theory and social cognitive theory.

30 minutes structured PA per day.

Teachers received 4-hour training, and a binder of

daily lesson plans.

Teachers used ‘achievement charts’ to monitor

children’s progress with stickers.

Control


ActiGraph

GT3X

accelerometer

1 day

% of time

MVPA: ≥3

METs


in % of MVPA,

31.80 (8.37) to

33.92 (6.95) vs.

30.33 (6.69) to

29.80 (8.48),

p=.0130; and % of

VPA, 22.27 (6.65)

to 24 (5.72) vs.

21.13 (5.26) to

21.06 (7.3), p=.016.

Non-significant

change in % of

sedentary activity.








classes

Sample: 885-1154 children aged 4-

5, mean age 4.4 (.5), 51.2% female,

86% Black.

Intervention: 60 classes.

Control: 38 classes.

Cluster RCT

Duration: 9

months





daily lesson plans.



Control


ActiGraph

GT3X

accelerometer

1 day

% of time

MVPA: ≥3

METs


in % of MVPA,

23.9 (6.9) vs. 22.5

(4.8), p=.016;

and % of VPA,

17.5 (5.5) vs. 15.7

(3.6), p<.001.

Non-significant

change in % of

sedentary activity.



classes



children, mean age 4.6 (.6), 52.5%

female, 90.6% Black.

Control: 8 classes, 136 children,

mean age 4.7 (.3), 55.9% female,

94.1% Black.

Cluster RCT

Duration: 8

weeks





daily lesson plans.



Control


ActiGraph

GT3X

accelerometer

1 day

% of time

MVPA: ≥3

METs

Significant

decrease in % of

sedentary activity,

48.84 (11.1) to

48.54 (10.04) vs.

48.68 (10.81) to

50.68 (10.22),

p=.034.


in % of MVPA,

32.14 (8.33) to

33.03 (7.15) vs.

31.71 (7.83) to

29.83 (8.44),

p<.001; % of VPA,

22.58 (6.7) to 23.39

(6.05) vs. 22.34

(6.47) to 21.15

(7.35), p<.001.



classes

Sample: 273 Black children aged 4-

5, mean age 4.4 (.5), 47.6% female.


children.

Cluster RCT

Duration: 9

months





daily lesson plans.



ActiGraph

GT3X

accelerometer

1 day

% of time

MVPA: ≥3

METs


in % of MVPA,

35.3 (7.7) vs. 33.3

(7.1), p=.031;

and % of VPA,

17.9 (4.4) vs. 15.8

(3.7), p<.001.






Control: 8 classes, 129 children. Control


Non-significant

change in % of

sedentary activity.


Setting: 8 Head Start centers


Intervention: 4 centers, 132

children, mean age 4.4 (.6).

Control: 4 centers, 131 children,

mean age 4.3 (.6).

Cluster RCT

Duration:

18 weeks

Mighty Moves Intervention

15-20 minutes/day, 4 days/week; total 72 lessons and

143 activities.

12-week Food Friends nutrition program.

Graphics were developed to depict each Food Friends

character participating in PA.

Each class received an activity binder, music CD,

activity mats, flashcards, puppets, scarves, balls,

beanbags, ropes, and parents’ materials.

Educational handouts and music CD were sent home.

Control

12-week Food Friends nutrition program.

Walk4Life

pedometer

(W4L Classic)

6 days

steps/day

Non-significant

change in PA.

12 Country: Switzerland





female.


mean age 3.3 (.6), 51% female.

Cluster RCT

Duration: 9

months

PA Intervention

Socio-ecological model.

Teachers: received 5 workshops on PA and health;

one meeting/two months.

Childcare environment: more activity-friendly

environment; indoor movement space; portable PA

equipment.

Parents: involved in information and discussion

sessions; received flyers.

Control

Usual care.

ActiGraph

GT1M

accelerometer

1 day

counts/minute,

and

epochs/hour

MVPA: ≥420

counts/epoch

Non-significant

change in PA.

14 Country: Belgium

Setting: 40 preschools

Sample: 583 children aged 4-5,


Play equipment group: 10 centers,

145 children.

Markings group: 10 centers, 147

children.

Play equipment + markings

Cluster RCT

Duration:

N/A

Play Equipment Intervention

Each school received 2 skip balls, 2 soft throwing

discs, 2 tail balls, 2 spider balls, 8 throwing rings, 2

funny shaped balls, 2 sets of aiming rings, 3 bean

bags, 8 hoops, 2 soft grab balls, 2 soft balls, 10

colored wipes, and 2 jumping bags.

Markings Intervention

The playground markings consisted of a “trail”, a

“river with crossings” and a flower shaped hopscotch.

ActiGraph

GT1M

accelerometer

recess time

after lunch

% of time

Non-significant

change in % of

sedentary

activity, % of

LPA, % of

moderate PA,

and % of VPA.






group: 10 centers, 145 children.

Control group: 10 centers, 146

children.

18 Country: Germany



mean age 5.1, 48% female.


children.

Control: 19 centers, 376 children.

Cluster RCT

Duration: 9

months

Participatory Intervention

General system theory.

State-sponsored PA Program. PLUS

Three parent-teacher meetings.

Parent and preschools received:

An intervention-specific website.

An introductory video.

A book with 15 project ideas.

State-sponsored PA Program

Two 1-hour gym classes per week.

One parent-gym trainer meeting.

Actiheart

accelerometer

6 days

minutes/day

Significant

decrease in

sedentary activity,

631.3 (68.3) to

623.9 (66.8) vs.

631.4 (63.2) to

628.1 (67.1),

p=.014.

Non-significant

change in MVPA.

19 Country: Belgium

Setting: 27 daycare centers,

kindergartens, preschools




children.

Control: 12 centers, 171 children.

Cluster RCT

Duration:

12 months

ToyBox Intervention

PRECEDE-PROCEED model.

Teachers received 3 training sessions.

20-week structured PA.

Parents received 2 newsletters, 2 tip-cards, and one

poster through children.

Environmental change in classrooms.

Control

Usual care.

ActiGraph

GT1M, GT3X,

GT3X+

accelerometer

6 days

% of time

Significant change

in % of MVPA, 7.4

to 8.6 vs. 7.5 to 8.1,

p<.05.

Non-significant

change in % of

LPA.

23 Country: Israel

Setting: 4 preschool classes


Intervention: 2 classes, 54 children,




Cluster RCT

Duration: 4

months

Intervention

Parents received two orientation lectures on childhood

obesity and benefits of exercise in the first 2 months.

Nutrition: nutrition curriculum in class; dietary

information on working sheets/flyers.

PA: 45 minutes/day exercise training, 6 days/week;

encouraged to reduce sedentary activities and increase

PA after school.

Control

Parents received two orientation lectures on childhood

obesity and benefits of exercise in the first 2 months.

Pedometers

3 days

steps/day

Significantly

increase in PA,

6927 (364) vs. 5489

(284), p=.003.






24 Country: Australia




children, 46% female.


40% female.

Cluster RCT

Duration: 6

months

Intervention

Social ecological model.

Daily structured fundamental movement skill

development sessions, 20 minutes/session.

Increased physical activity opportunities.

Staff role modeling.

Limited screen and sedentary time.

Provided a physical activity promoting physical

environment.

Control

Usual care.

Yamax

SW200 and

SW7000

pedometers

1 day

steps/minute

Non-significant

change in PA.

25 Country: Midwestern U.S.





female, 1% Hispanic, 97% Black.


mean age 4.3 (.5), 55% female, 5%

Hispanic, 91% Black.

Cluster RCT

Duration:

14 weeks

Teacher-delivered Weight Control Intervention

Social cognitive theory and self-determination theory.

Two 20 minutes lessons on nutrition and PA per week.

Two 20 minutes PA sessions per week.

Parents received weekly newsletters with a homework

assignment.

Control

One 20 minutes lesson on general health concepts per

week.

Parents received weekly newsletters without a

homework assignment.

ActiGraph

GT1M

accelerometer

7 days

minutes/day

MVPA: ≥420

counts/15

second epoch


in MVPA, 98.6

(30.2) to 109.9

(2.0) vs. 98.8 (26.0)

to 102.5 (2.0),

p=.02.

36 Country: Australia


Sample: 97 children aged 3-5, mean

age 4.1

Intervention: 1 center, 52 children.

Control: 1 center, 45 children.

Cluster RCT

Duration:

20 weeks

Jump Start Intervention

Professional development for teachers: 4 30-minute

workshops.

Structured lessons and unstructured activities for

children: 20 minutes structured lesson, 3 times/week;

unstructured activities were in afternoons.

Control

Usual care.

ActiGraph

MTI/CSA

WAM-7164

accelerometer

2 days

counts/minute,

and % of time

MVPA: ≥3

METs

Non-significant

change in total

PA, % of sedentary

activity, LPA,

MPA, VPA.

48 Country: United Kingdom

Setting: 8 SureStart children’s

centers

Sample: 79 children aged 3-5, mean

Cluster RCT

Duration:

10 weeks

Active Play Intervention I

Social-ecological model.

Intervention occurred every other week and had 5

contact sessions, 70 minutes/session.

ActiGraph

GT1M

accelerometer

7 days

Non-significant

change in sedentary

activity, LPA, and

MVPA.






age 3.7


children, 50% female.


46.7% female.

20 minutes PA/session for children.

20 minutes workshop/session for parents.

40 minutes PA/session parents-children together.

Each family received a log book; an active dance

DVD; resources and instructional materials; 5 test

messages to provide support between sessions.

Control

Usual care.

minutes/day

49 Country: United Kingdom



mean age 4.5 (.6), 48.3% female

Intervention: 6 preschools, 109

children, mean age 4.7 (.5).

Control: 6 preschools, 131 children,

mean age 4.5 (.6).

Cluster RCT

Duration: 6

weeks

Follow-up:

6 months

Active Play Intervention II

Socio-ecological model.

Active play 60 minutes/week.

Each preschool received a resource pack including 20

activity cards, user manual, exemplar lesson plans,

signposting information, and a poster.

Control

Usual care.

ActiGraph

GT1M

accelerometer

7 days

minutes/day

Non-significant

change in sedentary

activity, MVPA,

and VPA after

intervention or at

follow-up.

55 Country: Switzerland


Sample: 40 preschool classes, 652

children aged 3.8-6.8



female.



Cluster RCT

Duration:

12 months

Intervention

Children: 4 sessions of 45 minutes PA/week; 22

sessions on nutrition, media use, and sleep; received a

funny PA or nutrition activity card every other week;

received a CD with music for PA cards; stickers on a

classroom poster showed progress.

Teachers: 2 workshops on intervention; formal

meetings to exchange experiences.

Parents: 3 information and discussion evenings;

information leaflets.

Environment: installed fixed and mobile equipment;

poster hung up on classroom walls; each class

received a game on health behaviors.

Control

Usual care.

ActiGraph

MTI/CSA

WAM-7164

accelerometer

5 days

counts/minute

Non-significant

change in PA.

59 Country: Scotland

Setting: 36 nurseries



Cluster RCT

Duration:

24 weeks

Intervention

Nursery element: PA program including 30

minutes/week for 24 weeks.

Teachers attended 3 training sessions.

ActiGraph

MTI/CSA

WAM-7164

accelerometer

Non-significant

change in PA

and % of sedentary

activity.






children, mean age 4.2 (.3), 52.2%

female.



6-week poster display at each center.

Home element: each family received a resource pack

with guidelines on linking PA at center and at home;

and two education leaflets on opportunities for

increasing PA and encourage families to seek

opportunities.

Control

Usual care.

6 days

% of time

MVPA: >3200

counts/minute

Quasi-experimental (QE) Design




Center-based Intervention: 2

centers, 118 children, mean age 4.2

(.6), 49% female.

Center- and home-based

intervention: 1 center, 66 children,


Control: 1 center, 69 children,


QE: non-

equivalent

groups

design

Duration:

18 weeks

Center-based Intervention

Early childhood development theory and general

system theory.

30-45 minutes structured outdoor play/day.

15-20 minutes PA during recess.

Classroom activities: Sesame Street Workshop

Healthy Habits for Life resource kit, including 9

modules, one module/2 weeks.

Teachers received 6-hour initial and 4-hour follow-up

training.

Center- and Home-based Intervention

Center-based intervention. PLUS

Seven peer educators.

Parents viewed posters.

Take-home bag including a storybook, family

activities, and games.

Control

Parents received monthly newsletters emphasizing

pre-reading skills.

Pedometer

3 days

steps/day


in PA in both

intervention groups.

Non-significant PA

differences between

the two intervention

groups.

Note. *=reference number. RCT=randomized controlled trials; QE=quasi-experimental; PA=physical activity; LPA=light physical activity; MPA=moderate

physical activity; VPA=vigorous physical activity; MVPA=moderate to vigorous physical activity; MI=motivational interviewing; N/A=not applicable.

Compared to RCT designs, QE designs lack random assignment of study participants. Head Start in the U.S. is federally-funded program serving low-income

families with children ≤ 5 years (4). SureStart children’s center in the United Kingdom provide free childcare services to families with children ≤ 5 years and are

located in disadvantaged parts of England (48).





Table 2 Risk of Bias Assessment for Included Studies (N = 23)

Study* Random Sequence Generation Blinding of Outcome

Assessment

Valid PA Measure Clear Explanation of

Withdrawal

2 Unclear Yes Yes Yes


5 Unclear Unclear No Yes

6 Unclear Unclear No No



10 Unclear No Yes Yes

12 Unclear No No Yes


18 Yes (envelops) Yes Yes Yes


23 Unclear Unclear Yes Yes

24 Yes (computer) No No Yes


32 Unclear Unclear Yes Yes

36 Yes (computer) Yes No Yes


49 Yes (drawing) No Yes Yes

52 Yes (computer) Unclear Yes Yes

55 Yes (envelops) Yes Yes Yes


63,64 Unclear Yes No Yes

72 No Unclear Yes No

Note. *=reference number. yes=low risk of bias, no=high risk of bias, unclear=insufficient information to permit judgment of ‘low risk’ or ‘high risk’. Studies 5,

6, 7, and 8 described the same intervention.

Interventions to Increase Physical Activity in Middle-Age Women at the Workplace

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