Means of Optimizing Physical Activity in the Preschool Environment

Abstract

During early childhood, the preschool years serve as a formative time for the development of movement skills and healthy, active behaviors. Currently, one fifth of children in this population are overweight or obese and only half of the children participate in sufficient activity to meet recommendations. Physical activity guidelines for preschool children include both structured and unstructured activities of various intensities, limitations on sedentary behaviors, fundamental motor skill competence, and the inclusion of caregivers to facilitate activity. The majority of US children are enrolled in preschool programs, so this environment has the potential to significantly influence young children’s activity levels. Factors that have been associated with physical activity levels within the preschool setting include the influence of caregivers, the preschool environment, outdoor play, and motor skill development and competence. This review evaluated 16 publications in order to examine whether these factors had a significant impact on physical activity in the preschool setting. The findings from this review suggest the use of a multicomponent model, including the factors evaluated, may be the optimal strategy to increase activity levels in preschool children. Policy related to these factors should be created and implemented in order to facilitate optimal physical activity environments for preschool children.

‘. . . the daycare/preschool environment appears to be an ideal setting for providing physical activity opportunities and intervening to increase daily physical activity.’

Physical activity is critical to the optimal growth and development of young children. Physical activity during early childhood has been linked to positive health, improved motor skill development, and continued physical activity later in life.^1-5 Despite evidence demonstrating the importance of physical activity for young children,^2,3,5 data show that only 54% of preschool children participate in sufficient activity in order to meet physical activity guidelines (at least 60 minutes of structured activity and 60 minutes up to several hours of unstructured activity). ⁶ A comprehensive review by Tucker et al ⁶ found that young children spent anywhere from 3% to 6% of their time in moderate-to-vigorous physical activity (MVPA), indicating that the majority of preschool children did not meet recommended physical activity levels outlined in the National Association of Sport and Physical Education (NASPE) Active Start guidelines. ⁷ More recently, Reilly ⁸ reviewed 12 studies that objectively measured physical activity within child care settings to determine if the children met NASPE recommendations for physical activity. On average, the children in the studies reviewed did not meet NASPE guidelines for physical activity and accumulated high levels of sedentary activity. ⁸ The Institute of Medicine has also issued physical activity guidelines that recommend preschool-aged children engage in at least 15 minutes per hour of total activity (light, moderate, and vigorous intensity) in the child care setting. ⁹ Pate et al found similar levels of compliance with these recommendations in 2 samples of preschool children (41.6% and 50.2%) compared with samples using the NASPE guidelines. ¹⁰ These data indicate that most young children do not meet physical activity recommendations and there is a need to target this population in order to increase physical activity levels.

The published physical activity guidelines (Active Start and Institute of Medicine) are consensus-based recommendations for preschool children concerning the required amounts of physical activity needed to achieve health outcomes.^7,9 Physical activity recommendations for the preschool child differ significantly from school-aged and adolescent youth. Preschoolers’ physical activity is primarily characterized as play and their activity patterns tend to be sporadic, varying from rest to vigorous intensity. ¹¹ Also, there is a focus on the development and achievement of fundamental motor skill competence through play. These differences in preschoolers’ activity behaviors led to guidelines that include both structured and unstructured activities of various intensities, limitations on sedentary behaviors, opportunities for indoor and outdoor play that include a variety of portable equipment and sufficient space, fundamental motor skill motor competence, and the inclusion of caregivers/parents/guardian to facilitate activities that meet these recommendations.^7,9

In the United States, 51% of 3-year-old children and 69% of 4-year-old children are enrolled in preschool programs. ¹² Therefore, the daycare/preschool environment appears to be an ideal setting for providing physical activity opportunities and intervening to increase daily physical activity. A number of factors associated with physical activity levels in preschool children have been identified in the literature. These factors include biological, physiological, and psychosocial variables; the environment (home and care settings); and the caregiver (interactions and training).^13-20 The 2012 Physical Activity Guidelines for Americans Midcourse Report, which provides strategies for increasing physical activity levels among youth, has recognized preschool setting as an environment to target to increase physical activity levels in youth. ²¹

In accordance with the physical activity guidelines and the Midcourse Report, several factors previously listed have the potential to optimize physical activity levels in young children in the preschool setting.^7,21 These include the caregivers, caregiver professional development and curricula related to physical activity, the children’s preschool environment (indoor and outdoor), and motor skill competence. The purpose of this review is to summarize the impact of interventions intended to increase physical activity levels in the preschool setting. This review is intended to inform researchers, clinicians, parents, educators, and administrators about the effectiveness of a variety of strategies to optimize preschool physical activity. Future research directions and implications for the health and well-being of the child will also be discussed.

Identification of Studies

A comprehensive literature search was performed using PubMed and SportDiscus. The following search terms were used to locate relevant articles: physical activity, preschool, play, outdoor play, indoor play, daycare, policy, teacher, playground, equipment, motor competence, motor skill development, and intervention. Additional references were found in the citations of relevant articles. Publications had to be in English, there was no limit on country or origin, and published in the year 2000 or later. Studies were included if they met the following criteria: the target population was in the preschool age range (2-6 years of age), intervention studies, site of the intervention was a preschool or daycare environment, and objectively measured physical activity was a primary outcome variable of the study. The initial database search yielded 1432 studies, and after duplicates were removed, titles, abstracts, and papers were screened resulting in 16 studies to be included in this review. Figure 1 presents a breakdown of the excluded articles and the rationale for their exclusion. Based on the articles located, publications were classified into different types of interventions that were considered means of optimizing physical activity levels in preschool children. If most of the studies identified in a particular category resulted in increased levels of physical activity, a “+” was used to describe the impact of the intervention on physical activity levels. Interventions that did not elicit an increase in physical activity were classified using a “−,” and intervention strategies that had split or mixed results were denoted using a “0.” A representation of the interventions with the individual impact of each intervention as well as the overall resultant changes in physical activity in preschool children are included in the following sections (Table 1).

Figure 1.

Study Identification Flow Diagram

Table 1.

Physical Activity Interventions and the Impact on Physical Activity in Preschool Children.

Factors	References With Individual Impact (−/0/+)	Overall Impact (−/0/+)
Caregiver influence
Professional development/training	22-25 (+)	−
	26-32 (−)
Caregiver-led activities	22-25 (+)	−
	26-28, 31, 32 (−)
Preschool environment and equipment
Indoor space	30 (+)	+
Outdoor play opportunities	25 (+), 36 (−)	0
Fixed equipment (outdoors)	37 (+)	+
Portable equipment (indoor and outdoor)	25, 38, 39 (+)	+
	30, 32 (−)
Motor skill development and competence
Intervention studies	28, 47 (−)	−

Caregiver Influence

Preschool children need constant supervision, so with the exception of sleeping/napping, they are usually in the presence of adults. The caregiver is typically a parent/guardian or a teacher. Caregivers have the ability to influence play and physical activity in young children through supervision of activities, facilitation of structured activities, and modeling of activity behaviors. For the purpose of this review, the following studies will focus on teachers in early childhood education programs/settings. This section will be broken down into interventions that include caregiver professional development/training and caregiver-led physical activities at preschool.

On average, children spend approximately 7 hours per day in a preschool setting. The role that teachers play in relation to preschool physical activity differs from that of parents. Teachers are often constrained by policies and practices specific to the setting they are working in, which may alter the teacher’s behavior as well as children’s activity behaviors. Teacher education and training, as well as caregiver-led activity, may also play a role in how teachers impact the physical activity levels in preschool children.

Professional Development/Training and Caregiver-Led Activities

The majority of the studies in this section (9 of 11, 82%) incorporated both professional development/training in the area of physical activity and caregiver-led activities in the preschool environment. Professional development/training is critical to caregivers providing appropriate play opportunities as well as facilitating activities for young children. Incorporating this training that targets the use of caregiver-led activities may improve physical activity levels in preschool children. In a study by Bonis et al, the Nutrition and Physical Activity Self-Assessment for Child Care (NAP SACC) program was utilized to provide an intervention to promote a healthy environment through staff training on physical activity. As a result of the implementation of the program, there was a significant increase in accelerometer-measured MVPA in the experimental group. ²² The Hip-Hop to Health Jr. Obesity Prevention Effectiveness Trial included training for preschool staff on nutrition and physical activity. The staff then implemented the intervention, which included a two 20-minute sessions of physical activity, over 14 weeks. Postintervention analysis revealed significantly higher MVPA in the intervention group compared with the control group. ²³ Annesi et al conducted an intervention that included 30 minutes of caregiver-led daily activity, which was highly structured and designed to also improve self-regulation. Caregiver training on this protocol took place during a 4-hour session. After the 8-week intervention, there was an increase of 40 minutes of additional MVPA in the experimental group. ²⁴ Pate and colleagues implemented the SHAPES intervention that included teacher training and the delivery of structured activity opportunities in the classroom. These increased activity opportunities contributed to higher levels of MVPA in the intervention group compared with control participants. ²⁵

The Activity Begins at Childhood intervention program was designed to improve physical activity levels and body composition in young children. There were 2 intervention arms for this trial, one included classroom-delivered physical activity and the other included the classroom activity plus a home activity component. Caregivers were trained and were given a training resource manual for reference during the 6-month intervention. Despite the intervention targeting the school and home settings, no significant differences in physical activity levels among the groups were found at follow-up. ²⁶ A gross motor skill intervention program (Jump Start) conducted in Australia provided professional development workshops on motor skill development for caregivers. Caregivers facilitated both structured and unstructured activity 60 minutes per week (20 minutes × 3 sessions). There was no difference from baseline to follow-up in sedentary or activity levels; however, the effect sizes were small to moderate for sedentary and all intensity levels of activity. ²⁷ Reilly et al also focused on motor skill development in a 24-week intervention. Caregivers were trained and delivered the intervention 3 times per week (30 minutes per session). Assessments were conducted at baseline and after the intervention (6 months). Findings from this study indicated no change in sedentary and physical activity levels as a result of the intervention. ²⁸

O’Dwyer et al conducted a randomized cluster trial that included training for caregivers on active play. There were no differences in physical activity or sedentary measures between the intervention group and the comparison group. ²⁹ In Switzerland, Bonvin et al conducted an intervention aimed at improving motor skills in young children. Caregivers received training for the program but were not restricted by time requirements or strictly adhering to the curriculum. Findings from this study indicate that there was no difference in physical activity levels between the intervention and control groups. ³⁰ Roth and colleagues implemented an intervention that included caregiver training and activity lessons (games and exercises). The intervention took place during a full academic year. The preschool children participated in a daily 30-minute activity session and also had physical activity homework. Physical activity was assessed at baseline, the midpoint of the year, end of the year, and 2 to 4 months post intervention. Accelerometer data revealed no differences between the intervention and control groups as a result of this program. ³¹ A multilevel intervention conducted in Australia included training for the childcare center staff, resources, and support through phone calls and in-person visits. This intervention lasted 4 months and encouraged staff to deliver 20-minute motor skill development sessions, to provide additional opportunities for play throughout the day, and reduce sedentary activities. The intervention group had a higher step count at baseline and follow-up compared with the control group. However, pedometer-measured steps did not increase from baseline to follow-up in either group. ³²

Overall, only about one third of the inventions (4 of 11, 37%) that included professional development/training were successful at improving physical activity levels. The majority of these studies (9 of 11, 82%) also included caregiver-led activities, which resulted in about one half of the studies (4 of 9, 44%) showing increases in physical activity levels. Due to the lack of research investigating the teacher’s role in children’s physical activity levels, it is extremely important to continue research in this area to truly understand the teacher’s role and how to include the teacher in interventions designed to increase physical activity in this population. These findings suggest that physical activity training and professional development opportunities may contribute to physical activity promotion and facilitation should be a priority for care centers and preschools.

Preschool Environment and Equipment

The preschool setting also plays a critical role in the physical activity levels of young children. In general, the preschool itself may influence the physical activity levels of the children enrolled in the program. This section is dedicated to determining the influence that the preschool environment (ie, indoor and outdoor settings) has on the physical activity levels of the children.

Indoor Environment

The physical environment of the preschool provides the space for children to engage in physical activity. Factors associated with the physical environment have been shown to have an impact on the physical activity levels of young children. The primary factor that has been studied in recent years is the size of the environment and the capacity of the site to allow engagement in physical activity. The literature suggests positive associations between the physical environment, in particular the size of the indoor space, and preschool MVPA.^14,16,17,33 Larger indoor spaces can accommodate a variety of physical activities and have been shown to have a positive influence on the MVPA.^14,16,17,33 Only one study identified intervened through changes in the indoor space. Due to the difficulty of increasing the space in a preschool setting, alternatives include the use of space or activity-specific equipment in the space. Bonvin et al provided resources for caregivers to alter their space to make it more conducive to physical activity. This was achieved primarily through the use of equipment to create obstacle courses to allow children to increase activity in an indoor setting. Although there were no changes in physical activity following this intervention, physical activity was positively associated with access to the improved indoor space. ³⁰ Despite no significant findings with changes to the indoor environment, this is a promising area that should be explored further through interventions involving the alteration of the indoor space to be more conducive to physical activity and play. Additionally, the outdoor environment has been established as a determinant of physical activity. The influence of the various components, such as the amount and length of outdoor time and equipment availability, in the outdoor environment on preschool MVPA is described in detail in the following section.

Outdoor Environment

The availability of outdoor play opportunities is an important determinant in children’s physical activity levels. There are many benefits to outdoor play for children including reductions in childhood obesity and obesity-related disorders, improved mental health, and a lower prevalence of vitamin D deficiency. ³⁴ In addition to health benefits, outdoor play provides an opportunity for children to engage in both unstructured and structured play as a means of meeting physical activity guidelines. Hofferth found that during the years 1997 to 2003 there was a 37% decrease in outdoor physical activity in children (6-12 years old). ³⁵ Based on tracking of physical activity, these results may indicate that outdoor physical activity opportunities in early childhood may influence the propensity for older children and adolescents to engage in outdoor activity opportunities. By creating and promoting these experiences for younger children, there is the potential for higher levels of outdoor physical activity in other youth age groups.

Licensed preschool and daycare facilities are typically required to provide a certain amount of daily outdoor play. These requirements vary by state. Outdoor play has been shown to have a positive influence on physical activity levels in preschool children. Research investigating outdoor play is diverse in nature, and aspects of outdoor play that influence physical activity levels include outdoor play opportunities and the type of equipment available (fixed vs portable). This section will focus on the associations of these aspects of outdoor play and physical activity.

Outdoor Play Opportunities

A small number of studies have assessed the amount of outdoor playtime and the impact it has on physical activity levels in preschool children. Alhassan and colleagues implemented an intervention in Latino preschool children that provided 2 additional 30-minute outdoor recess sessions (60 minutes total) during the school day in addition to the regular 30-minute outdoor session that both the experimental and control groups had. ³⁶ There were no significant differences in activity counts between groups. The SHAPES intervention implemented by Pate et al encouraged opportunities for both structured and unstructured outdoor play. These opportunities in conjunction with increased indoor play sessions and the use of indoor obstacle courses resulted in higher levels of daily MVPA in the intervention preschools. ²⁵ The findings from these studies are mixed. In order to optimize physical activity levels during outdoor time, the sessions may need to be shortened and occur more frequently versus extending outdoor sessions. ³⁷ Additionally, facilitation of play by teachers may also aid in the optimization of activity on the playground.

Type of Equipment (Fixed and Portable)

The type of equipment, fixed or portable, also affects the activity levels of preschool children. Fixed equipment includes play structures, swings, slides, and can also include permanent playground markings. Balls, toys, and gardening tools are considered portable equipment. One intervention focused on playground markings in an outdoor play space to improve physical activity in the preschool setting. Stratton and Mullan used heart rate telemetry to quantify significant changes in intensities of physical activity levels, both moderate and vigorous intensity, as a result of the intervention. Markings on the playground appear to prompt different types of physical activity, examples of markings include hopscotch, mazes, and ladders. ³⁸ Five studies included the addition of portable equipment as a component of the intervention.^{25,30,32,38,39} Portable play equipment (balls, toys) allows children the ability to move freely while playing with equipment. Three studies found that introducing portable equipment resulted in higher MVPA in preschool children.^25,38,39 In the SHAPES study, portable equipment such as balls and scarves were added to the preschool environment. ²⁵ Hannon et al included portable equipment that facilitated locomotor and manipulative play and also found these implements increased all intensity activity and decreased sedentary behavior. ³⁹ The portable equipment used in the intervention by Engelen et al included nontraditional play equipment. Some of the materials included tires, boxes, and fabric. The addition of these loose materials led to a significant increase in accelerometer counts. ⁴⁰ Finch et al found no change in physical activity with the addition of portable equipment. ³² Bonvin et al also found no change in activity but did note that the intervention that included portable equipment was a predictor of preschool physical activity in that specific intervention group. ³⁰ Based on these studies, it appears that equipment (fixed and portable) has an overall positive impact of MVPA in preschool children.

The diversity of the preschool environment leads to varying influences on physical activity levels of preschool children. Alterations to the physical environment and the addition of fixed and portable equipment positively affected the activity levels of preschool children. Results were mixed with regard to changes in the number or length of outdoor bouts and did not appear to change physical activity levels. These findings suggest that there are a variety of factors that can be manipulated in the preschool school environment to potentially influence physical activity levels.

Motor Skill Development and Competence

The development of motor skills and achievement of motor competence are highlighted as key components in the NASPE physical activity guidelines. Fundamental motor skills are a critical basis for motor development and eventual motor competence. ⁴¹ In early childhood, the development of motor competence is achieved through regular physical activity. There is evidence that suggests that there is a proficiency barrier that exists between fundamental motor skills and transitional and sport skills.^42,43 Youth who do not overcome this proficiency barrier are at risk for inadequate physical activity levels as well as obesity. Therefore, it is important that children develop and achieve competence in motor skills in order to help with the maintenance of an active lifestyle so that physical activity guidelines can be met. Although motor skill development and competence are considered individual, rather than environmental factors, these concepts were included in the review since interventions designed to increase physical activity may incorporate activities that promote motor skill development and competence.

Several studies have found positive associations between physical activity levels and motor skill performance in young children.^1,33,44-47 Although there have been numerous interventions implemented in order to improve the motor skill development of young children, few studies have looked at the impact of the intervention on physical activity levels. Two interventions introduced enhanced physical activity programing during the preschool day. In both studies, the authors note significant improvement in motor skill competence in the intervention groups but physical activity and sedentary behavior did not change over the course of either study.^28,48 Although these studies did not show increases in physical activity levels, there were significant improvements in motor competence as a result of the interventions. Motor competency is influenced by physical activity during early childhood but appears to drive physical activity levels as youth enter middle childhood. Therefore, changes in motor competency may lead to eventual increases in physical activity as a result of improved motor proficiency.

Conclusions

The majority of the studies (75%) in this review included a multilevel approach, and it appears that the multicomponent model may be the ideal approach for increasing physical activity levels in preschool children. Due to the fact that results from these intervention studies show mixed findings with regard to changes in the physical activity levels in the care settings, components of interventions need to be carefully chosen and properly implemented in order to elicit desired changes. The components of the preschool setting included in this review, specifically portable and fixed equipment, show promise to increasing physical activity and require further research in order to determine their use as a method of optimizing physical activity in preschool children.

Implications for Preschool/Care Settings

Optimizing preschool physical activity levels has important implications for the future physical activity levels of youth. Due to the tracking of physical activity through the lifespan, behaviors learned as a young child may continue through to adulthood. Educating caregivers on the importance of physical activity as well as strategies to increase levels of activity in order to meet recommendations is crucial to the promotion and facilitation of play opportunities in young children. The creation of physical activity policy aimed at providing sufficient structured and unstructured play sessions at preschool will also aid in the effort to assist young children in meeting physical activity recommendations. These policies should be taken into account when building or renovating facilities so that the spaces that can accommodate and promote physical activity are available to children. Policy should also address staff training on physical activity as well as continuing professional development as well as strategies for translating the policy into practice and enforcing the policy in the preschool setting.