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Understanding physical activity behavior of young children who are highly active may provide important guidance for promoting physical activity in preschools.
To describe the movement characteristics of high-active (HA) children during attendance at preschools.
Children in 20 preschools (n=231) wore accelerometers and were classified into tertiles of moderate-to-vigorous physical activity (MVPA). Children’s movement characteristics were observed using the Observational System for Recording Physical Activity in Children – Preschool Version (OSRAC-P). Mixed-model analyses compared movement types between high-active (HA) children and lower-active (LA) children during the total school day.
HA (n=77) children were observed to be more active than LA children (n=154) indoors (p<0.001), but no differences were observed outdoors. HA children were more frequently observed running, crawling, climbing, jumping, skipping, swinging, and throwing across the total school day than LA children. Outdoors, HA children participated in more swinging and throwing and less jumping or skipping than LA children. Indoors, HA children spent more time pulling, pushing and running and less time walking than LA children.
HA children have unique activity patterns. Further interventions to increase physical activity of all preschoolers should increase the time spent outside and include varied activity types throughout the entire school day.
More than one in five children ages 2 to 5 are at risk for overweight (1), and overweight and obesity have significant negative health consequences in children (2–4). Physical activity is a critical health behavior for obesity prevention (5). Recent guidelines from the United States (6), Australia (7), the United Kingdom (8), recommend three hours per day of physical activity for young children. Unfortunately, a majority of preschool children do not meet any of these guidelines (9,10). A review of 39 studies found that only 54 percent of young children accumulated 60 minutes of moderate-to-vigorous (MVPA) physical activity per day (11).
Because a large percentage of children ages 3 to 5 attends preschool, the preschool setting has the potential to contribute significantly to young children’s physical activity levels (12). However, previous studies have found that children are primarily inactive while attending preschools (9–11,13). One study found that only 13.7 percent of preschools provided opportunities for 120 minutes of physical activity per day (14) and, on average, children accumulated less than 60 minutes of physical activity in childcare settings (10). Despite these overall low levels of physical activity, some young children are very active during preschool (11). Much less is known about the mode of physical activity in young children than the intensity, frequency and duration (Reilly 2010; Oliver 2007). By learning more about the context of high-active preschoolers’ physical activity, future interventions can select and create programs and environments best conducive to these types of physical activity. For example, interventions can include more of the types of activities that high-active children participate in and select group contexts that are more likely to lead to higher levels of physical activity.
In addition, information about the environment in which physical activity occurs is important because the environment plays a role in physical activity levels of young children (15). One environmental context that influences physical activity in children is the indoor versus outdoor setting. Studies of both preschool and elementary students have shown that children are more active when outside than when inside (16–19). Alhassan et al. (20) suggested that low levels of recess activity may result from the types of physical activities that preschool children participate in while on the playground. High-active (HA) children may participate in different types of movement (e.g., walking, running, crawling), particularly while outside (21). Understanding these differences may inform future interventions what types of activities to include specifically for indoor or outdoor settings.
Several methods have been used to measure physical activity in young children (9,22), including accelerometry and direct observation. Both are objective, valid measures of physical activity, and each method has unique strengths and limitations. Using both methods provides a more complete description of physical activity, yet few studies have used the two objective measures. This study used both accelerometry to objectively measure physical activity throughout the school day and direct observation to describe behavioral and contextual factors of young children’s physical activity.
The purpose of this study was to describe the physical activity behavior of high-active children while directly observed in indoor and outdoor preschool settings. To accomplish this, we utilized two objective measures of physical activity, accelerometry to identify high-active (HA) and lower-active (LA) children and direct observation to compare the types and intensities of activities in which HA and LA children participate. A clearer understanding of the physical activity behavior of high-active young children may provide important information to policy makers and preschool administrators and teachers about the ideal types and settings for physical activity in young children.
The 20 participating preschools were part of the Children’s Activity and Movement in Preschool Study (CHAMPS). The preschools included commercial childcare centers, church-affiliated preschools and Head Start Centers. The children ranged in age from three to five and typically attended preschool for three or more days per week for more than four hours per day. Cross-sectional data were collected in two waves over two and a half years. Parents provided informed consent for all children who participated in the data collection. The University of South Carolina Institutional Review Board approved the study.
Physical activity during the school day was measured across two weeks using ActiGraph accelerometers (model 7164; ActiGraph, Pensacola, FL) (23). Parents were instructed to have the child wear the accelerometer during all waking hours, except during bathing and swimming, for two weeks. Data collectors recorded arrival and dismissal times. Sixty minutes of consecutive zeros were considered non-wear time. Participants with at least three complete days of data were included in the analyses. A 15-second sampling epoch was used to better capture the short bursts of activity typically performed by children in this age group (24). Moderate-to-vigorous physical activity (MVPA) was defined as ≥420 counts per 15 seconds from cutoffs developed specifically for 3–5 year-old children (23).
The Observational System for Recording Physical Activity in Children – Preschool Version (OSRAC-P) is a validated momentary time sampling direct observation system (25). This focal-child system uses a 5-second observe interval, followed by a 25-second record interval, for each 30-second observation interval. Each child was observed for 10 to 12 30-minute sessions, resulting in 600 to 720 30-second intervals observed per child. Staff coded each observation for intensity (ranging from 1–5), type, and location of physical activity as well as social and environmental contexts, including equipment use, play in open space and group composition. Inter-observer reliability for OSRAC-P has been previously reported to be above 0.80 across children, preschools and time of day (26).
Parents completed a survey that included age and demographic information (gender, race, and parent education). Height was measured to the nearest 0.1 cm using a portable stadiometer (Shorr Productions, Olney, MD). Weight was measured to the nearest 0.1 kg using an electronic scale (Model 770; Seca, Hamburg, Germany). BMI was calculated from these heights and weights (kg/m2).
Descriptive statistics were calculated using SAS 9.2. Only children who had three days of accelerometry data and complete direct observation data were included in the analysis. First, accelerometry data were used to classify children into sex-specific activity tertiles. As the physical activity data was negatively skewed, children were split into tertiles of physical activity based on minutes of MVPA per hour (upper tertile; >10.17 min/hr MVPA, lowest tertile; <6.03 min/hr MVPA). Then, children were classified as high-active (HA; upper tertile) or lower-active (LA; middle and lower tertiles). The direct observation data from OSRAC-P were then used to compare physical activity types, behaviors, and contexts between the HA and LA groups.
Mixed-model analysis of variance was used to compare OSRAC-P data between HA and LA children. The dependent variables were directly-observed intensity levels, movement types, and socio-environmental contexts. Separate analyses were performed for observations during the total school day, while children were indoors and while outdoors. Preschool center was included as a random variable to control for the clustering within preschools. A separate analysis was performed to compare physical activity behaviors while children were observed being physically active. For this analysis, only observations that were coded as non-sedentary behaviors with OSRAC-P (3-slow easy movement; 4-moderate movement; 5-fast movement) were included. Models were adjusted for sex, race, and parent education.
A total of 231 children wore accelerometers and were directly observed using the OSRAC-P. The average accelerometer wear time was 8.03 (1.59) hours per day on 7.20 (2.00) days. The average age was 4.2 years in the HA group and 4.3 in the LA group (p=0.77). There were no differences between the HA and LA groups in sex, racial distribution, or BMI (see Table 1). Parent education was equal between the two activity groups, with over 50 percent of parents completing at least a two-year college degree.
Based on the observational data, HA children participated in higher intensity activity than LA children while in indoor settings (3.60% time spent in MVPA vs. 2.70%, p<0.0001). In outdoor settings, the activity intensity did not differ between HA and LA children (17.81% vs. 19.14%, p=.50).
The observational data showed that both the HA and LA groups spent the majority of time in sedentary movement types (sitting and standing), with no significant differences in the percentage of sedentary behaviors observed between the two groups. HA children spent more time than LA children engaged in higher intensity movement types during the total school day, including running, climbing, jumping and swinging, and throwing. The only gender difference was for throwing, with high-active boys having the highest percentage of intervals throwing (p=.01).
When children were active (light, moderate or vigorous activity) during the total school day, HA children were observed more frequently swinging and throwing and less frequently walking than LA children (See Table 2). When they were active outside, HA children were observed swinging and throwing more and jumping/skipping less than LA children. When active inside, HA children spent more time pulling or pushing and running and less time walking than LA children.
HA children played more on fixed equipment, and less in open spaces, and played individually more often than LA children during the total school day, although the differences were not statistically significant (See Table 3).
This study identified distinct physical activity behaviors in HA children. As expected, staff observed HA children participating in higher intensity activities, but only while indoors. This study provides additional support for including more time for outdoor play in preschools. Not only are children overall more active while outdoors (18), butbecause HA and LA children were equally active while outdoors, providing children with more outside time may level the playing field and help all children increase physical activity levels. Unfortunately, very little time is spent outside during preschool (18,19). Despite the reported feasibility and acceptability to parents of increasing outdoor time during school (27), increasing time outdoors requires overcoming many teacher barriers (28). The most common reported barriers include a lack of resources and time often due to academic conflicts (29,30). Many teachers and directors are also cautious of including physical activity, such as running, in the classroom (30). Interventions including physical activity with rules and expectations may be a useful tool to teach self-control and has been successfully included in preschool interventions (31). Notwithstanding, outdoor physical activity may be more acceptable to current centers. Despite outdoor activity being more acceptable to teachers and children havehigher levels of physical actvitiy outside than inside, children are still are not sufficiently active while outdoors. A previous report on the children included in the current study found that young children spent only 17 percent of time outdoors in moderate-to-vigorous physical activity (18). To increase overall levels of physical activity, preschools should increase the time children spend outdoors as well as increase physical activity opportunities throughout the school day (14,32). Interventions should reduce barriers to including physical activity indoors.
When children are physically active, HA children appear to choose different movement types than LA children. In this study, HA children engaged in a wider variety of activities, confirming previous results from a small sensitivity analysis in the home environment (21). HA children may prefer different activities and resulting movement types. Although this study did not examine reasons for these differences, evidence from elementary-age children suggests that HA and LA children have different determinants of physical activity (33). Other factors may uniquely influence preschool children such as differences in motor skills (34,35), personality and other factors intrinsic to the child (36). Other influences include the preschool center. Children in preschools with physical activity promoting policies and practices typically have higher physical activity levels (37). While the analysis controlled for the preschool center, specific differences, such as equipment and physical resources was not directly accounted for.
HA children participated more in some movement types that are low intensity, including throwing, crawling and lying down, which was unexpected. These behaviors may be indicative of more active forms of play, such as sports games, organized play, falling on the ground while playing tag, etc. These forms of play, rather than the specific movement type, may lead to higher overall physical activity levels. Thus teachers and future interventions should encourage overall active play instead of focusing on specific higher intensity activities.
The preschool children in this study participated in these play-like activities such as crawling and climbing, which is in contrast to older children. To understand the types of physical activities older children participated in, Sleap et al. (38) used direct observation, similar to the current study. In contrast to the current study, however, they found that older children participated mostly in organized running and chasing games. Teachers and adults should encourage developmentally appropriate activities. In addition, due to the potential increased role of alternate activity types such as crawling, climbing, and jumping in young children compared to adults, researchers need methods to detect these activity modes when measuring physical activity in young children.
Strengths of this study include a racially and socioeconomically diverse sample of children in various types of preschools. This study used multiple measures to assess the broad construct of physical activity (39). Both accelerometry and direct observation, which are considered to be two of the most valid measures of physical activity in children (40), were used to describe the unique physical activity patterns of HA and LA children.
However, both methods also have limitations that were attenuated by including both methods. While accelerometers do not accurately detect all patterns of movement and underestimate upper body movements typical in this population of young children, direct observation confirmed that HA children were more active than LA children. Because direct observation was limited to the time the children were in school, analysis was limited to physical activity during the school day. Children may have different physical activity patterns at home (e.g., participating in afterschool activities, daycare, or sports). Limited evidence, however, suggests that participation in organized activities, which makes up a large percentage of out of school time, is not associated with increased levels of physical activity in preschoolers (41). The low frequency that some activity codes were observed in this sample may have resulted in reduced statistical power. Behavior in young children occurs in short bouts (25), which may make it more difficult to capture. Additionally, there was a small amount of time spent outdoors over the total sample, again decreasing the ability to detect differences. However, the large sample size and reliable measures increased the power to detect these differences.
In conclusion, HA children participated in a different pattern of physical activity than LA children. Future physical activity interventions in preschools should include more outdoor time and encourage a wide variety of physical activity types. Further research is needed to determine whether group or individual contexts promote physical activity in young children.
This study was funded by National Institute of Child Health and Human Development grant R01HD043125. Erin K Howie’s participation in this research was supported in part by research training grant T32-GM081740 from the National Institutes of Health, National Institute of General Medical Sciences. The authors thank Carrie Zier, Nazeema Kapacee, Rebecca Polizzotto, Kristen Swaney, and Amy Burghardt, as well as all the parents, participating preschools and children. Without their help and support, this study would not have been possible.
RP, WB, and MD conceived the study and supervised experiments. MD and EH analyzed data. KM carried out experiments. All authors were involved in writing the paper and had final approval of the submitted and published versions.
Conflict of Interest
The authors have no known conflict of interest.