Physical Activity Opportunities in US Early Child Care Programs

To produce a nationally representative sample of CACFP-participating ECE programs, SNACS employed multistage cluster sampling, beginning with a random probability proportional to child population size sample of 20 states, then sampling 80 random metropolitan areas and nonmetropolitan county clusters within these states. SNACS then selected separate samples for each program type (Head Start and child care centers) within each sampled area. The final stage sampled 1 classroom including children aged 12 to 71 months in each recruited program. Classrooms including infants aged <12 months were excluded. The final sample of 227 included 96 child care centers and 131 Head Start programs, approximately evenly divided between small (1–39 children), medium (40–79 children), and large (≥80 children) programs. The mean number of children per observed classroom was 14 (range 2–38).

Analyses incorporate program-level weights reflecting selection probability, nonresponse adjustment, and light trimming of extreme weights; weighted results can be considered representative of CACFP-participating ECE programs nationally.³⁵ Table 1 presents analysis sample characteristics.

The SNACS environmental observation instrument was based on the validated Environment and Policy Assessment and Observation tool³⁶  as adapted for the previous Preschool Eating and Activity Study.³⁷  The SNACS instrument was assessed for content validity by several internal and external experts, and pretested in 5 northeastern US child care centers. Study leads trained 88 field observers in a multiday training session before data collection; all field observers had to pass reliability certification.

Observations were conducted from February to July 2017. On 1 day in each sampled classroom, an observer recorded presence of designated outdoor and indoor spaces for physical activity (playground or other on-site outdoor playspace, such as a field, grassy area, or other open area, or parking lot used by children for play; separate indoor room or gym for active play), minutes the class spent in these spaces, and presence of known physical activity facilitators and barriers, including weather (too hot, too cold, or precipitation) and staff participation in active play. The observer also recorded minutes outside designated playspaces where >50% of children were physically active, sedentary, or neither.

The institutional review board at Abt Associates approved SNACS.

Preschool-aged children generally accumulate physical activity in short (<1 minute) bursts;^38,39  CFOC guidance thus focuses on opportunities afforded to children to be active, which may include both time in playspaces specifically designated for physical activity (eg, a playground or indoor gym) and time in other locations where staff permits or encourages children to be active. “Physical activity opportunity duration” was thus operationalized as the sum of:

1. minutes children spent in designated indoor or outdoor playspaces (whether they were active or not); and

2. minutes when >50% of children were active (eg, running or dancing) outside of designated playspaces.

Conversely, sedentary occasions are conceptualized as occasions when children are not given the opportunity to be active; long periods in which children are not active or do not have the opportunity to be active have been extensively documented as a problem in child care settings both in the United States and internationally.^11–15  “Sedentary occasion duration” was thus operationalized as minutes outside of designated playspaces when >50% of children were sitting or lying down, including meals, snacks, naps, and screen time. Time outside of designated playspaces when >50% of children were neither active nor sedentary (eg, free play in classroom) was coded as “neither.”

Operating hours and associated observation lengths were typically longer in child care centers than in Head Start programs (Supplemental Fig 1). To facilitate comparisons across program types, we therefore computed physical activity opportunity counts and durations adjusted to an 8-hour day by dividing by observation length in minutes, then multiplying by 480 minutes. Tables report both adjusted and unadjusted measures.

Programs were classified as meeting CFOC guidance overall if they met guidance for both total physical activity opportunity duration and number of outdoor physical activity opportunities. CFOC guidance⁹  does not specify length of a full child care day. For total physical opportunity duration guidance, our operationalization assumed an 8-hour day such that use of the adjusted duration measure was appropriate. Programs were classified as meeting CFOC guidance for total physical opportunity duration if adjusted total physical activity opportunity duration was ≥60 minutes per 8-hour day for children aged 12 to 35 months and ≥90 minutes per 8-hour day for children aged 36 to 71 months. CFOC guidance additionally recommends ≥2 outdoor physical activity opportunities daily, weather permitting. However, because the count of physical activity opportunities is discrete, using the adjusted count measure in our operationalization presented challenges; for example, a program with an observation length of 8 hours would meet guidance with 2 opportunities, whereas a program with an observation length of 8 hours and 1 minute would need 3 outdoor physical activity opportunities to meet guidance. After consulting with external experts, we therefore used unadjusted observation length to operationalize CFOC guidance on number of outdoor physical activity opportunities. Absent weather restrictions, programs needed ≥1 observed outdoor physical activity opportunity for observations ≥2.5 hours and <6 hours; ≥2 opportunities for observations ≥6 hours and <12 hours; and ≥3 opportunities for observations ≥12 hours. This analysis excluded 2 programs with observations <2.5 hours. Programs not meeting benchmarks because of weather were classified as meeting the guidance. We chose this relatively lenient operationalization because the voluntary CFOC guidance does not specify recommendations for part-day programs.

We report weighted descriptive tabulations of observed playspace characteristics, physical activity opportunity minutes, sedentary occasion minutes, and physical activity opportunity counts. We used t tests for differences in means and mean percentages between child care centers and Head Start programs.

We conducted multivariate linear regressions using ordinary least squares to assess the relationship of physical activity opportunity duration per 8-hour day with observed indoor and outdoor barriers to physical activity. Key predictors were binary indicators for potential barriers (separate models for each barrier). Models additionally included indicators for program size, sponsored/independent status, metropolitan status, area percentage of minority children, area poverty rate, and geographic region as additional covariates.

Almost all ECE programs observed (97%) had dedicated outdoor playspace (eg, playground, grassy field, or parking lot; Table 2). Only 34% had a separate dedicated indoor playspace (eg, gym or other room separate from main classroom; Table 2). Of those without a separate indoor playspace, virtually all (99.8%) indicated a classroom was available for indoor play.

At least 1 sedentary occasion was observed in all ECE programs (100%), with a mean of 33 minutes per hour devoted to sedentary activities. Excluding meals, snacks, and naps, 15 minutes per hour were sedentary (Table 3).

Nearly all ECE programs (99%) provided ≥1 physical activity opportunity on the observation day (Table 3). Among programs offering ≥1 physical activity opportunity, a mean of 13 minutes per hour were devoted to physical activity (Table 3), with a mean of 5 physical activity opportunities per 8-hour day (Table 4).

Outdoor physical activity opportunities were observed in 94% of child care centers, compared with 79% of Head Start programs (P < .05; Table 3). Among programs offering ≥1 outdoor physical activity opportunity, about 9 minutes per hour were devoted to outdoor physical activity (Table 3), with a mean of <2 outdoor opportunities per 8-hour child care day (Table 4).

Indoor physical activity opportunities were observed in 93% of ECE programs (Table 3). Among programs offering ≥1 indoor physical activity opportunity, about 5 minutes per hour were devoted to indoor physical activity (Table 3). Fewer indoor physical activity opportunities per 8-hour day were observed in child care centers than in Head Start programs (3 vs 4, P < .01; Table 4).

Sixty-four percent of ECE programs offered sufficient outdoor physical activity opportunities to meet CFOC benchmarks (Table 4). Observers noted weather prevented outdoor play in ∼10% of programs. Thus, in total, 74% of ECE programs were classified as meeting CFOC guidance for number of outdoor physical activity opportunities (weather permitting) (Table 4). Fewer child care centers than Head Start programs had outdoor play limited by weather (6% vs 19%, P < .01; Table 4); however, compliance with CFOC guidance for number of outdoor physical activity opportunities (weather permitting) did not significantly differ overall by program type. Fifty percent of ECE programs met CFOC guidance for total time allotted to physical activity (Table 4). Altogether, only 43% of ECE programs met CFOC guidance for both the number of outdoor physical activity opportunities and for total minutes spent in those physical activity opportunities (Table 4).

Weather (heat, cold, precipitation, or other poor conditions, in roughly equal proportions) prevented outdoor active play in 12% of ECE programs (Table 5). After adjusting for program characteristics, weather restrictions were associated with an average of 74 fewer daily minutes allotted to physical activity opportunities (P < .001; Table 5). The magnitude of the difference in minutes associated with weather restrictions was larger in child care centers than in Head Start programs (84 minutes vs 46 minutes, P < .001; Table 5).

Staff not joining in children’s outdoor active play (staff did not participate in play with children) (61% of programs) was associated with 31 fewer minutes allotted to physical activity opportunities (P < .001; Table 5). After adjusting for program demographic characteristics, no potential indoor barrier was significantly associated with minutes allotted to physical activity opportunities (Table 5).

In this study of physical activity opportunities and sedentary occasions in a nationally representative sample of CACFP-participating ECE programs, virtually all programs offered both physical activity opportunities and sedentary occasions during the child care day. This pattern mirrors other, smaller observational studies.^37,40–44 

Given the critical role of child care staff as gatekeepers in allowing and encouraging physical activity,⁴⁵  it is as important to measure sedentary time when children are not permitted to be active as to measure time when they have opportunity to be active. Best practice guidelines emphasize limiting time children are expected to stay seated during care.⁴⁶  At least 1 sedentary occasion was observed in 100% of ECE programs, consistent with previous studies describing periods of inactivity during care.^11–15  However, mean sedentary time (15 minutes per hour, excluding meals, snacks, and naps) was lower in SNACS than found previously,^{15,34,37,40,47–49}  likely because SNACS observers recorded sedentary time only when >50% of children in the classroom were seated or lying down (group-level assessments), whereas other studies^{32,34,37,40,42–45,48–51}  employed accelerometers or observed individual children (individual-level assessments).

Both the CFOC guidance in place at the time of SNACS data collection and the recently updated Physical Activity Guidelines for Americans (2nd edition),⁵²  which for the first time included recommendations for preschool-aged children, explicitly focus for this age group on opportunities to be active rather than actual accumulated physical activity levels. SNACS mean physical activity opportunity duration (13 minutes per hour) was slightly higher than in previous studies,^{15,34,37,38,43}  likely because of inclusion of time in spaces designated for activity, independent of actual child activity levels. As noted above, children in this age group may engage in intermittent, short-duration physical activity over the course of a longer period when given the opportunity to be active; therefore, it is important to account for all time spent in spaces permitting unconstrained activity.^14,40  Although nearly all ECE programs had designated outdoor playspaces on-site, only just over one-third had designated indoor playspaces, additionally highlighting the importance of teachers’ gatekeeper role in allowing and encouraging physical activity, both within the classroom and other spaces not specifically designated for activity.⁴⁵  Multiple short physical activity opportunities are preferred to a single long opportunity of identical duration because young children are most active for the first 10 to 15 minutes,^53,54  with added time not typically increasing measured physical activity levels.⁵⁵  Observed outdoor physical activity opportunity counts in SNACS are similar to previous reports,^37,41  but less than what programs typically schedule,^21,37,56  indicating potential for improvement.

Observed time for outdoor physical activity, which is strongly correlated with measured physical activity levels,^7,40,57–59  was similar for SNACS and other, geographically limited observational studies.^7,30,37,40  However, children in SNACS were not necessarily active during all outdoor time allotted. SNACS categorized all outdoor time (independent of child activity levels) as physical activity opportunities because the purpose was to assess opportunities to be active. Additional research in a large, nationally representative sample is needed to assess whether young children attain international recommendations of ≥180 minutes daily of light, moderate, and vigorous physical activity.^60–63 

More child care centers (94%) than Head Start programs (79%) offered outdoor physical activity opportunities on the observation day. This difference is largely attributable to weather; weather prevented outdoor play in 19% of Head Start programs, but just 6% of child care centers. It is unclear whether these findings reflect chance observation day weather differences, or differences between child care centers and Head Start programs in ability or willingness to accommodate inclement weather. Regardless, the mean outdoor physical activity opportunity count did not differ by program type, implying more outdoor opportunities in Head Start programs than in child care centers when weather did not prevent outdoor play. Furthermore, minutes allocated to outdoor physical activity opportunities were similar in Head Start programs and child care centers (9 minutes per hour), and overall compliance with CFOC guidance did not differ.

Head Start programs had significantly more total physical activity opportunities than did child care centers (6 vs 5) because of a greater number of indoor physical activity opportunities in Head Start programs (4 vs 3). Previous literature reports higher-quality physical activity environments⁶⁴  and lower obesity rates⁶⁵  in Head Start programs than other ECE programs. In addition to state child care licensing criteria, Head Start programs are subject to more stringent federal physical activity guidelines.⁶⁶  Further, many Head Start programs participate in voluntary initiatives integrating movement into classroom activities (eg, I Am Moving, I Am Learning⁶⁷ ), potentially mitigating weather effects. Consistent with this hypothesis, inclement weather had a smaller effect on total physical activity opportunity minutes in Head Start programs when encountered (46 fewer minutes) than in child care centers (84 fewer minutes). Child care centers might similarly benefit from indoor-based physical activity curricula.⁶⁸ 

Across both ECE program types, inclement weather was the barrier associated with the largest observed reduction in physical activity opportunity duration, with 74 fewer minutes per 8-hour day on average observed in programs where weather prevented outdoor play on the observation day. SNACS confirms findings from other studies suggesting weather as a barrier to children’s physical activity^37,69,70  and echoes a large international study using accelerometers to demonstrate precipitation and wind speed as significant barriers.⁷¹  However, there may have been insufficient opportunities for SNACS to test the influence of weather as a barrier to outdoor play because classrooms were observed on only 1 day and weather prevented outdoor play on only 12% of those days.

Inclement weather can be particularly problematic when lacking a dedicated indoor playspace.³²  In SNACS, only one-third of programs had such a space, fewer than previously reported in regional US studies,^{30,37,41,72,73}  although virtually all programs without a dedicated indoor space indicated a classroom was available for indoor play. Surprisingly, SNACS did not find lack of indoor playspace was a significant barrier to physical activity; in fact, no indoor barrier examined was significantly associated with a reduction in total physical activity opportunity duration. This may reflect the fact that indoor physical opportunities comprised only about a third of total physical activity opportunity duration in ECE programs, such that indoor barriers may generally be less influential than barriers to outdoor activity.

The barrier to outdoor physical activity observed most frequently (61% of programs) was staff not joining in children’s active play. This barrier was associated with significantly less observed physical activity time overall, about 30 minutes fewer per 8-hour day. Staff not joining in children’s active play while indoors was observed in fewer ECE programs (37%), and in contrast (like other indoor barriers examined) was not significantly associated with less observed physical activity time overall. CFOC and other guidelines^9,74  recommend teacher-led structured activities (active play led by staff and teachers, such as stretching exercises, musical games, or dance) based on research demonstrating the importance of staff encouragement of young children’s activity through prompts.^32,73,75  Recent studies, however, suggest children are neither more active^32,76  nor less vigorously active⁴⁰  during teacher-led than child-led activities.

A limitation of SNACS was lack of an objective measure of children’s individual physical activity durations or intensities. Despite growing evidence that regular physical activity provides health benefits to preschool-aged children, current guidance does not identify a specific amount of physical activity needed.^77,78  SNACS was therefore designed to assess compliance with existing guidelines recommending durations and number of outdoor opportunities for young children to be active.

A second limitation is that a single observation day may not capture usual physical activity practices for individual programs. Mitigating this concern is SNACS’s large sample size (227 programs); nationally representative sample across US regions with varied climates; and observations occurring in winter, spring, and early summer. Another SNACS limitation was that it included no observations of children’s physical activity and sedentary time outside child care. However, a recent study³⁷  found children cannot compensate at home for levels of activity or inactivity during care.

Finally, SNACS was observational, and thus not able to test experimentally for causal effects of potential barriers to physical activity. SNACS findings suggest weather and staff not joining in active play are significant barriers in both program types, with lack of outdoor playspace additionally a barrier in Head Start settings. Future research should explicitly test effects of mitigating or removing these barriers. In addition, although staff not joining in active play was a frequently observed barrier, weather restrictions and particularly lack of outdoor playspace were infrequently observed, limiting ability to draw firm conclusions about associations with physical activity opportunity duration.

SNACS is a nationally representative study of physical activity opportunities and sedentary occasions in US ECE programs participating in CACFP. The large majority of child care centers and all Head Start programs participate in CACFP, and many states tie licensing requirements to CACFP guidelines. Thus, SNACS may hold lessons for the broader population of US child care settings.

Fewer than half (43%) of CACFP programs met daily CFOC guidance for both the number of outdoor physical activity opportunities and total physical activity opportunity duration, even employing a relatively lenient interpretation of the guidance. Though many programs have ≥2 outdoor physical activity opportunities planned on daily schedules consistent with CFOC guidance, previous reports suggest that programs may not adhere to those schedules.^21,37  SNACS findings suggest this problem may be common. Ensuring a time and place for outdoor activity, adhering to daily physical activity schedules, and promoting staff engagement in active play may improve opportunities for US children to engage in regular physical activity critical for healthy development.

We thank Lindsay LeClair, Andrew McFadden, and Don LaLiberty for their contributions.

CACFP

Child and Adult Care Food Program

CFOC

Caring for Our Children

ECE

early child care

SNACS

Study of Nutrition and Activity in Child Care Settings

USDA

US Department of Agriculture