Parks provide opportunities for physical activity for children. This study examined sex differences in correlates of park-based physical activity because differences may indicate that a standard environmental intervention to increase activity among children may not equally benefit boys and girls.
The System for Observation Play and Recreation in Communities was used to measure physical activity among 2,712 children and adolescents in 20 neighborhood parks in Durham, North Carolina, in 2007. Sedentary activity, walking, vigorous park activity, and energy expenditure were the primary outcome variables. Hierarchical logit regression models of physical activity were estimated separately for boys and girls.
Type of activity area and presence of other active children were positively associated with boys’ and girls’ physical activity, and presence of a parent was negatively associated. A significant interaction involving number of recreation facilities in combination with formal activities was positively associated with girls’ activity. A significant interaction involving formal park activity and young boys (aged 0–5 y) was negatively associated with park-based physical activity.
Activity area and social correlates of park-based physical activity were similar for boys and girls; findings for formal park programming, age, and number of facilities were mixed. Results show that girls’ physical activity was more strongly affected by social effects (eg, presence of other active children) whereas boys’ physical activity was more strongly influenced by the availability of park facilities. These results can inform park planning and design. Additional studies are necessary to clarify sex differences in correlates of park-based physical activity.
Most US children do not accumulate the recommended 60 minutes of daily physical activity, and adherence to recommendations is significantly lower among girls (
Availability of a variety of recreation facilities and proximity to them have been associated with increased physical activity among adults (
Previous studies provide evidence that associations between environmental variables and physical activity vary between boys and girls (
Direct observations were conducted in 20 neighborhood parks in Durham, North Carolina, in 2007. To ensure socioeconomic diversity of population and inclusion of neighborhoods with a mixture of races/ethnicities, this study focused on the mostly residential central area of the city. Simple random sampling was used to select 20 of 38 available parks. Mean park size was 10.3 acres (range, 0.5–45.9 acres). For each park, a 400-meter network buffer was constructed using ArcGIS 9.1 (Esri) to define park service areas (
Park-based physical activity was measured using the System for Observing Play and Recreation in Communities (SOPARC) (
The SOPARC age category was modified to account for 3 age categories: young child (0–5 y), middle-child (6–12 y), and older children or adolescents (13–18 y). The observation codes for different age groups were introduced after the research staff was able to recognize and code SOPARC physical activity levels. Age was determined by observable physical and biological features (eg, height) and social context (eg, with a parent). The description of the training protocols are reported elsewhere (
| Child Sex, Age | κ Coefficient (% Observer Agreement) | |||||
|---|---|---|---|---|---|---|
| Training (127 Paired Observations) | Week 1 (130 Paired Observations) | Week 4 (152 Paired Observations) | Week 5 (117 Paired Observations) | Week 7 (120 Paired Observations) | Week 8 (75 Paired Observations) | |
| Female, YC, S | 0.67 (93.7) | 0.57 (96.2) | 0.66 (98.7) | 0.56 (94.0) | 0.80 (97.5) | 0.81 (97.3) |
| Female, YC, W | 0.26 (92.1) | 0.38 (95.4) | 0.74 (98.7) | 0.15 (92.3) | 0.59 (98.3) | 0 (98.7) |
| Female, YC, V | 0.56 (93.7) | 0 (99.2) | 1.00 (100) | −0.01 (98.3) | 0.66 (99.2) | 0 (98.7) |
| Male, YC, S | 0.63 (96.1) | 0.39 (97.7) | 0.80 (98.7) | 0.84 (98.3) | 0.79 (98.3) | 0.49 (97.3) |
| Male, YC, W | 0.77 (96.1) | 0.71 (98.5) | 0.80 (98.7) | 0.59 (98.3) | 0.56 (97.5) | 0.66 (98.7) |
| Male, YC, V | 0.65 (96.9) | 1.00 (100) | 0.80 (99.3) | 0.24 (97.4) | 0.80 (99.2) | 1.00 (100) |
| Female, MC, S | 0.68 (92.9) | 0 (99.2) | 0.66 (97.4) | 0.81 (98.3) | 0.95 (99.2) | 0.87 (98.7) |
| Female, MC, W | 0.44 (89.0) | 0.49 (97.7) | 0.63 (97.4) | 0.66 (98.3) | 1.00 (100) | 0 (98.7) |
| Female, MC, V | 0.49 (91.3) | 0.66 (99.2) | 0.63 (97.4) | 0 (98.3) | 1.00 (100) | (100) |
| Male, MC, S | 0.55 (89.0) | 1.00 (100) | 0.65 (97.4) | 0.59 (96.6) | 0.75 (96.7) | 0.90 (98.7) |
| Male, MC, W | 0.60 (91.3) | (100) | 0.66 (96.7) | 0.66 (99.2) | 0.87 (98.3) | 0.66 (98.7) |
| Male, MC, V | 0.51 (94.5) | 0 (99.2) | 0.93 (99.3) | 0.49 (98.3) | 0.56 (97.5) | (100) |
| Female, OC, S | 0.55 (96.9) | (100) | 0.66 (99.3) | 0.66 (99.2) | 0.66 (99.2) | 1.00 (100) |
| Female, OC, W | 0.43 (96.1) | (100) | 0.89 (99.3) | (100) | 1.00 (100) | (100) |
| Female, OC, V | (100) | (100) | 1.00 (100) | (100) | 0 (99.2) | (100) |
| Male, OC, S | 0.68 (94.5) | (100) | 0.50 (99.3) | 0.83 (99.2) | 0.66 (99.2) | 0 (98.7) |
| Male, OC, W | 0.66 (93.7) | (100) | (100) | 0.62 (97.4) | 0.66 (99.2) | −0.03 (93.3) |
| Male, OC, V | 0.83 (97.7) | (100) | 0.66 (99.3) | 0.80 (99.2) | (100) | 0 (98.7) |
Abbreviations: MC, middle child; OC, older child; S, sedentary physical activity; V, vigorous physical activity; W, walking or moderately active physical activity; YC, young child.
Young child = age 0 to 5 years, middle child = age 6 to 12 years, old child = age 13 to 18 years.
No variability observed; therefore, a weighted κ cannot provide a meaningful test statistic.
Presence of an adult was coded by observers as 1) not present, 2) supervising adult (eg, teacher, coach), 3) parent or caregiver, or 4) don’t know (mean κ, 0.6). Presence of other active children was a dichotomous variable indicating the presence of other moderately or very active children in an activity area (1 = yes). Formality of play was measured using 4 attributes: no play observed, free play, informal organized play (eg, group playground play, pick-up soccer), and formal organized play (eg, individual or group athletic event) (mean κ, 0.8).
SOPARC observations were conducted in predetermined zones (park activity areas) in each park. The areas for SOPARC observations were mapped by 3 members of the research team. Mean acres for SOPARC zones was 0.35 (standard deviation, 0.45). Environmental features in each activity area were measured using the Environmental Assessment of Public Recreation Spaces (EAPRS) instrument (
First, differences in energy expenditure among boys and girls were compared for different activity settings (eg, playgrounds, sport fields, courts). Second, sex-stratified logit models of park-based physical activity were estimated to examine whether different patterns of associations existed for boys and girls.
Analysis of variance was used to test for sex differences in intensity of physical activity associated with different park activity areas. Hierarchical generalized regression models stratified by sex were used to examine whether social and environmental correlates of park-based physical activity varied between boys and girls. Hierarchical generalized linear models (
Characteristics of park users and activity areas are shown in
| Characteristic | Girls | Boys |
|---|---|---|
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| Girls | 1,180 (43.5) | — |
| Boys | — | 1,532 (56.5) |
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| Sedentary | 662 (56.1) | 765 (49.9) |
| Walking | 370 (31.4) | 558 (36.4) |
| Vigorous | 148 (12.5) | 209 (13.6) |
|
| ||
| 0–5 y | 595 (50.4) | 560 (36.6) |
| 6–12 y | 463(39.2) | 648 (42.3) |
| 13–18 y | 122 (10.3) | 324 (21.1) |
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| ||
| No play | 255 (21.9) | 318 (21.0) |
| Free play | 793 (68.1) | 811 (53.5) |
| Informal organized | 68 (5.8) | 244 (16.1) |
| Formal organized | 48 (4.1) | 142 (9.4) |
| Parent/guardian present | 660 (55.9) | 684 (44.6) |
| Supervising adult present | 235 (19.9) | 384 (25.1) |
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| Girls only or boys and girls, no. of park areas | 89 | — |
| Boys only or boys and girls, no of park areas | — | 95 |
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| Playground | 24 (26.9) | 24 (25.3) |
| Courts | 14 (15.7) | 15 (15.8) |
| Fields | 7 (7.8) | 10 (10.5) |
| Trail/walking path | 11 (12.4) | 12 (12.6) |
| Shelter/picnic area | 14 (15.7) | 14 (14.7) |
| Open space | 11 (12.4) | 15 (15.8) |
| Other | 8 (8.9) | 5 (5.3) |
|
| 23.8 | 26.3 |
|
| 15,966 (20,499) | 15,938 (19,279) |
|
| 1.1 (0.8) | 1.1 (0.8) |
|
| 1.3 (1.5) | 1.2 (1.4) |
Abbreviation: SD, standard deviation.
Regarding supervision, a parent or guardian was more likely to be present among girls (55.9%, girls vs 44.6%, boys). Presence of other adult supervisors was more likely to be observed among boys (25.1%, boys vs 19.9%, girls). Activity levels were similar across boys and girls, with boys slightly more active than girls overall. Of girls, 56.1% were observed in sedentary activity compared with 49.9% of boys. Of girls, 31.4% were observed in walking activity behaviors compared with 36.6% of boys.
Examination of the fixed effects indicated that significant variation existed in thresholds (intercepts) across all park activity areas between sedentary activity and vigorous activity (intercept 1) but not between sedentary and walking (intercept 2) (
| Characteristic | Girls (Level 1 N = 1,180, Level 2 N = 87) | Boys (Level 1 N = 1,532, Level 2 N = 95) | ||||
|---|---|---|---|---|---|---|
| Estimate (SE) |
| Odds Ratio (95% CI) | Estimate (SE) |
| Odds Ratio (95% CI) | |
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| Intercept 1 | −1.91 (0.461) | <.001 | — | −2.32 (0.374) | <.001 | — |
| Intercept 2 | 0.172 (0.456) | .70 | — | −0.124 (0.368) | .73 | — |
| Age category 1 (0–5 y) | 0.438 (0.394) | .26 | 1.54 (0.77–2.31) | 0.338 (0.307) | .27 | 1.4 (0.79 to 2.00) |
| Age category 2 (6–12 y) | 0.336 (0.395) | .39 | 1.39 (0.62– 2.16) | 0.151 (0.282) | .59 | 1.16 (0.60 to 1.71) |
| Age category 3 | 1[Reference] | |||||
| Parent present | −0.756 (0.193) | <.001 | 0.469 (0.09–0.85) | −0.423 (0.172) | .01 | 0.655 (0.32 to 0.99) |
| Supervising nonparental adult present | −0.322 (0.22) | .14 | 0.725 (0.29–1.16) | −0.339 (0.178) | .05 | 0.712 (0.36 to 1.06) |
| Formality of play | −0.251 (0.314) | .42 | 0.778 (0.16–1.39) | 0.203 (0.202) | .31 | 1.23 (0.83 to 1.63) |
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| Age 1 × formality of play | −0.164 (0.334) | .62 | 0.849 (0.19–1.50) | −0.46 (0.215) | .03 | 0.631 (0.20 to 1.06) |
| Age 2 × formality of play | −0.229 (0.336) | .49 | 0.795 (0.14–1.45) | −0.17 (0.194) | .38 | 0.806 (0.46 to 1.22) |
| Age 3 × formality of play | 1[Reference] | |||||
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| Zone size, area in ft2 | 3.19E–06 (7.29E–06) | .66 | 1 (0.99–1.00) | −6.76E–06 (−6.12E–06) | .27 | 1 (−0.99 to 1.00) |
| Recreational facilities | −0.394 (0.211) | .06 | 0.674 (0.26–1.09) | 0.099 (0.2) | .62 | 1.1 (0.71 to 1.49) |
| Park amenities | −0.025 (0.107) | .81 | 0.975 (0.76–1.18) | 0.022 (0.098) | .81 | 1.02 (0.83 to 1.21) |
| Other active children in area (1= yes) | 1.58 (0.167) | <.001 | 4.85 (4.52–5.18) | 1.14 (0.143) | <.001 | 3.12 (2.83 to 3.40) |
| Zone type | ||||||
| Picnic/shelter | −1.03 (0.545) | .05 | 0.357 (−0.71 to 1.43) | −1.22 (0.334) | .01 | 0.295 (−0.36 to 0.94) |
| Courts | 0.253 (0.436) | .56 | 1.29 (0.44–2.14) | 0.746 (0.337) | .02 | 2.11 (1.45 to 2.77) |
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| Recreational facilities × formality of play | 0.343 (0.109) | .002 | 2.21 (1.99–2.42) | 0.032 (0.107) | .77 | 1.03 (0.82 to 1.24) |
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| Level 2 variance (τ00) | 0.793 (0.255) | — | — | 0.648 (0.192) | — | — |
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| −2 log L | 9,205.41 | — | — | 11,757 | — | — |
| Independence −2 log L | 9,251.73 | — | — | 11,805.15 | — | — |
| χ2 | 46.32 | <.001 | — | 48.15 | <.001 | — |
Abbreviations: E, exponent value; SE, standard error; —, not applicable
Sedentary was used as reference category for the ordinal outcome variable.
Age 1 = 0 to 5 years; age 2 = 6 to 12 years; age 3 = age 13 to 18 years. Age category 3 was used as reference category.
Examination of the fixed effects indicated that significant variation existed in thresholds (intercepts) across park activity areas between sedentary and vigorous activity (intercept 1) but not between sedentary and walking (intercept 2). Controlling for predictor variables, boys across park activity areas were no less likely to be observed sedentary as they were to be observed walking.
In sum, high levels of girl’s park-based activity were associated with presence of other active children and a combination of formal activity and an increasing number of recreation facilities in park activity areas. Common correlates between girls and boys were presence of a parent and presence of other active children and a low likelihood of increased activity associated with picnic areas. Among boys, increased activity was also associated with athletic courts.
Neighborhood parks have potential to help children accumulate recommended levels of daily physical activity. This study sought to determine whether social and environmental correlates of park-based physical activity differed between boys and girls. Multivariate sex-specific models provided evidence of similarities and noteworthy differences in social and environmental correlates for boys and girls. Models for boys and girls showed that the type of park activity area was associated with increased likelihood of vigorous activity but not with walking intensity activity. This finding is important in 3 respects. First, it indicates that characteristics of park activity areas may be uniquely associated with vigorous activity, a “relative rare” intensity level (
Relationships between social correlates and physical activity were similar for boys and girls; however, noteworthy differences emerged. Presence of other active children had a stronger positive association with park-based physical activity than any other predictor variable. The association was stronger among girls where presence of other active children increased the odds of higher activity levels by 4.85 times compared with 3.12 times for boys. Methods used in the current study precluded assessment of relationships among children. The findings are nevertheless consistent with studies that show friendships among adolescents are strong predictors of their physical activity levels (
Differences between boys and girls were observed for interactions involving formality of park activities. Among boys in the 0 to 5 age group, formal park activity was associated with a low level of physical activity. Thus, park programming designed to promote physical activity for young boys could minimize formal games and emphasize free play (
Strengths of this study include use of sex-stratified models to examine social and environmental correlates of park-based physical activity; measurement of 3 different age groups of children; use of validated assessment tools (SOPARC and EAPRS) to measure actual park use, park-based physical activity, and environmental features; statistical analyses adjusted for clustering within park activity areas; and parks sampled from racially diverse neighborhoods. Primary limitations were that observations of children occurred at 1 point in time and not continuously during the course of children’s visit to the park; energy expenditure was not measured directly; the study design was cross-sectional; we did not know whether parks users were demographically similar to the park service area population; and results were not generalizable beyond the summer season.
To our knowledge this is the first study using sex-stratified models to examine social and environmental correlates of park-based physical activity among children and adolescents. Overall, similar patterns of associations were observed for boys and girls. Characteristics of activity areas, presence of parents, and presence of other active children exhibited similar effects. Key differences were type of activity areas among boys, formality of park activity among young boys, and presence of recreation facilities interacting with formality of park activity among girls. Public parks and recreation facilities are important community resources for promoting physical activity (
Park-program specialists and researchers should consider the role parents and other children play in encouraging activity. Our results indicate that parents may discourage high intensity activity among children with a more noticeable influence among girls. Presence of other active children appears conducive to higher intensity activity, especially for girls. Presence of specific park facilities should also be considered. Courts were more conducive for boys’ activity. However, picnic areas were less conducive to physical activity among both boys and girls. A combination of organized park activities and recreation facilities produced greater activity among girls.
These findings suggest that environmental correlates that support physical activity in parks differ across age groups and between girls and boys. Enhanced knowledge about social and environmental factors that increase the frequency and intensity of physical activity among children should help park administrators, programmers, and planners to design parks that meet the needs of children of all ages and of both sexes. To better understand how parks benefit children’s physical activity, potential differences in the characteristics of park environments that encourage or discourage boys’ and girls’ physical activity should be further examined.
This study was funded by a grant from Active Living Research (no. 59449), a research program of the Robert Wood Johnson Foundation. The authors thank the City of Durham, North Carolina, Parks and Recreation Department, for its assistance with this study.
The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions.