Associations between sport and screen-entertainment with mental health problems in 5-year-old children

BACKGROUND

Few studies have examined the benefits of regular physical activity, and risks of sedentary behaviour, in young children. This study investigated associations between participation in sports and screen-entertainment (as components of physical activity and sedentary behaviour), and emotional and behavioural problems in this population.

METHODS

Cross-sectional analysis of data from 13470 children (50.9% boys) participating in the nationally representative UK Millennium Cohort Study. Time spent participating in sports clubs outside of school, and using screen-entertainment, was reported by the child's mother at child age 5 years, when mental health was also measured using the Strengths and Difficulties Questionnaire.

RESULTS

45% of children did not participate in sport clubs and 61% used screen-entertainment for >/= 2 hours per day. Children who participated in sport had fewer total difficulties; emotional, conduct, hyperactivity-inattention and peer relationship problems; and more prosocial behaviours. These relationships were similar in boys and girls. Boys and girls who used screen-entertainment for any duration, and participated in sport, had fewer emotional and behavioural problems, and more prosocial behaviours, than children who used screen-entertainment for >/= 2 hours per day and did not participate in sport.

CONCLUSIONS

Longer durations of screen-entertainment usage are not associated with mental health problems in young children. However, our findings suggest an association between sport and better mental health. Further research based on longitudinal data is required to examine causal pathways in these associations and to determine the potential role of this and other forms of physical activity in preventing mental health disorders.

Maintenance of change in the Active-for-Life initiative

BACKGROUND

There is a notable gap in translating efficacious interventions to community-based organizations. Further, physical activity interventions have been less successful in promoting longer-term maintenance.

PURPOSE

This study examined 6-month maintenance of improvements seen in Active for Life (AFL), a translational research initiative.

METHODS

Participants from seven of 12 AFL sites enrolled in Years 3 and 4 were surveyed 6 months after completing the 6-month telephone-based Active Choices program (AC, one site) or the 20-week or 12-week group-based Active Living Every Day program (ALED, six sites). Repeated measures analyses controlled for site clustering and covariates. Programs were implemented from 2003 to 2007 and analysis was conducted in 2009.

RESULTS

For the AC (n=368) and ALED (n=2151) programs, respectively, participants were aged 72.0 and 70.8 years on average, were 70% and 78% non-Hispanic white, and were 72% and 83% women; 46% and 50% returned 6-month follow-up surveys. For AC, improvements from pre- to post-test were maintained at follow-up for physical activity; satisfaction with body function (SBF); and BMI. For ALED Year 3, there was a decrease at follow-up for physical activity and SBF. Body mass index decreased from pretest to follow-up. For ALED Year 4, increases in physical activity and reductions in BMI were maintained at follow-up. Satisfaction with body function increased from pretest to 12 weeks post-test, declined at 20 weeks, and was maintained at follow-up.

CONCLUSIONS

Improvements were generally maintained at the 6-month follow-up. When behavioral decay occurred, follow-up values remained more favorable than at pretest. Given the broad reach of this translational initiative, the results suggest the viability of evidence-based programming as an effective public health practice.

Assessing children's physical activity in their homes: the observational system for recording physical activity in children-home

The present study describes the development and pilot testing of the Observation System for Recording Physical Activity in Children-Home version. This system was developed to document physical activity and related physical and social contexts while children are at home. An analysis of interobserver agreement and a description of children's physical activity in various settings are presented. The system, which was shown to be reliable, provides a direct observation tool for researchers who are interested in assessing and intervening in physical activity in the home environment.

Sedentary behavior and obesity in a large cohort of children

The purpose of this study was to examine the association between sedentary behavior and obesity among 12-year-old children, while adjusting for moderate-to-vigorous physical activity (MVPA) and other potential confounding variables. Cross-sectional analyses were carried out with data from 5,434 children who participated in the Avon Longitudinal Study of Parents and Children (ALSPAC). Fat mass was derived using dual-energy X-ray emission absorptiometry, and height and weight measurements were used to calculate BMI (kg/m(2)). The children wore an accelerometer for 7 days. The cut points for sedentary behavior and MVPA were <or=199 and >or=3,600 counts per minute (cpm), respectively. Logistic regression analyses were performed to estimate odds ratios (ORs), adjusting for potential confounders of physical activity that included gender, social factors, early life factors, and maturation. The minimally adjusted association between sedentary behavior and obesity was positive, OR = 1.18 (1.08, 1.28). After adjusting for the series of potential confounders of physical activity the positive association remained, OR = 1.32 (1.14, 1.53). The crude association between 15 min of MVPA per day and obesity was negative, OR = 0.54 (0.48, 0.62). When 15 min of MVPA per day was additionally controlled for in the models, the positive associations between sedentary behavior and obesity were negated. Sedentary behavior was positively associated with obesity in the 12-year-old children, but this association was not independent of MVPA; low levels of MVPA among the sedentary children increased the odds of obesity. These findings support the importance of specifically engaging in MVPA during childhood to reduce the prevalence of obesity.

Social and environmental factors associated with preschoolers' nonsedentary physical activity

The twofold purposes of the investigation were (a) to describe with direct observation data the physical activity behaviors and the accompanying social and environmental events of those behaviors for children in preschools and (b) to determine which contextual conditions were predictors of moderate to vigorous physical activity (MVPA) and nonsedentary physical activity (i.e., light activity + MVPA) for 3-, 4-, and 5-year-old children during their outdoor play. The results indicate that preschoolers' physical activity is characterized as sedentary in nature throughout their preschool day (i.e., 89% sedentary, 8% light activity, and 3% MVPA). During outdoor play periods, when children are most likely to be physically active, some contextual and social circumstances better predict their physical activity. Implications for policy makers, practitioners, and researchers are discussed.

The relationship between the food environment and fruit and vegetable intake of adolescents living in Residential Children's Homes

The purpose of this study was to examine the relationship between food environments and fruit and vegetable (FV) consumption of adolescents (n=246) living in Residential Children's Homes (RCHs) in North and South Carolina, USA. Administrators of 21 RCHs completed the Physical Activity and Dietary Environmental Assessment (PADEA), an instrument assessing FV-related environmental variables of RCHs: (i) policies, (ii) availability, (iii) social environment, (iv) community collaboration and (v) administrative support. Two different approaches using mixed-effects regression models were used to compare FV consumption of adolescents living in RCHs with more conducive food environments compared with adolescents living in RCHs with less conducive environments. Using one approach, PADEA variables were analyzed as categorical data and in the second approach, PADEA variables were analyzed as continuous data. Results indicated greater FV consumption among adolescents residing in RCHs with more conducive food environments compared with less conducive RCHs. Specifically, adolescents living in RCHs with higher levels of administrative support and more FV policies reported greater FV intake compared with adolescents living in RCHs with less support and fewer policies. Food environments are related to adolescents' dietary behaviors and interventions targeting FV consumption should include strategies to increase administrative support and the development of FV-related policies.

Electronic media exposure and its association with activity-related outcomes in female adolescents: cross-sectional and longitudinal analyses

BACKGROUND

Few investigations have assessed in adolescent girls the cross-sectional and longitudinal associations between elevated exposure to electronic media (EM) and activity-related outcomes such as compliance with physical activity (PA) standards or cardiorespiratory fitness (CRF).

METHODS

Four-hundred thirty-seven white and African American girls were assessed at the 8th, 9th, and 12th grades. PA and EM (TV/video watching, electronic games, Internet use) were self-reported, and CRF was estimated using a cycle-ergometer test. Hi EM exposure was defined as >or=four 30-minute blocks/d.

RESULTS

8th-, 9th-, and 12th-grade girls in the Hi EM group showed lower compliance with PA standards and had lower CRF than the Low EM group (P

CONCLUSION

Girls reporting exposure to EM for 2 or more hours per day are more likely to exhibit and maintain low PA and CRF levels throughout adolescence. These results enhance the scientific basis for current public health recommendations to limit adolescent girls' daily exposure to television, electronic games, and Internet use to a combined maximum of 2 hours.

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Key Words Collapse

MESH Headings

• Adolescent
• Computers
• Cross-Sectional Studies
• Female
• Health Knowledge, Attitudes, Practice
• Health Promotion
• Humans
• Internet
• Longitudinal Studies
• Mass Media
• Motor Activity
• Outcome Assessment, Health Care
• Physical Fitness
• Television
• Time Factors

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Grants

• R01 HL057775 NHLBI NIH HHS

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Age-related change in physical activity in adolescent girls

PURPOSE

To determine the annual rate at which physical activity changes in girls during middle school using both objective and self-report measures of physical activity.

METHODS

Participants were sixth- and eighth-grade girls from the control schools in the Trial of Activity for Adolescent Girls (TAAG). Random cross-sectional samples initially were drawn from sixth-grade girls (n=786) and 2 years later from eighth-grade girls (n=1545). A cohort of 501 girls was in both the sixth- and the eighth-grade samples. The girls wore an accelerometer for 6 days and completed the 3-Day Physical Activity Recall. Data were summarized using 3.0-, 4.6-, and 6.5-metabolic equivalent cutpoints for accelerometry and self-reported physical activity. Analyses were performed using repeated-measures analysis of variance in PROC MIXED.

RESULTS

More than 40% of the girls were white, approximately 20% were African American, and 20% were Hispanic. The annual percent decrease in physical activity in the cross-sectional sample was approximately 4% (-1.76 min moderate-to-vigorous physical activity/day), using accelerometer data. The percent decrease in physical activity based on self-report data was higher, 6% to 13%, depending on the physical activity variable. Declines tended to be larger in African American girls, but the ethnic differences were not statistically significant.

CONCLUSIONS

Based on comparisons of cross-sectional samples of sixth- and eighth-grade girls, objectively measured physical activity declined at a rate of 4% per year.

Policies and characteristics of the preschool environment and physical activity of young children

OBJECTIVE

The purpose of this study was to examine policies and characteristics of preschools and the extent to which they influence the physical activity of 3- to 5-year-old children during the preschool day.

METHODS

A total of 299 children from 20 preschools wore accelerometers for an average of 8.1 hours/day (SD: 1.5 hours/day), for 5.5 days (SD: 2.1 days). A researcher completed the Early Childhood Environment Rating Scale-Revised for each preschool to assess quality. Classrooms and playgrounds were measured, and the preschool director was interviewed about physical activity policies. For each policy or characteristic, preschools were divided into 2 groups on the basis of whether the characteristic/policy was presumed to promote or not promote physical activity.

RESULTS

Children spent fewer minutes per hour in sedentary activity and more minutes per hour in moderate/vigorous physical activity in preschools that had higher quality scores, less fixed playground equipment, more portable playground equipment, lower use of electronic media, and larger playgrounds. Five preschools had all 5 of these characteristics, and children in those preschools had significantly more moderate/vigorous physical activity minutes per hour and fewer sedentary minutes per hour compared with children in the other preschools.

CONCLUSION

Children in the top 5 physical activity-promoting preschools accumulated >60 minutes of moderate/vigorous physical activity per day, compared with the children in the other preschools, who accumulated <60 minutes of moderate/vigorous physical activity per day.

A Field-Based Testing Protocol for Assessing Gross Motor Skills in Preschool Children: The CHAMPS Motor Skills Protocol (CMSP)

The purpose of the study was to develop a valid and reliable tool for use in assessing motor skills in preschool children in field based settings. The development of the CHAMPS (Children's Activity and Movement in Preschool Study) Motor Skills Protocol (CMSP) included evidence of its reliability and validity for use in field-based environments as part of large epidemiological studies. Following pilot work, 297 children (3-5 years old) from 22 preschools were tested using the final version of the CMSP and the TGMD-2. Reliability of the CMSP and interobserver reliability were determined using intraclass correlation procedures (ICC; ANOVA). Concurrent validity was assessed using Pearson correlation coefficients to compare the CMSP to the original Test of Gross Motor Development (2(nd) Edition) (TGMD-2). Results indicated that test reliability, interobserver reliability and validity coefficients were all high, generally above R/r = 0.90. Significant age differences were found. Outcomes indicate that the CMSP is an appropriate tool for assessing motor development of 3-, 4-, and 5-year-old children in field-based settings that are consistent with large-scale trials.

Predictors of increased physical activity in the Active for Life program

INTRODUCTION

Targeting of evidence-based programs can be improved by knowing who benefits least and most. We examined pretest predictors of increased physical activity among participants enrolled in Active for Life.

METHODS

Participants (N = 1,963) from 9 community-based organizations took part in a 6-month telephone-based or a 20-week group-based behavioral physical activity program and completed a pretest survey; 1,335 participants returned posttest surveys. Interactions tested whether increases in physical activity differed over time, according to baseline characteristics.

RESULTS

In the telephone-based program, participants who were younger and less active at pretest and those who had higher pretest social support showed greater intervention effects. In the group-based program, younger participants, those less active at pretest, women, Hispanics/Latinos, heavier participants, and those who reported more health conditions and osteoporosis showed greater intervention effects.

CONCLUSION

Participant response to the 2 programs varied by age, baseline activity level, and other factors. For 6 of the 8 variables associated with differential outcomes, the least active group improved the most, which suggests that the programs worked especially well for participants most in need. Participants who were older than 75 years (both groups) and those who reported lower physical activity social support (in the telephone-based program) on entry did not respond as well and may require alternative or more intensive intervention strategies.

Active for life: final results from the translation of two physical activity programs

BACKGROUND

Most evidence-based programs are never translated into community settings and thus never make a public health impact.

DESIGN

Active for Life (AFL) was a 4-year translational initiative using a pre-post, quasi-experimental design. Data were collected from 2003 to 2007. Analyses were conducted in 2005 and 2008.

SETTING/PARTICIPANTS

Nine lead organizations at 12 sites participated. Active Choices participants (n=2503) averaged 65.8 years (80% women, 41% non-Hispanic white). Active Living Every Day (ALED) participants (n=3388) averaged 70.6 years (83% women, 64% non-Hispanic white).

INTERVENTION

In AFL, Active Choices was a 6-month telephone-based and ALED a 20-week group-based lifestyle behavior change program designed to increase physical activity, and both were grounded in social cognitive theory and the transtheoretical model. The interventions were evaluated in Years 1, 3, and 4. An adapted shortened ALED program was evaluated in Year 4.

MAIN OUTCOME MEASURE

Moderate- to vigorous-intensity physical activity, assessed with the CHAMPS self-reported measure.

RESULTS

Posttest survey response rates were 61% for Active Choices and 70% for ALED. Significant increases in moderate- to vigorous-intensity physical activity, total physical activity, and satisfaction with body appearance and function, and decreases in BMI were seen for both programs. Depressive symptoms and perceived stress, both low at pretest, also decreased over time in ALED. Results were generally consistent across years and sites.

CONCLUSIONS

Active Choices and ALED were successfully translated across a range of real-world settings. Study samples were substantially larger, more ethnically and economically diverse, and more representative of older adult's health conditions than in efficacy studies, yet the magnitude of effect sizes were comparable.

Self-efficacy moderates the relation between declines in physical activity and perceived social support in high school girls

OBJECTIVE

To test whether self-efficacy for overcoming barriers to physical activity has direct, indirect (i.e., mediated), or moderating relations with naturally occurring change in perceived social support and declines in physical activity during high school.

METHODS

Latent growth modeling was used with measures completed in the 8th, 9th, and 12th grades by a cohort of 195 Black and White girls.

RESULTS

Self-efficacy was stable and moderated the relation between changes in physical activity and perceived social support. Girls who maintained a perception of strong social support had less of a decline in physical activity if they also had high self-efficacy. However, girls having high self-efficacy had a greater decline in physical activity if they perceived declines in social support.

CONCLUSIONS

Randomized controlled trials of physical activity interventions based on social cognitive theory should consider that the influence of girls' perceptions of social support on their physical activity may differ according to their efficacy beliefs about barriers to physical activity.

Directly observed physical activity levels in preschool children

BACKGROUND

Millions of young children attend preschools and other structured child development programs, but little is known about their physical activity levels while in those settings. The purpose of this study was to describe the physical activity levels and demographic and school-related correlates of physical activity in children attending preschools, using a direct observation measurement system.

METHODS

The Observational System for Recording Physical Activity in Children-Preschool Version was used to measure physical activity levels and related factors in four hundred ninety-three 3- to 5-year-old children in 24 preschools. A minimum of six hundred 30-second observation intervals were recorded for each child. Physical (height/weight) and demographic data also were collected.

RESULTS

Children engaged in moderate-to-vigorous physical activity (MVPA) during less than 3% of the observation intervals and were sedentary during more than 80% of the observation intervals. Boys were more likely than girls to engage in MVPA (p = .01), and 3-year-old boys were more active than 4- and 5-year-old boys (p = .01). The preschool that a child attended explained 27% of the variance in activity levels.

CONCLUSIONS

The study indicates that young children are physically inactive during most of their time in preschool. The preschool that a child attended was a stronger predictor of physical activity level than any other factor examined. Additional research is needed to identify the characteristics of preschools in which children are more active.

Motor skill performance and physical activity in preschool children

Children with better-developed motor skills may find it easier to be active and engage in more physical activity (PA) than those with less-developed motor skills. The purpose of this study was to examine the relationship between motor skill performance and PA in preschool children. Participants were 80 three- and 118 four-year-old children. The Children's Activity and Movement in Preschool Study (CHAMPS) Motor Skill Protocol was used to assess process characteristics of six locomotor and six object control skills; scores were categorized as locomotor, object control, and total. The actigraph accelerometer was used to measure PA; data were expressed as percent of time spent in sedentary, light, moderate-to-vigorous PA (MVPA), and vigorous PA (VPA). Children in the highest tertile for total score spent significantly more time in MVPA (13.4% vs. 12.8% vs. 11.4%) and VPA (5% vs. 4.6% vs. 3.8%) than children in middle and lowest tertiles. Children in the highest tertile of locomotor scores spent significantly less time in sedentary activity than children in other tertiles and significantly more time in MVPA (13.4% vs. 11.6%) and VPA (4.9% vs. 3.8%) than children in the lowest tertile. There were no differences among tertiles for object control scores. Children with poorer motor skill performance were less active than children with better-developed motor skills. This relationship between motor skill performance and PA could be important to the health of children, particularly in obesity prevention. Clinicians should work with parents to monitor motor skills and to encourage children to engage in activities that promote motor skill performance.

Physical activity and neighborhood resources in high school girls

BACKGROUND

Physical activity behavior is influenced by a person's physical environment, but few studies have used objective measures to study the influences of the physical environment on physical activity behavior in youth. The purpose of this study was to examine the relationship between selected neighborhood physical activity resources and physical activity levels in high school girls.

METHODS

Participants were students in schools that had participated in a large physical activity intervention trial. The 3-Day Physical Activity Recall was completed by 1506 12th-grade girls. Data on physical activity facilities and resources in the participating communities were collected using a variety of methods. Physical activity resources within a 0.75-mile street-network buffer around each girl's home were counted using ArcGIS, version 9.1. Mixed-model regression models were used to determine if there was a relationship between three physical activity variables and the number of physical activity resources within the 0.75-mile buffer. Data were collected in 2002-2003 and analyzed in 2006-2007.

RESULTS

On average, 3.5 physical activity resources (e.g., schools, parks, commercial facilities) were located within the 0.75-mile street-network buffer. Thirty-six percent of the girls had no physical activity resource within the buffer. When multiple physical activity resources were considered, the number of commercial physical activity facilities was significantly associated with reported vigorous physical activity, and the number of parks was associated with total METs in white girls.

CONCLUSIONS

Multiple physical activity resources within a 0.75-mile street-network buffer around adolescent girls' homes are associated physical activity in those girls. Several types of resources are associated with vigorous physical activity and total activity in adolescent girls. Future studies should examine the temporal and causal relationships between the physical environment, physical activity, and health outcomes related to physical activity.

Physical fitness and performance. Cardiorespiratory fitness in girls-change from middle to high school

PURPOSE

To determine how factors are related to change in cardiorespiratory fitness (CRF) across time in middle school girls followed through high school.

METHODS

Adolescent girls (N = 274, 59% African American, baseline age = 13.6 +/- 0.6 yr) performed a submaximal fitness test (PWC170) in 8th, 9th, and 12th grades. Height, weight, sports participation, and physical activity were also measured. Moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) were determined by the number of blocks reported on the 3-Day Physical Activity Recall (3DPAR). Individual differences and developmental change in CRF were assessed simultaneously by calculating individual growth curves for each participant, using growth curve modeling.

RESULTS

Both weight-relative and absolute CRF increased from 8th to 9th grade and decreased from 9th to 12th grade. On average, girls lost 0.16 kg.m.min.kg.yr in weight-relative PWC170 scores (P < 0.01) and gained 10.3 kg.m.min.yr in absolute PWC170 scores. Girls reporting two or more blocks of MVPA or one or more blocks of VPA at baseline showed an average increase in PWC170 scores of 0.40-0.52 kg.m.min.kg.yr (weight relative) and 22-28 kg.m.min.yr (absolute) in CRF. In weight-relative models, girls with higher BMI showed lower CRF (approximately 0.37 g.m.min.kg.yr), but this was not shown in absolute models. In absolute models, white girls (approximately 40 kg.m.min.yr) and sport participants (approximately 28 kg.m.min.yr) showed an increase in CRF over time.

CONCLUSION

Although there were fluctuations in PWC170 scores across time, average scores decreased during 4 yr. Physical activity was related to change in CRF over time; BMI, race, and sport participation were also important factors related to change over time in CRF (depending on expression of CRF-weight-relative vs absolute). Subsequent research should focus on explaining the complex longitudinal interactions between CRF, physical activity, race, BMI, and sports participation.

Associations among physical activity, health indicators, and employment in 12th grade girls

OBJECTIVES

This study compared physical activity, sedentary behaviors, and other health indicators between 1381 employed and nonemployed 12th grade girls.

METHODS

The girls were from 22 high schools in South Carolina (2002-2003); 56% of the girls were African American, and the mean age was 17.7 (0.6) years. Physical activity and sedentary behaviors were measured using the 3-Day Physical Activity Recall (3DPAR). Fitness, depressive symptoms, and smoking behavior were assessed.

RESULTS

Fifty percent of the girls were employed, and on average, employed girls worked 9.6 30-minute blocks per day. Girls who worked reported significantly (p < or = 0.001) higher average total metabolic equivalents (METs) (mean [M] 66.4, SE 0.5) than girls who did not work (M 59.5, SE 0.5). Also, a higher percent of girls who worked reported 2+ blocks of moderate to vigorous physical activity (MVPA) (89.3%), and fewer (20.2%) reported 4+ blocks of electronic media (EM) compared with girls who did not work (MVPA 62.7%, EM 41.7%). After on-the-job activity was subtracted, total METs for girls who worked was reduced to 48.0 (SE 0.4), and only 48.5% reported 2 or more blocks on average of MVPA. No significant differences (p > 0.05) were found between girls who reported working (W) and those who did not (NW) for body mass index (BMI) (W: M 25.2, SE 0.2; NW: M 24.6, SE 0.2), depression scores (W: M 14.4, SE 0.5; NW: M 14.4, SE 0.5), fitness (W: M 11.3 kg . m/min/kg, SE 0.2; NW: M 11.7 kg . m/min/kg, SE 0.2), or smoking during the past 30 days (W: 18.5%; NW: 17.4%).

CONCLUSIONS

Nearly one third of employed high school girls' total physical activity occurred while they were at work. Employed girls also spent less time using electronic media. Employment was not associated with fitness, smoking, or depressive symptoms in 12th grade girls.

Towards an understanding of salient neighborhood boundaries: adolescent reports of an easy walking distance and convenient driving distance

Numerous studies have examined the association between the surrounding neighborhood environment and physical activity levels in adolescents. Many of these studies use a road network buffer or Euclidean distance buffer around an adolescent's home to represent the appropriate geographic area for study (i.e., neighborhood). However, little empirical research has examined the appropriate buffer size to use when defining this area and there is little consistency across published research as to the buffer size used. In this study, 909 12^th grade adolescent girls of diverse racial and geographic backgrounds were asked to report their perceptions of an easy walking distance and a convenient driving distance. These two criterions are often used as the basis for defining one's neighborhood.

The mean easy walking distance in minutes reported by adolescent girls was 14.8 minutes (SD = 8.7). The mean convenient driving distance in minutes reported was 17.9 minutes (SD = 10.8). Nested linear multivariate regression models found significant differences in reported 'easy walking distance' across race and BMI. White adolescents reported on average almost 2 minutes longer for an easy walking distance compared to African American adolescents. Adolescents who were not overweight or at risk for overweight reported almost 2 minutes fewer for an easy walking distance relative to those who were overweight or at risk for overweight. Significant differences by urban status were found in the reported 'convenient driving distance'. Those living in non-urban areas reported on average 3.2 minutes more driving time as convenient compared to those living in urban areas. Very little variability in reported walking and driving distances was explained by the predictors used in the models (i.e., age, race, BMI, physical activity levels, urban status and SES).

This study suggests the use of a 0.75 mile buffer to represent an older female adolescent's neighborhood, which can be accessed through walking. However, determining the appropriate area inclusive of car travel should be tailored to the geographic location of the adolescent since non-urban adolescents are willing to spend more time driving to destinations. Further research is needed to understand the substantial variability across adolescent perceptions of an easy walking and convenient driving distance.

Long-term effects of a physical activity intervention in high school girls

BACKGROUND

Physical activity (PA) decreases during childhood and adolescence, and PA levels are significantly lower in females than males, particularly during adolescence. Schools are attractive settings in which to implement interventions designed to promote PA in girls and young women, but few studies have tested the sustained effects of such interventions.

DESIGN

Cross-sectional. Data were collected in 2002-2003 and analyzed in 2006-2007.

SETTING/PARTICIPANTS

1594 adolescent girls in 22 high schools.

INTERVENTION

The intervention, Lifestyle Education for Activity Program (LEAP), was designed to increase physical activity in 9th-grade girls through two channels: changes in instructional practices and changes in the school environment. This study (LEAP 2) examined the extent to which effects of the intervention were maintained when the girls were in the 12th grade.

MAIN OUTCOME MEASURES

Number of 30-minute blocks per day of vigorous physical activity.

RESULTS

Girls in the intervention schools that most fully implemented and maintained the intervention were more likely than girls in the other schools to participate in an average of one or more blocks of vigorous physical activity per day (p=0.04, odds ratio=1.49, 95% confidence interval=1.01-2.20).

CONCLUSIONS

A comprehensive physical activity intervention that is fully implemented and maintained can increase participation in vigorous physical activity by high school girls.

Enrollment in physical education is associated with overall physical activity in adolescent girls

Little is known about population-level contributions of school physical education to overall physical activity (PA) in youth. Because PA levels are lower in girls than boys, it is particularly important that the effects of PE programs in adolescent girls be understood. Thus, the purpose of this study was to determine the association of enrollment in physical education and overall physical activity participation in adolescent girls. A measurement protocol was administered to cross-sectional samples of 8th-, 9th-, and 12th-grade girls participating in a school-based PA intervention study (1998-2003). PA was assessed with the 3-Day Physical Activity Recall. Three-way analyses of variance were performed to compare groups formed on the basis of physical education enrollment. For each grade group of girls, those who were enrolled in physical education reported more moderate-to-vigorous PA and more vigorous PA than nonenrolled girls. When activity in physical education classes was deleted, 8th- and 9th-grade physical education enrollees were not more active than nonenrollees; however, 12th-grade physical education enrollees remained more active than nonenrollees. Girls who were enrolled in physical education were more physically active than nonenrolled girls in all three grade levels. These findings suggest that expanded enrollment in physical education may increase American adolescent girls' PA level.

Commercial venues as supports for physical activity in adolescent girls

OBJECTIVE

The purposes of this study were to describe the types and availability of commercial facilities for physical activity (PA) in six diverse geographic areas (Washington DC and Maryland; South Carolina; Minnesota; Louisiana; Arizona; and California) and to assess the relationship between those facilities and the non-school PA of adolescent girls.

METHODS

A total of 1556 6th grade girls participating in the Trial of Activity for Adolescent Girls (TAAG) wore accelerometers for 7 days providing 6 days of complete data, completed questionnaires in 2003 and had their residential addresses geocoded. Nearby commercial facilities available to provide PA (i.e. dance studios, youth organizations) within a 1-mile radius of participants' residences were identified and geocoded. The association between the presence of any commercial PA facility and girls' PA was determined using a multi-level design and controlling for demographic characteristics and other potential confounders. Analyses were conducted in 2005-2006.

RESULTS

Sixty-eight percent of the girls had at least one commercial PA facility near their homes. Availability and types of commercial PA facilities differed by where participants lived. Girls who lived near one or more commercial PA facilities had higher non-school MET-weighted moderate-to-vigorous PA than girls who had none near their homes.

CONCLUSIONS

The findings suggest that commercial PA facilities are important contributors to the accumulation of PA among adolescent girls.

Change in physical activity participation among adolescent girls from 8th to 12th grade

BACKGROUND

Physical activity levels of girls decline in adolescence, but little is known about changes in participation in specific types of physical activity. This study examined change in participation in specific activities during adolescence in girls.

METHODS

Girls (N = 398, age 13.6 +/- 0.6 y at baseline, 58.5% African American) from 31 middle and 24 high schools in South Carolina completed the 3-Day Physical Activity Recall (3DPAR) in 8th, 9th, and 12th grades. Girls reported their predominant activity and its intensity level in each 30-min time block on the previous 3 d.

RESULTS

Vigorous physical activity declined from 45.4% in 8th grade to 34.1% in 12th grade. The probability of participating in several forms of vigorous physical activity in 12th grade was strongly associated with participation in those activities in 8th grade.

CONCLUSION

Early-in-life participation in sports and other forms of vigorous physical activity are important to the maintenance of physical activity during adolescence in girls.

Correlates of self-regulation for physical activity among older adults

OBJECTIVES

To examine correlates of self-regulation (personal regulation of goal-directed behavior or performance) for physical activity (PA) in older adults.

METHODS

A convenience sample (N=296) of older adults was surveyed (M age=70.4 years).

RESULTS

Hierarchical regression analyses revealed current PA engagement and sets of sociodemographic, health-related, and theoretical variables as independent correlates of self-regulation (model R2 = 37%, P < 0.0001). In the final model, female gender, older age, social support, self-efficacy, and greater PA were positive, independent correlates.

CONCLUSIONS

Self-regulatory strategies are vital to PA promotion across the life span. Therefore, it is important to understand factors associated with self-regulation and use this information for intervention design and implementation.

Family support for physical activity in girls from 8th to 12th grade in South Carolina

OBJECTIVE

To examine the relationship between perceived family support and other selected correlates of physical activity (PA) with changes in PA over time.

METHODS

A total of 421 girls in South Carolina completed questionnaires at 8th, 9th and 12th grades (1998-2003). Family support for PA, PA self-efficacy, perceived behavioral control, attitudes, availability of equipment, and PA were measured.

RESULTS

Growth curve analysis showed that family support, perceived behavioral control, and self-efficacy were independently related to age-related changes in PA as reflected by total METs. Girls who reported lower family support at the 8th grade measure had more rapid declines in PA, and a unit change in family support was related to approximately 1/3 of a standard deviation change in total METs.

CONCLUSIONS

Maintenance of support from family members may reduce the decline in PA independent of girls' self-efficacy and perceived behavioral control.

Goals and intentions mediate efficacy beliefs and declining physical activity in high school girls

BACKGROUND

According to theory, girls who set goals about increasing their physical activity and who are dissatisfied with their current activity level are likely to form intentions to be active and to carry out those intentions, especially if they have high efficacy and control beliefs about being physically active. We tested those ideas while observing naturally occurring change during high school.

METHODS

A cohort of 431 black and white girls was tested at the end of their 9th- and 12th-grade academic years. Confirmatory factor analysis established the structural invariance of the measures across the 3-year study period. Structural equation modeling and panel analysis were used to determine whether changes in goal setting and satisfaction would mediate relations of self-efficacy and perceived behavioral control with changes in intention and physical activity. Testing occurred between February and May in 1999 and 2004. Data were analyzed in 2006.

RESULTS

Goal setting and intention mediated the indirect relation between self-efficacy and change in physical activity. Perceived behavioral control and physical activity change were related directly and also indirectly by a path mediated through satisfaction and intention. Black girls had lower self-efficacy, but changes in other variables were unrelated to race.

CONCLUSIONS

These observations of longitudinal relations elaborate application of self-efficacy theory and the theory of planned behavior to physical activity by showing that goal setting and satisfaction mediate the relations of self-efficacy and perceived behavioral control with changes in intention and physical activity. The results encourage additional research to identify the sources and development of physical activity goals, and their attainment, among girls, and whether experimental manipulation of goals and intentions can mitigate the decline in girls' physical activity during high school.

Physical self-concept and self-esteem mediate cross-sectional relations of physical activity and sport participation with depression symptoms among adolescent girls

The authors tested whether physical self-concept and self-esteem would mediate cross-sectional relations of physical activity and sport participation with depression symptoms among 1,250 girls in 12th grade. There was a strong positive relation between global physical self-concept and self-esteem and a moderate inverse relation between self-esteem and depression symptoms. Physical activity and sport participation each had an indirect, positive relation with global physical self-concept that was independent of objective measures of cardiorespiratory fitness and body fatness. These correlational findings provide initial evidence suggesting that physical activity and sport participation might reduce depression risk among adolescent girls by unique, positive influences on physical self-concept that operate independently of fitness, body mass index, and perceptions of sports competence, body fat, and appearance.

Examining the link between program implementation and behavior outcomes in the lifestyle education for activity program (LEAP)

Lifestyle Education for Activity Program (LEAP) was a comprehensive, school-based intervention designed to promote physical activity in high school girls. The intervention focused on changes in instructional practices and the school environment to affect personal, social, and environmental factors related to physical activity. Multiple process evaluation tools and an organizational assessment tool were developed to monitor program implementation from a framework called the LEAP essential elements, which characterized complete and acceptable intervention delivery; secular trends were also monitored. Using process data, LEAP intervention schools were categorized into low- and high-implementing groups and compared with control schools on nine essential elements assessed at the organizational level. The Wilcoxon scores test revealed that low- and high-implementing intervention, and control schools differed significantly on two of nine administrator-reported organizational-level components: having a physical activity team and having a faculty-staff health promotion program. A mixed-model analysis of covariance indicated that, compared to control schools, a greater percentage of girls in high-implementing schools reported engaging in vigorous physical activity. Process evaluation can be used to understand the relationship between level of implementation and successful program outcome.

Validation and calibration of an accelerometer in preschool children

OBJECTIVE

Obesity rates in young children are increasing, and decreased physical activity is likely to be a major contributor to this trend. Studies of physical activity in young children are limited by the lack of valid and acceptable measures. The purpose of this study was to calibrate and validate the ActiGraph accelerometer for use with 3- to 5-year-old children.

RESEARCH METHODS AND PROCEDURES

Thirty preschool children wore an ActiGraph accelerometer (ActiGraph, Fort Walton Beach, FL) and a Cosmed portable metabolic system (Cosmed, Rome, Italy) during a period of rest and while performing three structured physical activities in a laboratory setting. Expired respiratory gases were collected, and oxygen consumption was measured on a breath-by-breath basis. Accelerometer data were collected at 15-second intervals. For cross-validation, the same children wore the same instruments while participating in unstructured indoor and outdoor activities for 20 minutes each at their preschool.

RESULTS

In calibrating the accelerometer, the correlation between Vo(2) (ml/kg per min) and counts was r = 0.82 across all activities. The only significant variable in the prediction equation was accelerometer counts (R(2) = 0.90, standard error of the estimate = 4.70). In the cross-validation, the intraclass correlation coefficient between measured and predicted Vo(2) was R = 0.57 and the Spearman correlation coefficient was R = 0.66 (p < 0.001). Cut-off points for moderate- and vigorous-intensity physical activity were identified at 420 counts/15 s (Vo(2) = 20 mL/kg per min) and 842 counts/15 s (Vo(2) = 30 mL/kg per min), respectively. When these cutpoints were applied to the cross-validation data, percentage agreement, kappa, and modified kappa for moderate activity were 0.69, 0.36, and 0.38, respectively. For vigorous activity, the same measures were 0.81, 0.13, and 0.62.

DISCUSSION

Accelerometer counts were highly correlated with Vo(2) in young children. Accelerometers can be appropriately used as a measure of physical activity in this population.

Cardiorespiratory fitness levels among US youth 12 to 19 years of age: findings from the 1999-2002 National Health and Nutrition Examination Survey

OBJECTIVES

To assess cardiorespiratory fitness levels in youth aged 12 to 19 years and to examine associations between fitness and age, sex, race/ethnicity, and self-reported physical activity in this age group.

DESIGN

Cross-sectional study.

SETTING

The National Health and Nutrition Examination Survey's mobile examination center, throughout the United States from 1999-2002.

PARTICIPANTS

A representative sample of 4732 youth aged 12 to 19 years was examined; 3287 completed the treadmill test and were included in the analysis. The National Center for Health Statistics conducted the survey. Main Exposures Age, sex, race/ethnicity, weight status, self-reported physical activity, and television viewing. Main Outcome Measure Estimated maximal oxygen uptake (VO2max) determined by a submaximal treadmill exercise test.

RESULTS

Estimated VO2max (mL.kg(-1) . min(-1)) was higher in males (mean +/- SE, 46.4 +/- 0.4) than in females (mean +/- SE, 38.7 +/- 0.3) but did not differ across race/ethnicity groups. Among males, older participants had higher VO2max values, while in females, younger participants had higher values. For both males and females, those in the normal weight group had higher fitness levels than those in the at risk for overweight and overweight groups. Approximately one third of both males and females failed to meet recommended standards for cardiorespiratory fitness.

CONCLUSIONS

In US youth, cardiorespiratory fitness is lower in males and females who are overweight than in those of normal weight, but fitness is not related to race/ethnicity. Youth who have low levels of physical activity and high levels of sedentary behavior are also more likely to have lower cardiorespiratory fitness.

School-level intraclass correlation for physical activity in sixth grade girls

PURPOSE

The Trial for Activity in Adolescent Girls (TAAG) is a group-randomized trial (GRT) to reduce the usual decline in moderate to vigorous physical activity (MVPA) among middle school girls. We report the school-level intraclass correlation (ICC) for MVPA from the TAAG baseline survey of sixth grade girls and describe the relationship between the schedule of data collection and the ICC.

METHODS

Each of six sites recruited six schools and randomly selected 60 sixth grade girls from each school; 74.2% participated. Girls were grouped in waves defined by the date measurements began and asked to wear an Actigraph accelerometer for 6 d. Occasional missing data were replaced by imputation, and counts above 1500 per 30 s were treated as MVPA, converted into metabolic equivalents (METs), and summed over 6 a.m.-midnight to provide MET-minutes per 18-h day. Mixed-model regression was used to estimate ICC.

RESULTS

The school-level ICC were higher when estimated from a single wave compared with three waves (e.g., 0.057 vs 0.022) and across weekdays compared with weekend days (e.g., 0.024 vs 0.012). Power in a new trial would be greater with some schedules (e.g., 88% given three waves and 6 d) than with others (e.g., 23% given one wave and Tuesday only).

CONCLUSIONS

The schedule of data collection can have a dramatic effect on the ICC for MVPA. In turn, this can have a dramatic effect on the standard error for an intervention effect and on power. Investigators will need to consider the expected magnitude of the ICC and the validity of the MVPA estimates associated with their data collection schedule in planning a new study.

Sport participation and physical activity in adolescent females across a four-year period

PURPOSE

To determine the odds of engaging in future moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) in adolescent female sport participants. A secondary purpose was to compare activity levels of three groups of girls, those who played sports at three time points, those who dropped out, and those who did not participate in sports.

METHODS

Data were collected at three time points, eighth, ninth, and 12th grades, in 429 adolescent girls across the state of South Carolina. Demographic, sport participation and physical activity (PA) data were collected using surveys. Odds ratios were calculated to determine the association between sport participation and future PA behavior. PA was also compared for three sport participation groups (nonparticipants, dropouts, or three-year participants) using analysis of variance.

RESULTS

For MVPA, ninth grade participants were more likely to be active in 12th grade (OR = 1.74 [1.13, 2.67]), and eighth and ninth grade participants more likely to be active in 12th grade than nonparticipants (OR = 1.54 [confidence interval 1.01, 2.35]). For VPA, sport participants had higher odds of being active at all future time points. Three-year participants were significantly more vigorously active than nonparticipants and dropouts at all three time points (p < .01).

CONCLUSIONS

Adolescent girls who participate in sports in eighth, ninth, and 12th grades are more likely to be vigorously active in 12th grade. These findings are novel in providing evidence that sport participation contributes to overall vigorous physical activity during late adolescence, when overall physical activity is known to decline precipitously.

Results of the first year of active for life: translation of 2 evidence-based physical activity programs for older adults into community settings

OBJECTIVES

Translating efficacious interventions into practice within community settings is a major public health challenge. We evaluated the effects of 2 evidence-based physical activity interventions on self-reported physical activity and related outcomes in midlife and older adults.

METHODS

Four community-based organizations implemented Active Choices, a 6-month, telephone-based program, and 5 implemented Active Living Every Day, a 20-week, group-based program. Both programs emphasize behavioral skills necessary to become more physically active. Participants completed pretest and posttest surveys.

RESULTS

Participants (n=838) were aged an average of 68.4 +/-9.4 years, 80.6% were women, and 64.1% were non-Hispanic White. Seventy-two percent returned posttest surveys. Intent-to-treat analyses found statistically significant increases in moderate-to-vigorous physical activity and total physical activity, decreases in depressive symptoms and stress, increases in satisfaction with body appearance and function, and decreases in body mass index.

CONCLUSIONS

The first year of Active for Life demonstrated that Active Choices and Active Living Every Day, 2 evidence-based physical activity programs, can be successfully translated into community settings with diverse populations. Further, the magnitudes of change in outcomes were similar to those reported in the efficacy trials.

Assessing preschool children's physical activity: the Observational System for Recording Physical Activity in children-preschool version

In this paper we present initial information concerning a new direct observation system-the Observational System for Recording Physical Activity in Children-Preschool Version. The system will allow researchers to record young children's physical activity levels while also coding the topography of their physical activity, as well as detailed indoor and outdoor social and nonsocial contextual information. With respect to interobserver agreement (IOA), the kappa and category-by-category agreement mean of those obtained for the three illustrative preschools were generally above .80. Hence, our IOA data indicated that trained observers in the three preschools frequently agreed on the eight observational categories and accompanying codes. The results for preschoolers' level of physical activity indicated they spent the majority of observational intervals in sedentary activity (i.e., more than 80% intervals) and were observed in moderate to vigorous physical activity much less frequently (i.e., 5% or fewer intervals). For the 15 indoor and 12 outdoor activity contexts, variability across both the activity contexts and the three preschools were evident. Nevertheless, three classroom contexts-transition, snacks, and naptime--accounted for the greatest porportion of coded activity contexts for the children. In the three preschools, 4 of 17 physical activity types--sit and squat, lie down, stand, and walk--accounted for the topography of much of children's physical activity behavior Systematic observation of more representative preschool samples might better inform our present understanding of young children's physical activity in community preschool programs.

Perceptions of physical and social environment variables and self-efficacy as correlates of self-reported physical activity among adolescent girls

OBJECTIVE

This cross-sectional study examined the direct and indirect effects of perceived equipment accessibility, neighborhood safety, and social support on self-reported physical activity among older adolescent girls.

METHODS

Adolescent girls (n = 1,655) who were in the 12th grade completed a battery of questionnaires that included self-report measures of the perceived physical environment, social support, barriers self-efficacy, and physical activity.

RESULTS

Perceived neighborhood safety did not exhibit direct or indirect effects on self-reported physical activity. Perceived equipment accessibility exhibited an indirect effect on self-reported physical activity that was accounted for by barriers self-efficacy. Perceived social support exhibited direct and indirect effects on self-reported physical activity; the indirect effect was accounted for by barriers self-efficacy. The relationships were independent of parental education and body mass index (BMI).

CONCLUSIONS

Perceived physical environmental factors indirectly influenced self-reported physical activity, and perceived social environmental factors both directly and indirectly influenced self-reported physical activity in this sample of older adolescent girls.