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1.
Pediatr Obes ; 13 Suppl 1: 64-71, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30270519

RESUMEN

INTRODUCTION: This manuscript describes the prevalence and attributes of community programmes and policies (CPPs) to address childhood obesity documented as occurring in 130 diverse US communities. METHODS: Key informant interviews (N = 1420) and document abstraction were used to identify and characterize CPPs to promote physical activity and healthy nutrition occurring during a 10-year retrospective study period. Data were collected in 2013-2015 and analysed in 2016. RESULTS: Across all 130 communities, 9681 distinct CPPs were reported as occurring by key informants. Of these, 5574 (58%) focused on increasing physical activity, 2596 (27%) on improving nutrition and 1511 (16%) on both behaviours. The mean number of CPPs per community was 74.0, with a range of 25 to 295 across all communities. Most CPPs occurred more than once (63%) and on average lasted 6.1 years. The greatest number of reported CPPs occurred in school settings (44%). CONCLUSIONS: Communities showed a wide range of investment in the amount of CPPs occurring in settings that affect opportunities for children to engage in physical activity and healthy nutrition. The pattern of implementation of CPPs showed variation over time, with an increase in more recent years. This observational study provides new and valuable information about what US communities are doing to prevent childhood obesity.


Asunto(s)
Promoción de la Salud/estadística & datos numéricos , Obesidad Infantil/prevención & control , Servicios Preventivos de Salud/estadística & datos numéricos , Niño , Estudios Transversales , Dieta Saludable/estadística & datos numéricos , Ejercicio Físico , Conducta Alimentaria , Femenino , Humanos , Estudios Longitudinales , Masculino , Estado Nutricional , Obesidad , Prevalencia , Salud Pública/estadística & datos numéricos , Estudios Retrospectivos , Estados Unidos
2.
Pediatr Obes ; 13 Suppl 1: 7-13, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29900696

RESUMEN

BACKGROUND: Residential environments may significantly influence youth physical activity (PA). However, few studies have examined detailed street quality attributes via observational audits in relation to context-specific PA among youth. OBJECTIVES: The objective of this study was to explore whether the overall quality of street environments, as well as specific attributes, was associated with neighbourhood-based and street-based PA within a national sample of youth in the Healthy Communities Study. METHODS: Data were collected from 4616 youth from 130 communities across the USA. Youth PA in the neighbourhood and on the participant's street was captured using 7-d recall interviews. Windshield survey observational audits documented five street quality variables: burned, boarded up or abandoned residential units, litter, overall condition of residences, street type and presence of sidewalks in good condition. RESULTS: Youth with no litter on their street reported significantly lower neighbourhood-based PA and youth living on a side street, cul-de-sac, dead-end or one-way street reported greater neighbourhood-based PA. No significant associations were detected for the overall street quality index or with street-based PA. CONCLUSIONS: Specific street quality attributes may be associated with youth PA. Further research and collaboration between diverse disciplines and agencies should focus on understanding and improving street quality to promote youth PA and health.


Asunto(s)
Planificación Ambiental/estadística & datos numéricos , Ejercicio Físico , Salud Pública/estadística & datos numéricos , Características de la Residencia/estadística & datos numéricos , Adolescente , Estudios Transversales , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Auditoría Médica , Factores Sociológicos , Estados Unidos
3.
Pediatr Obes ; 13 Suppl 1: 72-81, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29900697

RESUMEN

BACKGROUND: Community initiatives to promote physical activity in children are common, but evidence supporting their effectiveness is limited. OBJECTIVES: The objective of this study is to examine the relationships between community programmes and policies and children's physical activity in a large and diverse sample of US communities. METHODS: Programmes and policies to promote children's physical activity were assessed in 130 communities by key informant interviews, and physical activity behaviours were measured by self-report and parental report in samples of children in each community (total n = 5138). Associations between composite indices of community programmes and policies and indicators of total and moderate-to-vigorous physical activity were examined without and with adjustment for demographic factors. RESULTS: An index reflecting the 6-year history of the number of behaviour change strategies used in community programmes and policies was positively associated with children's moderate-to-vigorous physical activity. This association was attenuated with adjustment for demographic factors. Effect modification analyses found that the association was positive among non-Hispanic children but was negative for Hispanic children. CONCLUSIONS: Community initiatives to promote physical activity in children were positively associated with children's physical activity in non-Hispanic children. Such initiatives were negatively associated with physical activity in Hispanic children, suggesting that future research should consider unique cultural factors when designing community initiatives to promote activity in this population sub-group.


Asunto(s)
Ejercicio Físico , Obesidad Infantil/prevención & control , Servicios Preventivos de Salud/estadística & datos numéricos , Salud Pública/estadística & datos numéricos , Niño , Estudios Transversales , Femenino , Humanos , Estudios Longitudinales , Masculino , Estudios Retrospectivos , Autoinforme , Estados Unidos
4.
Pediatr Obes ; 13 Suppl 1: 36-45, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29900698

RESUMEN

BACKGROUND: Physical activity helps prevent excessive weight gain in youth. Few studies have examined regional variations in common activities, walking and bicycling. OBJECTIVE: The primary aim was to examine participation in previous 7-day walking/bicycling for active transport and for fun/exercise by region, gender and age groups. METHODS: Children (n = 2693) from 130 diverse, geographically distributed US communities reported participation in previous 7-day walking/bicycling. Mixed model ANOVAs were used to compare walking/bicycling by region, gender and age groups using Healthy Communities Study data. RESULTS: Walking/bicycling for fun/exercise was higher in the Midwest, South and West compared with the Northeast, with the same regional patterns for boys, girls and 9-11-year olds. Walking/bicycling to non-school destinations was higher in the Midwest compared with the South and Northeast, with the same pattern for girls and 9-11-year olds. Walking/bicycling to school was higher Midwest, Northeast and West compared with the South, with similar patterns for girls and 12-15-year olds. CONCLUSIONS: Walking/bicycling for fun/exercise and to non-school destinations had higher prevalence than active transport to school. The Northeast reported lower walking/bicycling for fun/exercise; the South and Northeast reported lower walking/bicycling to non-school destinations. Program/policy initiatives should consider contextual demographic influences, as well as purpose/destination of walking/bicycling.


Asunto(s)
Ciclismo/estadística & datos numéricos , Caminata/estadística & datos numéricos , Adolescente , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Recreación , Instituciones Académicas , Transportes/estadística & datos numéricos , Estados Unidos
5.
Pediatr Obes ; 13 Suppl 1: 82-92, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29493122

RESUMEN

BACKGROUND: Although a national epidemic of childhood obesity is apparent, how community-based programmes and policies (CPPs) affect this outcome is not well understood. OBJECTIVES: This study examined the longitudinal relationship between the intensity of CPPs in 130 communities over 10 years and body mass index (BMI) of resident children. We also examined whether these relationships differ by key family or community characteristics. METHODS: Five thousand one hundred thirty-eight children in grades K-8 were recruited through 436 schools located within 130 diverse US communities. Measures of height, weight, nutrition, physical activity and behavioural and demographic family characteristics were obtained during in-home visits. A subsample of families consented to medical record review; these weight and height measures were used to calculate BMI over time for 3227 children. A total of 9681 CPPs were reported during structured interviews of 1421 community key informants, and used to calculate a time series of CPP intensity scores within each community over the previous decade. Linear mixed effect models were used to assess longitudinal relationships between childhood BMI and CPP intensity. RESULTS: An average BMI difference of 1.4 kg/m2 (p-value < 0.01) was observed between communities with the highest and lowest observed CPP intensity scores, after adjusting for community and child level covariates. BMI/CPP relationships differed significantly by child grade, race/ethnicity, family income and parental education; as well as community-level race/ethnicity. CONCLUSIONS: These results indicate that, over time, more intense CPP interventions are related to lower childhood BMI, and that there are disparities in this association by sociodemographic characteristics of families and communities.


Asunto(s)
Índice de Masa Corporal , Obesidad Infantil/prevención & control , Servicios Preventivos de Salud/estadística & datos numéricos , Salud Pública/estadística & datos numéricos , Peso Corporal , Niño , Preescolar , Ejercicio Físico , Composición Familiar , Femenino , Disparidades en Atención de Salud/estadística & datos numéricos , Humanos , Estudios Longitudinales , Masculino , Obesidad Infantil/epidemiología , Instituciones Académicas/estadística & datos numéricos , Estados Unidos/epidemiología
6.
Health Educ Res ; 29(3): 491-502, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24659421

RESUMEN

Despite evidence that preschoolers spend the majority of their time in sedentary activities, few physical activity interventions have focused on preschool-age children. Health promotion interventions that can be integrated into the daily routines of a school or other setting are more likely to be implemented. The Study of Health and Activity in Preschool Environments employed a flexible approach to increasing physical activity opportunities in preschools' daily schedules through recess, indoor physical activity and physical activity integrated into academic lessons. Eight preschools were randomly assigned to receive the study's physical activity intervention. Teachers in these schools partnered with university-based interventionists across 3 years to design and implement a flexible and adaptive intervention. The intervention approach included trainings and workshops, site visits and feedback from intervention personnel, newsletters, and physical activity equipment and materials. Teachers reported a high acceptability of the intervention. The purpose of this article is to describe the evolution of a multi-component physical activity intervention in preschools, including (i) a description of the intervention components, (ii) an explanation of the intervention process and approach, and (iii) a report of teachers' perceptions of barriers to implementation.


Asunto(s)
Promoción de la Salud/métodos , Actividad Motora , Preescolar , Conducta Cooperativa , Promoción de la Salud/organización & administración , Humanos , Servicios de Salud Escolar/organización & administración
7.
Obes Rev ; 14(8): 645-58, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23601571

RESUMEN

The purpose of this review was to examine the factors that predict the development of excessive fatness in children and adolescents. Medline, Web of Science and PubMed were searched to identify prospective cohort studies that evaluated the association between several variables (e.g. physical activity, sedentary behaviour, dietary intake and genetic, physiological, social cognitive, family and peer, school and community factors) and the development of excessive fatness in children and adolescents (5-18 years). Sixty-one studies met the eligibility criteria and were included. There is evidence to support the association between genetic factors and low physical activity with excessive fatness in children and adolescents. Current studies yielded mixed evidence for the contribution of sedentary behaviour, dietary intake, physiological biomarkers, family factors and the community physical activity environment. No conclusions could be drawn about social cognitive factors, peer factors, school nutrition and physical activity environments, and the community nutrition environment. There is a dearth of longitudinal evidence that examines specific factors contributing to the development of excessive fatness in childhood and adolescence. Given that childhood obesity is a worldwide public health concern, the field can benefit from large-scale, long-term prospective studies that use state-of-the-art measures in a diverse sample of children and adolescents.


Asunto(s)
Adiposidad/fisiología , Dieta , Estilo de Vida , Obesidad/epidemiología , Adolescente , Niño , Preescolar , Femenino , Humanos , Masculino , Obesidad/etiología , Factores de Riesgo , Medio Social
8.
Obesity (Silver Spring) ; 21(3): E280-93, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23592682

RESUMEN

OBJECTIVE: The purpose of this study is to determine whether time spent in objectively measured physical activity is associated with change in body mass index (BMI) from ages 9 to 15. DESIGN AND METHODS: The participants were enrolled in the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (n = 938). At ages 9, 11, 12, and 15 the time spent in moderate-to-vigorous physical activity (MVPA) was objectively measured, and BMI was calculated (kg/m(2) ). Longitudinal quantile regression was used to analyze the data. The 10th, 25th, 50th, 75th, and 90th BMI percentiles were modeled as the dependent variables with age and MVPA (h/day) modeled as predictors. Adjustment was also made for gender, race, sleep, healthy eating score, maternal education, and sedentary behavior. RESULTS: A negative association between MVPA and change in BMI was observed at the 90th BMI percentile (-3.57, 95% CI -5.15 to -1.99 kg/m(2) per hour of MVPA). The negative association between time spent in MVPA and change in BMI was progressively weaker toward the 10th BMI percentile (-0.27, 95% CI -0.62 to 0.07 kg/m(2) per hour of MVPA). The associations remained similar after adjusting for the covariates, and when the analyses were stratified by gender. CONCLUSION: Time spent in MVPA was negatively associated with change in BMI from age 9 to 15. The association was strongest at the upper tail of the BMI distribution, and increasing time spent in MVPA could help reduce the prevalence of childhood obesity.


Asunto(s)
Índice de Masa Corporal , Actividad Motora , Obesidad/epidemiología , Obesidad/prevención & control , Adolescente , Estatura , Peso Corporal , Niño , Femenino , Humanos , Estudios Longitudinales , Masculino , Prevalencia , Conducta Sedentaria , Estados Unidos/epidemiología
9.
Int J Obes (Lond) ; 37(7): 961-5, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23318716

RESUMEN

OBJECTIVE: To determine the association between accelerometry-derived sedentary behavior and body mass index (BMI) z-score in preschool children, and to determine whether the association changed when applying three different accelerometry cutpoints for sedentary behavior. DESIGN AND SUBJECTS: Cross-sectional design. Data came from two completed studies: Children's Activity and Movement in Preschool Study (CHAMPS) and the Environmental Determinants of Physical Activity in Preschool Children (EDPAPC) study. Children of ages 3-5 years with complete data on sedentary behavior, BMI z-score, physical activity and other covariates were included in the analyses (N=263 in CHAMPS and N=155 in EDPAPC). Accelerometry data were summarized as time spent in sedentary behavior (min h(-1)) using three different cutpoints developed specifically for preschool children (<37.5, <200 and <373 counts per 15 s). Linear mixed regression models were used to determine the association between time spent in sedentary behavior and BMI z-score; age, gender, race, parental education, preschools and moderate-to-vigorous physical activity (MVPA) were included as covariates. RESULTS: In both CHAMPS and EDPAPC studies, no independent association between time spent in sedentary behavior and BMI z-score was observed after adjusting for MVPA. The observed null association between sedentary behavior and BMI z-score was maintained even with different sedentary behavior cutpoints. CONCLUSIONS: Regardless of cutpoints used, accelerometry-derived sedentary behavior was not independently associated with BMI z-score in two independent samples of preschool children. Longitudinal studies addressing this research question are needed.


Asunto(s)
Conducta Infantil , Ejercicio Físico , Conductas Relacionadas con la Salud , Obesidad/prevención & control , Conducta Sedentaria , Acelerometría , Índice de Masa Corporal , Preescolar , Estudios Transversales , Escolaridad , Femenino , Humanos , Masculino , Obesidad/epidemiología , Prevalencia , Factores de Riesgo , Instituciones Académicas , Factores de Tiempo , Estados Unidos/epidemiología
10.
Pediatr Obes ; 8(2): 142-9, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23042629

RESUMEN

BACKGROUND: Understanding the physical activity behaviour of young children who are highly active may provide important guidance for promoting physical activity in preschools. OBJECTIVES: The objective of this study was to describe the movement characteristics of high-active (HA) children during attendance at preschools. METHODS: Children in 20 preschools (n = 231) wore accelerometers and were classified into tertiles of moderate-to-vigorous physical activity. Children's movement characteristics were observed using the Observational System for Recording Physical Activity in Children-Preschool Version. Mixed-model analyses compared movement types between HA children and lower-active (LA) children during the total school day. RESULTS: HA (n = 77) children were observed to be more active than LA children (n = 154) indoors (P < 0.001), but no differences were observed outdoors. HA children were more frequently observed running, crawling, climbing, jumping, skipping, swinging and throwing across the total school day than LA children. Outdoors, HA children participated in more swinging and throwing and less jumping or skipping than LA children. Indoors, HA children spent more time pulling, pushing and running, and less time walking than LA children. CONCLUSIONS: HA children have unique activity patterns. Further interventions to increase physical activity of all preschoolers should increase the time spent outside and include varied activity types throughout the entire school day.


Asunto(s)
Conducta Infantil , Obesidad/prevención & control , Escuelas de Párvulos/estadística & datos numéricos , Acelerometría , Preescolar , Ejercicio Físico , Femenino , Promoción de la Salud , Humanos , Masculino , Actividad Motora , Obesidad/epidemiología , Juego e Implementos de Juego , Estados Unidos/epidemiología
11.
Int J Obes (Lond) ; 37(1): 54-60, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22430304

RESUMEN

OBJECTIVE: To determine if time spent in objectively measured sedentary behavior is associated with a change in body mass index (BMI) between ages 9 and 15 years, adjusting for moderate-to-vigorous physical activity (MVPA). DESIGN: Prospective observational study of children at ages 9 (2000), 11 (2002), 12 (2003) and 15 years (2006). Longitudinal quantile regression was used to model the influence of predictors on changes at the 10th, 25th, 50th, 75th and 90th BMI percentiles over time. SUBJECTS: Participants were enrolled in the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development and include both boys and girls (n=789). MEASUREMENTS: Objectively measured BMI (kg m(-2)) was the outcome variable and objectively measured sedentary behavior was the main predictor. Adjustment was also made for MVPA, gender, race, maternal education, hours of sleep and healthy eating index. RESULTS: Increases in BMI were observed at all percentiles, with the greatest increase observed at the 90th BMI percentile. Spending more time in sedentary behavior (h per day) was associated with additional increases in BMI at the 90th, 75th and 50th BMI percentiles, independent of MVPA and the other covariates (90th percentile=0.59, 95% confidence interval (95% CI): 0.19-0.98 kg m(-2); 75th percentile=0.48, 95% CI: 0.25-0.72 kg m(-2); and 50th percentile=0.19, 95% CI: 0.05-0.33 kg m(-2)). No associations were observed between sedentary behavior and changes at the 25th and 10th BMI percentiles. CONCLUSION: Sedentary behavior was associated with greater increases in BMI at the 90th, 75th and 50th BMI percentiles between ages 9 and 15 years, independent of MVPA. Preventing an increase in sedentary behavior from childhood to adolescence may contribute to reducing the number of children classified as obese.


Asunto(s)
Índice de Masa Corporal , Conducta Infantil , Computadores , Obesidad/epidemiología , Conducta Sedentaria , Televisión , Adolescente , Distribución por Edad , Niño , Conducta Infantil/psicología , Ingestión de Energía , Ejercicio Físico , Femenino , Humanos , Estudios Longitudinales , Masculino , Países Bajos/epidemiología , Obesidad/prevención & control , Obesidad/psicología , Padres/psicología , Distribución por Sexo , Encuestas y Cuestionarios , Factores de Tiempo
12.
Health Place ; 18(5): 951-5, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22809713

RESUMEN

After-school hours are considered critical for children's physical activity (PA) and sedentary behaviors (SB); however, whether the after-school setting influences children's activity patterns is unknown. This study examined the influence of after-school setting (i.e., parent report of the child's usual after-school setting) on 5th grade children's PA and SB, and differences by race/ethnicity. Boys whose parents reported they usually attended an after-school program had higher PA than boys who usually went home after school. A significant interaction between race/ethnicity and after-school setting showed that minority girls whose parents reported they usually attended an after-school program had higher PA and engaged in less SB compared with those who usually went home, whereas the activity patterns of white girls did not differ by after-school setting. Children's usual after-school setting affects their activity patterns; after-school programs may potentially increase PA in boys and minority girls.


Asunto(s)
Actividades Recreativas , Actividad Motora , Conducta Sedentaria , Niño , Femenino , Humanos , Masculino , South Carolina
13.
Health Educ Res ; 27(2): 319-30, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22156233

RESUMEN

Sustained intervention effects are needed for positive health impacts in populations; however, few published examples illustrate methods for assessing sustainability in health promotion programs. This paper describes the methods for assessing sustainability of the Lifestyle Education for Activity Program (LEAP). LEAP was a comprehensive school-based intervention that targeted change in instructional practices and the school environment to promote physical activity (PA) in high school girls. Previous reports indicated that significantly more girls in the intervention compared with control schools reported engaging in vigorous PA, and positive long-term effects on vigorous PA also were observed for girls in schools that most fully implemented and maintained the intervention 3 years following the active intervention. In this paper, the seven steps used to assess sustainability in LEAP are presented; these steps provide a model for assessing sustainability in health promotion programs in other settings. Unique features of the LEAP sustainability model include assessing sustainability of changes in instructional practices and the environment, basing assessment on an essential element framework that defined complete and acceptable delivery at the beginning of the project, using multiple data sources to assess sustainability, and assessing implementation longitudinally.


Asunto(s)
Educación en Salud , Promoción de la Salud , Estilo de Vida , Actividad Motora , Evaluación de Programas y Proyectos de Salud/métodos , Adolescente , Femenino , Educación en Salud/organización & administración , Humanos , Entrevistas como Asunto , Masculino
14.
Br J Sports Med ; 43(1): 14-8, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19019903

RESUMEN

Most children and adolescents do not meet the recommended 60 minutes or more of moderate to vigorous physical activity per day. One attractive approach to increasing physical activity in young people is providing activity through structured after-school programmes. This paper provides a review of the scientific literature on the effects of after-school programmes on physical activity in children and adolescents. After-school physical activity interventions provided mixed results; some increased children's physical activity, others did not. Although after-school programmes have the potential to help children and adolescents engage in regular, enjoyable physical activity, the research on these programmes is limited and, in some cases, methodologically weak. Additional, well-controlled studies are needed to identify the components of after-school programmes that promote physical activity and to determine the level of activity that can be attained when children and adolescents participate in these programmes.


Asunto(s)
Promoción de la Salud/métodos , Obesidad/prevención & control , Educación y Entrenamiento Físico/organización & administración , Instituciones Académicas/organización & administración , Adolescente , Niño , Femenino , Humanos , Masculino , Educación y Entrenamiento Físico/normas , Proyectos Piloto , Ensayos Clínicos Controlados Aleatorios como Asunto , Servicios de Salud Escolar
15.
Health Educ Res ; 21(6): 896-910, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17099074

RESUMEN

Physical activity levels begin to decline in childhood and continue falling throughout adolescence, with girls being at greatest risk for inactivity. Schools are ideal settings for helping girls develop and maintain a physically active lifestyle. This paper describes the design and implementation of 'Lifestyle Education for Activity Program', or LEAP. LEAP used a health team approach with participatory strategies to provide training and support, instructional capacity building and opportunities to adapt school instructional program and environmental supports to local needs. The social-ecological model, based on social cognitive theory, served as the organizing framework for the LEAP intervention and elements of the coordinated school health program model as intervention channels. For the 12 intervention schools, LEAP staff documented 191 visits and interactions with 850 individuals over the 2-year period. Teachers reported successful implementation of most components of the intervention and demonstrated optimism for sustainability. These results indicate that a facilitative approach to intervention implementation can be used successfully to engage school personnel, and to change instructional programs and school environments to increase the physical activity level of high school girls.


Asunto(s)
Ambiente , Educación en Salud/organización & administración , Actividad Motora , Instituciones Académicas/organización & administración , Adolescente , Conducta del Adolescente , Femenino , Humanos , Evaluación de Programas y Proyectos de Salud , Servicios de Salud Escolar/organización & administración
16.
J Sports Med Phys Fitness ; 45(3): 419-23, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16230995

RESUMEN

AIM: Endothelin-1 (ET-1) is a potent vasoconstricting peptide released mostly from vascular endothelial cells. Isolated exercise sessions of relatively long duration (=or>30 min) have produced increases in plasma ET-1 concentration while shorter exercise sessions usually have not. The purpose of the present study was to verify an effect of exercise duration at a steady work rate on plasma ET-1 concentration. METHODS: Eleven endurance-trained males (age 27+/-6 years; maximal oxygen consumption--VO2max--56+/-7 mLxkg-1xmin-1, body fat 11+/-5%; mean+/-SD) exercised on a treadmill at 70% VO2max on 2 occasions separated by at least 2 weeks. During a short-duration session, subjects expended approximately 3,360 kJ (60+/-2 min). During a long-duration session, subjects expended approximately 6,300 kJ (112+/-4 min). Six of the subjects performed the 3,360 kJ session before the 6,300 kJ session while the other 5 subjects performed the 6,300 kJ session first. RESULTS: The short-duration session did not cause plasma ET-1 concentration to change immediately after exercise (0.23+/-0.01 pmolxL-1 before exercise, 0.22+/-0.02 pmolxL-1 after exercise, mean+/-SE). However, 10 of 11 subjects had increased ET-1 after the long-duration session (0.28+/-0.02 pmolxL-1 before exercise, 0.32+/-0.02 pmolxL-1 after exercise, P=0.0004). A treatment-by-time effect was present (P=0.003). CONCLUSION: These results demonstrate an effect of exercise duration on plasma ET-1 concentration. Exercise duration is, therefore, an essential consideration when investigating exercise's effect on ET-1.


Asunto(s)
Endotelina-1/sangre , Ejercicio Físico/fisiología , Resistencia Física/fisiología , Adulto , Endotelio Vascular/fisiología , Prueba de Esfuerzo , Fluidoterapia , Humanos , Masculino , Consumo de Oxígeno/fisiología , Estudios Prospectivos , Factores de Tiempo
17.
Int J Obes Relat Metab Disord ; 27(7): 834-9, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12821970

RESUMEN

OBJECTIVE: To compare the physical activity levels of overweight and non overweight 3- to 5-y-old children while attending preschool. A secondary aim was to evaluate weight-related differences in hypothesized parental determinants of child physical activity behavior. DESIGN: Cross-sectional study. SUBJECTS: A total of 245, 3- to 5-y-olds (127 girls, 118 boys) and their parent(s) (242 mothers, 173 fathers) recruited from nine preschools. Overweight status determined using the age- and sex-specific 85th percentile for body mass index (BMI) from CDC Growth Charts. MEASUREMENTS: Physical activity during the preschool day was assessed on multiple days via two independent objective measures-direct observation using the observation system for recording activity in preschools (OSRAP) and real-time accelerometry using the MTI/CSA 7164 accelerometer. Parents completed a take-home survey assessing sociodemographic information, parental height and weight, modeling of physical activity, support for physical activity, active toys and sporting equipment at home, child's television watching, frequency of park visitation, and perceptions of child competence. RESULTS: Overweight boys were significantly less active than their nonoverweight peers during the preschool day. No significant differences were observed in girls. Despite a strong association between childhood overweight status and parental obesity, no significant differences were observed for the hypothesized parental influences on physical activity behavior. CONCLUSIONS: Our results suggest that a significant proportion of overweight children may be at increased risk for further gains in adiposity because of low levels of physical activity during the preschool day.


Asunto(s)
Ejercicio Físico , Obesidad/epidemiología , Preescolar , Estudios Transversales , Femenino , Humanos , Estilo de Vida , Masculino , Responsabilidad Parental , Prevalencia
18.
Prev Med ; 34(1): 100-8, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11749102

RESUMEN

BACKGROUND: We previously developed questionnaires based on contemporary theories to measure physical activity determinants among youth [Motl et al., Prev Med 2000; 31:584-94]. The present study examined the factorial invariance and latent mean structure of unidimensional models fit to the questionnaires measuring attitude, subjective norm, perceived behavioral control, and self-efficacy about physical activity among black and white adolescent girls. METHODS: Black (n = 896) and white (n = 823) girls in the 8th grade completed the questionnaires measuring attitude, subjective norm, perceived behavioral control, and self-efficacy about physical activity. The responses were subjected to analyses of factorial invariance and latent mean structure using confirmatory factor analysis with full-information maximum likelihood estimation in AMOS 4.0. RESULTS: The unidimensional models of the four questionnaires generally demonstrated invariance of the factor structure, factor loadings, and factor variance across race but not invariance of the variance-covariance matrices or item uniquenesses. The analyses of latent mean structure demonstrated that white girls had higher latent mean scores on the measures of attitude and self-efficacy than black girls; there were similar, but smaller, differences between white and black girls on the measures of subjective norm and perceived behavioral control. CONCLUSIONS: The questionnaires can be employed in interventions to test the mediating influences of attitude, subjective norm, perceived behavioral control, and self-efficacy on participation in physical activity by black and white adolescent girls.


Asunto(s)
Conducta del Adolescente/etnología , Actitud Frente a la Salud/etnología , Negro o Afroamericano/psicología , Cognición , Ejercicio Físico/psicología , Conductas Relacionadas con la Salud/etnología , Relaciones Interpersonales , Encuestas y Cuestionarios , Población Blanca/psicología , Adolescente , Análisis Factorial , Femenino , Humanos , Autoeficacia , South Carolina
19.
Int J Obes Relat Metab Disord ; 25(6): 822-9, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11439296

RESUMEN

OBJECTIVE: To compare the physical activity (PA) patterns and the hypothesized psychosocial and environmental determinants of PA in an ethnically diverse sample of obese and non-obese middle school children. DESIGN: Cross-sectional study. SUBJECTS: One-hundred and thirty-three non-obese and 54 obese sixth grade children (mean age of 11.4+/-0.6). Obesity status determined using the age-, race- and gender-specific 95th percentile for BMI from NHANES-1. MEASUREMENTS: Objective measurements were collected of PA over a 7-day period using the CSA 7164 accelerometer: total daily counts; daily moderate (3-5.9 METs) physical activity (MPA); daily vigorous physical activity (> or =6 METs; VPA); and weekly number of 5, 10 and 20 min bouts of moderate-to-vigorous physical activity (> or =3 METs, MVPA). Self-report measures were collected of PA self-efficacy; social influences regarding PA, beliefs about PA outcomes; perceived PA levels of parents and peers, access to sporting and/or fitness equipment at home, involvement in community-based PA organizations; participation in community sports teams; and hours spent watching television or playing video games. RESULTS: Compared to their non-obese counterparts, obese children exhibited significantly lower daily accumulations of total counts, MPA and VPA as well as significantly fewer 5, 10 and 20 min bouts of MVPA. Obese children reported significantly lower levels of PA self-efficacy, were involved in significantly fewer community organizations promoting PA and were significantly less likely to report their father or male guardian as physically active. CONCLUSIONS: The results are consistent with the hypothesis that physical inactivity is an important contributing factor in the maintenance of childhood obesity. Interventions to promote PA in obese children should endeavor to boost self-efficacy perceptions regarding exercise, increase awareness of, and access to, community PA outlets, and increase parental modeling of PA.


Asunto(s)
Ejercicio Físico , Conductas Relacionadas con la Salud , Obesidad/etiología , Australia , Índice de Masa Corporal , Niño , Estudios Transversales , Ejercicio Físico/psicología , Femenino , Humanos , Masculino , Encuestas Nutricionales , Padres/psicología , Aptitud Física , Autoeficacia , Medio Social , Factores de Tiempo
20.
Am J Prev Med ; 21(2): 110-7, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11457630

RESUMEN

BACKGROUND: Enjoyment has been implicated as a determinant of physical activity among youth, but advances in understanding its importance have been limited by the use of measures that were not adequately validated. The present study examined: (1) the factorial validity of the Physical Activity Enjoyment Scale (PACES), and (2) the construct validity of PACES scores. METHODS: Adolescent girls (N=1797), who were randomly assigned to calibration (n=899) and cross-validation (n=898) samples, completed the PACES and measures of factors influencing enjoyment of physical education, physical activity, and sport involvement. The factorial validity of the PACES and the measure of factors influencing enjoyment of physical education was tested using exploratory and confirmatory factor analysis. The hypothesized relationships among the measures were tested using structural equation modeling. RESULTS: Unidimensional models fit the PACES and the measure of factors influencing enjoyment of physical education in the calibration and cross-validation samples. The hypothesized relationships between the PACES and the measures of factors influencing enjoyment of physical education, physical activity, and sport involvement were supported in the entire sample, were similar in African-American and Caucasian girls, and were independent of physical fitness. CONCLUSIONS: Evidence of factorial validity and convergent evidence for construct validity indicate that the PACES is a valid measure of physical activity enjoyment among adolescent girls, suitable for use as a mediator variable in interventions designed to increase physical activity.


Asunto(s)
Actitud , Ejercicio Físico/psicología , Adolescente , Femenino , Humanos , Reproducibilidad de los Resultados , Estadística como Asunto
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