507 research outputs found

    Group-based physical activity trajectories in children transitioning from elementary to high school

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    Background: Physical activity has been observed repeatedly to decline as children transition into adolescence; however, few studies have explored the possibility that sub-groups of children experience unique patterns of change during this transition. The purpose of this longitudinal study was to examine the physical activity trajectories in clusters of youth transitioning from 5th to 11th grade. Methods: Participants (n = 652) were recruited as 5th graders (ages 10–12 years) from elementary schools (n = 21) in two school districts. Demographic, anthropometric, and physical activity data were collected once per year when children were in 5th, 6th, 7th, 9th, and 11th grades. Children wore accelerometers for 7 consecutive days. Groupbased trajectory modeling statistical techniques were applied to identify patterns of physical activity trajectories. Posterior probabilities confirmed participants’ membership in their respective group. Results: Three distinct physical activity trajectories were identified. Group 1 (n = 27) remained highly active over time, and physical activity increased from ages 14 to 16 years. Group 2 (n = 365) was active at baseline, but activity declined and remained low as group members aged. Group 3 (n = 260) had the lowest levels of physical activity at all ages, and activity declined from ages 10 to 16 years. Conclusions: While most children experienced a decline in physical activity as they transitioned into high school, some remained highly active and increased their level of physical activity. Future studies should test physical activity interventions for youth that are tailored for age-related trajectory groups

    Physical activity and academic achievement in children: A historical perspective

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    AbstractAs the focus on academic achievement has increased, physical activity (PA) opportunities in schools have decreased in the United States. In an attempt to discover how the decline in PA may affect academic achievement, researchers have been studying the effects of PA on cognition and academic achievement in children for more than 50 years. This review takes a historical perspective on the science of PA and academic achievement prior to and during the past 5 years. A total of 125 published articles were included and reviewed. Fifty-three of these articles were published in the past 5 years. In recent years, the overall quality of the studies has increased, but the results continue to be inconsistent. Many use cross-sectional designs and the methods vary substantially. The majority of conclusions show a positive effect of PA on constructs related to academic achievement. Future studies should use strong study designs to examine the types and doses of PA needed to produce improvements in academic achievement

    Fibrinolytic Responses to Moderate Intensity Exercise: Comparison of Physically Active and Inactive Men

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    The purposes of this study were to compare fibrinolytic responses to moderate intensity exercise in physically active and inactive men and during morning and evening exercise. Fourteen physically inactive men (mean age, 34.7 ± 4.0 years) and 12 regularly active men (34.8 ± 4.0 years) performed two exercise sessions, morning and evening, at 50% of maximal oxygen consumption. Tissue plasminogen activator (TPA) andplasminogen activator inhibitor-1 (PAI-1) activity were measured before and after exercise. Data were analyzed using a three-way ANOVA with repeated measures. TPA actively increased with exercise in both groups, although the active group demonstrated greater increases than the inactive group. Postexercise TPA activity was greater with evening than morning exercise. The inactive group exhibited greater PAI-1 activity than the active group. PAI-1 activity was higher during the morning than evening but did not change with exercise for either group. We conclude that moderate intensity exercise increases TPA activity in physically active and inactive men, with greater increases seen in active men, particularly during evening exercise. Moderate intensity exercise does not appear to affect PAI-1 activity. The lower PAI-1 activity in men may be one mechanism whereby regular physical activity lowers the risk of coronary artery disease

    Associations among neighborhood socioeconomic deprivation, physical activity facilities, and physical activity in youth during the transition from childhood to adolescence

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    BACKGROUND: This study aims to examine the longitudinal association of neighborhood socioeconomic deprivation (SED) with physical activity in youth during the transition from elementary to middle school, and to determine if access to physical activity facilities moderates this relationship. METHODS: Data were obtained from the Transitions and Activity Changes in Kids (TRACK) study, which was a multilevel, longitudinal study designed to identify the factors that influence changes in physical activity as youth transition from elementary to middle school. The analytic sample for the current study included 660 youth with complete data in grades 5 (baseline) and 7 (follow-up). A repeated measures multilevel framework was employed to examine the relationship between SED and physical activity over time and the potential moderating role of elements of the built environment. RESULTS: Decreases in physical activity varied by the degree of neighborhood SED with youth residing in the most deprived neighborhoods experiencing the greatest declines in physical activity. Access to supportive physical activity facilities did not moderate this relationship. CONCLUSION: Future research studies are needed to better understand how neighborhood SED influences youth physical activity over time

    The contribution of dance to daily physical activity among adolescent girls

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    <p>Abstract</p> <p>Background</p> <p>Structured physical activity (PA) programs are well positioned to promote PA among youth, however, little is known about these programs, particularly dance classes. The aims of this study were to: 1) describe PA levels of girls enrolled in dance classes, 2) determine the contribution of dance classes to total moderate-to-vigorous physical activity (MVPA), and 3) compare PA between days with a dance class (program days) and days without a dance class (non-program days).</p> <p>Methods</p> <p>Participants were 149 girls (11-18 years) enrolled in dance classes in 11 dance studios. Overall PA was assessed with accelerometry for 8 consecutive days, and girls reported when they attended dance classes during those days. The percent contribution of dance classes to total MVPA was calculated, and data were reduced to compare PA on program days to non-program days. Data were analyzed using mixed models, adjusting for total monitoring time.</p> <p>Results</p> <p>Girls engaged in 25.0 ± 0.9 minutes/day of MVPA. Dance classes contributed 28.7% (95% CI: 25.9%-31.6%) to girls' total MVPA. Girls accumulated more MVPA on program (28.7 ± 1.4 minutes/day) than non-program days (16.4 ± 1.5 minutes/day) (p < 0.001). Girls had less sedentary behavior on program (554.0 ± 8.1 minutes/day) than non-program days (600.2 ± 8.7 minutes/day) (p < 0.001).</p> <p>Conclusions</p> <p>Dance classes contributed a substantial proportion (29%) to girls' total MVPA, and girls accumulated 70% more MVPA and 8% less sedentary behavior on program days than on non-program days. Dance classes can make an important contribution to girls' total physical activity.</p

    Objectively Measured Sedentary Behavior in Preschool Children: Comparison Between Montessori and Traditional Preschools

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    Background: This study aimed to compare the levels of objectively-measured sedentary behavior in children attending Montessori preschools with those attending traditional preschools. Methods: The participants in this study were preschool children aged 4 years old who were enrolled in Montessori and traditional preschools. The preschool children wore ActiGraph accelerometers. Accelerometers were initialized using 15-second intervals and sedentary behavior was defined as/15-second. The accelerometry data were summarized into the average minutes per hour spent in sedentary behavior during the in-school, the afterschool, and the total-day period. Mixed linear regression models were used to determine differences in the average time spent in sedentary behavior between children attending traditional and Montessori preschools, after adjusting for selected potential correlates of preschoolers’ sedentary behavior. Results: Children attending Montessori preschools spent less time in sedentary behavior than those attending traditional preschools during the in-school (44.4. min/hr vs. 47.1 min/hr, P=0.03), after-school (42.8. min/hr vs. 44.7 min/hr, P=0.04), and total-day (43.7 min/hr vs. 45.5 min/hr, P = 0. 009) periods. School type (Montessori or traditional), preschool setting (private or public), socio-demographic factors (age, gender, and socioeconomic status) were found to be significant predictors of preschoolers’ sedentary behavior. Conclusions: Levels of objectively-measured sedentary behavior were significantly lower among children attending Montessori preschools compared to children attending traditional preschools. Future research should examine the specific characteristics of Montessori preschools that predict the lower levels of sedentary behavior among children attending these preschools compared to children attending traditional preschools

    Physical Activity Levels of Adolescent Girls During Dance Classes

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    Background: The aims of this study were to describe the physical activity levels of girls during dance classes and to identify factors associated with moderate-to-vigorous physical activity (MVPA) in those classes. Methods: Participants were 137 girls (11 to 18 years-old) enrolled in ballet, jazz, or tap dance classes from 11 dance studios. Participants wore an accelerometer during the selected dance class on 2 separate days. Factors hypothesized to be associated with MVPA were dance style, instructional level, instructor\u27s experience, percent of class time spent in choreography, and participants\u27 age, race/ethnicity, BMI-for-age percentile, and years of dance training. Data were analyzed using generalized linear mixed models. Results: Girls engaged in 9.8 minutes of MVPA, 6.0 minutes of moderate, 3.8 minutes of vigorous, 39.3 minutes of light, and 10.9 minutes of sedentary behavior per hour of dance class participation. Jazz/tap classes provided more MVPA than ballet classes, and intermediate level classes provided more MVPA than advanced level classes. Girls with more dance training obtained more MVPA than girls with less dance training. Conclusion: Dance classes provide valuable opportunities for adolescent girls to be physically active

    Correlates to Performance on Field Tests of Muscular Strength

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    Field tests of upper body muscular strength and endurance (UBMSE) are often administered to children, but little is known about the determinants of performance on these tests. Therefore the purpose of this investigation was to examine potential determinants of performance on several common field tests of UBMSE including pull-ups, flexed-arm hang, push-ups, and two types of modified pull-ups. Subjects were 56 girls, and 38 boys, ages 9 to 11 years. Potential determinants assessed were age, height, weight, gender, % fat, physical activity, and laboratory measures of muscular strength and endurance. Multiple regression analysis revealed that the laboratory measures of UBMSE failed to account for significant fractions of variance in performance on four of the five tests. However, % fat was significantly associated with performance on four of five tests. These results indicate that factors other than muscular strength and endurance account for most of the variance in performance, and that % fat appears to be a particularly important determinant of performance

    Moderate Intensity Exercise Training Improves Cardiorespiratory Fitness in Women

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    Among women, there is an increased prevalence of sedentary lifestyle and less participation in physical activity at levels recommended by the Surgeon General. As a result, women have been identified as a target group in public health initiatives to increase physical activity. The health-related benefits of habitual, moderate intensity physical activity are well documented in the epidemiological literature, but less is known about the effect of such physical activity on cardiorespiratory fitness. Our hypothesis was that moderate and vigorous exercise training regimens of similar estimated energy expenditure would result in similar changes in cardiorespiratory fitness. Eighteen sedentary premenopausal women with the following baseline characteristics [x ± SE]: maximal oxygen consumption (VO2max) = 29.5 ± 1.5ml ● kg-1 ● min-1; age=33 ± 1 years; height=162.6 ± 0.9 cm; mass = 62.7 ± 2.3 kg, were randomly assigned to either vigorous (HI, 80% VO2max, n=10) or moderate intensity (MOD, 40% VO2max, n=8) cycle ergometer training groups. Exercise training was conducted 3-4 (3.37 ± 0.05) days/week for 12 weeks in a supervised and progressive manner, with estimated exercise energy expenditure equated across both training groups. VO2max and time to exhaustion increased significantly in both groups (p\u3c0.05), with no difference between groups. Both groups had lower (p\u3c0.05) posttraining submaximal heart rates (HR), respiratory exchange ratios (RER), and ratings of perceived exertion (RPE) during graded exercise testing, with no significant differences between the groups in posttraining values. Women participating in moderate intensity exercise training as recommended in basic public health guidelines demonstrate an increase in cardiorespiratory fitness similar to that elicited by vigorous training
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