Average Moderate-to-vigorous Physical Activity Research Articles

Relationship between objectively measured intensity of physical activity and self-reported enjoyment of physical activity.

Physical activity is an important factor for the maintenance of health. Enjoyment of physical activity is essential to motivate persons to engage in sufficient physical activity. We examined whether self-reported enjoyment of PA is associated with objective measurement of the intensity of PA.A cardiovascular examination program was provided for individuals aged 40–75 years without a history of cardiovascular events in Greifswald, Germany between 2012 and 2013. Participants (n = 255) were asked to wear a three-axial accelerometer device (ActiGraph, GT3X +, Pensacola, Florida, USA) for 7 consecutive days. After wearing the device, the participants were asked to complete the 18-item self-administered physical activity enjoyment scale (PACES). Participants' (n = 200) daily minutes of moderate-to-vigorous physical activity (MVPA) and their enjoyment of PA were analysed in a linear regression approach.The mean age of the participants was 56.3 ± 9.7 years, 41.0% were male. The average MVPA duration was 44.4 ± 27.3 min per day. In the regression analysis, enjoyment of PA was positively associated with MVPA (β = 0.18, 95% CI (0.05; 0.31), p = 0.009), participants with higher enjoyment of PA showed higher MVPA.We found a positive association between MVPA and enjoyment of PA, although for male participants only. Between bouted MVPA and enjoyment of PA there was no significant relationship.

Moderate-to-vigorous physical activity, executive functions and prefrontal brain oxygenation in children: A functional near-infrared spectroscopy study

ABSTRACTDespite accumulating evidence that regular exercise improves executive functioning, the underlying neurophysiological mechanisms have rarely been investigated. The present study aimed to compare cognitive performance as well as task-specific concentration changes in oxygenated haemoglobin in the prefrontal cortex between children with higher and lower moderate-to-vigorous physical activity (MVPA). Physical activity was measured over 7 consecutive days using actigraphy. Afterwards, participants (N = 50) completed verbal fluency tests (VFTs) and mental arithmetic (MA) for the assessment of cognitive flexibility and working memory capacity. During the tasks, changes of oxygenated haemoglobin were measured with functional near-infrared spectroscopy. Using average MVPA of 11-year-old children as cut-point, the sample was divided into children with lower and higher MVPA. Analyses of variance revealed no significant differences in correct and false responses on the cognitive tests between groups. With regard to oxygenated haemoglobin, no group differences were found for concentration changes in response to the cognitive tasks. In conclusion, VFTs and MA increased children’s activation in prefrontal regions associated with cognitive flexibility and working memory, respectively. However, these executive functions and cortical activation were not different between children with lower and higher MVPA.

Longitudinal relationships between self-concept for physical activity and neighborhood social life as predictors of physical activity among older African American adults

BackgroundEngaging in regular physical activity (PA) as an older adult has been associated with numerous physical and mental health benefits. The aim of this study is to directly compare how individual-level cognitive factors (self-efficacy for PA, self-determined motivation for PA, self-concept for PA) and neighborhood perceptions of the social factors (neighborhood satisfaction, neighborhood social life) impact moderate-to-vigorous physical activity (MVPA) longitudinally among older African American adults.MethodsData were analyzed from a sub-set of older African American adults (N = 224, Mage = 63.23 years, SD = 8.74, 63.23% female, MBody Mass Index = 32.01, SD = 7.52) enrolled in the Positive Action for Today’s Health trial. MVPA was assessed using 7-day accelerometry-estimates and psychosocial data (self-efficacy for PA, self-determined motivation for PA, self-concept for PA, neighborhood satisfaction, neighborhood social life) were collected at baseline, 12-, 18-, and 24-months.ResultsMultilevel growth modeling was used to examine within- and between-person effects of individual-level cognitive and social environmental factors on MVPA. At the between-person level, self-concept (b = 0.872, SE = 0.239, p < 0.001), and neighborhood social life (b = 0.826, SE = 0.176, p < 0.001) predicted greater MVPA, whereas neighborhood satisfaction predicted lower MVPA (b = −0.422, SE = 0.172, p = 0.015). Among the between-person effects, only average social life was moderated by time (b = 0.361, SE = 0.147, p = 0.014), indicating that the impact of a relatively positive social life on MVPA increased across time. At the within-person level, positive increases in self-concept (b = 0.294, SE = 0.145, p = 0.043) and neighborhood social life (b = 0.270, SE = 0.113, p = 0.017) were associated with increased MVPA.ConclusionsThese results suggest that people with a higher average self-concept for PA and a more positive social life engaged in greater average MVPA. Additionally, changes in perceptions of one’s neighborhood social life and one’s self-concept for PA were associated with greater MVPA over 2 years. These factors may be particularly relevant for future interventions targeting long-term change and maintenance of MVPA in older African Americans.Trial registrationClinicalTrials.Gov #NCT01025726 registered 1 December 2009.

Associations Among Perceived Motor Competence, Motor Competence, Physical Activity, And Health-related Physical Fitness Of Children Ages 10-15 Years Old.

PURPOSE: To examine the associations among perceived motor competence (PMC), motor competence (MC), moderate to vigorous physical activity (MVPA), and health-related physical fitness during middle childhood and early adolescence. METHODS: Participants were 47, 10-15-year-old youth (12.2 ± 1.64 yrs, 50.2 ± 16.2 kg, 157 ± 13.1 cm). Each participant made two visits, separated by at least 7 days, in East Tennessee or northwest Ohio, during which they completed the Bruininks-Oseretsky Test of Motor Proficiency, 2nd Edition, Harter’s PMC questionnaire (Harter, 1978), and the FITNESSGRAM battery for health-related physical fitness. Actigraph GT3X+ accelerometers were worn for seven days to measure MVPA. RESULTS: There were significant (p ≤ 0.05) positive correlations between physical fitness and both MC (rs = 0.44, p < 0.01) and PMC (rs = 0.32, p < 0.05). Additionally, a significant positive correlation was discovered between PMC and MC (rs = 0.47, p < 0.05). There were no significant correlations between average daily MVPA and the other variables. CONCLUSION: Results indicated that higher MC and PMC were associated with higher levels of health-related physical fitness. The interrelationship of these three variables was consistent with previous studies linking the development of fundamental motor skills to participation in complex movement behaviors, such as sports and other lifetime fitness activities, and the development and strengthening of PMC (Stodden & Robertson, 2009; Hands et. al., 2008; Cliff et al., 2011; Zask et al., 2012; Barnett et al., 2010).

Longitudinal associations of parental and peer influences with physical activity during adolescence: findings from the COMPASS study.

To examine temporal variations in parental and peer influences on adolescent physical activity (PA) and whether these variations predicted changes in PA. We analyzed data from Years 1, 2 and 3 of the COMPASS study. Participants were 22 909 students in Grades 9 to 12 (mean age [years] = 15.42 ± 1.12, 46% boys, 85% White), who had completed the following survey items on 2 or more consecutive occasions: age, sex, grade, race/ethnicity, moderate-to-vigorous physical activity (MVPA), parental encouragement and parental instrumental support for PA, and number of active peers. We used a linear-mixed model to investigate longitudinal effects of parental and peer influences on changes in square-root transformed average MVPA. We used a generalized-estimating-equations (GEE) model to investigate compliance with Canadian PA guidelines for youth. These models included parental encouragement, instrumental support and number of active peers as time-varying predictors, adjusting for sociodemog raphic factors and grade as covariates, and accounting for the clustering within children and schools. We found that adolescents perceived significantly less parental encouragement and instrumental support and reported fewer active peers as they got older. In addition, the adjusted models suggest that, for a one-unit increase in the score of parental encouragement, parental instrumental support and number of active peers, average MVPA significantly increased by 0.22 units, 0.23 units and 0.16 units, respectively. For the same one-unit increase, adjusted odds of an adolescent complying with the PA guidelines increased by 9%, 4% and 6%, respectively. Promoting parental support and facilitating the formation and maintenance of a physically active friendship network may play an important role in attenuating declines in PA during adolescence.

Validity and Reliability of Fitbit Flex for Step Count, Moderate to Vigorous Physical Activity and Activity Energy Expenditure.

ObjectivesTo examine the validity and reliability of the Fitbit Flex against direct observation for measuring steps in the laboratory and against the Actigraph for step counts in free-living conditions and for moderate-to-vigorous physical activity (MVPA) and activity energy expenditure (AEE) overall.MethodsTwenty-five adults (12 females, 13 males) wore a Fitbit Flex and an Actigraph GT3X+ during a laboratory based protocol (including walking, incline walking, running and stepping) and free-living conditions during a single day period to examine measurement of steps, AEE and MVPA. Twenty-four of the participants attended a second session using the same protocol.ResultsIntraclass correlations (ICC) for test-retest reliability of the Fitbit Flex were strong for walking (ICC = 0.57), moderate for stair stepping (ICC = 0.34), and weak for incline walking (ICC = 0.22) and jogging (ICC = 0.26). The Fitbit significantly undercounted walking steps in the laboratory (absolute proportional difference: 21.2%, 95%CI 13.0–29.4%), but it was more accurate, despite slightly over counting, for both jogging (6.4%, 95%CI 3.7–9.0%) and stair stepping (15.5%, 95%CI 10.1–20.9%). The Fitbit had higher coefficients of variation (Cv) for step counts compared to direct observation and the Actigraph. In free-living conditions, the average MVPA minutes were lower in the Fitbit (35.4 minutes) compared to the Actigraph (54.6 minutes), but AEE was greater from the Fitbit (808.1 calories) versus the Actigraph (538.9 calories). The coefficients of variation were similar for AEE for the Actigraph (Cv = 36.0) and Fitbit (Cv = 35.0), but lower in the Actigraph (Cv = 25.5) for MVPA against the Fitbit (Cv = 32.7).ConclusionThe Fitbit Flex has moderate validity for measuring physical activity relative to direct observation and the Actigraph. Test-rest reliability of the Fitbit was dependant on activity type and had greater variation between sessions compared to the Actigraph. Physical activity surveillance studies using the Fitbit Flex should consider the potential effect of measurement reactivity and undercounting of steps.

The Effect of Self-Efficacy on Behavior and Weight in a Behavioral Weight-Loss Intervention.

To determine whether eating self-efficacy (ESE) and physical activity self-efficacy (PASE) are predictive of dietary intake, physical activity, and weight change within a behavioral weight-loss intervention, and whether dietary intake and physical activity mediate relationships between self-efficacy and weight change. The study sample included 246 participants from a randomized trial with complete data on study variables at 12 months. ESE, PASE, calories consumed, minutes of moderate-to-vigorous physical activity (MVPA), and weight were measured at baseline, 6, and 12 months. ESE at baseline was associated with 12-month percent weight loss (PWL), and was mediated by average calories consumed at 6 and 12 months. Change in ESE from baseline to 6 months was associated with calories consumed at 12 months and 12-month percent weight loss, but the mediated relationship was not significant. Baseline PASE was not associated with average MVPA at 6 and 12 months or 12-month PWL, but change in PASE from baseline to 6 months was associated with 12-month PWL through its effect on MVPA at 12 months. Increases in ESE and PASE during the active phase of the intervention are predictive of dietary intake, physical activity and weight loss at later points, but further research should include explorations of the reciprocal relationship between behavior and self-efficacy to better inform intervention strategies that target self-efficacy and promote behavior change. (PsycINFO Database Record

A Multimodal Counseling-Based Adolescent Physical Activity Intervention

PurposeNational guidelines recommend adolescents achieve 60 minutes of moderate-to-vigorous physical activity (MVPA)/day, yet few adolescents meet these guidelines. MethodsWe piloted a novel quasi-randomized physical activity intervention to promote adolescent's use of their surrounding built environment among 30 intervention and 30 control overweight/obese adolescents aged 10–16 years living in greater Boston from 2013 to 2015. Location-specific MPVA was measured by accelerometry and global positioning system for three one-week periods (Time 1 [T1], Time 2 [T2], and Time 3 [T3]). One month after T1, intervention participants received individualized counseling on how to use their surrounding built environment to increase MVPA, and control participants received standard-of-care lifestyle modification counseling; both groups received their T1 physical activity data. T2 assessment occurred the week after the counseling visit and T3 assessment 3–4 months later. The main outcome was change in average daily minutes of MVPA; the secondary outcome was meeting national MVPA guidelines. Multivariable modeling accounted for covariates (baseline MVPA, body mass index, age, sex, race/ethnicity) and clustering by study group and town. ResultsAmong the 60 adolescents recruited, 55 (92%) completed data collection. Short-term (T2) intervention effects included increased average MVPA of +13.9 minutes intervention versus −.6 minutes control (p < .0001). Differential increase in mean daily MVPA was sustained at T3 (9.3 minutes more in intervention group; p = .0006). The proportion of adolescents in the intervention group who achieved 60 minutes/day of MVPA increased from 11% (T1) to 21% (T2), whereas declining (7%–0%) among controls. ConclusionsIndividualized counseling about the built environment can help increase MVPA among overweight and obese adolescents.

Quantified-self for obesity: Physical activity behaviour sensing to improve health outcomes

Event Abstract Back to Event Quantified-self for obesity: Physical activity behaviour sensing to improve health outcomes Jennifer Murphy1*, David Taylor1, Mian Ahmad1, Suzanne I. Alsters2, Sanjay Purkayastha1, Samantha Scholtz3, Ramin Ramezani4, Ivo Vlaev5, Ahmed R. Ahmed6, Harvinder Chahal6, Alexandra I. Blakemore*2 and Ara Darzi*1 1 Imperial College London, Department of Surgery, Cancer and Investigative Medicine, United Kingdom 2 Imperial College London, Section of Investigative Medicine, Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, United Kingdom 3 Imperial College London, Department of Investigative Medicine, United Kingdom 4 University of California, Los Angeles, Wireless Health Institute, United States 5 University of Warwick, Behavioural Science Group, Warwick Business School, United Kingdom 6 Imperial College Healthcare NHS Trust, St. Mary’s Hospital, Imperial Weight Centre, United Kingdom Background Physical activity is effective for long-term weight loss maintenance following calorie restriction diets; however, there is a lack of research on its effects on weight loss following bariatric surgery1. Previous studies objectively measuring physical activity have shown that while there is a wide range of activity levels in bariatric patients, the majority achieve significantly less than the recommended 30min/day moderate-to-vigorous physical activity (MVPA) guidelines for health-related benefits2-5. It is important to gain a better understanding of physical activity profiles in this heterogeneous group over time and to ascertain whether increased physical activity is associated with better weight loss outcomes, improved quality of life and resolution of comorbid conditions. Aims The primary aim of this study is to assess the feasibility of continuously monitoring physical activity via a smartphone app with minimal user interaction required, and to characterise the physical activity profiles of bariatric surgery patients. Method 255 patients aged 18-65years with a BMI >35kg/m2 and who were either awaiting or had previously underwent bariatric surgery were recruited from the Imperial Weight Centre. Physical activity [i.e. step count, walk time (mins) and distance walked (km)] was recorded using the free, commercial ‘Moves’ app (Protogeo), with an adjunct app recording weight, mood and wakefulness data. Physical activity data tracked by the Moves app for at least 8 hours per day between the hours of 6am-10pm was categorised as follows: 1) Average walking time (mins) of light, moderate and vigorous intensity per day, 2) ‘Moderate to Vigorous physical activity (MVPA)’; average daily walking time with >80steps/min; 3) average light and MVPA in bouts of 10 minutes per day, and 4) average MVPA in 10 minute bouts of activity per day. Results Data from 147 participants (mean age 42.95, SD±11.50; 70.7% female) met inclusion criteria for data analysis. The average BMI of patients awaiting surgery (n=52) was 47.1kg/m2 (SD±9.53) and average weight loss percentage for post-surgery patients (n=95) at the time of recruitment was 14.62% (SD±10.71) encompassing a post-surgery period from 10 days to >2 years. Participants were tracked for a median of 26 days each (range 1-139 days, partly depending on when they were recruited). 61% of participants (n=89) achieved an average of at least 30 minutes of light and MVPA per day. 57% (n=84) achieved one or more bouts of light and MVPA for a minimum of 10 minutes per day but only averaging 15.31 minutes (SD±2.89). 66% of participants (n=97) walked at a moderate-to-vigorous pace at >80 steps/min, but only for an average of 6 minutes (SD±2.83) per day. 54% (n=80) performed MVPA in bouts of 10 minutes, but only averaging at 15 minutes (SD±3.26). Conclusions We have shown that it is possible to passively monitor physical activity in a large patient population in a cost-effective way. The results demonstrate that while two thirds of bariatric patients achieved an average of 30 minutes walking per day, this was not of sufficient intensity to gain health-related benefits. Further analysis will examine whether increased activity is associated with successful weight loss outcomes, improved mood and psychological functioning, and increased quality of life. We will also employ machine-learning techniques to identify the factors that are critical for a successful outcome following bariatric surgery. Recruitment will continue to the end of the project (April 2016) and tracking will continue into 2017.

Built Environment Influences of Children’s Physical Activity: Examining Differences by Neighbourhood Size and Sex

Neighbourhoods can facilitate or constrain moderate-to-vigorous physical activity (MVPA) among children by providing or restricting opportunities for MVPA. However, there is no consensus on how to define a child’s neighbourhood. This study examines the influence of the neighbourhood built environment on objectively measured MVPA among 435 children (aged 9–14 years) in London (ON, Canada). As there is no consensus on how to delineate a child’s neighbourhood, a geographic information system was used to generate measures of the neighbourhood built environment at two buffer sizes (500 m and 800 m) around each child’s home. Linear regression models with robust standard errors (cluster) were used to analyze the relationship between built environment characteristics and average daily MVPA during non-school hours on weekdays. Sex-stratified models assessed sex-specific relationships. When accounting for individual and neighbourhood socio-demographic variables, park space and multi-use path space were found to influence children’s MVPA. Sex-stratified models found significant associations between MVPA and park space, with the 800 m buffer best explaining boys’ MVPA and the 500 m buffer best explaining girls’ MVPA. Findings emphasize that, when designing built environments, programs, and policies to facilitate physical activity, it is important to consider that the size of the neighbourhood influencing a child’s physical activity may differ according to sex.

Using Video Modeling, Prompting, and Behavior-Specific Praise to Increase Moderate-to-Vigorous Physical Activity for Young Children With Down Syndrome

Children with Down syndrome may be at increased risk of problems associated with inactivity. Early intervention to increase physical activity may lead to increased participation in typical activities and long-term increases in quality of life (e.g., decreased likelihood of obesity-related illness). A multi-component intervention, including video modeling, prompting, and behavior-specific praise, was implemented to increase the physical activity behaviors of three young children with Down syndrome on a typical preschool playground. Results, evaluated in the context of an A-B-A-B withdrawal design, showed increases in moderate-to-vigorous physical activity (MVPA) for all children during intervention conditions. To evaluate social validity of behavior changes, average data values in each condition were graphed alongside normative comparison data of typically developing peers, showing that average MVPA for participants during intervention conditions was lower than average peer values but was within the range demonstrated by peers.

Physical Activity and Variation in Momentary Behavioral Cognitions: An Ecological Momentary Assessment Study.

Decisions to perform moderate-to-vigorous physical activity (MVPA) involve behavioral cognitive processes that may differ within individuals depending on the situation. Ecological momentary assessment (EMA) was used to examine the relationships of momentary behavioral cognitions (ie, self-efficacy, outcome expectancy, intentions) with MVPA (measured by accelerometer). A sample of 116 adults (mean age, 40.3 years; 72.4% female) provided real-time EMA responses via mobile phones across 4 days. Multilevel models were used to test whether momentary behavioral cognitions differed across contexts and were associated with subsequent MVPA. Mixed-effects location scale models were used to examine whether subject-level means and within-subjects variances in behavioral cognitions were associated with average daily MVPA. Momentary behavioral cognitions differed across contexts for self-efficacy (P = .007) but not for outcome expectancy (P = .53) or intentions (P = .16). Momentary self-efficacy, intentions, and their interaction predicted MVPA within the subsequent 2 hours (Ps < .01). Average daily MVPA was positively associated with within-subjects variance in momentary self-efficacy and intentions for physical activity (Ps < .05). Although momentary behavioral cognitions are related to subsequent MVPA, adults with higher average MVPA have more variation in physical activity self-efficacy and intentions. Performing MVPA may depend more on how much behavioral cognitions vary across the day than whether they are generally high or low.

Associations between objectively assessed and questionnaire-based sedentary behaviour with BMI-defined obesity among general population children and adolescents living in England.

ObjectivesSedentary behaviour (SB) is an emerging candidate risk factor for obesity in young people. Evidence to date is conflicting and it is unclear how different SB types are associated with obesity independently of physical activity. The objective of this study was to examine associations between a range of objectively measured and questionnaire-based SB indicators with obesity and body mass index (BMI) to assess whether these associations were independent of physical activity.Participants4469 (705 with accelerometer data) children aged 5–15 years from the 2008 Health Survey for England.OutcomesThe outcome was adiposity, classified using age-specific and sex-specific BMI SD scores (continuous) and obesity cut-offs (binary). Questionnaire-based measures comprised TV time, non-TV sitting time (such as homework, drawing, time at a computer or playing video games), total sitting time (TV time+non-TV sitting time) and average daily MVPA time. Objective SB and moderate to vigorous physical activity (MVPA) time were measured using an Actigraph GT1M accelerometer, with cut-offs of 100 and 200 counts per minute for SB, and 2802 counts per minute for MVPA. Multiple logistic and multiple linear regression models examined associations between each indicator of sedentary time with obesity and BMI SD scores.ResultsTV time (but not non-TV sitting or objectively-measured SB) was consistently associated with higher levels of obesity and BMI SD score, even after adjusting for MVPA and other potential confounders. Weaker associations were observed for total sitting time.ConclusionsTV viewing (but not other forms of objectively-measured or questionnaire-based sedentary time) was associated with obesity in children and adolescents. Although a causal relationship cannot be established, TV time may be a reasonable target for obesity prevention in young populations.

Development of an accelerometer-linked online intervention system to promote physical activity in adolescents.

Most adolescents do not achieve the recommended levels of moderate-to-vigorous physical activity (MVPA), placing them at increased risk for a diverse array of chronic diseases in adulthood. There is a great need for scalable and effective interventions that can increase MVPA in adolescents. Here we report the results of a measurement validation study and a preliminary proof-of-concept experiment testing the impact of Zamzee, an accelerometer-linked online intervention system that combines proximal performance feedback and incentive motivation features to promote MVPA. In a calibration study that parametrically varied levels of physical activity in 31 12-14 year-old children, the Zamzee activity meter was shown to provide a valid measure of MVPA (sensitivity in detecting MVPA = 85.9%, specificity = 97.5%, and r = .94 correspondence with the benchmark RT3 accelerometer system; all p < .0001). In a subsequent randomized controlled multi-site experiment involving 182 middle school-aged children assessed for MVPA over 6 wks, intent-to-treat analyses found that those who received access to the Zamzee intervention had average MVPA levels 54% greater than those of a passive control group (p < 0.0001) and 68% greater than those of an active control group that received access to a commercially available active videogame (p < .0001). Zamzee’s effects on MVPA did not diminish significantly over the course of the 6-wk study period, and were statistically significant in both females and males, and in normal- vs. high-BMI subgroups. These results provide promising initial indications that combining the Zamzee activity meter with online proximal performance feedback and incentive motivation features can positively impact MVPA levels in adolescents.

Association of Body Composition and Physical Activity in Adolescents with Down Syndrome

Obesity is highly prevalent among persons with Down syndrome (DS). Low levels of moderate to vigorous physical activity (MVPA) likely contribute to this health disparity, but only low associative relationships have been found with body mass index (BMI). Due to characteristics of DS (e.g. short stature, unique fat distribution), BMI may not be precise enough to study this relationship. Three component analysis from dual-energy X-ray absportiometry (DXA) may assist with better understanding the association between body composition and MVPA. PURPOSE: To examine the association between total and regional fat mass from DXA and levels of MVPA from actigraphy. METHODS: Preliminary analyses were conducted with 6 adolescents (15±1.8yrs, 66% male) with DS who completed a DXA scan measuring total and regional (i.e. arms, legs, trunk) fat mass. BMI percentiles (CDC) from direct anthropometric measures were also calculated. Each participant wore a triaxial accelerometer for seven days at the waist. Puyau cut points, minimum wear time of 10 hours per day for 4 days, and 20 minute non-wear period criteria were used. Analyses include 1) descriptive statistics of DXA derived fat mass, BMI, and MVPA; and 2) bivariate correlations. RESULTS: Average percent body fat from DXA was 31% (±12%) with moderate to high body fatness detected in 66% of the sample. Average BMI was at the 89th (±11) percentile. Average MVPA was only 17.32 minutes per day. One participant met the guideline of 60 minutes of MVPA on a single day and 3 participants exceeded the 30 minute threshold on at least one day. The association between body fat and MVPA was stronger from DXA (r = −.794) than from BMI percentile (−.473). Among regional segments, associations were also high including the arms (−.871), legs (−.802), and trunk (−.782). Correlations did not reach significance (p<.05) due to sample size, but the r2 values are meaningful. CONCLUSION: Excess fatness and low MVPA are common in DS. This preliminary analysis found a stronger association between MVPA and body fat from DXA than from BMI. DXA may provide a more precise measure of excess body fat in DS. Greater use of DXA may help to better understand factors influencing body composition. A more comprehensive analysis will be possible with a larger sample and typically developing control group; currently in progress. Supported by NIH F31 HD079227.

Feasibility Of Teaching Henry (Healthy Exercise And Nutrition Recommendations For Youth) Intervention In Rural Appalachia

The majority of youth do not meet the recommendations for healthy diet and activity, due in part to a lack of knowledge. Unfortunately, educating young children on the benefits of and recommendations for a healthy lifestyle may be difficult. Child-friendly characters in children’s literature serve as role models for youth to understand and accept new ideas and thus provide an effective medium to improve both knowledge and participation in healthy behaviors. PURPOSE: The purpose of this study was to assess the feasibility of a character-based intervention aimed to increase children’s knowledge of and participation in healthy diet and activity behaviors. METHODS: All children (6-11 y) participating in an existing after-school program completed a questionnaire on activity and nutrition knowledge, self-efficacy, and current habits at baseline and follow-up. A subset of children was recruited for anthropometric (height, weight, and waist circumference) and behavioral measures (diet and physical activity). A triaxial accelerometer was worn for 7 days at both time-points and established cut-points were used to determine daily minutes of moderate-to-vigorous physical activity (MVPA). Nutrition behavior was assessed by a valid 1-day dietary recall questionnaire. The intervention consisted of six 40-min lessons (1/week) centered on the healthy lifestyle choices of characters in an age-appropriate storybook. A three-way mixed model ANOVA was used to assess changes in knowledge and behavior from baseline to follow-up by age and gender (p<0.05). RESULTS: Six children volunteered for the measurement portion of the study, while 21 completed the questionnaires. Following the intervention, children’s knowledge of the definitions, benefits, and recommendations for PA increased by 21.9% (p<0.01), PA self-efficacy increased by 37.3% (p=0.02), and average daily MVPA increased by 17 min/day (p=0.44). Children’s nutrition knowledge plus self-efficacy increased by 18.3% (p<0.01) and reported vegetable intake increased from 3.5 to 5.1 servings after the intervention (p=0.28). CONCLUSION: A child-friendly character-based intervention is successful in promoting positive changes in both knowledge of and participation in healthy behaviors in school-aged children. Funded by Appalachian Rural Health Institute Scholars Program, Provost’s Undergraduate Research Fund, and College of Health Sciences and Professions Research Grant

ICook 4‐H: Report of the correlation between the Block Kids Physical Activity Screener and accelerometer‐derived physical activity in 9‐10 year old children (LB460)

OBJECTIVE: To examine the relationship between the Block Kids Physical Activity Screener ( BKPAS) and accelerometer derived physical activity in 9‐10 year old children participating in iCook 4‐H, a 5‐state, family‐centered, childhood obesity intervention.METHODS: A cross‐sectional study was conducted in 116 children who met accelerometer compliance standards and completed the BKPAS. Moderate‐to‐vigorous physical activity (MVPA) and sedentary time (ST) were measured by accelerometry and the BKPAS. Children wore an accelerometer (ActiGraph GT3X+) for 7 consecutive days and completed a computerized parent‐assisted BKPAS. Mean daily minutes of accelerometer derived MVPA and ST were evaluated during waking hours (7a‐9p). In the BKPAS, average MVPA and screen time minutes per day were calculated from questions that queried frequency and duration from the previous 7 days. Relationships between accelerometry and the BKPAS were assessed via Spearman Correlation Coefficient. Statistical significance was set at p 蠄 0.05. RESULTS: Accelerometer derived MVPA was significantly correlated with the BKPAS (r= 0.26, P = 0.01), but no association was found for ST (r = 0.13, P = 0.16). CONCLUSIONS: Results are positive for the self‐reported BKPAS and validation work is continuing, specifically for ST.Grant Funding Source: USDA‐AFRI grant #2012‐68001‐19605 and respective state Agricultural Experiment Stations.

Predicting Objectively Assessed Physical Activity From the Content and Regulation of Exercise Goals: Evidence for a Mediational Model

Grounded in self-determination theory (Deci & Ryan, 2000), the purpose of this work was to examine effects of the content and motivation of adults' exercise goals on objectively assessed moderate-to-vigorous physical activity (MVPA). After reporting the content and motivation of their exercise goals, 101 adult participants (Mage = 38.79 years; SD = 11.5) wore an ActiGraph (GT1M) accelerometer for seven days. Accelerometer data were analyzed to provide estimates of engagement in MVPA and bouts of physical activity. Goal content did not directly predict behavioral engagement; however, mediation analysis revealed that goal content predicted behavior via autonomous exercise motivation. Specifically, intrinsic versus extrinsic goals for exercise had a positive indirect effect on average daily MVPA, average daily MVPA accumulated in 10-min bouts and the number of days on which participants performed 30 or more minutes of MVPA through autonomous motivation. These results support a motivational sequence in which intrinsic versus extrinsic exercise goals influence physical activity behavior because such goals are associated with more autonomous forms of exercise motivation.

Physical Activity across Body Composition and Sex in Low Income Mexican and White American Youth

PURPOSE: The purpose of this study was to determine whether physical activity (PA) differs across different body composition and sex in low income Mexican and White youth in the United States. METHODS: Participants were 195 youth (78 boys and 117 girls with a M±SD age of 14.8±1.5 years). Approximately 51% were Mexican American and 49% were White youth. PA was assessed using a piezoelectric pedometer with a moderate to vigorous physical activity (MVPA) timer. Participants wore the pedometers for 7 days and recorded daily time worn on a PA log. MANOVA was used to determine the interactions of race (White vs. Mexican), sex (M vs. F), BMI classification (<85th percentile vs. ≥85th percentile), and waist circumference (WC) classification (<90th percentile vs. ≥90th percentile) on average steps/day and average MVPA/day for the weekend (WE) and weekdays (WD). RESULTS: Results of the MANOVA indicated a significant three-way interaction between race, sex, and BMI categories for average MVPA time on the WE (p=0.034). Then a 2x2 factorial ANOVA by sex was performed using race and BMI categories as the factors. No significant interaction was found, but the males showed a significant difference between overweight and normal weight categories, with the normal weight participants performing more WE MVPA, but no difference was found between the two races. For the females, a significant main effect was found for race, with white showing higher activity than Mexican on the WE, but no difference was found between BMI categories. The MANOVA also indicated significant main effect of race for average MVPA time on the WE (p=0.002) and WD (p=0.050), showing higher MVPA in White as compared to Mexican participants. The MANOVA also showed a main effect of sex for all dependent variables (WE steps/day p<0.001, WD steps/day p=0.001, WE MVPA p=0.008, WD MVPA p=0.008), with males taking more steps/day and showing higher MVPA for both WE and WD. Chi square showed observed number of overweight youth was significantly different than expected in all groups (p<0.01). CONCLUSIONS: White were more active than Mexican American youth with Mexican American girls least active, although low PA was seen regardless of race and sex. Effective interventions to increase daily PA for low income and ethnic minority youth in the United States must become a higher public priority.

The longitudinal influence of home and neighbourhood environments on children's body mass index and physical activity over 5 years: the CLAN study

To determine the independent contributions of family and neighbourhood environments to changes in youth physical activity and body mass index (BMI) z-score over 5 years. In 2001, 2004 and 2006, 301 children (10-12 years at baseline) had their height and weight measured (BMI was converted to z-scores using Centers for Disease Control and Prevention reference charts; see http://www.cdc.gov/growthcharts) and moderate-to-vigorous physical activity (MVPA) assessed using accelerometers. In 2001, parents reported on the home environment (social support, role modelling, rules and restrictions, physical environment) and perceived neighbourhood environment (local traffic, road safety, sporting venues, public transport), and Geographic Information Systems were used to map features of the neighbourhood environment (destinations, road connectivity, traffic exposure). Generalized estimating equations were used to predict average BMI z-score and MVPA over time from baseline home and perceived and objective neighbourhood environment factors. Among boys, maternal education and heavy traffic were inversely associated, and sibling physical activity, maternal role modelling of MVPA and the presence of dead-end roads were positively associated with MVPA. Having unmarried parents, maternal MVPA role modelling and number of home sedentary items were positively associated with BMI z-score among boys. Among girls, having siblings, paternal MVPA role modelling, physical activity rules and parental physical activity co-participation were positively associated with MVPA. Having unmarried parents and maternal sedentary behaviour role modelling were positively associated, and number of sedentary behaviour rules and physical activity items were inversely associated with BMI z-score among girls. The home environment seems more important than the neighbourhood environment in influencing children's physical activity and BMI z-score over 5 years. Physical activity and weight gain programmes among youth should focus on parental role modelling, rules around sedentary and active pursuits, and parental support for physical activity. Intervention studies to investigate these strategies are warranted.