Jordan A. Carlson

Interactions between psychosocial and built environment factors in explaining older adults' physical activity

OBJECTIVE To evaluate ecological model predictions of cross-level interactions among psychosocial and environmental correlates of physical activity in 719 community-dwelling older adults in the Baltimore, Maryland and Seattle, Washington areas during 2005-2008. METHOD Walkability, access to parks and recreation facilities and moderate-to-vigorous physical activity (MVPA) minutes per week (min/week) were measured objectively. Neighborhood aesthetics, walking facilities, social support, self-efficacy, barriers and transportation and leisure walking min/week were self-reported. RESULTS Walkability interacted with social support in explaining total MVPA (B=13.71) and with social support (B=7.90), self-efficacy (B=7.66) and barriers (B=-8.26) in explaining walking for transportation. Aesthetics interacted with barriers in explaining total MVPA (B=-12.20) and walking facilities interacted with self-efficacy in explaining walking for leisure (B=-10.88; Ps<.05). Summarizing across the interactions, living in a supportive environment (vs. unsupportive) was related to 30-59 more min/week of physical activity for participants with more positive psychosocial attributes, but only 0-28 more min/week for participants with less positive psychosocial attributes. CONCLUSION Results supported synergistic interactions between built environment and psychosocial factors in explaining physical activity among older adults. Findings suggest multilevel interventions may be most effective in increasing physical activity.

Physical Activity During Youth Sports Practices

OBJECTIVE To document physical activity (PA) during organized youth soccer and baseball/softball practices. DESIGN Cross-sectional study. SETTING Community sports leagues in San Diego County, California. PARTICIPANTS Two hundred youth aged 7 to 14 years were recruited from 29 teams in 2 youth sports in middle-income cities with an approximately equal distribution across sports, sex, and age groups. MAIN EXPOSURE Youth sports practices. OUTCOME MEASURES A sample of players wore accelerometers during practices. Minutes of PA at multiple intensity levels were calculated using established cutoff points. Participants were categorized as meeting or not meeting guidelines of at least 60 minutes of moderate to vigorous PA (MVPA) during practice. RESULTS The overall mean for MVPA was 45.1 minutes and 46.1% of practice time. Participants on soccer teams (+13.7 minutes, +10.6% of practice time), boys (+10.7 minutes, +7.8% of practice time), and those aged 7 to 10 years (+7.0 minutes, +5.8% of practice time) had significantly more MVPA than their counterparts. Participants on soccer teams spent an average of 17.0 more minutes and 15.9% more of practice time in vigorous-intensity PA than those on baseball/softball teams. Overall, 24% of participants met the 60-minute PA guideline during practice, but fewer than 10% of 11-to 14-year-olds and 2% of girl softball players met the guideline. CONCLUSIONS Participation in organized sports does not ensure that youth meet PA recommendations on practice days. The health effects of youth sports could be improved by adopting policies that ensure participants obtain PA during practices.

Dietary-Related and Physical Activity-Related Predictors of Obesity in Children: A 2-Year Prospective Study

BACKGROUND This observational study examined cross-sectional and 24-month longitudinal associations of physical activity and dietary behaviors with change in BMI and percent body fat among children aged 6–9 years old. METHODS Data were from the control group (n = 271; 48% Latino) of a community-based childhood obesity prevention program. Assessments were conducted at baseline and at 24 months and included height and weight, bioelectrical impedance–derived percent body fat, and 10 physical activity and dietary behaviors measured via parent report of their child. Cross-sectional analysis of variances (ANOVA) (normal weight, overweight, obese) and longitudinal mixed-effects linear regression models were used to investigate the relation of each physical activity and dietary behavior with BMI and percent body fat. RESULTS At baseline, obese children engaged in less physical activity and more sedentary behavior than normal-weight children (p < 0.05). Increased physical activity (p < 0.01) and number of breakfasts eaten with family (p < 0.05) were associated with decreased BMI z-score and percent body fat. Decreased sedentary behavior and sugar-sweetened beverage consumption were associated with decreased percent body fat (p < 0.05) but not BMI. CONCLUSIONS In this cohort of 271 children, increased physical activity and eating breakfast with family and reduced screen-based sedentary behaviors and sugar-sweetened beverage consumption were associated with more favorable trends in adiposity. Therefore, attention to these behaviors may be of particular importance. Results also suggest that future studies should include percent body fat as an outcome for a more precise assessment of the association of behavior with adiposity.

Association between neighborhood walkability and GPS-measured walking, bicycling and vehicle time in adolescents

OBJECTIVES To investigate relations of walking, bicycling and vehicle time to neighborhood walkability and total physical activity in youth. METHODS Participants (N=690) were from 380 census block groups of high/low walkability and income in two US regions. Home neighborhood residential density, intersection density, retail density, entertainment density and walkability were derived using GIS. Minutes/day of walking, bicycling and vehicle time were derived from processing algorithms applied to GPS. Accelerometers estimated total daily moderate-to-vigorous physical activity (MVPA). Models were adjusted for nesting of days (N=2987) within participants within block groups. RESULTS Walking occurred on 33%, active travel on 43%, and vehicle time on 91% of the days observed. Intersection density and neighborhood walkability were positively related to walking and bicycling and negatively related to vehicle time. Residential density was positively related to walking. CONCLUSIONS Increasing walking in youth could be effective in increasing total physical activity. Built environment findings suggest potential for increasing walking in youth through improving neighborhood walkability.

Is the relationship between the built environment and physical activity moderated by perceptions of crime and safety

BackgroundDirect relationships between safety concerns and physical activity have been inconsistently patterned in the literature. To tease out these relationships, crime, pedestrian, and traffic safety were examined as moderators of built environment associations with physical activity.MethodsExploratory analyses used two cross-sectional studies of 2068 adults ages 20–65 and 718 seniors ages 66+ with similar designs and measures. The studies were conducted in the Baltimore, Maryland-Washington, DC and Seattle-King County, Washington regions during 2001–2005 (adults) and 2005–2008 (seniors). Participants were recruited from areas selected to sample high- and low- income and walkability. Independent variables perceived crime, traffic, and pedestrian safety were measured using scales from validated instruments. A GIS-based walkability index was calculated for a street-network buffer around each participant’s home address. Outcomes were total physical activity measured using accelerometers and transportation and leisure walking measured with validated self-reports (IPAQ-long). Mixed effects regression models were conducted separately for each sample.ResultsOf 36 interactions evaluated across both studies, only 5 were significant (p < .05). Significant interactions did not consistently support a pattern of highest physical activity when safety was rated high and environments were favorable. There was not consistent evidence that safety concerns reduced the beneficial effects of favorable environments on physical activity. Only pedestrian safety showed evidence of a consistent main effect with physical activity outcomes, possibly because pedestrian safety items (e.g., crosswalks, sidewalks) were not as subjective as those on the crime and traffic safety scales.ConclusionsClear relationships between crime, pedestrian, and traffic safety with physical activity levels remain elusive. The development of more precise safety variables and the use of neighborhood-specific physical activity outcomes may help to elucidate these relationships.

A pilot study evaluating a one-session attention modification training to decrease overeating in obese children

There are a number of neurocognitive and behavioral mechanisms that contribute to overeating and obesity, including an attentional bias to food cues. Attention modification programs, which implicitly train attention away from specific cues, have been used in anxiety and substance abuse, and could logically be applied to food cues. The purpose of this study was to evaluate the initial efficacy of a single session attention modification training for food cues (AMP) on overeating in overweight and obese children. Twenty-four obese children who eat in the absence of hunger participated in two visits and were assigned to an attention modification program (AMP) or attentional control program (ACC). The AMP program trained attention away 100% of the time from food words to neutral words. The ACC program trained attention 50% of the time to neutral and 50% of the time to food. Outcome measures included the eating in the absence of hunger free access session, and measures of craving, liking and salivation. Results revealed significant treatment effects for EAH percent and EAH kcal (group by time interactions p<.05). Children in the ACC condition showed a significant increase over time in the number of calories consumed in the free access session (within group t=3.09, p=.009) as well as the percent of daily caloric needs consumed in free access (within group t=3.37, p=.006), whereas children in the AMP group demonstrated slight decreases in these variables (within group t=-0.75 and -0.63, respectively). There was a trend suggesting a beneficial effect of AMP as compared to ACC for attentional bias (group by time interaction p=.073). Changes in craving, liking and saliva were not significantly different between groups (ps=.178-.527). This is the first study to demonstrate that an AMP program can influence eating in obese children. Larger studies are needed to replicate and extend these results.

Validity of Palms Gps Scoring of Active and Passive Travel Compared with Sensecam

PURPOSE The objective of this study is to assess validity of the personal activity location measurement system (PALMS) for deriving time spent walking/running, bicycling, and in vehicle, using SenseCam (Microsoft, Redmond, WA) as the comparison. METHODS Forty adult cyclists wore a Qstarz BT-Q1000XT GPS data logger (Qstarz International Co., Taipei, Taiwan) and SenseCam (camera worn around the neck capturing multiple images every minute) for a mean time of 4 d. PALMS used distance and speed between global positioning system (GPS) points to classify whether each minute was part of a trip (yes/no), and if so, the trip mode (walking/running, bicycling, or in vehicle). SenseCam images were annotated to create the same classifications (i.e., trip yes/no and mode). Contingency tables (2 × 2) and confusion matrices were calculated at the minute level for PALMS versus SenseCam classifications. Mixed-effects linear regression models estimated agreement (mean differences and intraclass correlation coefficients) between PALMS and SenseCam with regard to minutes/day in each mode. RESULTS Minute-level sensitivity, specificity, and negative predictive value were ≥88%, and positive predictive value was ≥75% for non-mode-specific trip detection. Seventy-two percent to 80% of outdoor walking/running minutes, 73% of bicycling minutes, and 74%-76% of in-vehicle minutes were correctly classified by PALMS. For minutes per day, PALMS had a mean bias (i.e., amount of over or under estimation) of 2.4-3.1 min (11%-15%) for walking/running, 2.3-2.9 min (7%-9%) for bicycling, and 4.3-5 min (15%-17%) for vehicle time. Intraclass correlation coefficients were ≥0.80 for all modes. CONCLUSIONS PALMS has validity for processing GPS data to objectively measure time spent walking/running, bicycling, and in vehicle in population studies. Assessing travel patterns is one of many valuable applications of GPS in physical activity research that can improve our understanding of the determinants and health outcomes of active transportation as well as its effect on physical activity.

State policies about physical activity minutes in physical education or during school.

BACKGROUND School policies can change practices on a relatively permanent basis. This study investigated adoption and implementation of state-level policies specifying minutes (or percent) of physical activity in physical education (PE) or during school. METHODS Policies were identified from existing databases and rated as having weak, moderate, or strong wording. Interviews with state-level PE coordinators were conducted to investigate the level of implementation, monitoring, and enforcement of the identified policies. RESULTS Sixteen states had a policy that met inclusion criteria (19 policies total); 11 states had a policy addressing minutes of physical activity during school, 2 had a policy addressing percent of PE time to be spent in physical activity, and 3 had policies addressing both. None of the 19 policies were rated as having strong wording and 5 were rated as having moderate wording. The range in minutes of physical activity per week addressed in the policies was 60 to 300. Four of the 5 (elementary) and 5 of 5 (middle) policies addressing percent of PE spent physically active specified 50%. The only monitoring efforts reported consisted of schools self-reporting progress to the state. CONCLUSIONS More states need to adopt school physical activity policies and policy language needs to be more specific to prevent potential loopholes. Monitoring and evaluation strategies, beyond school self-report, are likely needed for these policies to lead to increases in physical activity.

Reliability and validity of brief psychosocial measures related to dietary behaviors

BackgroundMeasures of psychosocial constructs are required to assess dietary interventions. This study evaluated brief psychosocial scales related to 4 dietary behaviors (consumption of fat, fiber/whole grains, fruits, and vegetables).MethodsTwo studies were conducted. Study 1 assessed two-week reliability of the psychosocial measures with a sample of 49 college students. Study 2 assessed convergent and discriminant validity of the psychosocial measures with dietary nutrient estimates from a Food Frequency Questionnaire on 441 men and 401 women enrolled in an Internet-based weight loss intervention study.ResultsStudy 1 test-retest reliability ICCs were strong and ranged from .63 to .79. In study 2, dietary fat cons, fiber/whole grain cons and self-efficacy, fruit and vegetable cons and self-efficacy, and healthy eating social support, environmental factors, enjoyment, and change strategies demonstrated adequate correlations with the corresponding dietary nutrient estimates.ConclusionsBrief psychosocial measures related to dietary behaviors demonstrated adequate reliability and in most cases validity. The strongest and most consistent scales related to dietary behaviors were healthy eating change strategies and enjoyment. Consistent convergent validity was also found for the cons of change scales. These measures can be used in intervention studies to evaluate psychosocial mediators of dietary change in overweight and obese individuals.

Built environment characteristics and parent active transportation are associated with active travel to school in youth age 12-15

Purpose To investigate the relation of factors from multiple levels of ecological models (ie, individual, interpersonal and environmental) to active travel to/from school in an observational study of young adolescents. Methods Participants were 294 12–15-year olds living within two miles of their school. Demographic, psychosocial and perceived built environment characteristics around the home were measured by survey, and objective built environment factors around home and school were assessed in Geographic Information Systems (GIS). Mixed effects multinomial regression models tested correlates of engaging in 1–4 (vs 0) and 5–10 (vs 0) active trips/week to/from school, adjusted for distance and other covariates. Results 64% of participants reported ≥1 active trip/week to/from school. Significant correlates of occasional and/or habitual active travel to/from school included barriers (ORs=0.27 and 0.15), parent modelling of active travel (OR=3.27 for habitual), perceived street connectivity (OR=1.78 for occasional), perceived pedestrian safety around home (OR=2.04 for habitual), objective street connectivity around home (OR=0.97 for occasional), objective residential density around home (ORs=1.10 and 1.11) and objective residential density around school (OR=1.14 for habitual). Parent modelling interacted with pedestrian safety in explaining active travel to/from school. Conclusions Results supported multilevel correlates of adolescents’ active travel to school, consistent with ecological models. Correlates of occasional and habitual active travel to/from school were similar. Built environment attributes around schools, particularly residential density, should be considered when siting new schools and redeveloping neighbourhoods around existing schools.