PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (95)
 

Clipboard (0)
None

Select a Filter Below

Journals
Year of Publication
Document Types
1.  Correlates of Adiposity among Latino Preschool Children 
Journal of physical activity & health  2012;11(1):10.1123/jpah.2012-0018.
Background
Childhood obesity is at record high levels in the US and disproportionately affects Latino children. However, studies examining Latino preschool children’s obesity-related risk factors are sparse. This study determined correlates of Latino preschoolers’ (ages 3–5 years) adiposity to inform future obesity interventions and policies.
Methods
Latino preschoolers (n=96) from four Head Start centers in Houston, Texas were recruited. Parents reported acculturation and neighborhood safety. Children’s and parents’ height and weight were measured. Children’s television (TV) viewing was measured by TV diaries and physical activity by accelerometers. Linear regression was used with body mass index (BMI) z-score as the dependent variable and covariates sequentially added and retained in four blocks: (1) child age, gender, parent education and BMI, (2) neighborhood safety and parent and child acculturation, (3) TV viewing, and (4) moderate-to-vigorous physical activity (MVPA).
Results
In the final model (n=96), only neighborhood disorder (beta=0.30, p=0.005) and MVPA (beta=−0.21, p=0.049) were significantly associated with BMI z-score.
Conclusions
Among Latino preschoolers, higher neighborhood disorder and lower MVPA were associated with greater children’s BMI z-scores.
doi:10.1123/jpah.2012-0018
PMCID: PMC3750103  PMID: 23250380
Hispanic; obesity; neighborhood safety; physical activity; television viewing
2.  Physical Activity and Survival after Cancer Diagnosis in Men 
Journal of physical activity & health  2012;11(1):10.1123/jpah.2011-0257.
Background
The number of cancer survivors is increasing rapidly; however, little is known about whether engaging in physical activity after a cancer diagnosis is associated with lower mortality rates in men.
Methods
We conducted a prospective cohort study of 1,021 men (mean age, 71.3 years) who were diagnosed with cancer (other than non-melanoma skin cancer). Men reported their physical activities (walking, stair climbing, and participation in sports and recreational activities) on questionnaires in 1988, a median of 6 years after their cancer diagnosis. Physical activity was updated in 1993 and men were followed until 2008, with mortality follow-up >99% complete, during which 777 men died (337 from cancer, 190 from cardiovascular disease).
Results
In multivariate analyses, the relative risks for all-cause mortality associated with expending <2100, 2100–4199, 4200–8399, 8400–12,599, and ≥12,600 kJ/week in physical activity were 1.00 (referent), 0.77, 0.74, 0.76, and 0.52, respectively; p, trend <0.0001. Higher levels of physical activity also were associated with lower rates of death from cancer and cardiovascular disease; p, trend = 0.01 and 0.002, respectively.
Conclusions
Engaging in physical activity after cancer diagnosis is associated with better survival among men.
doi:10.1123/jpah.2011-0257
PMCID: PMC3610766  PMID: 23250326
epidemiology; exercise; mortality
3.  Personal, Behavioral, and Socioenvironmental Correlates of Physical Activity Among Adolescent Girls: Cross-Sectional and Longitudinal Associations 
Background
Physical activity (PA) declines sharply and rapidly during adolescence, especially among girls, posing a risk for inactivity and obesity in adulthood. This study identified personal, behavioral, and socioenvironmental correlates of concurrent and 6-month longitudinal PA among adolescent girls.
Methods
Data were gathered from 356 adolescent girls (mean age 15.8 ± 1.2 years; > 75% racial/ethnic minorities) in the Minneapolis/St. Paul area in 2007–2009. Linear regression analyses controlling for age, race/ethnicity, and school were conducted predicting baseline and follow-up levels of total PA and moderate-to-vigorous PA (MVPA) assessed via 3-Day Physical Activity Recall. Models were fit for each correlate individually and for all correlates together, mutually adjusted.
Results
For concurrent PA, significant positive predictors when adjusting for the influence of all other variables included self-efficacy, support from friends and teachers, and friends’ PA. Total screen time and distance from school to PA resources related inversely to concurrent PA. In mutually-adjusted models, 6-month PA was positively related to self-worth, family support, and parent PA and inversely related to total screen time.
Conclusions
PA interventions with adolescent girls might be enhanced by involving adolescents’ social networks and also by helping adolescents feel better about their self-worth and athletic abilities.
doi:10.1123/jpah.2011-0239
PMCID: PMC4107657  PMID: 23250194
adolescence; exercise; predictors; females
4.  Safety and Efficacy of Supervised Strength Training Adopted in Pregnancy 
Objective
Describe safety and efficacy of a supervised, low-to-moderate intensity strength training program adopted during pregnancy among women at increased risk for back pain.
Methods
32 women adopted strength training twice per week for 12 weeks. Data on musculoskeletal injuries, symptoms, blood pressure, and the absolute external load used for 5 of 6 exercises were obtained during each session. A submaximal lumbar extension endurance exercise test was performed at weeks 5, 10, and 13.
Results
The mean (± SD) exercise session attendance rate was 80.5% (± 11.3%). No musculoskeletal injuries occurred. Potentially adverse symptoms (eg, dizziness) were infrequent (2.1% of sessions). Repeated-measures ANOVA showed large increases in the external load across 12 weeks (all P values < .001) and the percentage increases in external load from weeks 1 to 12 were 36% for leg press, 39% for leg curl, 39% for lat pull down, 41% for lumbar extension and 56% for leg extension. Training was associated with a 14% increase in lumbar endurance. Blood pressure was unchanged following acute exercise sessions and after 12 weeks of exercise training.
Conclusion
The adoption of a supervised, low-to-moderate intensity strength training program during pregnancy can be safe and efficacious for pregnant women.
PMCID: PMC4203346  PMID: 21487130
blood pressure; exercise; physical activity; resistance training; symptoms; weight lifting
5.  Validity of ActiGraph 2-Regression Model and Matthews and NHANES and Cut-Points for Assessing Free-Living Physical Activity 
BACKGROUND
The purpose of this study was to compare the 2006 and 2010 Crouter algorithms, for the ActiGraph accelerometer, and the NHANES and Matthews cut-points, to indirect calorimetry during a 6-hr free-living measurement period.
METHODS
Twenty-nine participants (mean±SD; age, 38±11.7 yrs; BMI, 25.0±4.6 kg.m−2) were monitored for 6-hrs while at work or during their leisure time. Physical activity (PA) data was collected using an ActiGraph GT1M and energy expenditure (METs) was measured using a Cosmed K4b2. ActiGraph prediction equations were compared to the Cosmed for METs and time spent in sedentary behaviors, light PA (LPA), moderate PA (MPA) and vigorous PA (VPA).
RESULTS
The 2010 Crouter algorithm overestimated time spent in LPA, MPA, and VPA by 9.0%-44.5% and underestimated sedentary time by 20.8%. The NHANES cut-points overestimated sedentary time and LPA by 8.3%-9.9% and underestimated MPA and VPA by 50.4%-56.7%. The Matthews cut-points overestimated sedentary time (9.9%) and MPA (33.4%) and underestimated LPA (25.7%) and VPA (50.1%). The 2006 Crouter algorithm was within 1.8% of measured sedentary time, however, mean errors ranged from 34.4%-163.1% for LPA, MPA, and VPA.
CONCLUSION
Of the ActiGraph prediction methods examined, none of them was clearly superior for estimating free-living PA compared to indirect calorimetry.
PMCID: PMC4199088  PMID: 22975460
Motion Sensor; Accelerometry; Oxygen Consumption; Activity Counts Variability; Objective Monitors
6.  The Role of Exergaming in Improving Physical Activity: A Review 
Background
The high prevalence of obesity in America can be attributed to inadequate energy expenditure as a result of high levels of physical inactivity. This review presents an overview of the current literature on physical activity, specifically through active videogame systems (exergaming) and how these systems can help to increase physical activity levels.
Methods
The search strategy for this review was to identify previous studies which investigated energy expenditure levels using a single active video game or a combination of active videogames.
Results
Based on data from 27 studies, a strong correlation exists between exergaming and increased energy expenditure (up to 300% above resting levels). The majority of active videogames tested were found to achieve physical activity levels of moderate intensity, which meet American College of Sports Medicine guidelines for health and fitness.
Conclusions
Exergaming is a new and exciting strategy to potentially improve physical activity levels and reduce obesity among Americans.
doi:10.1123/jpah.2011-0425
PMCID: PMC4180490  PMID: 25078529
Exercise; energy expenditure; videogaming; obesity
7.  Physical Activity and Physical Function in Older Adults With Knee Osteoarthritis 
Purpose
To assess correlates of physical activity, and to examine the relationship between physical activity and physical functioning, in 160 older (66 ± 6 years old), overweight/obese (mean body mass index = 33.5 ± 3.8 kg/m2), sedentary (less than 30 mins of activity, 3 days a week) individuals with knee osteoarthritis.
Methods
Physical activity was measured with accelerometers and by self-report. Physical function was assessed by 6-min walk distance, knee strength, and the Short Physical Performance Battery. Pain and perceived function were measured by questionnaires. Pearson correlations and general linear models were used to analyze the relationships.
Results
The mean number of steps taken per day was 6209 and the average PAEE was 237 ± 124 kcal/day. Participants engaged in 131 ± 39 minutes of light physical activity (LPA) and 10.6 ± 8.9 minutes of moderate-vigorous physical activity (MPA/VPA). Total steps/day, PAEE, and minutes of MPA/VPA were all negatively correlated with age. The 6-min walk distance and lower extremity function were better in those who had higher total steps/day, higher PAEE, higher minutes of MPA/VPA, and a higher PASE score.
Conclusions
This study demonstrates that a population who has higher levels of spontaneous activity have better overall physical function than those who engage in less activity.
PMCID: PMC4142418  PMID: 23307503
exercise; aging; overweight; obese
8.  A Qualitative Study of Interviewer-Administered Physical Activity Recalls by Children 
Background
Qualitative methods were used to better understand how to obtain interviewer-administered recalls of physical activity from children.
Methods
Subjects were 24 third- and fifth-grade children from one school in Columbia, South Carolina. Cognitive interviews targeted different retention intervals (about the same or previous school day). Round 1's protocols used an open format and had four phases (obtain free recall, review free recall, obtain details, review details). Round 2's protocols used a chronological format and had three phases (obtain free recall, obtain details, review details). Trained coders identified discrepancies across interview phases in children's recalls of physical activity at physical education (PE) and recess. Based on the school's schedule, children's reports of PE and recess were classified as omissions (scheduled but unreported) or intrusions (unscheduled but reported).
Results
Across interview phases, there were numerous discrepancies for Round 1 (regardless of grade, sex, or retention interval) but few discrepancies for Round 2. For Rounds 1 and 2, respectively, 0% and 0% of children omitted PE, while 33% and 0% intruded PE; 44% and 56% of children omitted recess, while 33% and 0% intruded recess.
Conclusions
Results provide important information for facilitating interviewer-administered recalls of physical activity with elementary-age children.
PMCID: PMC3972012  PMID: 23072783
physical activity; pediatrics; qualitative research; measurement; recall measures; children; developmental
9.  Recent physical activity in relation to DNA damage and repair using the comet assay 
Background
Limited evidence suggests that very high-intensity exercise is positively associated with DNA damage but moderate exercise may be associated with DNA repair.
Methods
Participants were 220 healthy, Washington State 50–76 year-olds in the validity/biomarker sub-study of the VITamins And Lifestyle (VITAL) cohort, who provided blood samples and completed questionnaires assessing recent physical activity and demographic and health factors. Measures included nested activity subsets: total activity, moderate- plus high-intensity activity, and high-intensity activity. DNA damage (n=122) and repair (n=99) were measured using the comet assay. Multivariate linear regression was used to estimate regression coefficients and associated 95% confidence intervals (CIs) for relationships between MET-hours per week of activity and each DNA outcome (damage, and 15- and 60-minute repair capacities).
Results
DNA damage was not associated with any measure of activity. However, 60-minute DNA repair was positively associated with both total activity (β=0.21, 95% CI: 0.0057, 0.412; p=0.044) and high-intensity activity (β=0.31, 95% CI: 0.20, 0.60; p=0.036), adjusting for age, sex, BMI, and current multivitamin use.
Conclusions
This study is the first to assess broad ranges of activity intensity levels related to DNA damage and repair. Physical activity was unrelated to DNA damage but was associated with increased repair.
doi:10.1123/jpah.2012-0278
PMCID: PMC3844056  PMID: 23574930
Exercise; Body Mass Index; cancer prevention
10.  Leisure-time Physical Activity in Pregnancy and the Birth Weight Distribution: Where is the effect? 
BACKGROUND
Leisure-time physical activity (LTPA) is recommended during pregnancy and has been associated with lower risk of delivering a large infant. We sought to characterize the effect of LTPA across the entire birth weight distribution.
METHODS
Women enrolled in the Pregnancy Outcomes and Community Health (POUCH) Study (1998–2004) were followed-up in 2007. Follow-up efforts were extensive for a subcohort and minimal for the remainder (non-subcohort). Thus, 596 subcohort and 418 non-subcohort women who delivered at term participated. Offspring were categorized as small-, appropriate-, or large-for-gestational-age (SGA, AGA, and LGA, respectively) based on gender and gestational age-specific birth weight z-scores (BWz). At follow-up, women recalled pregnancy LTPA and were classified as inactive, insufficiently active or meeting LTPA recommendations. Linear, logistic, and quantile regression analyses were conducted separately by subcohort status.
RESULTS
Meeting LTPA recommendations decreased odds of LGA significantly among the non-subcohort (aOR=0.30, 95%CI: 0.14–0.64) and non-significantly among the subcohort (aOR=0.68, 95%CI: 0.34–1.34). In quantile regression, meeting LTPA recommendations reduced BWz among the upper quantiles in the non-subcohort.
CONCLUSIONS
LTPA during pregnancy lowered odds of LGA and reduced BWz among the upper quantiles, without shifting the entire distribution. LTPA during pregnancy may be useful for reducing risks of large fetal size.
PMCID: PMC4051283  PMID: 22207373
exercise; prenatal; maternal; fetal macrosomia; cohort studies
11.  New Insights Into Compliance With a Mobile Phone Diary and Pedometer Use in Sedentary Women 
Objectives
The purposes of this study were 1) to determine compliance with a pedometer and mobile phone-based physical activity diary, and 2) to assess concordance between self-reported daily steps recorded and transmitted by a mobile phone and pedometer-measured daily steps in sedentary women.
Methods
In this 3-week pilot clinical study, 41 sedentary women who met all inclusion criteria were recruited from local communities. We asked the participants to wear a pedometer every day and to report their daily steps using a mobile phone diary each night before retiring. In the first week, women were asked to monitor their daily steps (baseline steps). In the second and third weeks, they were asked to increase their steps by 20% from the previous week. Although the pedometer can automatically store the most recent 41 days’ performance, the participants were not informed of this function of the pedometer.
Results
Overall compliance was 93.8% with pedometer use and 88.3% with the mobile phone physical activity diary. Bland Altman plots showed that the agreement between self-reported daily steps by mobile phone diary and pedometer-recorded daily steps from week 1 to week 3 was high.
Conclusion
The combination of a pedometer and a mobile phone diary may enhance the quality of self-reported data in clinical studies.
PMCID: PMC4036092  PMID: 21487139
physical activity; cell phone; diary; self-report; adherence; compliance; concordance
12.  Energy Cost of Common Activities in Children and Adolescents 
Background
The Compendium of Energy Expenditures for Youth assigns MET values to a wide range of activities. However, only 35% of activity MET values were derived from energy cost data measured in youth; the remaining activities were estimated from adult values.
Purpose
To determine the energy cost of common activities performed by children and adolescents and compare these data to similar activities reported in the compendium.
Methods
Thirty-two children (8–11 years old) and 28 adolescents (12–16 years) completed 4 locomotion activities on a treadmill (TRD) and 5 age-specific activities of daily living (ADL). Oxygen consumption was measured using a portable metabolic analyzer.
Results
In children, measured METs were significantly lower than compendium METs for 3 activities [basketball, bike riding, and Wii tennis (1.1–3.5 METs lower)]. In adolescents, measured METs were significantly lower than compendium METs for 4 ADLs [basketball, bike riding, board games, and Wii tennis (0.3–2.5 METs lower)] and 3 TRDs [2.24 m·s−1, 1.56 m·s−1, and 1.34 m·s−1 (0.4–0.8 METs lower)].
Conclusion
The Compendium of Energy Expenditures for Youth is an invaluable resource to applied researchers. Inclusion of empirically derived data would improve the validity of the Compendium of Energy Expenditures for Youth.
PMCID: PMC4007486  PMID: 22398418
physical activity measurement; Compendium of Energy Expenditures for Youth; energy expenditure
13.  A Mixed Methods Comparison of Perceived Benefits and Barriers to Exercise between Obese and Non-Obese Women 
Background
Obese women have lower levels of physical activity than non-obese women, but it is unclear what drives these differences.
Methods
Mixed methods were used to understand why obese women have lower physical activity levels. Findings from focus groups with obese white women age 50 and older (N=19) were used to develop psychosocial items for an online survey of white women (N=195). After examining the relationship between weight group (obese vs. non-obese) and exercise attitudes, associated items (p<0.05) were tested for potential mediation of the relationship between weight and physical activity.
Results
Obese women were less likely than non-obese women to report that they enjoy exercise (OR 0.4, 95%CI 0.2–0.8) and were more likely to agree their weight makes exercise difficult (OR=10.6, 95%CI 4.2–27.1) and they only exercise when trying to lose weight (OR=3.8, 95%CI 1.6–8.9). Enjoyment and exercise for weight loss were statistically significant mediators of the relationship between weight and physical activity.
Conclusions
Exercise interventions for obese women may be improved by focusing on exercise enjoyment and the benefits of exercise that are independent of weight-loss.
PMCID: PMC3904548  PMID: 23714626
Physical Activity; Disparities; Weight; Mediation; Qualitative
14.  Feasibility and acceptability of using pedometers as an intervention tool for Latin 
Background
Due to high rates of inactivity and related chronic illnesses among Latinas,1 the current study examined the feasibility and acceptability of using pedometers as an intervention tool in this underserved population.
Methods
Data were taken from a larger randomized, controlled trial2 and focused on the subsample of participants (N=43) who were randomly assigned to receive a physical activity intervention with pedometers and instructions to log pedometer use daily and mail completed logs back to the research center each month for six months.
Results
Retention (90.7% at six months) and adherence to the pedometer protocol (68.89% returned ≥ 5 of the 6 monthly pedometer logs) were high. Overall, participants reported increased physical activity at six months and credited pedometer use for helping them achieve these gains (75.7%). Participants who completed a high proportion (5/6) of pedometer logs reported significantly greater increases in physical activity and related process variables (stages of change, self-efficacy, behavioral processes of change, social support from friends) than those who were less adherent (completed > 5 pedometer logs).
Conclusions
Pedometers constitute a low-cost, useful tool for encouraging self-monitoring of physical activity behavior in this at-risk group.
PMCID: PMC3971921  PMID: 22820735
15.  Communicating Prevention Messages to Policy Makers: The Role of Stories in Promoting Physical Activity 
Background
While effective interventions to promote physical activity have been identified, efforts to translate these interventions into policy have lagged behind. In order to improve the translation of evidence into policy, researchers and public health practitioners need to consider new ways for communicating health promoting messages to state and local policymakers.
Methods
In this article, we describe issues related to the translation of evidence supporting physical activity promotion, and offer some communication approaches and tools that are likely to be beneficial in translating research to policy.
Results
We discuss the use of narrative (i.e., stories) and describe its potential role in improving communication of research in policy-making settings. In addition, we provide an outline for the development and design of policy briefs on physical activity, and for how to target these briefs effectively to policy-oriented audiences.
Conclusions
Improvements in researchers' and practitioners' abilities to translate the evidence they generate into high-quality materials for policy makers can greatly enhance efforts to enact policies that promote physical activity.
PMCID: PMC3963269  PMID: 20440020
narrative communication; policy; translation; dissemination
16.  Injuries in Sedentary Individuals Enrolled in a 12-Month, Randomized, Controlled, Exercise Trial 
Background
The risk of musculoskeletal injury with the introduction of moderate-to-vigorous exercise in sedentary adults is not well established. The purpose of this report is to examine the effect of a 12-month exercise intervention on musculoskeletal injury and bodily pain in predominately overweight, sedentary, men (n=102) and women (n=100), aged 40–75 years.
Methods
Participants were randomized to a moderate-to-vigorous aerobic exercise intervention (EX) (6 d/wk, 60 min/d, 60–85% max. heart rate) or usual lifestyle control (CON). Participants completed a self-report of musculoskeletal injury and body pain at baseline and 12-months.
Results
The number of individuals reporting an injury (CON; 27% vs. EX; 28%, p= .95) did not differ by group. The most commonly injured site was lower leg/ankle/foot. The most common causes of injury were sports/physical activity, home maintenance or “other”. In the control group, bodily pain increased over the 12 months compared to the exercise group (CON −7.9, EX −1.4, p=.05). Baseline demographics and volume of exercise were not associated with injury risk.
Conclusions
Previously sedentary men and women randomized to a 12-month aerobic exercise intervention with a goal of 360 min/wk reported the same number of injuries as those in the control group and less bodily pain.
PMCID: PMC3960980  PMID: 22368219
musculoskeletal; physical activity; bodily pain; overweight
17.  Sedentary behavior, health-related quality of life and fatigue among breast cancer survivors 
Background
Many cancer survivors experience declines in health-related quality of life (HRQOL) and increases in fatigue as a result of cancer and its treatment. Exercise is linked to improvements in these outcomes, but little is known about the role of sedentary behavior. In a large, ethnically-diverse cohort of breast cancer survivors, we examined the relationship between sedentary time, HRQOL, and fatigue, and examined if that relationship differed by recreational moderate-vigorous physical activity (MVPA) level.
Methods
Participants were 710 women diagnosed with stage 0-IIIA breast cancer in the Health, Eating, Activity, and Lifestyle Study. Women completed questionnaires at approximately 30-months postdiagnosis (sedentary time; recreational MVPA) and 41-months postdiagnosis (HRQOL; fatigue). In multivariate models, we regressed these outcomes linearly on quartiles of daily sedentary time, and a variable jointly reflecting sedentary time quartiles and MVPA categories (0; > and <; ≥9 MET-hrs/wk).
Results
Sedentary time was not independently related to subscales or summary scores of HRQOL or fatigue. Additionally, comparisons of women with high vs. low (Q4:Q1) sedentary time by MVPA level did not result in significant differences in HRQOL or fatigue.
Conclusion
In this breast cancer survivor cohort, self-reported sedentary time was not associated with HRQOL or fatigue, 3.5 years postdiagnosis.
PMCID: PMC3794705  PMID: 22820125
health behavior; survivorship; epidemiology
18.  Physical activity and mortality among middle-aged and older adults in the United States 
Background
Physical activity (PA) has been routinely linked to lower all-cause mortality, yet extant research in the United States is primarily based on non-representative samples. Evidence is scant on the relative and independent merits of leisure-time (LTPA) versus non-leisure-time (NLTPA) activities and how the PA-mortality link may vary across racial-ethnic-gender groups.
Methods
Data were from Health and Retirement Study which began in 1992 collecting data on individuals aged 51 to 61 years who were subsequently surveyed once every two years. The present study assessed group-specific effects of LTPA and NLTPA measured in 1992 on mortality that occurred during the 1992–2008 follow-up period. Cox proportional hazard analyses were performed to examine the PA-mortality link.
Results
Net of a wide range of controls, both LTPA and NLTPA showed a gradient negative relation with mortality. No gender-PA interaction effects were evident. Some interaction effects of PA with race-ethnicity were found but they were weak and inconsistent. The mortality reduction effects of PA seemed robust across racial-ethnic-gender groups.
Conclusions
Regardless of personal background, PA is a major health promoting factor and should be encouraged in aging populations. More research is needed to assess relative merits of different types and domains of PA.
doi:10.1123/jpah.2011-0281
PMCID: PMC3929528  PMID: 23363569
physical activity; mortality; aging; race; ethnicity
19.  Exercise adherence, cardiopulmonary fitness and anthropometric changes improve exercise self-efficacy and health-related quality of life 
Background
Regular exercise increases exercise self-efficacy and health-related quality of life (HRQOL); however, the mechanisms are unknown. We examined the associations of exercise adherence and physiological improvements with changes in exercise self-efficacy and HRQOL.
Methods
Middle-aged adults (N=202) were randomized to 12 months aerobic exercise (360 minutes/week) or control. Weight, waist circumference, percent body fat, cardiopulmonary fitness, HRQOL (SF-36), and exercise self-efficacy were assessed at baseline and 12 months. Adherence was measured in minutes/day from activity logs.
Results
Exercise adherence was associated with reduced bodily pain, improved general health and vitality, and reduced role-emotional scores (Ptrend≤0.05). Increased fitness was associated with improved physical functioning, bodily pain and general health scores (Ptrend≤0.04). Reduced weight and percent body fat were associated with improved physical functioning, general health, and bodily pain scores (Ptrend<0.05). Decreased waist circumference was associated with improved bodily pain and general health but with reduced role-emotional scores (Ptrend≤0.05). High exercise adherence, increased cardiopulmonary fitness and reduced weight, waist circumference and percent body fat were associated with increased exercise self-efficacy (Ptrend<0.02).
Conclusions
Monitoring adherence and tailoring exercise programs to induce changes in cardiopulmonary fitness and body composition may lead to greater improvements in HRQOL and self-efficacy that could promote exercise maintenance.
PMCID: PMC3923574  PMID: 23036856
physical activity; intervention study; aerobic; physical fitness
20.  Walking for Transportation Among Latino Adults in San Diego County: Who Meets Physical Activity Guidelines? 
Background
U.S. Latinos engage in non-leisure-time walking (NLTW) more than other ethno-racial groups. Studies are needed to explore factors associated with NLTW to inform interventions for effective physical activity promotion.
Purpose
To examine the social-ecological correlates of NLTW among Mexican-origin Latinos.
Methods
Individual, social, and environmental level factors and PA were assessed in a telephone survey completed by 672 Mexican-origin adults randomly sampled in San Diego County. Data were collected in 2006 and analyzed in 2009.
Results
Participants were mostly female (71%), with an average age of 39 years. Less than one third met PA guidelines for NLTW (29%). Structural equation modeling showed that NLTW was positively associated with being female, but negatively associated with living in the U.S. ≥12 years, and being U.S.-born.
Conclusions
In this sample NLTW differed by various indicators of acculturation and gender. These findings might help inform the development of interventions to promote NLTW and thus physical activity in Mexican-origin adults.
PMCID: PMC3898633  PMID: 21885880
physical activity; chronic disease; community-based research; health behavior; special needs populations
21.  Evaluation of two self-report measures of physical activity with accelerometry in young adults 
Background
The purpose of this paper is to evaluate self-reported physical activity of young adults using one-week and one-year recall measures with an accelerometer as the criterion measure.
Methods
Participants were a subsample (N=121, 24±1.7 yrs) from a large longitudinal cohort study. Participants completed a detailed one-year physical activity recall, wore an accelerometer for one week and then completed a brief one-week physical activity recall when they returned the accelerometer.
Results
Mean values for moderate-to-vigorous physical activity (MVPA) from the three instruments were 3.2, 2.2, and 13.7 hours/wk for the accelerometer, one-week recall, and one-year recall, respectively (all different from each other, p<0.001). Spearman correlations for moderate, vigorous, and MVPA between the accelerometer and the one-week recall (0.30, 0.50, and 0.40, respectively) and the one-year recall (0.31, 0.42, and 0.44, respectively) demonstrated adequate validity.
Conclusions
Both recall instruments may be used for ranking physical activity at the group level. At the individual level, the one-week recall performed much better in terms of absolute value of physical activity. The one-year recall overestimated total physical activity but additional research is needed to fully test its validity.
PMCID: PMC3521871  PMID: 22241145
physical activity assessment; measurement; motion sensors; instrument psychometrics
22.  Defining Accelerometer Thresholds for Physical Activity in Girls Using ROC Analysis 
Background
Receiver operating characteristic (ROC) analysis is a common method used in diagnostic and screening tests to define thresholds levels of a factor that discriminates between 2 levels of another factor. The purpose of this analysis was to use ROC analysis to determine the optimal accelerometer-measured physical activity (PA) thresholds for predicting selective cardiovascular disease (CVD) risk factors.
Methods
ROC was performed using data from Stanford Girls Health Enrichment Multisite Studies trial. PA was assessed for multiple days using accelerometers. CVD variables were overweight, elevated triglyceride, reduced HDL-C, hypertension, impaired fasting glucose, fasting insulin, and clustering of multiple CVD risk factors.
Results
A sample of 261 girls participated, of which 208 had complete CVD risk measures (mean ± SD age = 9.4 ± 0.9yrs, BMI = 20.7 ± 4.8kg/m2). An average of ≥11.1 minutes/day at ≥2,600 counts/min was the maximally sensitive and specific threshold for discriminating girls who were overweight, ≥16.6 minutes/day at ≥2,000 counts/min for hyperinsulinemia or with ≥2 CVD risk factors. The Area Under the Curve for overweight, hyperinsulinemia, and ≥2 CVD risk factors was of 0.66, 0.58, and 0.60, respectively. The sensitivity and specificity associated with overweight, hyperinsulinemia, and ≥2 CVD risk factors were 60.3% and 72.9%, 53.3% and 83.9%, 44.0% and 84.7%, respectively.
Conclusion
Empirically-derived thresholds of PA to optimally discriminate between girls with and without CVD risk were lower in this sample than generally recommended. This ROC approach should be repeated in other populations to determine optimal PA thresholds with clinical validity for research, surveillance and program evaluation.
PMCID: PMC3863586  PMID: 20231754
receiver operating characteristics; ActiGraph; African-American; girls
23.  The Perceived Importance of Physical Activity: Associations with Psychosocial and Health-Related Outcomes 
Background
The purpose of this study was to assess the extent to which participation in a 12-month exercise program changed the degree of importance that older adults attached to physical activity. Additionally, associations among changes in physical activity importance and health-related and psychosocial outcomes were examined.
Methods
Community-dwelling older adults (N = 179) were recruited to participate in a 12-month exercise trial examining the association between changes in physical activity and fitness with changes in brain structure and psychological health. Participants were randomly assigned to a walking condition or a flexibility, toning, and balance condition. Physical, psychological, and cognitive assessments were taken at months 0, 6, and 12.
Results
Involvement in a 12-month exercise program increased the importance that participants placed on physical activity; this positive change was similar across exercise condition and sex. Changes in importance, however, were only associated with changes in physical health status and outcome expectations for exercise midway through the intervention. There were no significant associations at the end of the program.
Conclusions
Regular participation in physical activity can positively influence the perceived importance of the behavior itself. Yet, the implications of such changes on physical activity-related outcomes remain equivocal and warrant further investigation
PMCID: PMC3856648  PMID: 22820124
24.  The Influence of Neighborhood Socioeconomic Status and Walkability on TV viewing time 
Background
Influences on TV viewing time, which is associated with adverse health outcomes such as obesity and diabetes, need clarification.
Purpose
We assessed the relation of neighborhood socioeconomic status (SES) and walkability with TV viewing time in the Black Women’s Health Study, a prospective study of African American women.
Methods
We created neighborhood SES and walkability scores using data from the U.S. census and other sources. We estimated odds ratios for TV viewing 5+ hours/day compared to 0–1 hours/day for quintiles of neighborhood SES and walkability scores.
Results
Neighborhood SES was inversely associated with TV viewing time. The odds ratio for watching 5+ hours/day in the highest compared to the lowest quintile of neighborhood SES was 0.66 (95% CI 0.54–0.81). Neighborhood walkability was not associated with TV viewing time.
Conclusions
Neighborhood SES should be considered in devising strategies to combat the high levels of sedentariness prevalent in African American women.
PMCID: PMC3786398  PMID: 22207592
TV viewing time; neighborhood factors; African American women
25.  Objective Habitual Physical Activity and Estradiol Levels in Obese Latina Adolescents 
Background
Lifetime physical activity (PA) is associated with decreased breast cancer (BC) risk; reports suggest that PA during adolescence contributes strongly to this relationship. PA lowers production of sex hormones, specifically estradiol, or decreases insulin resistance (IR), thereby lowering risk. Overweight Latina adolescents are insulin resistant and exhibit low levels of PA, potentially increasing their future BC risk.
Methods
37 obese Latina adolescents (15.7 ±1.1 yrs) provided measures of PA using accelerometry; plasma follicular phase estradiol, sex-hormone binding globulin, total and free testosterone, dehydroepiandrosterone-sulfate (DHEAS); IR using HOMA-IR; body composition via DEXA. Partial correlations and stepwise linear regressions assessed cross-sectional relationships between sex hormones, IR and PA. Body composition, and age were included a priori as covariates.
Results
Estradiol was negatively associated with accelerometer counts per minute (CPM) (r= −0.4; p=0.02), percent time spent in moderate PA (%MPA) (r= −0.5; p=0.006), and percent time in moderate or vigorous PA (%MVPA) (r= −0.5; p=0.007). DHEAS was positively associated with CPM (r=0.4, p=0.009), %MPA (r=0.3, p=0.04), and %MVPA (r=0.3, p=0.04). Other sex hormones and IR were not associated with PA measures.
Conclusion
This study is the first to show that higher habitual PA was inversely associated with estradiol in obese adolescents.
PMCID: PMC3779056  PMID: 23038707
Accelerometer; insulin resistance; sex hormones; breast cancer

Results 1-25 (95)