Differential Use of Strategic Constructs of the Transtheoretical Model across Accelerometer-determined Sedentary Time.

Objectives: In this study, we investigated the differences in strategic constructs of the Transtheoretical Model (TTM) across accelerometer-determined sedentary time. Methods: A total of 201 college students participated in a TTM questionnaire for sedentary behavior and wore an accelerometer for 7 consecutive days to assess sedentary time. Multivariate analyses of variances (MANOVA) with post hoc pairwise comparisons were conducted to determine mean differences in the strategic constructs across quintiles of sedentary time. Tests for linear trends were conducted using orthogonal polynomial coefficients. Results: Compared with participants in higher quintiles of sitting time, 8 out of 10 processes of change (eg, mostly consciousness raising [η² p = .09]) were used significantly more frequently by those in the lowest quintile (p < .05) with negative linear trends (ptrend < .05). We found no statistically significant differences in the constructs of self-efficacy and decisional balance across the quintiles. Conclusions: Based on this preliminary analysis it appears that several intervention methods such as awareness raising, incentivization, self-motivation, and social norm building would be more beneficial to reduce sitting time or to protect their current sitting time from relapse.

Transit Use by Children and Adolescents: An Overlooked Source of and Opportunity for Physical Activity?

BACKGROUND: The potential for adults to accrue significant physical activity through public transit use is a topic of interest. However, there are no data on analogous questions among children. The goal of this analysis was to quantify patterns of transit use and correlates of transit-related physical activity among children aged 5 to 17 years. METHODS: Data for this cross-sectional study came from the 2012 California Household Travel Survey. Probit regressions modeled the probability of transit use; negative binomial regressions modeled minutes/day in transit-related active travel. RESULTS: Public transit use accounted for 3% of trips in California in 2012. Older Hispanic youth and those residing in areas with greater housing density and county size had a higher probability of transit use. Driver licensure, home ownership, household income, and vehicles in household were negatively correlated with public transit use. Race/ethnicity, income, and transit type were correlated with time spent in active travel to/ from transit. CONCLUSIONS: Given its importance as a source of physical activity for some children, researchers should consider assessment of public transit-related activity in physical activity measurement instruments. Efforts to encourage active travel should consider how to incorporate transit-related activity, both from a measurement perspective and as an intervention strategy.

Bone mineral density across a range of physical activity volumes: NHANES 2007-2010.

INTRODUCTION: The association between aerobic physical activity volume and bone mineral density (BMD) is not completely understood. The purpose of this study was to clarify the association between BMD and aerobic activity across a broad range of activity volumes, particularly volumes between those recommended in the 2008 Physical Activity Guidelines for Americans and those of trained endurance athletes. METHODS: Data from the 2007-2010 National Health and Nutrition Examination Survey were used to quantify the association between reported physical activity and BMD at the lumbar spine and proximal femur across the entire range of activity volumes reported by US adults. Participants were categorized into multiples of the minimum guideline-recommended volume based on reported moderate- and vigorous-intensity leisure activity. Lumbar and proximal femur BMD were assessed with dual-energy x-ray absorptiometry. RESULTS: Among women, multivariable-adjusted linear regression analyses revealed no significant differences in lumbar BMD across activity categories, whereas proximal femur BMD was significantly higher among those who exceeded the guidelines by 2-4 times than those who reported no activity. Among men, multivariable-adjusted BMD at both sites neared its highest values among those who exceeded the guidelines by at least 4 times and was not progressively higher with additional activity. Logistic regression estimating the odds of low BMD generally echoed the linear regression results. CONCLUSIONS: The association between physical activity volume and BMD is complex. Among women, exceeding guidelines by 2-4 times may be important for maximizing BMD at the proximal femur, whereas among men, exceeding guidelines by ≥4 times may be beneficial for lumbar and proximal femur BMD.

Application of the American Heart Association/American College of Sports Medicine Adult Preparticipation Screening Checklist to a nationally representative sample of US adults aged >=40 years from the National Health and Nutrition Examination Survey 2001 to 2004.

BACKGROUND: Although the American Heart Association/American College of Sports Medicine's Preparticipation Questionnaire (AAPQ) is a recommended preexercise cardiovascular screening tool, it has never been systematically evaluated. The purpose of this research is to provide preliminary evidence of its effectiveness among adults aged ≥40 years. METHODS AND RESULTS: Under the assumption that participants would respond to AAPQ items as they responded to a general health survey, we calculated the sex- and age-specific proportions of adult participants in the National Health and Nutrition Examination Survey 2001 to 2004 who would receive a recommendation for physician consultation based on AAPQ referral criteria. Additionally, we compared recommended AAPQ referrals to a similar assessment using the Physical Activity Readiness Questionnaire in the study sample. AAPQ referral proportions were higher with older age. Across all age groups ≥40 years, 95.5% (94.3% to 96.8%) of women and 93.5% (92.2% to 94.7%) of men in the United States would be advised to consult a physician before exercise. Prescription medication use and age were the most commonly selected items. When referral based on AAPQ was compared with that of the Physical Activity Readiness Questionnaire, the 2 screening tools produced similar results for 72.4% of respondents. CONCLUSIONS: These results suggest that >90% of US adults aged ≥40 years would receive a recommendation for physician consultation by the AAPQ. Excessive referral may present an unnecessary barrier to exercise adoption and stress the healthcare infrastructure.

Sedentary and active: self-reported sitting time among marathon and half-marathon participants.

BACKGROUND: Emerging evidence suggests that combined physical activity (PA) and inactivity may be more important for chronic disease risk than PA alone. A highly active yet highly sedentary population is needed to study this interaction. The present purpose is to describe the sitting habits of a group of recreational runners and determine if sitting varies with reported training duration or anticipated running velocity. METHODS: Marathon and half-marathon participants completed the Multicontext Sitting Time Questionnaire and reported peak training duration, anticipated finishing time, and demographic information. Sitting time was described across 5 contexts for workdays and nonworkdays. Total sitting time was analyzed by tertiles of training duration and anticipated event running velocity. RESULTS: 218 participants took part in this study. Median reported training time was 6.5 hours per week. Median total sitting time was higher on workdays than nonworkdays (645 and 480 minutes, respectively, P < .0001). Total sitting time was not associated with training duration or anticipated event running velocity. CONCLUSIONS: These results suggest that recreational distance runners are simultaneously highly sedentary and highly active, supporting independence of sedentary behaviors and moderate- to vigorous-intensity PA. This population may provide the characteristics needed to study the joint effects of active and sedentary behaviors on health outcomes.

Framework for physical activity as a complex and multidimensional behavior.

CONTEXT: The selection of the most psychometrically appropriate self-report tool(s) to measure specific physical activity constructs has been a challenge for researchers, public health practitioners, and clinicians, alike. The lack of a reasonable gold standard measure and inconsistent use of established and evolving terminology have contributed to these challenges. The variation of self-report measures and quality of the derived summary estimates could be attributed to the absence of a standardized conceptual framework for physical activity. OBJECTIVE: To present a conceptual framework for physical activity as a complex and multidimensional behavior that differentiates behavioral and physiological constructs of human movement. PROCESS: The development of a conceptual framework can provide the basic foundation from which to standardize definitions, guide design and development of self-report measures, and provide consistency during instrument selection. CONCLUSIONS: Based on our proposed conceptual framework for physical activity, we suggest that physical activity is more clearly defined as the behavior that involves human movement, resulting in physiological attributes including increased energy expenditure and improved physical fitness. Utilization of the proposed conceptual framework can result in better instrument choices and consistency in methods used to assess physical activity and sedentary behaviors across research and public health practice.

Reported physical activity and sedentary behavior: why do you ask?

CONTEXT: Advances in device-based measures have led researchers to question the value of reported measures of physical activity or sedentary behavior. The premise of the Workshop on Measurement of Active and Sedentary Behaviors: Closing the Gaps in Self-Report Methods, held in July 2010, was that assessment of behavior by self-report is a valuable approach. OBJECTIVE: To provide suggestions to optimize the value of reported physical activity and sedentary behavior, we 1) discuss the constructs that devices and reports of behavior can measure, 2) develop a framework to help guide decision-making about the best approach to physical activity and sedentary behavior assessment in a given situation, and 3) address the potential for combining reported behavior methods with device-based monitoring to enhance both approaches. PROCESS: After participation in a workshop breakout session, coauthors summarized the ideas presented and reached consensus on the material presented here. CONCLUSIONS: To select appropriate physical activity assessment methods and correctly interpret the measures obtained, researchers should carefully consider the purpose for assessment, physical activity constructs of interest, characteristics of the population and measurement tool, and the theoretical link between the exposure and outcome of interest.

The Women on the Move Through Activity and Nutrition (WOMAN) study: final 48-month results.

The Women on the Move through Activity and Nutrition (WOMAN) study was designed to test whether a nonpharmacological intervention including qualitative and quantitative dietary changes to induce weight loss and increased physical activity levels would reduce blood triglyceride levels and number of low-density lipoprotein particles (LDL-P). Such decreases in lipoproteins and other risk factors could reduce or slow progression of subclinical cardiovascular disease (CVD). Study participants were randomized to either the intervention (Lifestyle Change) or assessment (Health Education) group. Most of the intervention ended at the 30-month visit. The last 48-month examination was completed in 9/2008. There was very substantial weight loss and increased exercise during the first 30 months of the trial resulting in significant decreases in CV risk factors. Most of the intervention effect was lost through 48 months. Weight loss was 3.4 kg in Lifestyle Intervention and 0.2 kg in the Health Education at 48 months (P = 0.000). There were no significant changes at 48 months in lipid levels, blood pressure (BP), glucose, insulin, or in the subclinical measures of coronary calcium, carotid intima media thickness, or plaque. There was a significant decrease in long-distance corridor walk time in the Lifestyle vs. Health Education groups. Significant lifestyle changes can be achieved that result in decreases in CV risk factors. Whether such changes reduce CV outcomes is still untested in clinical trials of weight loss or exercise. Long-term maintenance of successful lifestyle changes, weight loss and reduced risk factors is the hurdle for lifestyle interventions attempting to prevent CV and other chronic diseases.

Association of leisure physical activity and sleep with cardiovascular risk factors in postmenopausal women.

OBJECTIVE: The aim of this study was to examine the individual and combined associations of leisure-time physical activity and sleep with cardiovascular risk factors in postmenopausal women. METHODS: We analyzed 48-month cross-sectional follow-up data from 393 participants of the Women on the Move Through Activity and Nutrition Study, a behavioral weight loss trial. Leisure-time physical activity data were collected with the past-year Modifiable Activity Questionnaire, whereas sleep data were collected with the Pittsburgh Sleep Quality Index. We compared physical activity and sleep categories using analysis of variance, post hoc Scheffe tests, and multivariate analyses based on groups above/below the median leisure-time physical activity level, above/below the sleep quality value of 5, and above/below the sleep duration of 7 hours/day. RESULTS: The average sleep quality and sleep duration did not significantly differ between women with high and women with low physical activity levels. When women with good sleep quality were compared, higher physical activity levels were associated with lower body mass index (2.0 kg/m; 25, 75 quartiles, 0.3, 3.6), waist circumference (6.3 cm; 1.7, 10.9), and total body fat (2.1%; 0.3, 4.0; P < 0.05). When participants with poor sleep quality were compared, highly active women had lower trunk fat, total body fat, and insulin levels than less active women did (P < 0.05). In multivariate analysis, physical activity was significantly associated with high-density lipoprotein level, trunk fat, and total body fat after controlling for sleep quality, sleep duration, age, hormone therapy and smoking status, and body mass index. CONCLUSIONS: The combined associations of leisure-time physical activity and sleep suggest that cardiovascular risk factors are more favorable in highly active women relative to less active women regardless of sleep.

Girls on the Run: a quasi-experimental evaluation of a developmentally focused youth sport program.

BACKGROUND: Evidence supporting the effectiveness of a developmental-focused youth sport (DYS) program designed exclusively for elementary school aged girls is mounting. The purpose of this study was to evaluate the impact of on the Girls on the Run program on psychological and physical assets among 3rd- to 5th-grade girls. METHODS: A longitudinal quasi-experimental study was conducted to evaluate intervention effects among 877 participants categorized into 1 of 3 groups (never, newly, and previously exposed). A 64-item self-report survey measured developmental assets at 3 time-points. Nested random effects ANOVA models were used to compare demographic factors and psychological and physical assets between exposure groups and to compare longitudinal differences in these assets. RESULTS: After adjustment for multiple comparisons, previous program participants had significantly higher physical activity commitment (P = .006) and physical activity levels (P = .047) at preintervention than never exposed. From pre- to postintervention body image improved in newly exposed participants (P = .03). Physical activity increased from preintervention to follow-up among never and newly exposed participants (all P < .05). CONCLUSIONS: Although we were unable to fully confirm the study hypotheses, the results of the current study provide new evidence to support future long-term studies examining the effectiveness of an innovative DYS program for 3rd- to 5th-grade girls.

Test-retest reliability and validity of the 400-meter walk test in healthy, middle-aged women.

BACKGROUND: The 400 m walk test has been used in older adults; however, the applicability in middle-aged populations is unknown. METHODS: Data were obtained from the Evaluation of Physical Activity Measures in Middle-Aged Women (PAW) Study and included 66 women (52.6 ± 5.4 years). Participants were instructed to walk at a brisk, maintainable pace; time taken to complete the 400 m was recorded in seconds. Intraclass correlation coefficients (ICC) were used to assess test-retest reliability. Spearman rank order correlation coefficients were used to examine the concurrent validity of the walk test with cardiorespiratory fitness and associations with physical activity, body composition, flexibility, static balance, and muscular fitness, adjusted for age and body mass index. RESULTS: Participants completed the walk at visits 4 and 5 in 248.0 and 245.0 seconds, respectively. The walk test had excellent reproducibility [ICC = 0.95 (95% CI: 0.92, 0.97)] and was significantly associated with estimated (ρ = -0.43; P < 0.0001) and measured (ρ = -0.56; P < 0.001) VO2max. The walk test was also significantly related to physical activity, body composition, flexibility, and balance. CONCLUSIONS: These findings support the utility of the 400 m walk test to estimate cardiorespiratory fitness and reflect free-living physical activity in healthy, middle-aged women.

Physical activity and coronary artery calcification in two cohorts of women representing early and late postmenopause.

OBJECTIVE: The aim of this study was to examine the association between physical activity (PA) and coronary artery calcification (CAC) among two cohorts of postmenopausal (PM) women representing early and late postmenopause. METHODS: The cross-sectional relationship between PA and CAC was examined in 173 younger PM women (mean age ± SD, 56.8 ± 2.9 y) from the Women on the Move Through Activity and Nutrition (WOMAN) study and 121 older PM women (mean age ± SD, 73.9 ± 3.8 y) from the Walking Women Follow-up (WWF) study who had complete PA and CAC data. PA was measured objectively using a pedometer over a 7-day period in both cohorts. CAC was assessed using electron beam tomography. Descriptive statistics were used to describe median levels of PA and CAC, as well as proportions of detectable CAC (0 vs > 0). RESULTS: Fifty-seven percent of WOMAN study participants and 74% of WWF study participants had detectable CAC. The median (interquartile range) CAC score was 1.4 (0-23.3) for participants in the WOMAN study and 38.8 (0-264.4) among WWF study participants. Median (interquartile range) step counts were 6,447 (4,823-8,722) steps per day in the WOMAN study and 5,466 (3,610-7,576) steps per day for WWF study participants. Among WWF study participants, there was a statistically significant inverse association between pedometer steps and CAC (P for trend = 0.002); no association was found among WOMAN study participants. CONCLUSIONS: Among older PM women, higher levels of PA were associated with lower CAC. However, the relationship was not observed in PM women, likely due to the lower prevalence of CAC in this age group.

Association between self-reported resistance training and self-rated health in a national sample of U.S. men and women.

BACKGROUND: Self-rated health (SRH) is a predictor of several clinical outcomes, including mortality. Physical activity is associated with SRH; however, the specific role that resistance training (RT) plays in this relationship is unknown. We explored the independent association between self-reported RT and SRH in a cross-sectional survey (National Physical Activity and Weight Loss Study; NPAWLS) conducted by the University of South Carolina Prevention Research Center in 2002. METHOD: Subjects were 9651 men and women (mean age 46.5 yrs) classified as having high or low SRH; and they were categorized into 2 groups: (1) meeting nationally recommended levels for RT (>or= 2 days/week); (2) not meeting levels (<2 days/week or no RT). RESULTS: Meeting national recommendations was associated with male gender (P < .01), normal BMI (P < .01), and higher education (P < .01). When compared to individuals with low SRH, those with high SRH were 2 times as likely to meet recommended levels of RT (OR = 2.32; 95% CI = 1.96 to 2.76). The model modestly attenuated when fully adjusted for confounding variables, including other exercise (OR = 1.79; 95% CI = 1.49 to 2.15). CONCLUSION: This study identifies the specific positive relationship between RT and SRH, further supporting the health benefits of meeting the national recommendations for RT.