Background: Schools are a setting in which students learn about the importance of lifelong physical activity (PA). Best practice guidelines indicate that schools should provide students with adequate physical education (PE) minutes and opportunities to engage in PA throughout the school day. Methods: Data from the nationally representative School Nutrition and Meal Cost Study in 2014–2015 were utilized to assess PA practices (including PE) at 412 public elementary schools. These data were linked to state- and district-level policy data from the National Wellness Policy Study to examine the relationships between state law and school district policies and school practices. Results: Just over half of the schools were in a state with a policy regarding PE minutes. The comprehensiveness and strength of PA policies were higher at the district level than the state level, but were still low overall. Comprehensiveness of PA policies at the state level, but not at the district level, was related to schools within those states that provide more PA practices. Conclusions: Existence of PE and PA policies at the state level appears to be an important predictor of school PA practices. Having more comprehensive policies at the state level may be an important facilitator of school implementation of comprehensive PA practices.
Hannah G. Calvert, Lindsey Turner, Julien Leider, Elizabeth Piekarz-Porter and Jamie F. Chriqui
Ignacio Perez-Pozuelo, Thomas White, Kate Westgate, Katrien Wijndaele, Nicholas J. Wareham and Soren Brage
Background: Wrist-worn accelerometry is the commonest objective method for measuring physical activity in large-scale epidemiological studies. Research-grade devices capture raw triaxial acceleration which, in addition to quantifying movement, facilitates assessment of orientation relative to gravity. No population-based study has yet described the interrelationship and variation of these features by time and personal characteristics. Methods: 2,043 United Kingdom adults (35–65 years) wore an accelerometer on the non-dominant wrist and a chest-mounted combined heart-rate-and-movement sensor for 7 days free-living. From raw (60 Hz) wrist acceleration, we derived movement (non-gravity acceleration) and pitch and roll (forearm) angles relative to gravity. We inferred physical activity energy expenditure (PAEE) from combined sensing and sedentary time from approximate horizontal arm angle coupled with low movement. Results: Movement differences by time-of-day and day-of-week were associated with forearm angles; more movement in downward forearm positions. Mean (SD) movement was similar between sexes ∼31 (42) mg, despite higher PAEE in men. Women spent longer with the forearm pitched >0°, above horizontal (53% vs 36%), and less time at <0° (37% vs 53%). Diurnal pitch was 2.5–5° above and 0–7.5°below horizontal during night and daytime, respectively; corresponding roll angles were ∼0° (hand flat) and ∼20° (thumb-up). Differences were more pronounced in younger participants. All diurnal profiles indicated later wake-times on weekends. Daytime pitch was closer to horizontal on weekdays; roll was similar. Sedentary time was higher (17 vs 15 hours/day) in obese vs normal-weight individuals. Conclusions: More movement occurred in forearm positions below horizontal, commensurate with activities including walking. Findings suggest time-specific population differences in behaviors by age, sex, and BMI.
Salomé Aubert, Julien Aucouturier, Jeremy Vanhelst, Alicia Fillon, Pauline Genin, Caroline Ganière, Corinne Praznoczy, Benjamin Larras, Julien Schipman, Martine Duclos and David Thivel
Background: Insufficient levels of physical activity and increasing sedentary time among children and youth are being observed internationally. The purpose of this paper is to summarize findings from France’s 2018 Report Card on physical activity for children and youth, and to make comparisons with its 2016 predecessor and with the Report Cards of other countries engaged in the Global Matrix 3.0. Methods: The France’s 2018 Report Card was developed following the standardized methodology established for the Global Matrix 3.0 by grading 10 common physical activity indicators using best available data. Grades were informed by national surveys, peer-reviewed literature, government and nongovernment reports, and online information. Results: The expert panel awarded the following grades: overall physical activity, D; organized sport participation and physical activity, C−; active play, INC; active transportation, C−; sedentary behaviors, D−; physical fitness, B–; family and peers, INC; school, B; community and the built environment, INC; and government, C. Conclusions: Very concerning levels of physical activity and sedentary behaviors among French children and youth were observed, highlighting the urgent need for well-designed national actions addressing the presented physical inactivity crisis. The top 3 strategies that should be implemented in priority to improve the lifestyle of French children and youth are provided.
Elizabeth Lorenzo, Jacob Szeszulski, Michael Todd, Scherezade K. Mama and Rebecca E. Lee
Background: Active transportation (AT) increases physical activity, reducing cardiometabolic risk among non-Hispanic white adults; however, research on these linkages in racial/ethnic minority women is sparse. This study explored these associations in 327 African American and Hispanic/Latina women. Methods: This analysis used sociodemographics, self-reported AT via the International Physical Activity Questionnaire, accelerometer-measured moderate to vigorous physical activity (MVPA), body mass index, systolic and diastolic blood pressures, resting heart rate, and body fat percentage (BF). Unadjusted bivariate associations and associations adjusted for sociodemographic factors were examined. Results: AT users had higher levels of objective MVPA, but this was not statistically significant. AT was not associated with cardiometabolic risk factors in adjusted models (Ps > .05); however, systolic blood pressure was lower for AT users. MVPA was negatively associated with diastolic blood pressure and BF overall, body mass index and BF in African American women, and BF in Hispanic/Latina women (Ps <.05). Conclusions: MVPA was associated with improvements in body mass index, diastolic blood pressure, and BF among minority women, and these relationships may vary by race/ethnicity. Practitioners should recommend increased participation in MVPA. Future research, using longitudinal designs should investigate AT’s potential for increasing MVPA and improving cardiometabolic health along with the role of race/ethnicity in these associations.
Matthew Pearce, Tom R.P. Bishop, Stephen Sharp, Kate Westgate, Michelle Venables, Nicholas J. Wareham and Søren Brage
Harmonization of data for pooled analysis relies on the principle of inferential equivalence between variables from different sources. Ideally, this is achieved using models of the direct relationship with gold standard criterion measures, but the necessary validation study data are often unavailable. This study examines an alternative method of network harmonization using indirect models. Starting methods were self-report or accelerometry, from which we derived indirect models of relationships with doubly labelled water (DLW)-based physical activity energy expenditure (PAEE) using sets of two bridge equations via one of three intermediate measures. Coefficients and performance of indirect models were compared to corresponding direct models (linear regression of DLW-based PAEE on starting methods). Indirect model beta coefficients were attenuated compared to direct model betas (10%–63%), narrowing the range of PAEE values; attenuation was greater when bridge equations were weak. Directly and indirectly harmonized models had similar error variance but most indirectly derived values were biased at group-level. Correlations with DLW-based PAEE were identical after harmonization using continuous linear but not categorical models. Wrist acceleration harmonized to DLW-based PAEE via combined accelerometry and heart rate sensing had the lowest error variance (24.5%) and non-significant mean bias 0.9 (95%CI: −1.6; 3.4) kJ·day−1·kg−1. Associations between PAEE and BMI were similar for directly and indirectly harmonized values, but most fell outside the confidence interval of the criterion PAEE-to-BMI association. Indirect models can be used for harmonization. Performance depends on the measurement properties of original data, variance explained by available bridge equations, and similarity of population characteristics.
Melanna F. Cox, Greg J. Petrucci Jr., Robert T. Marcotte, Brittany R. Masteller, John Staudenmayer, Patty S. Freedson and John R. Sirard
Purpose: Develop a direct observation (DO) system to serve as a criterion measure for the calibration of models applied to free-living (FL) accelerometer data. Methods: Ten participants (19.4 ± 0.8 years) were video-recorded during four, one-hour FL sessions in different settings: 1) school, 2) home, 3) community, and 4) physical activity. For each setting, 10-minute clips from three randomly selected sessions were extracted and coded by one expert coder and up to 20 trained coders using the Observer XT software (Noldus, Wageningen, the Netherlands). The coder defines each whole-body movement which was further described with three modifiers: 1) locomotion, 2) activity type, and 3) MET value (used to categorize intensity level). Percent agreement was calculated for intra- and inter-rater reliability. For intra-rater reliability, the criterion coder coded all 12 clips twice, separated by at least one week between coding sessions. For inter-rater reliability, coded clips by trained coders were compared to the expert coder. Intraclass correlations (ICCs) were calculated to assess the agreement of intensity category for intra- and inter-rater comparisons described above. Results: For intra-rater reliability, mean percent agreement ranged from 91.9 ± 3.9% to 100.0 ± 0.0% across all variables in all settings. For inter-rater reliability, mean percent agreement ranged from 88.2 ± 3.5% to 100.0 ± 0.0% across all variables in all settings. ICCs for intensity category ranged from 0.74–1.00 and 0.81–1.00 for intra- and inter-rater comparisons, respectively. Conclusion: The DO system is reliable and feasible to serve as a criterion measure of FL physical activity in young adults to calibrate accelerometers, subsequently improving interpretation of surveillance and intervention research.
Kevin Lanza, Brian Stone Jr, Paul M. Chakalian, Carina J. Gronlund, David M. Hondula, Larissa Larsen, Evan Mallen and Regine Haardörfer
Background: Research has not yet examined how hot weather moderates the relationship between the built environment and outdoor physical activity levels. The authors posited that hot days will increase the magnitude of the expected directional effect of built environment features on physical activity. Methods: This longitudinal study included 134 US adults from the Three city Heat and Electrical failure AdapTation study. Adults self-reported physical activity for multiple summer days (nstudy-days = 742) in 2016. Hot days were defined as ≥90th percentile of daily maximum heat index. Built environment features included density, safety, trees, hilliness, connectivity, access to parks, and access to shops + services. Separate growth curve models with interaction terms (ie, hot day × built environment feature) were run for daily minutes of outdoor physical activity (ie, any activity and recommended activity). Results: Neither hot days nor built environment features impacted outdoor physical activity significantly, and hot days did not moderate the relationship between built environment features and physical activity (P > .05). Conclusions: With adults failing to modify behavior on hot days, cities may be placing adults at increased risk of exertional heat illness. The authors recommend incorporating the risk of exertional heat illness in health impact assessments and deploying heat management strategies.
Sheri J. Hartman, Dori Pekmezi, Shira I. Dunsiger and Bess H. Marcus
Background: Latinas have high rates of sedentary behavior and related health disparities, but it is unknown if interventions to increase physical activity will also reduce sedentary time. The current study examined changes in objectively measured sedentary time among Latinas in a randomized controlled trial of a physical activity intervention. Methods: Spanish-speaking Latinas (N = 202) were randomized to an exercise or wellness group and wore an accelerometer at baseline, 6 months, and 12 months. Results: Participants were sedentary on an average of 8.86 hours per day (SD = 2.60) at baseline. The intervention group had significantly greater increases in sedentary time compared with the control group, with the intervention group engaging in 146 more minutes per week of sedentary time at 6 months and 254 minutes per week of sedentary time at 12 months than the control group (P = .02). The intervention effect on sedentary behavior remained after controlling for moderate to vigorous physical activity. Additionally, time spent in moderate to vigorous physical activity was positively associated with more sedentary time (P = .04). Conclusion: An intervention to increase moderate to vigorous physical activity resulted in greater sedentary time, raising concerns regarding compensation and highlighting the need for interventions to address both physical activity and sedentary behavior to improve public health.
Brian M. Wood, Herman Pontzer, Jacob A. Harris, Audax Z.P. Mabulla, Marc T. Hamilton, Theodore W. Zderic, Bret A. Beheim and David A. Raichlen
The rapid adoption of lightweight activity tracking sensors demonstrates that precise measures of physical activity hold great value for a wide variety of applications. The corresponding growth of physical activity data creates an urgent need for methods to integrate such data. In this paper, we demonstrate methods for 1) synchronizing accelerometer and Global Positioning System (GPS) data with optimal corrections for device-related time drift, and 2) producing principled estimates of step counts from GPS data. These methods improve the accuracy of time-resolved physical activity measures and permit pedestrian travel from either sensor to be expressed in terms of a common currency, step counts. We show that sensor-based estimates of step length correspond well with expectations based on independent measures, and functional relationships between step length, height, and movement speed expected from biomechanical models. Using 123 person-days of data in which Hadza hunter-gatherers wore both GPS devices and accelerometers, we find that GPS-based estimates of daily step counts have a good correspondence with accelerometer-recorded values. A multivariate linear model predicting daily step counts from distance walked, mean movement speed, and height has an R 2 value of 0.96 and a mean absolute percent error of 16.8% (mean absolute error = 1,354 steps; mean steps per day = 15,800; n = 123). To best represent step count estimation error, we fit a Bayesian model and plot the distributions of step count estimates it generates. Our methods more accurately situate accelerometer-based measures of physical activity in space and time, and provide new avenues for comparative research in biomechanics and human movement ecology.
Jennifer McConnell-Nzunga, Katie A. Weatherson, Louise Masse, Valerie Carson, Guy Faulkner, Erica Lau, Heather McKay, Viviene Temple, Luke Wolfenden and Patti J. Naylor
Background: Physical activity (PA) is critical to early child development, and child care is a key setting for promotion. The authors investigated differences in daily PA and sedentary behavior practices as well as physical environments between family child care (FCC) and group child care (GCC) settings for children aged 3–5 years in Canada. Methods: Group child care (n = 581) and FCC (n = 357) managers completed surveys assessing the implementation of PA promoting practices and description of their environments. Crosstabulation and chi-square tests of association were used to examine differences between GCC and FCC. Results: The prevalence of facilities implementing 120 minutes of active play (odds ratio [OR] 2.23; 95% confidence interval [CI], 1.58–3.15), <30 minutes on screens (OR 1.35; 95% CI, 1.02–1.80), and 60-minute outdoors daily (OR 1.99; 95% CI, 1.4–2.9) was more likely in FCC compared with GCC. However, implementation of fundamental movement skill activities (OR 1.40; 95% CI, 1.01–1.92), breaking up prolonged sitting (OR 1.86; 95% CI, 1.36–2.5), and outdoor space for large group running games (OR 1.74; 95% CI, 1.07–2.83) were more likely in GCC. Conclusions: Child care setting was associated with daily PA and sedentary practices and outdoor space for PA. Interventions to support PA in child care should be tailored to different settings and the facilitators explored.