Implementing classroom physical activity breaks: Associations with student physical activity and classroom behavior

ObjectiveTo investigate the relation of classroom physical activity breaks to students' physical activity and classroom behavior.MethodsSix elementary-school districts in California implemented classroom physical activity interventions in 2013–2014. Students' (N = 1322) accelerometer-measured moderate-to-vigorous physical activity (MVPA) during school and teachers' (N = 397) reports of implementation and classroom behavior were assessed in 24 schools at two time points (both post-intervention). Mixed-effects models accounted for nested data.ResultsMinutes/day of activity breaks was positively associated with students' MVPA (βs = .07–.14; ps = .012–.016). Students in classrooms with activity breaks were more likely to obtain 30 min/day of MVPA during school (OR = 1.75; p = .002). Implementation was negatively associated with students having a lack of effort in class (β = − .17; p = .042), and student MVPA was negatively associated with students being off task or inattentive in the classroom (β = − .17; p = .042). Students provided with 3–4 physical activity opportunities (classroom breaks, recess, PE, dedicated PE teacher) had ≈ 5 more min/day of school MVPA than students with no opportunities (B = 1.53 min/opportunity; p = .002).ConclusionsImplementing classroom physical activity breaks can improve student physical activity during school and behavior in the classroom. Comprehensive school physical activity programs that include classroom-based activity are likely needed to meet the 30 min/day school physical activity guideline.     

Spatial analysis of crime incidence and adolescent physical activity

ObjectivesAdolescents do not achieve recommended levels of physical activity. Crime is believed to be a barrier to physical activity among youth, but findings are inconsistent. This study compares the spatial distribution of crime incidences and moderate-to-vigorous physical activity (MVPA) among adolescents in Massachusetts between 2011 and 2012, and examines the correlation between crime and MVPA.MethodsEighty adolescents provided objective physical activity (accelerometer) and location (Global Positioning Systems) data. Crime report data were obtained from the city police department. Data were mapped using geographic information systems, and crime and MVPA densities were calculated using kernel density estimations. Spearman's correlation tested for associations between crime and MVPA.ResultsOverall, 1694 reported crimes and 16,702 min of MVPA were included in analyses. A strong positive correlation was present between crime and adolescent MVPA (ρ = 0.72, p < 0.0001). Crime remained positively associated with MVPA in locations falling within the lowest quartile (ρ = 0.43, p < 0.0001) and highest quartile (ρ = 0.32, p < 0.0001) of crime density.ConclusionsThis study found a strong positive association between crime and adolescent MVPA, despite research suggesting the opposite relationship. This counterintuitive finding may be explained by the logic of a common destination: neighborhood spaces which are desirable destinations and promote physical activity may likewise attract crime.     

Where can they play? Outdoor spaces and physical activity among adolescents in U.S. urbanized areas

ObjectiveTo estimate behavior-specific effects of several objectively measured outdoor spaces on different types of moderate to vigorous physical activity (MVPA) in a large, diverse sample of U.S. adolescents.MethodsUsing data from Wave I (1994–1995) of the National Longitudinal Study of Adolescent Health (U.S., n = 10,359) and a linked geographic information system, we calculated percent greenspace coverage and distance to the nearest neighborhood and major parks. Using sex-stratified multivariable logistic regression, we modeled reported participation in wheel-based activities, active sports, exercise, and ≥ 5 MVPA bouts/week as a function of each outdoor space variable, controlling for individual- and neighborhood-level sociodemographics.ResultsAvailability of major or neighborhood parks was associated with higher participation in active sports and, in females, wheel-based activity and reporting ≥ 5 MVPA bouts/week [OR (95% CI): up to 1.71 (1.29, 2.27)]. Greater greenspace coverage was associated with reporting ≥ 5 MVPA bouts/week in males and females [OR (95% CI): up to 1.62 (1.10, 2.39) for 10.1 to 20% versus ≤ 10% greenspace] and exercise participation in females [OR (95% CI): up to 1.73 (1.21, 2.49)].ConclusionsProvision of outdoor spaces may promote different types of physical activities, with potentially greater benefits in female adolescents, who have particularly low physical activity levels.     

Joint effects of objectively-measured sedentary time and physical activity on all-cause mortality

ObjectiveExamine the joint effects of objectively-measured sedentary time and moderate-to-vigorous physical activity (MVPA) on all-cause mortality.MethodsThe present study included data from the 2003–2006 National Health & Nutrition Examination Survey, with mortality follow-up data (via National Death Index) through 2011 (N = 5575 U.S. adults). Sedentary time (activity counts/min between 0 and 99) and MVPA (activity counts/min ≥ 2020) were objectively measured using the ActiGraph 7164 accelerometer.ResultsThe median age of the participants was 50 yrs; proportion of men was 50.2%; proportion of whites was 53.8%, 18.7% for blacks; median follow-up was 81 months; and 511 deaths occurred over the follow-up period. After adjusting for age, gender, race-ethnicity, cotinine, weight status, poverty level, C-reactive protein and comorbid illness (summed score of 0–8 chronic diseases), and for a 1 min increase in MVPA and sedentary time, both MVPA (HR_adjusted = 0.98; 95% CI: 0.96–0.99; P = 0.04) and sedentary time (HR_adjusted = 1.001; 95% CI: 1.0003–1.002; P = 0.008) were independently associated with all-cause mortality. Further, MVPA was associated with all-cause mortality among those with greater (above median) sedentary time (HR_adjusted = 0.95; 95% CI: 0.93–0.97; P < .001). Sedentary time was not associated with all-cause mortality among those engaging in above median levels of MVPA (HR_adjusted = 0.998; 95% CI: 0.996–1.001; P = .32), but sedentary time was associated with increased mortality risk among those below median levels of MVPA (HR = 1.002; 95% CI: 1.001–1.003; P < 0.001).ConclusionsSedentary time and MVPA are independently associated with all-cause mortality. Above median sedentary time levels did not negate the beneficial effects of MVPA on all-cause mortality risk.     

Objectively measured sedentary time and associations with insulin sensitivity: Importance of reallocating sedentary time to physical activity

ObjectiveThe aim of this study is to quantify associations between objectively measured sedentary time and markers of insulin sensitivity by considering allocation into light-intensity physical activity or moderate- to vigorous-intensity physical activity (MVPA).MethodsParticipants with an increased risk of impaired glucose regulation (IGR) were recruited (Leicestershire, United Kingdom, 2010–2011). Sedentary, light-intensity physical activity and MVPA time were measured using accelerometers. Fasting and 2-hour post-challenge insulin and glucose were assessed; insulin sensitivity was calculated by HOMA-IS and Matsuda-ISI. Isotemporal substitution regression models were used. Data were analysed in 2014.Results508 participants were included (average age = 65 years, female = 34%). Reallocating 30 min of sedentary time into light-intensity physical activity was associated a 5% (95% CI 1, 9%; p = 0.024) difference in Matsuda-ISI after adjustment for measured confounding variables. Reallocation into MVPA was associated with a 15% (7, 25%; p < 0.001) difference in HOMA-IS and 18% (8, 28%; p < 0.001) difference in Matsuda-ISI. Results for light-intensity physical activity were modified by IGR status with stronger associations seen in those with IGR.ConclusionsReallocating sedentary time into light-intensity physical activity or MVPA was associated with differences in insulin sensitivity, with stronger and more consistent associations seen for MVPA.     

Empowering adolescents to be physically active: Three-year results of the Sigue la Huella intervention

ObjectiveTo examine the effects of a school-based intervention called Sigue la Huella (Follow the Footstep) on adolescents' daily moderate-to-vigorous physical activity (MVPA).MethodThis quasi-experimental, cohort study took place in four secondary schools in Huesca (Spain) during the 2009–2010, 2010–2011, and 2011–2012 academic years (students aged 12–15 years). Two schools were assigned to the experimental condition (n = 368) and two schools to the control condition (n = 314). Sigue la Huella was based on the social ecological model and self-determination theory. MVPA was measured for 7 days on 4 occasions using accelerometers. Data were analyzed with individual growth curve models.ResultsThere was a significant difference in linear growth rate of daily MVPA between the experimental and the control group, independent of study wave, type of school (public vs. private), grade level and gender (p < 0.001). Specifically, MVPA increased in the experimental group (β = 7.02, 95% confidence interval (CI) = 1.27 to 12.78, p = 0.017) and tended to decrease in the control group (β = − 5.26, 95% CI = − 11.17 to 0.65, p < 0.081). The observed increase was larger in boys than in girls (p = 0.003).ConclusionsSigue la Huella had a positive effect on adolescents' daily MVPA over three school years. Both genders benefited from the intervention, although boys to a greater extent.     

Objectively assessed physical activity,fitness and subjective wellbeing

BackgroundThe existing evidence for a cross-sectional association between physical activity and subjective wellbeing is inconsistent, mainly because of the reliance on self reported physical activity, which might have conceptual overlap with subjective health.PurposeTo examine associations of objectively assessed physical activity and cardiorespiratory fitness with subjective wellbeing.MethodsA sub-sample of participants (921 men and women, mean age 44.6 ± 15.0 yrs, 46.4% men) from the 2008 Health Survey for England completed objective measures of physical activity (Actigraph) and an 8 min sub-maximal step test to estimate levels of cardiorespiratory fitness. The General Health Questionnaire and self-rated health was used as indicators of subjective wellbeing.ResultsThe recorded levels of moderate to vigorous physical activity (MVPA) were higher in participants reporting very good health (adjusted mean difference = 6.7, 95% CI, 1.1–12.4 min/d, p = 0.019) compared with participants reporting fair–poor health after adjustment for various confounders and fitness level. Neither physical fitness, objectively assessed sedentary time or light activity was related to self-rated health. There was also no association between objectively measured physical activity and fitness with psychological health, despite a robust association with self reported MVPA in the overall sample.ConclusionsObjectively assessed MVPA is independently associated with self-rated health. Self reported, but not objectively assessed MVPA, was associated with psychological health. The null findings with regards to psychological health might partly reflect selection biases associated with the healthy nature of this sub-sample of participants.     

Physically active vs. sedentary academic lessons: A dose response study for elementary student time on task

BackgroundPhysically active academic lessons are an effective intervention to reduce sedentary time and increase student physical activity. They have also been shown to enhance task engagement, as indicated by observations of attention and behavior control, time on task (TOT). However, it is not clear if the improved TOT stems from the physical activity or if it is the result of an enjoyable break from traditional instruction. If it is due to physical activity, what dose of intensity is required for the effect? This study was designed to test these questions.MethodsParticipants were 320 children (7–9 years) recruited from school districts in Central Texas in 2012. They were assigned by classroom (n = 20) to one of four conditions: 1) sedentary, standard lesson (n = 72); 2) sedentary academic game (n = 87); 3) low to moderate intensity PA (LMPA), academic game (n = 81); and 4) moderate to vigorous intensity PA (MVPA), academic game (n = 76). Measures included PA via accelerometer and TOT.ResultsMixed-method RMANOVA indicated TOT decreased following the standard lesson (p < 0.001), showed no change following the sedentary academic game (p = 0.68), and increased following the LMPA (p < 0.01) and MVPA (p < 0.001) academic games.ConclusionsWhile the sedentary, academic game prevented the reduction in TOT observed in the standard lesson, PA resulted in increased TOT. Future research should be designed to examine the potential academic benefits of the change in TOT.     

Daily movement patterns and predicted 10-yr risk for a first atherosclerotic cardiovascular disease (ASCVD) event using the pooled cohort risk equations among US adults

ObjectiveExamine the association between movement patterns and predicted risk of a first atherosclerotic cardiovascular disease (ASCVD) event.MethodsData from the 2003–2006 National Health and Nutrition Examination Survey (NHANES) were used (40–79 yrs; N = 2421). Participants wore an ActiGraph 7164 accelerometer to create four movement pattern groups; Group 1: ≥ 150 min/wk of moderate-to-vigorous physical activity (MVPA) and light-intensity physical activity (LIPA) ≥ sedentary behavior (SB); Group 2: ≥ 150 min/wk of MVPA and LIPA < SB; Group 3: < 150 min/wk of MVPA and LIPA ≥ SED; and Group 4: < 150 min/wk of MVPA and LIPA < SB. 10-yr risk for a first ASCVD event was estimated using the pooled cohort equations.ResultsAfter adjusting for age, gender, race–ethnicity and obesity, Group 2 (β = − 0.28; p = 0.44) was not significantly different than Group 1, but Groups 3 (β = 1.09; p = 0.01) and 4 (β = 1.44; p < 0.001) had a higher pooled risk score.ConclusionsThose in the least desirable movement pattern (Group 4) had the highest pooled risk score. Given the similar risk scores for Groups 1 and 2, future research is needed to determine if sufficient MVPA can counteract the potential consequences associated with an imbalanced LIPA:SB ratio (i.e., LIPA < SB).     

Dose–response association of physical activity with HbA1c: Intensity and bout length

ObjectiveThe aims of this study were to characterize the dose–response relationship between moderate-to-vigorous intensity physical activity (MVPA), and light-intensity activity with HbA1c in adults at low, moderate, and high risks of type 2 diabetes, and to compare the relationship of short (1 to 9 min) versus long (10 + min) bouts of MVPA with HbA1c.MethodsData from 2707 participants from the 2003–2006 National Health And Nutrition Examination Survey were analyzed in 2014–2015. Type 2 diabetes risk was classified into three groups based upon age (< 40 years; ≥ 40 years) and BMI (< 30; ≥ 30). The relationship between HbA1c and accelerometer-based physical activity variables was assessed using multiple regression models.ResultsThere was a curvilinear dose–response relationship between HbA1c with total activity and MVPA in adults at moderate or high risk for type 2 diabetes: higher amounts of physical activity were associated with lower HbA1c. The association of physical activity on HbA1c was stronger at lower levels of physical activity. There was no dose–response relationship in adults at low risk for type 2 diabetes. The relationship between short bouts with HbA1c was stronger than for bouts ≥ 10 min.ConclusionsIn adults at risk for type 2 diabetes, there is a dose–response relationship between physical activity and HbA1c levels such that the relationship: (1) is curvilinear; (2) is stronger when a higher percent of total activity comes from MVPA; and (3) is more potent with short bouts of MVPA. Fractionalized physical activity of at least moderate-intensity may contribute to long-term glucose control.     

Symptoms of specific anxiety disorders may relate differentially to different physical activity modalities in young adults

BackgroundAnxiety symptoms may be a barrier to physical activity (PA) such that persons who experience anxiety engage in less PA. The purpose of this study was to assess if symptoms of panic disorder, social phobia, generalized anxiety disorder (GAD) or agoraphobia are associated with frequency, intensity or type of PA in young adults.MethodsData on lifetime anxiety symptoms and current PA levels were collected in self-report questionnaires in 2007–2008 from 880 persons aged 18–24 years participating in the Nicotine Dependence in Teens (NDIT) study. The associations between anxiety symptom subtypes and different PA modalities were investigated in five multivariable logistic regression models, one for each of five PA indicators (i.e., meeting moderate-to vigorous PA (MVPA) guidelines, meeting strength training guidelines, meeting both MVPA and strength training guidelines, participating in team sports, frequent walking) as outcomes.Results37%, 47%, 40% and 21% of participants reported lifetime symptoms of panic disorder, social phobia, GAD, and agoraphobia, respectively. In multivariable logistic regression, participants who endorsed lifetime GAD symptoms were statistically significantly less likely to meet MVPA guidelines (OR 0.5, 95% CI 0.4–0.8, p < 0.05), and MVPA and strength training guidelines (OR 0.7, 95% CI 0.5–1.0, p < 0.05). Those with agoraphobia symptoms were more likely to walk frequently [OR (95% CI) = 1.6 (1.1, 2.3)].ConclusionPA interventions may need to be tailored to people who have experienced specific anxiety symptoms to maximize adherence to PA recommendations, and increase the potential for health benefits from PA participation.     

The association between discrepant weight perceptions and objectively measured physical activity

BackgroundSome individuals perceive themselves as being normal weight, despite having an excess body fat percentage (e.g., underestimate weight). Conversely, other individuals perceive themselves as being overweight, despite having a normal body fat percentage (e.g., overestimate weight). When perceived and actual weight statuses are incongruent, individuals possess a discrepant weight perception. The association between discrepant weight perceptions and engagement in moderate-to-vigorous physical activity (MVPA) has not been thoroughly investigated, which was this study's purpose.MethodsFor this cross-sectional study, data from the 2003–2006 National Health and Nutrition Examination Survey were utilized (N = 5462 adults). MVPA was assessed via accelerometry. Based on measured body mass index and whether participants considered themselves as overweight, underweight, or about the right weight, we classified individuals as accurate perception, overestimate weight (discrepant), or underestimate weight (discrepant). A negative binomial logistical regression was used to assess the association between discrepant weight perception (independent variable) and engagement in MVPA (outcome variable).ResultsFemales who said that they are normal weight, but were in fact overweight based on body mass index, engaged in 13% less MVPA (rate ratio = .87, 95% confidence interval: .769–.999, P = .05). Also, older adults (> 60 yrs) who said that they are normal weight, but were overweight based on body mass index, engaged in 23% less MVPA (rate ratio = .77, 95% confidence interval: .616–.965, P = .025).ConclusionDiscrepant weight perceptions were associated with less objectively measured MVPA. Interventions should take weight perceptions into consideration when designing and evaluating intervention impact.     

Proxy reports of physical activity were valid in older people with and without cognitive impairment

ObjectiveTo determine the validity of proxy reports of physical activity in people with symptoms of cognitive impairment.Study Design and SettingIn the Canadian Study of Health and Aging, a multicenter prospective cohort study, someone close to the participant (proxy) reported exercise levels for people who screened positive for cognitive impairment or were institutionalized (n = 2421), some of whom were subsequently diagnosed with cognitive impairment (n = 1612) and some of whom were diagnosed as having no cognitive impairment (n = 809). The reliability and validity of proxy reports of physical activity were examined by agreement with self-reports of physical activity (intraclass correlation coefficient) and by association with adverse health markers (Mantel–Haenzel χ²) and survival time (Cox proportional hazards).ResultsProxy reports of physical activity had moderate interrater reliability (0.55, 95% confidence interval: 0.49–0.61, P < 0.001). People in higher physical activity group had fewer adverse health outcomes than those in lower physical activity groups. Predictive validity was confirmed as people who had higher proxy-reported physical activity survived longer that those with lower physical activity.ConclusionProxy-reported physical activity appears to be a valid estimate of physical activity in people with symptoms or a diagnosis of cognitive impairment.     

The effects of objectively measured sedentary behavior on all-cause mortality in a national sample of adults with diabetes

BackgroundDiabetes is a highly prevalent chronic disease that has been increasing globally and is the seventh leading cause of death in the United States. Sedentary behavior is associated with increased risk of diabetes and is unfavorably related to all-cause mortality, but there are limited studies examining the sedentary–mortality relationship among those with diabetes, which was the purpose of this study.MethodsUsing data from the 2003–2006 NHANES, 712 adult participants with evidence of diabetes had complete data on the study variables. A multivariable Cox proportional hazard model was used to examine the association between objectively measured sedentary behavior and all-cause mortality among this diabetic sample.ResultsResults showed that for every 60 min/day increase in sedentary behavior, independent of moderate-to-vigorous physical activity (MVPA) and other covariates, adults with diabetes had a 13% increased risk of all-cause mortality (HR_adjusted = 1.13; 95% CI = 1.03–1.24; P = 0.01). However, after adjusting for total physical activity (light and MVPA), sedentary behavior was no longer associated with mortality risk (HR_adjusted = 1.04; 95% CI = 0.92–1.16; P = 0.46).ConclusionAmong those with diabetes, sedentary behavior may not have increased mortality risk independent of total physical activity behavior.     

Developmental trajectories of physical activity during elementary school physical education

ObjectivePhysical education (PE) during school provides an opportunity for children to be physically active. Few empirical studies have investigated developmental trajectories and determinants of objective moderate to vigorous physical activity (MVPA) during PE classes. The purpose of this study was to examine the developmental trajectories and determinants of MVPA during PE lessons in young children (8–12 years of age) in primary schools.MethodsStudents in grades 5–7 (n = 1202; 51.2% girls) were recruited from 17 elementary schools from the Geneva canton in 2012–2013. The percentage of time spent in accelerometer-assessed MVPA during regular PE lessons was used as a dependent variable.ResultsLinear mixed-model analyses revealed (a) that boys had a higher percentage of MVPA than girls, but none of the children reached the recommended activity levels (i.e., 50% of the PE class time spent in MVPA), (b) a linear decrease in the percentage of MVPA with age, (c) that higher perceived competence predicted a higher percentage of MVPA, and (d) that higher perceived competence reduced the negative linear effect of age among boys, but not among girls.ConclusionThe percentage of PE time spent in MVPA did not reach recommendations made by Centers for Disease Control and Prevention and decreased from 8 to 12 years old both for boys and girls. Perceived competence appears crucial to reduce MVPA decline for boys, but not for girls.     

Physical activity outcomes in afterschool programs: A group randomized controlled trial

IntroductionAfterschool programs (ASPs) across the US are working towards achieving the standard of all children accumulating 30 min of moderate-to-vigorous physical activity (MVPA) during program time. This study describes the two-year impact of an intervention designed to assist ASPs meeting the 30 min/day MVPA standard.MethodsUsing a two-year delayed treatment, group randomized controlled trial, 20 ASPs serving ~ 1700 children/year (6–12 yrs) were randomized to either an immediate (n = 10, baseline-2013 and 2 yrs intervention fall-2013-to-spring-2015) or delayed group (n = 10, baseline 2013–2014 and 1 yr intervention fall-2014-to-spring-2015). The intervention, Strategies-To-Enhance-Practice (STEPs), focused on programming MVPA in the daily schedule, training of staff and leaders, and ongoing technical support/assistance. Accelerometry-derived proportion of children meeting the 30 min/day MVPA standard was measured in the spring of each year. Mixed model logistic regressions were used to examine the change in the odds of achieving the MVPA standard. Analyses were conducted in 2015. Data were collected in one southeastern US state.ResultsImmediate boys (n = 677) and delayed girls (n = 658) increased the percent achieving 30 min MVPA/day from 35.9% to 47.0% (odds ratio [OR] = 1.88, 95% CI 1.18–3.00) and 13.1% to 19.1% (OR = 1.42, 95% CI 1.03–1.96). Immediate girls (n = 613) and delayed boys (n = 687) exhibited a nonsignificant increase from 19.1% to 21.6% (OR = 1.20, 95% CI 0.84–1.72) and 29.0% to 31.3% (OR = 1.13, 95%CI 0.80–1.58).ConclusionsSTEPs can have an impact on children's MVPA and time spent sedentary, yet was unable to fully achieve the goal of all children accumulating 30 min MVPA/day. Additional efforts are need to identify strategies ASPs can use to meet this important public health standard.     

Evaluation of policies to promote physical activity in afterschool programs: Are we meeting current benchmarks?

BackgroundPolicies now recommend afterschool programs (ASP, 3–6 pm) provide children a minimum amount of physical activity daily. We examined the extent to which children attending ASPs meet existing national and state-level policies that specify expected levels of physical activity (PA).MethodsAccelerometer-derived physical activity (light and moderate-to-vigorous, MVPA) of 253 children (5–13 years) was compared to policies that recommend varying amounts of PA children should achieve during an ASP.ResultsThe proportion of children achieving a policy ranged from 0.0% (California 60 min MVPA and North Carolina 20% of daily program time devoted to MVPA), 1.2% (California 30 min MVPA), to 48.2% (National Afterschool Association 30 min light plus MVPA). Random effects logistic models indicated boys (odds ratio [OR] range 2.0 to 6.27) and children from a minority background (Black/Hispanic, OR range 1.87 to 3.98) were more likely to achieve a recommended level of physical activity, in comparison to girls and White children. Neither age nor BMI were related to achieving a policy.ConclusionsThe PA of children attending ASP falls below policy recommended levels; however, these policies were developed in absence of data on expected PA levels during ASPs. Thus, concerted effort towards building a stronger ASP evidence-base for policy refinement is required.     

Quasi-causal associations of physical activity and neighborhood walkability with body mass index: A twin study

ObjectivePhysical activity, neighborhood walkability, and body mass index (BMI, kg/m²) associations were tested using quasi-experimental twin methods. We hypothesized that physical activity and walkability were independently associated with BMI within twin pairs, controlling for genetic and environmental background shared between them.MethodsData were from 6376 (64% female; 58% identical) same-sex pairs, University of Washington Twin Registry, 2008–2013. Neighborhood walking, moderate-to-vigorous physical activity (MVPA), and BMI were self-reported. Residential address was used to calculate walkability. Phenotypic (non-genetically informed) and biometric (genetically informed) regression was employed, controlling for age, sex, and race.ResultsWalking and MVPA were associated with BMI in phenotypic analyses; associations were attenuated but significant in biometric analyses (Ps < 0.05). Walkability was not associated with BMI, however, was associated with walking (but not MVPA) in both phenotypic and biometric analyses (Ps < 0.05), with no attenuation accounting for shared genetic and environmental background.ConclusionsThe association between activity and BMI is largely due to shared genetic and environmental factors, but a significant causal relationship remains accounting for shared background. Although walkability is not associated with BMI, it is associated with neighborhood walking (but not MVPA) accounting for shared background, suggesting a causal relationship between them.     

Daily movement patterns and biological markers among adults in the United States

ObjectiveTo examine the combined effects of sedentary (SED), light (LPA) and moderate-to-vigorous physical activity (MVPA) on biological markers among a nationally representative sample of U.S. adults.MethodsData from the 2003–2006 NHANES study was used, with 5580 adults (≥ 20 years) included in the study. Participants wore an ActiGraph 7164 accelerometer with accelerometry data used to create four movement pattern groups: ≥ 150 min/week of MVPA and LPA ≥ SED; ≥ 150 min/week of MVPA and LPA < SED; < 150 min/week of MVPA but LPA ≥ SED; and < 150 min/week of MVPA and LPA < SED. Blood samples were taken to assess various biological parameters (e.g., cholesterol).Results47.2% (SE: 1.2) of Americans engaged in < 150 min/week of MVPA and had a negative LPA–SED balance. In general, participants who engaged in ≥ 150 min/week of MVPA, regardless of LPA–SED balance, had more favorable biological levels; however, there was evidence showing that even if individuals engaged in < 150 min/week of MVPA, but if their LPA exceeded SED, they had more favorable levels of triglycerides and insulin.ConclusionsPrograms are needed to increase American's engagement in MVPA, and also ensure that LPA exceeds SED behavior.     

Maximizing children's physical activity using the LET US Play principles

BackgroundStaff in settings that care for children struggle to implement standards designed to promote moderate-to-vigorous physical activity (MVPA), suggesting a need for effective strategies to maximize the amount of time children spend in MVPA during scheduled PA opportunities. The purpose of this study was to compare the MVPA children accumulate during commonly played games delivered in their traditional format versus games modified according to the LET US Play principles.MethodsChildren (K–5th) participated in 1-hour PA sessions delivered on non-consecutive days (summer 2014). Using a randomized, counterbalanced design, one of the six games was played for 20 min using either traditional rules or LET US Play followed by the other strategy with a 10 min break in between. Physical activity was measured via accelerometry. Repeated-measures, mixed-effects regression models were used to estimate differences in percent of time spent sedentary and in MVPA.ResultsA total of 267 children (age 7.5 years, 43% female, 29% African American) participated in 50, 1-hour activity sessions. Games incorporating LET US Play elicited more MVPA from both boys and girls compared to the same games with traditional rules. For boys and girls, the largest MVPA difference occurred during tag games (+ 20.3%). The largest reduction in the percent of time sedentary occurred during tag games (boys − 27.7%, girls − 32.4%). Overall, the percentage of children meeting 50% time in MVPA increased in four games (+ 18.7% to + 53.1%).ConclusionLET US Play led to greater accumulation of MVPA for boys and girls, and can increase the percent of children attaining the 50% of time in MVPA standard.