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.     

A systematic review and meta-analysis of moderate-to-vigorous physical activity levels in elementary school physical education lessons

ObjectiveTo examine elementary school students' moderate-to-vigorous physical activity (MVPA) levels during physical education (PE) lessons.MethodsA systematic search of nine electronic databases was conducted (PROSPERO2014:CRD42014009649). Studies were eligible if they were in English; published between 2005–April 2014; assessed MVPA levels in PE lessons of elementary school children (aged four–12 years); and used an objective MVPA measure. Two reviewers retrieved articles, assessed risk of bias, and performed data extraction. The findings were synthesised using a meta-analysis.ResultsThe search yielded 5132 articles. Thirteen studies from nine countries met the inclusion criteria. Eight studies measured MVPA through observational measures, five used accelerometry and one used heart rate monitoring. The percentage of PE lesson time spent in MVPA ranged between 11.4–88.5%. Meta-analysis of seven studies (4 direct observations; 4 accelerometers) found that children spent a mean (95% CI) 44.8 (28.2–61.4)% of PE lesson time in MVPA. When measured using direct observation and accelerometers, children spent 57.6 (47.3–68.2) and 32.6 (5.9–59.3)% of PE lesson time in MVPA, respectively. The review has limitations; the search strategy was restricted to studies in English; theses, dissertations and conference abstracts were excluded; and six studies that provided insufficient data were excluded from the meta-analysis.ConclusionMVPA levels during elementary school PE lessons do not meet the United States Centre for Disease Control and Prevention and the United Kingdom's Association of Physical Education recommendation (50% of lesson time), but is higher than estimated in the previous review (34.2%). Interventions to increase MVPA in PE lessons are needed.     

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.     

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.     

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.     

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.     

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.     

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.     

Are eating habits associated with physical fitness in primary school children?

ObjectiveChildren's eating habits have mainly been related to anthropometric characteristics but less is known about their association with physical fitness.Methods278 French school children (131 boys and 147 girls) filled in eating habit questionnaires and completed anthropometric measurement (weight, height, skinfolds) and physical fitness tests. The 20-m Shuttle run test and the Squat Jump test were used to assess aerobic fitness and anaerobic (lower limb muscle power) fitness respectively.ResultsBreakfast consumption was associated with both aerobic fitness (p < 0.05) and lower limb muscle power (p < 0.01) while snacking was negatively related to Squat Jump performances (p < 0.05). There was no association between physical fitness and either the type of the consumed-beverages or TV watching during diner and lunch meals. Cumulated unhealthy eating habits was negatively associated with CRF stages and lower limb muscle power performances (p < 0.05).ConclusionFrench primary school children physical fitness is associated with their eating habits and decreases with the number of unhealthy eating behaviors cumulated.     

Abdominal obesity as a mediator of the influence of physical activity on insulin resistance in Spanish adults

ObjectiveThe aim of the study was to analyze the relationship between moderate-to-vigorous physical activity (MVPA) and insulin resistance (IR) in Spanish adults and to examine whether this relationship is mediated by abdominal obesity (waist circumference — WC).MethodsThe cross-sectional study included 1162 healthy subjects belonging to the EVIDENT study (mean age 55.0 ± 13.3 years; 61.8% women) from six different Spanish provinces. Moderate-to-vigorous physical activity (MVPA) was measured objectively over 7 days using Actigraph accelerometers, collecting data in 60-second epochs, and retaining respondents with ≥ 4 valid days for the analysis. The homeostasis model of assessment (HOMA-IR) was used to determine IR, and its individual components – fasting glucose and insulin – were determined using standard protocols. Linear regression models were fitted according to Baron and Kenny's procedures for mediation analysis.ResultsFasting insulin and HOMA-IR levels were significantly worse in adults who spent fewer minutes in MVPA (first quartile ≤ 30.1 and 22.7 min/day in men and women, respectively) after adjusting for age, sex, smoking habits, drinking habits, accelerometer wear time, sedentary time, and Mediterranean diet adherence. However, when WC was added to the ANCOVA models as a covariate, the effects disappeared. Mediation analysis reported that WC acts as a full mediator in the relationship between MVPA and IR (HOMA-IR and fasting insulin).ConclusionThese findings show that WC plays a pivotal role in the relationship between MVPA and IR, and therefore highlights that decreasing abdominal obesity might be considered as an intermediate outcome for evaluating interventions aimed at preventing diabetes mellitus.     

Gender differences in the clustering patterns of risk behaviours associated with non-communicable diseases in Brazilian adolescents

ObjectiveThe aim of this study is to investigate gender differences in the clustering of risk behaviours associated with chronic non-communicable diseases in Brazilian adolescents.MethodsA cross-sectional survey was conducted in 2011 comprising 6529 adolescents aged 15–19 years from Santa Catarina State, Brazil. Excessive screen-time, insufficient moderate to vigorous physical activity (MVPA), low fruit/vegetable intake and consumption of alcohol were investigated. Poisson regression was performed in the analysis of sociodemographic factors associated with the clustering of three or more risk behaviours.ResultsGirls presented with higher insufficient MVPA (76.3%), while boys presented with lower fruit or vegetable intake (53.0%) and greater consumption of alcohol (40.8%). A total of 21.2% of the teenagers had one risk behaviour, 37.3% had two, 28.5% had three, and 8.0% had all of the measured risk behaviours. Adolescents who did not work and boys who lived in urban areas exhibited more risk behaviours, whereas girls aged 17–19 years old and boys who had mothers with ≥ 12 years of study exhibited fewer risk behaviours.ConclusionThere was a difference between genders for individual risk behaviours, and a high degree of clustering in both genders. Prevention programs could focus on these behaviours in order to reduce negative health outcomes in adolescents.     

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.     

Correlates of moderate-to-vigorous physical activity among preschoolers during unstructured outdoor play periods

ObjectiveQuantify moderate-to-vigorous physical activity (MVPA) and its correlates in preschool children during outdoor unstructured play periods using direct observation.MethodsCross-sectional data consisting of 204 observation periods collected from 51 four- and five-year-old children using the Observation System for Recording Physical Activity in Children — Preschool (OSRAC-P) at a preschool in southern California, autumn and spring 2009–2010. Gender and BMI classification and OSRAC-P environmental codes were related to observed MVPA in multiple logistic regression models.ResultsLess than 21% of intervals were spent in MVPA overall. Boys and normal weight children engaged in higher intensity levels than their respective counterparts. More MVPA was associated with normal weight (OR = 2.49–3.25, R² = 3%), location (grass, playground, looping cycle path; OR = 3.21–4.90, R² = 4–12%), play context (ball/objects, wheel, open space; OR = 2.78–8.51, R² = 9%), and group composition (solitary, one-on-one; OR = 1.34–2.08, R² = 1%).ConclusionOpen spaces located in playgrounds and grass fields, and activity-genic portable equipment, manipulative objects, and riding vehicles are some design and equipment features that appear to foster MVPA. Lowering play space density and engaging children through teacher prompts and teacher-arranged activities may further increase MVPA on playgrounds.     

Establishing school day pedometer step count cut-points using ROC curves in low-income children

Previous research has not established pedometer step count cut-points that discriminate children that meet school day physical activity recommendations using a tri-axial ActiGraph accelerometer criterion. The purpose of this study was to determine step count cut-points that associate with 30 min of school day moderate-to-vigorous physical activity (MVPA) in school-aged children. Participants included 1053 school-aged children (mean age = 8.4 ± 1.8 years) recruited from three low-income schools from the state of Utah in the U.S. Physical activity was assessed using Yamax DigiWalker CW600 pedometers and ActiGraph wGT3X-BT triaxial accelerometers that were concurrently worn during school hours. Data were collected at each school during the 2014–2015 school year. Receiver operating characteristic (ROC) curves were used to determine pedometer step count cut-points that associated with at least 30 min of MVPA during school hours. Cut-points were determined using the maximum Youden's J statistic (J max). For the total sample, the area-under-the-curve (AUC) was 0.77 (p < 0.001) with a pedometer cut-point of 5505 steps (J max = 0.46, Sensitivity = 63%, Specificity = 84%; Accuracy = 76%). Step counts showed greater diagnostic ability in girls (AUC = 0.81, p < 0.001; Cut-point = 5306 steps; Accuracy = 78.8%) compared to boys (AUC = 0.72, p < 0.01; Cut-point = 5786 steps; Accuracy = 71.4%). Pedometer step counts showed good diagnostic ability in girls and fair diagnostic ability in boys for discriminating children that met at least 30 min of MVPA during school hours.     

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.     

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.     

Tri-axial accelerometer-assessed physical activity and its association with weight status in a sample of elementary-school children

Background and aimsObjective assessment of physical activity (PA) using accelerometers and pedometers has become more accurate and common practice in the study of childhood overweight. The study aimed: i) to compare PA levels and body shape of boys and girls, and assess compliance of active children with the PA recommendation; ii) to analyse associations between the risk of overweight and the moderate-to-vigorous physical activity (MVPA) in children.MethodsThe sample comprised 395 children (198 girls) aged 6–10 years. Height and weight were measured, and BMI was calculated subsequently. A tri-axial accelerometer was used to obtain seven consecutive days of MVPA, as well as the weekly time being sedentary. Logistic regression analysis was used to examine the afore-mentioned relationship among the risk of obesity and MVPA, controlling for confounders.ResultsAfter controlling for wearing time, boys spent significantly more minutes in the moderate-to-vigorous portion of PA than their female counterparts. About 47% of boys were active on week days by achieve the mean value of 60 min/day of MVPA; corresponding percentage for the weekend was just 32%. Among girls, only 22% were active on week days and 29% at the weekend. MVPA was not significantly associated with the risk of being overweight nor in female neither in male children. The final regression model revealed that girls of mothers with high educational level were less likely to be classified as overweight girls.ConclusionsFindings revealed no significantly relation between MVPA and obesity risk among Portuguese children. Future research should extend similar design to other lifestyle features of children to clarify potential predictors of being overweight at early ages.     

Dog walking among adolescents: Correlates and contribution to physical activity

PurposeTo assess the association of dog walking with adolescents' moderate-to-vigorous physical activity (MVPA) and body mass index (BMI), and identify correlates of dog walking.Methods/designParticipants were 12–17 year-olds (n = 925) from the Baltimore, MD and Seattle, WA regions. Differences in accelerometer-assessed minutes/day of MVPA and self-reported BMI (percentile) were compared among adolescents (1) without a dog (n = 441) and those with a dog who (2) did (≥ 1 days/week, n = 300) or (3) did not (n = 184) walk it. Correlates of (1) dog walking (any vs. none) among adolescents with dogs (n = 484), and (2) days/week of dog walking among dog walkers (n = 300) were investigated. Potential correlates included: demographic, psychosocial, home environment, perceived neighborhood environment, and objective neighborhood environment factors.Results52% of adolescents lived in a household with a dog, and 62% of those reported dog walking ≥ 1 day/week. Dog walkers had 4–5 more minutes/day of MVPA than non-dog-walkers and non-dog-owners. BMI was not associated with dog walking or ownership. Among households with dogs, adolescents who lived in objectively walkable neighborhoods were 12% more likely to walk their dog than those in less walkable neighborhoods. Among dog walkers, having a multi-family home, college-educated parent, lower perceived traffic safety, higher street connectivity and less mixed use were related to more days/week of dog walking.ConclusionsDog walkers had 7–8% more minutes/day of MVPA than non-dog walkers, and correlates of dog walking were found at multiple levels of influence. Results suggest multilevel interventions that include both environmental and psychosocial components to increase dog walking should be evaluated.     

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.     

Investigating links between moderate-to-vigorous physical activity and cognitive performance in elementary school students

BackgroundResearch has noted both physical and psychological benefits when children participate in physical activity. Recent studies indicate there may also be academic benefits and students may be more efficient learners after physical activity. This study investigated the influence of moderate-to-vigorous physical activity (MVPA) on four cognitive processes: planning, attention, simultaneous processing, and successive processing.MethodsParticipants were two classes of fourth-grade students in Ontario (n = 40). Using a counterbalanced design, students in the two classes completed standardized tests for each cognitive process both after no physical activity and following it (20 min MVPA within a 45 min lesson).ResultsThe results indicate that performance on the planning test significantly improved after physical activity (p < 0.001), controlling for sequence and habituation/retesting effects. No improvement was observed for attention, simultaneous processing, or successive processing.ConclusionPlanning is associated with problem solving skills and behaviour self-regulation. These skills may be improved in elementary school students immediately following physical activity.