Evaluating the Responsiveness of Accelerometry to Detect Change in Physical Activity

The responsiveness to change of the Actical and ActiGraph accelerometers was assessed in children and adolescents. Participants (N = 208) aged 6 to 16 years completed two simulated free-living protocols, one with primarily light-to-moderate physical activity (PA) and one with mostly moderate-to-vigorous PA. Time in sedentary, light, moderate, and vigorous PA was estimated using 8 previously developed cut-points (4 for Actical and 4 for ActiGraph) and 5-sec, 15-sec, and 30-sec epochs. Accelerometer responsiveness for detecting differences in PA between protocols was assessed using standardized response means (SRMs). SRM values ≥.8 represented high responsiveness to change. Both accelerometers showed high responsiveness for all PA intensities (SRMs = 1.2–4.7 for Actical and 1.1–3.3 for ActiGraph). All cut-points and epoch lengths yielded high responsiveness, and choice of cut-points and epoch length had little effect on responsiveness. Thus, both the Actical and ActiGraph can detect change in PA in a simulated free-living setting, irrespective of cut-point selection or epoch length.     

Correlates of Physical Activity Behavior in Rural Youth

Abstract

The purpose of this study was to identify correlates of physical activity behavior in a sample of rural, predominantly African American youth. Three hundred sixty-one fifth-grade students from two rural counties in South Carolina (69% African American, median age = 11 years) completed a questionnaire designed to measure beliefs and social influences regarding physical activity, physical activity self-efficacy, perceived physical activity habits of family members and friends, and access to exercise and fitness equipment at home. After school physical activity and television watching were assessed using the Previous Day Physical Activity Recall (PDPAR). Students were classified as physically active according to a moderate physical activity standard: two or more 30-min blocks at an intensity of 3 METs (metabolic equivalents) or greater, and a vigorous physical activity standard: one or more 30-min blocks at an intensity of 6 METs or greater. According to the moderate physical activity standard, 34.9% of students were classified as low-active. Multivariate analysis revealed age, gender, television watching, and exercise equipment at home to be significant correlates of low activity status. According to the vigorous physical activity standard, 32.1% of the students were classified as low-active. Multivariate analysis revealed age, gender, television watching, and self-efficacy with respect to seeking support for physical activity to be significant correlates of low activity status. In summary, gender and the amount of television watching were found to be the most important correlates of physical activity in rural, predominantly African American youth.     

Physical activities and sedentary pursuits in African American and Caucasian girls

The purposes of this study were to describe and compare the specific physical activity choices and sedentary pursuits of African American and Caucasian American girls. Participants were 1,124 African American and 1,068 Caucasian American eighth-grade students from 31 middle schools. The 3-Day Physical Activity Recall (3DPAR) was used to measure participation in physical activities and sedentary pursuits. The most frequently reported physical activities were walking, basketball, jogging or running, bicycling, and social dancing. Differences between groups were found in 11 physical activities and 3 sedentary pursuits. Participation rates were higher in African American girls (p < or = .001) for social dancing, basketball, watching television, and church attendance but lower in calisthenics, ballet and other dance, jogging or running, rollerblading, soccer, softball or baseball, using an exercise machine, swimming, and homework. Cultural differences of groups should be considered when planning interventions to promote physical activity.     

Physical Activity,Self-Regulation,and Early Academic Achievement in Preschool Children

Research Findings: The present study investigated whether active play during recess was associated with self-regulation and academic achievement in a prekindergarten sample. A total of 51 children in classes containing approximately half Head Start children were assessed on self-regulation, active play, and early academic achievement. Path analyses indicated that higher active play was associated with better self-regulation, which in turn was associated with higher scores on early reading and math assessments. Practice or Policy: Results point to the benefits of active play for promoting self-regulation and offer insight into possible interventions designed to promote self-regulation and academic achievement.     

Taste + odor interactions in compound aversion conditioning

In three experiments with rats, taste + odor interactions in compound aversion conditioning were investigated. In Experiment 1, two odors (0.02% almond and 0.02% orange) were compared on single-element odor aversions, taste (denatonium) potentiated odor aversions, and potentiated odor aversions following taste extinction. Although no odor differences were seen following single-element conditioning, both types of potentiated orange odor aversions were stronger than their almond odor counterparts. These data show that odors of similar conditionability are differentially potentiated by the same taste. To determine whether these differences were due to unique perceptual representations, the effects of elemental extinction or compound extinction on aversions to the compound were investigated in Experiments 2 and 3. In Experiment 2, orange odor extinction weakened responding to the compound significantly more than taste extinction did. In contrast, almond odor extinction and taste extinction produced similar decrements in responding to the compound in Experiment 3. These results suggest that the perceptual representation of these specific taste + odor compounds are different, and they are discussed in regard to configural and within-compound association accounts of potentiation.     

The Relationship between Different Criteria for Admission to Medical School and Student Success

The relevance of admission policy for educational outcome in medical schools is demonstrated by means of longitudinal data on the total population of several cohorts of students admitted to the German medical schools on the basis of a variety of criteria (n = 28,000 students). The correlations between the quantitative criteria for admission and performance on the First Medical Examination (which takes place after 2–3 years of study) were calculated. Secondly, the mean total scores on this examination that have been achieved at first attempt by groups of students admitted according to different selection criteria were compared. Thirdly, the rates of success on the medical examination at first attempt after two years of study were compared for the above‐mentioned groups of students. The most striking result is the large difference between the groups under comparison in terms of their success rates in the First Medical Examination. The highest pass rates (80%) are achieved by students selected on the basis of a combination of the average mark in the secondary school leaving certificate and the total score on the ‘Test for Medical Studies’, an aptitude test. Had the students been admitted at random, they would only have attained a pass rate of 48% (base rate). For those admitted on the basis of the result of an interview or on the basis of ‘waiting‐time’ (i.e. the number of semesters they had spent queuing) the pass rates are 49 and 45%. The results are interpreted in the light of different political and educational goals that are or can be envisaged when decisions on admission strategies are made.     

Accelerometer responsiveness to change between structured and unstructured physical activity in children and adolescents

This study examined if accelerometer-based assessments of physical activity were responsive to changes in physical activity level commensurate with performing structured versus unstructured activity in youth. Youth (6–16 years; N = 206) participated in a simulated after-school program that included structured and unstructured games on four occasions over a 3-year period. Recruitment occurred in 2007/2008 and data collection ended in 2011. Participants wore an Actigraph GT1M accelerometer on the hip. The Evenson cut-points were used to determine the time spent in each physical activity intensity, and standardized response means (SRM) were calculated and converted to standard effect sizes to be interpreted according to Cohen’s guidelines. SRMs ranged from trivial (0.16) to high (2.07), with the majority (75%) being classified as moderate or high. Our findings suggest that accelerometry was sensitive to differences in physical activity associated with structured compared to unstructured play, supporting the utility of accelerometry in evaluating activity-promoting interventions.