Ankle Accelerometry for Assessing Physical Activity Among Adolescent Girls: Threshold Determination,Validity, Reliability,and Feasibility

Purpose: Ankle accelerometry allows for 24-hr data collection and improves data volume/integrity versus hip accelerometry. Using Actical ankle accelerometry, the purpose of this study was to (a) develop sensitive/specific thresholds, (b) examine validity/reliability, (c) compare new thresholds with those of the manufacturer, and (d) examine feasibility in a community sample (low-income, urban adolescent girls). Method: Two studies were conducted with 6th- through 7th-grade girls (aged 10–14 years old): First was a laboratory study (n = 24), in which 2 Actical accelerometers were placed on the ankle and worn while measuring energy expenditure (Cosmed K4b2, metabolic equivalents [METs]) during 10 prescribed activities. Analyses included device equivalence reliability (intraclass correlation coefficient [ICC], activity counts of 2 Acticals), criterion-related validity (correlation, activity counts and METs), and calculations of sensitivity, specificity, kappa, and receiver-operating characteristic curves for thresholds. The second was a free-living study (n = 459), in which an Actical was worn for more than 7 days on the ankle (full 24-hr days retained). Analyses included feasibility (frequencies, missing data) and paired t tests (new thresholds vs. those of the manufacturer). Results: In the laboratory study, the Actical demonstrated reliability (ICC = .92) and validity (r = .81). Thresholds demonstrated sensitivity (91%), specificity (84%), kappa = .73 (p = .043), area under curve range = .81–.97. In the free-living study, 99.6% of participants wore the accelerometer; 84.1% had complete/valid data (mean = 5.7 days). Primary reasons for missing/invalid data included: improper programming/documentation (5.2%), failure to return device (5.0%), and wear-time ≤ 2 days (2.8%). The moderate-to-vigorous physical activity threshold (> 3,200 counts/minute) yielded 37.2 min/day, 2 to 4.5 times lower than that of the manufacturer's software (effect size = 0.74–4.05). Conclusions: Validity, reliability, and feasibility evidences support Actical ankle accelerometry to assess physical activity in community studies of adolescent girls. When comparing manufacturers' software versus new thresholds, a major difference was observed.     

Testing Social-Cognitive Theory to Explain Physical Activity Change in Adolescent Girls From Low-Income Communities

Purpose

The aim of this study was to test the hypothesized structural paths in Bandura's social-cognitive theory (SCT) model on adolescent girls' physical activity following a 12-month physical activity and dietary intervention to prevent obesity.

Method

We conducted a 12-month follow-up study of 235 adolescent girls (M _age = 13.2 years, SD = 0.4) from 12 secondary schools located in low-income communities. At baseline, participants completed SCT scales related to physical activity (i.e., self-efficacy, intention, parental support, and outcome expectations). At baseline and 12-month follow-up (postintervention), participants wore accelerometers for 7 days. Structural equation modeling was used to determine if Time 1 measures predicted physical activity at 12-month follow-up after adjusting for baseline activity.

Results

The model explained 28% and 34% of the variance in physical activity and intention, respectively. Model fit indexes indicated the data were a good fit to the model; however, only self-efficacy was associated with physical activity at 12 months. There was no support for intention or outcome expectations as proximal determinants of behavior. Self-efficacy was associated with outcome expectations and parental support; however, only outcome expectations predicted intention.

Conclusions

Current findings indicate a large proportion of the variance for physical activity and intention remains unexplained and that the proposed pathways in the SCT model were not fully supported. Future model testing may need to consider augmentation or integration of theoretical models, which may include ecological components if we are to advance our understanding of physical activity behavior in this subgroup of the adolescent population.     

Factors Associated With Transitional Shifts in College Students' Physical Activity Behavior

The Transtheoretical Model (Prochaska & Marcus, 1994) has been widely used as a framework for understanding exercise behavior change. The purpose of this study was to clarify equivocal research findings reported for model predictions when examining stage movement over time rather than static stages and to provide some evidence of the construct validity of transitional stages. Participants were female (n = 285) and male (n = 243) undergraduates (M age = 19.9 years, SD = 2.7) who completed previously validated questionnaires twice, separated by 9 weeks, that assessed stage of change, exercise behavior, processes of change, pros and cons of exercise, and exercise self-efficacy. Participants were classified into one of five transitional shift groups based on their responses at baseline and follow up: (a) stable sedentary, (b) stable active, (c) activity adopters, (d) activity relapsers, and (e) perpetual preparers. Results of a 5 (group) x 2 (time) repeated measures (RM) analysis of variance (ANOVA) examining exercise behavior revealed a significant interaction (p < .001) and supported transitional stage classification, with activity adopters and stable actives increasing exercise over time and relapsers decreasing activity. Separate 5 (group) x 2 (time) RM ANOVAs examining model constructs revealed no significant interaction for cognitive processes of change; however, activity adopters and stable actives reported significant (p < .01) increases in the use of behavioral processes over time, while only the activity relapsers and perpetual preparers reported decreases. Activity relapsers also reported significant (p < .05) decreases in the pros of exercise. No significant interactions were found for the cons of exercise behavior. Unlike findings reported in cross-sectional studies, increases in self-efficacy did not accompany increases in exercise stage. The findings strongly support examination of stage movement classifications rather than static stages, as these transitions provide greater insight into the mechanisms of exercise behavior change.     

青少年身体活动的家庭、学校、社区整体性治理研究

在推进体育治理能力和治理体系现代化背景下,创新青少年体育治理模式成为必然。采用文献综述法与逻辑分析法展开青少年身体活动的家庭、学校、社区整体性治理研究。青少年身体活动的家庭、学校、社区治理面临着身体活动时空分割化与政府垂直型管理体系之间的错位,身体活动社会组织多元化与管理机制不完善之间的矛盾,身体活动需求多样化与运行机制滞后化并存的困境。引入整体性治理理论,在"国家-社会"关系视角下阐述青少年身体活动整体性治理内涵,厘清政府主导、社会组织参与和家庭-学校-社区合作共治的关系,并从治理理念、治理结构、运行机制、治理手段等方面探讨青少年身体活动的家庭、学校、社区整体性治理路径。     

运用跨理论模型对高校教师体育锻炼行为改变阶段的研究

采用跨理论模型的相关问卷,对高校教师的体育锻炼行为进行了大样本调查。探讨中国现阶段高校教师体育锻炼行为的基本状况。结果显示:高校教师育锻炼行为存在阶段性的特点,且在前意向阶段男性人数最多,意向阶段女性人数最多;在5个变化阶段也存性别分布差异,男性分布呈递减趋势,女性分布一点突出明显;变化程序的6个下位因素与变化阶段的5个变化阶段存在相关。     

Pedometer-Determined Physical Activity and Its Comparison With the International Physical Activity Questionnaire in a Sample of Belgian Adults

Pedometer-determined physical activity (PA) levels in Belgian adults were provided and compared to PA scores reported in the International Physical Activity Questionnaire (IPAQ). The representative sample (N = 1,239) of the Belgian population took on average 9,655 (4,526) steps/day. According to pedometer indices 58.4% were insufficiently active. Steps/day differed significantly between gender (F = 5.0, p = .026), age groups (F = 3.3, p = .01), employment status (F = 6.2, p = .013), and days of monitoring (F = 7.4, p = .007). Steps/day were negatively correlated to the time spent sitting and positively to PA at work, in transport, and in leisure time (p < .001). Steps data can discriminate between PA levels reported in the IPAQ. Belgian population pedometer-determined PA levels are higher than those reported in samples of the United States; however, there is a wide distribution of ambulatory behavior.     

Physical Activity Correlates for Children With Autism Spectrum Disorders in Middle School Physical Education

Bat/ball contact produces visual (the ball leaving the bat), auditory ( the “crack” of the bat), and tactile (bat vibration) feedback about the success of the swing. We used a batting simulation to investigate how college baseball players use visual, tactile, and auditory feedback. In Experiment 1, swing accuracy (i.e., the lateral separation between the point of contact and “sweet spot”) was compared for no feedback (N), visual alone, auditory alone, and tactile alone. Swings were more accurate for all single-modality combinations as compared to no feedback, and visual produced the greatest accuracy. In Experiment 2, the congruency between visual, tactile, and auditory was varied so that in some trials, the different modalities indicated that the simulated ball contacted the bat at different points. Results indicated that batters combined information but gave more weight to visual. Batting training manuals, which typically only discuss visual cues, should emphasize the importance of auditory and tactile feedback in baseball batting.     

Physical Activity Practices in Elementary Schools and Associations With Physical Education Staffing and Training

Purpose: Authorities recommend that schools provide a variety of opportunities for students to obtain physical activity (PA) before, during, and after school. This study assessed the prevalence of several school PA practices—including measures of quantity and quality of physical education (PE)—in elementary schools and examined the associations of PA practices with school resources (PE staffing, training, and facilities). Method: Surveys were obtained from respondents in nationally representative samples of elementary schools from 2009–2010 to 2011–2012 (1,831 schools). Results: Few schools (20.8%) provided students with PE class every day, but most (76.3%) had an appropriate PE student-to-teacher ratio ( ≤ 25:1). Many schools (74.0%) offered 20 min of recess daily, but fewer than half offered organized opportunities for PA before or after school (e.g., sports). After controlling for demographics and school size, having a full-time PE teacher and requiring PE teachers to obtain PE-related continuing education (CE) were associated with PE practices such as offering ≥ 150 min of PE per week (for 3rd-grade students) and testing PE knowledge, skills, and fitness. Required CE was also associated with a higher likelihood of offering PA during the school day (i.e., activity breaks and PA outside of PE class) and before or after the school day (i.e., afterschool PA programs). Conclusion: Few schools offer a broad array of PA programming. However, PE staffing and CE are positively associated with many PA practices including those outside of PE, possibly indicating that PE staff serve a crucial role in promoting a whole-school PA-supportive environment.     

Baseline Intraocular Pressure Is Associated With Subjective Sensitivity to Physical Exertion in Young Males

Purpose: The purposes of this study were to (a) investigate the effect of physical effort (cycling for 60 min at 60 ± 5% of individually computed reserve heart-rate capacity), combined with 2 different levels of cognitive demand (2-back, oddball), on intraocular pressure (IOP) and subjective judgments of perceived exertion (ratings of perceived exertion [RPE]), affect (Affective Valence subscale of the Self-Assessment Manikin [SAM]), and mental workload (National Aeronautics and Space Administration Task Load Index [NASA-TLX]); and (b) ascertain whether baseline IOP, measured before exercise, is associated with individual differences in subjective assessments of effort and affective response during exercise. Method: Seventeen participants (M_age = 23.28 ± 2.37 years) performed 2 physical/cognitive dual tasks, matched in physical demand but with different mental requirements (2-back, oddball). We assessed IOP before exercise, after 2 min of active recovery, and after 15 min of passive recovery, and we also collected RPE and SAM measures during the sessions (28 measurement points). We used NASA-TLX and cognitive performance as checks of the mental manipulation. Results: (a) Intraocular pressure increased after concomitant physical/mental effort, with the effect reaching statistical significance after the 2-back task (p = .002, d = 0.35) but not after the oddball condition (p = .092, d = 0.29). (b) Baseline IOP was associated with subjective sensitivity to effort and showed statistical significance for the oddball condition (p = .03, ?_p² = .622) but not for the 2-back task (F < 1). Conclusions: Results suggest a relationship between IOP and physical/cognitive effort, which could have implications for the management of glaucoma. Additionally, a rapid measure of IOP could be used as a marker of individual effort sensitivity in applied settings.     

创新教育与终身体育

21世纪激烈的竞争需要创造性思维和创造性人才,加强创造力培养,尤其在高层人才的创造性培养上,是对人才培养提出的强烈要求。在分析创新教育与终身体育关系的基础上,对高校体育实现创新教育问题进行探讨,提出若干相关的构思与举措。     

Children's Activity Levels and Lesson Context during Third-Grade Physical Education

Abstract

Little is known about children's activity levels during physical education classes and how they relate to the national health objectives for the year 2000 (U.S. Public Health Service, 1991). We systematically observed students' physical activity and associated variables in 293 third-grade physical education lessons in 95 schools in 4 Child and Adolescent Trial for Cardio-vascular Health (CATCH) centers in California, Louisiana, Minnesota, and Texas. The influence of independent variables was assessed simultaneously by analysis of variance. Significant differences among study centers were evidenced for both physical activity and lesson context variables. Additionally, there were differences among variables for lesson location and teacher specialty, but not for teacher gender. Boys were more active than girls, but only during free play opportunities. The findings have widespread implications for educators responsible for developing and implementing health-related physical education programs, as well as for designing and conducting staff development.     

Effects of Instructional Physical Activity Courses on Overall Physical Activity and Mood in University Students

Purpose: The aim of this research was to assess the association between university-based instructional physical activity (PA) courses and changes in overall PA levels and negative mood and their interrelations. The study also sought to determine the amount of change in PA required to significantly improve mood in course enrollees. Method: Participants were university students initially completing PA below the level recommended for health who were either presently enrolled in an elective instructional PA course (treatment group, n = 52, 69% female) or not presently enrolled in such a course (comparison group, n = 32, 69% female). Validated surveys assessed volumes of PA completed per week and overall negative mood from baseline to course end. Mediation analyses assessed group effects on mood through PA changes and reciprocal relations between PA and mood changes. Results: There was a significantly greater increase in PA and significantly more reduction in negative mood in the treatment group. Change in PA completely mediated the relationship between group and change in negative mood, and change in mood completely mediated the relationship between group and PA. These findings indicated a reciprocal, mutually reinforcing relationship between changes in PA and mood. An increase in PA of at least 2 days/week was associated with a significant reduction in negative mood, with no greater effect for more increase. Conclusions: Results provided an improved understanding of the effects of university-based instructional PA courses and how they might be leveraged to improve students’ mental health and possibly contribute to their academic success.     

综合实践活动课程中体育内容实施的研究

综合实践活动课程中的体育内容设计与实施,离不开教师的组织、引导和监督,同时又要给学生充分自主活动的权力,发挥其观察力,想象力和创造力等。加强综合实践活动课程中的体育内容实施,是满足学生现实生活的需要、适应未来社会发展的需要和树立终身体育意识的需要。     

家庭体育教育与阳光体育运动的持续发展

家庭体育教育在阳光体育运动发展过程中扮演着中要角色。然而各方面数据表明现阶段家庭体育教育却存在较多问题,本文针对这些问题进行了分析并提出相关建议。     

Aerobic Capacity in Black Adolescent Girls

Abstract

Our purpose was to determine the aerobic capacities (VO₂max) of a group of black female adolescents (age = 11.4 ? 15.8 years) randomly chosen from a single urban school. Of 91 girls selected, 64 performed an incremental treadmill running test to volitional exhaustion and achieved VO₂max as determined from expired gas measures. Other measures included height (m), weight (kg), and calf and triceps skinfolds (for % fat estimates). Girls were also asked whether they had achieved menarche. VO₂max averaged 37.3 ± 6.2 ml·kg^?1 ·min^?1 and was significantly correlated (r[62]) with height (?.32, p < .01), body mass index (?.63, p < .001), and % fat (?.65, p < .001) but not with age (?.16, p > .10). Postmenarchal girls were significantly taller and older than premenarchal girls. Contrary to previous studies, the girls' VO₂max values were not related to biological age. Our subjects' aerobic capacity values averaged 14% less than those of nonblack U.S. female adolescents previously reported in the literature. This difference in VO₂max was primarily a function of body weight. Study implications support the possibility that overweight in adult black women may originate prior to or during early adolescence. Future longitudinal studies should be designed to investigate the effects of aerobic fitness on cardiovascular risk factor reduction in black adolescent girls.     

Middle School Physical Education Physical Activity Quantification

The objective of the study was to improve physical activity (PA) surveillance of the Healthy People 2010 Objective 22:10 (i.e., 50% of the lesson time engaged in PA) by establishing a pedometer steps/min guideline to quantify time engaged in PA during physical education. A sample of 180 middle school students had their PA measured via pedometry (steps/min) and behavioral observation (PA time). Factorial analyses of variance were used to examine PA differences. Linear and logistic regression, decision accuracy, and receiver-operating-characteristic (ROC) statistics were used to test steps/min cut points against the 50% PA recommendation. PA differences were not found (p > .01). Steps/min was a significant (p ≤ .01) predictor of PA time, and the binary outcome of meeting or not meeting the PA recommendation. A steps/min interval of 82–88 was an accurate indicator of the 50% PA recommendation. The ROC statistic was .97 (p ≤ .01), suggesting steps/min was an excellent discriminator of the binary outcome. Pedometer steps/min is a valid, objective, and practical approach for surveillance of physical education PA, a key physical education and public health outcome.     

高校课余体育活动现状及发展对策

通过对过去高校传统的课余体育活动组织形式和活动方法进行分析和总结，并结合《全民健身计划纲要》的精神，着重以人才培养作为出发点，结合学生的个性、兴趣等特征，提出了崭新的课余体育活动组织形式和方法，为求更好地开展高校校园课余体育活动提出较合理的建议。