Accuracy of Actigraph inclinometer to classify free-living postures and motion in adults with overweight and obesity

Sedentary behaviour (SB) is an independent health risk-factor and interrupting SB seems to be beneficial. SB is both defined by posture and intensity, thus objective measurement of postures remains a priority. The ActivPAL inclinometer (AP) has been used as a reference for postural estimation, but information on the validity of the Actigraph inclinometer (AG_incl) is scarce. We compared postural estimation from waist-worn AG_incl against thigh-worn AP, under free-living. Data from 10 participants (50.4 ± 11.4 years) were used and each 15s-block from 60-valid days was matched for the devices’ comparison. At group level, no differences were found for SB and standing-time between inclinometers (p ≥ 0.05). AG_incl underestimated stepping-time by 26.3 min and overestimated SB-to-upright transitions by 200.7 occasions (p < 0.05). Inter-individual variability was higher for SB and standing-time, and AG_incl was in better agreement with AP for the stepping-time (area under the ROC curve = 0.98, with 100% sensitivity and 94% specificity; CCC = 0.44). These results highlight potential error in estimating individual postures using AG_incl in overweight/obese adults and provide insights on the differences of using specific criteria on data-analysis. Our findings suggest that at the group level, AG_incl provides similar estimates compared to AP for SB and standing-time, but not for SB-to-upright transitions or stepping-time. (ClinicalTrials.govID:NCT02007681)     

Patterns of accelerometer-derived sedentary time across the lifespan

ABSTRACT

We aimed to describe ST and its patterns on a national level. A hip-worn accelerometer (ActiGraph GT1M) was used to collect data during waking hours from 4575 Portuguese’ participants from 2007–2009 (2683 females) aged 10–102 years old. Data was presented by sex, in 5-years age intervals, and by adolescents (n=2833), adults (n=1122), and older adults (n=620). Lambda-mu-sigma (LMS) smoothed percentile curves were estimated. Girls, women, and older women spent 61, 57, and 64% of wear time in ST, respectively. In males, ST represented 57, 60, and 62% of wear time respectively for boys, men, and older men. Comparing to other age groups, older adults spent a larger amount of ST in bouts ≥30-min (women: 33%, men: 39% of total ST). The number of breaks/ST hour were: 10.6 in girls, 11.7 in women, and 9.6 in older women. In males, the number of breaks/ST hour were: 11.2, 10.5, and 8.5 for boys, men, and older men. In conclusion, ST was not consistently higher at older ages. Instead, we found that the potential critical moments in which ST may be higher are during adolescence and in the transition from adulthood into older adulthood, which represents critical periods for interventions.     

Role of objectively measured sedentary behaviour in physical performance,frailty and mortality among older adults: A short systematic review

Sedentary behaviour (SB) has recently emerged as an independent risk factor for different health outcomes. Older adults accumulate long time in SB. Understanding the role that SB plays on health is crucial for a successful aging. This short systematic review summarizes the current evidence related to the effects of objectively measured SB on frailty, physical performance and mortality in adults ≥60?years old. The literature search produced 271 records for physical performance (n?=?119), frailty (n?=?31), and mortality (n?=?121). Finally, only 13 articles fulfilled the inclusion criteria and were included in this review. All articles but one included in the physical performance section (n?=?9) showed a negative association between longer time spent in SB and physical performance. A significant association of SB with higher odds of frailty was found, however this association disappeared after adjusting for cognitive status. Lastly, two of the three included studies showed positive associations between SB and mortality, but this effect decreased or even disappeared in the more adjusted models. In conclusion, there is consistency that SB is negatively associated with physical performance. However, the relationship between objectively measured SB and frailty incidence and mortality rates remains unclear and deserves further research. The use of homogenous criteria to assess SB and the inclusion of more robust research designs will help clarifying the independent effects that SB could have on physical performance, frailty, and mortality. This will ultimately help designing more efficient and comprehensive physical activity guidelines for older adults.     

我国儿童青少年体重过重和肥胖的原因及其预防对策

本文以我国儿童青少年为研究对象,基于社会健康观的视角,深入、全面地分析了儿童青少年学生体重过重和肥胖的原因、肥胖的标准。从体育学和营养学角度出发,提出对儿童青少年学生体重过重和肥胖预防和干预对策,并予以整合、提炼,试图为我国学校教育的健康教育提供参考。     

短时中等强度不同类型运动对小学生执行功能的影响

目的:本实验探讨短时中等强度不同类型运动对小学生执行功能的影响作用,为运动促进小学生执行功能发展提供理论依据和实践基础。研究对象与方法:选取四年级小学生160名,将学生随机分为短时中等强度不同类型运动组和对照组,其中有氧运动干预组40人,阻力运动干预组40人,灵敏运动干预组40人,对照组40人,采用E-primel.l系统测量被试实验前期-后期执行功能的抑制、刷新和转换三个子功能的变化。结果:(1)短时中等强度不同类型运动对执行功能整体的影响存在差异;(2)不同类型的运动对小学生执行功能的抑制功能存在显著性差异;(3)短时中等强度不同类型运动对小学生的刷新功能影响存在差异(4)短时中等强度不同类型运动对小学生的转换功能影响存在差异。结论:(1)短时中等强度的运动可以提高小学生的执行功能,对小学生执行功能起选择性的积极影响;(2)运动类型是运动对小学生执行功能起积极作用的影响因素;(3)短时中等强度不同类型运动对执行功能整体及其各个子功能的影响具有差异性,有氧运动相较于灵敏运动和阻力运动更有利于促进小学生执行功能的提高。     

大强度中长跑训练对青少年运动员免疫机能的影响

为研究长时间大强度运动训练对青少年免疫机能的影响,选取业余体校16 17岁青少年中长跑运动员20名(全部为男性),训练年限分别为7 9年,测试其在大强度训练期间1)外周血T细胞亚群包括CD3+、CD4+、CD8+以及CD4/CD8;2)外周血NK细胞毒活性;3)外周血细胞因子包括白细胞介素-1和白细胞介素-6。结果显示:大强度运动训练在一定程度上对青少年的免疫系统产生明显的抑制作用。     

Substitution of sedentary time with light physical activity is related to increased bone density in U.S. women over 50 years old. An iso-temporal substitution analysis based on the National health and Nutrition Examination Survey

Abstract

U.S. women are ageing. This is causing rises in osteoporosis prevalence and risk of fracture with related increases in health care costs. Replacing sedentary time with light physical activity may represent a cost effective public health solution to osteoporosis in elderly women. The National Health and Nutrition Examination Survey conducted over the period 2003–2006 provided cross-sectional data on bone mineral density and objectively assessed physical activity among 1,052 women aged 50–85 years old. Substitution analysis was applied to estimate increased bone mineral density and reduced osteoporosis for those women replacing 30?min of sedentary time with an equivalent amount of light physical activity. Substitution of 30?min of sedentary time with an equal amount of light physical activity was associated with increased bone mineral density of about 3?mg/cm2 and a 12% reduced risk of osteoporosis in the spine. When considering overweight women and women over 65 years of age, this association was reinforced and it extended to the pelvis, legs and trunk, resulting in a consistent bone mineral density increase of about 3–6?mg/cm2. The substitution of 30?min of sedentary time with an equal amount of light physical activity appears a possible primary prevention method to reduce osteoporosis and related increases in risk of fracture, mortality, and health care costs in women over 50 years old.     

儿童青少年体质健康与学业成绩的关系:有中介的调节模型

目的: 探讨我国儿童青少年体质健康水平与学业成绩之间关系的影响机制;以执行功能为中介变量,年龄为调节变量建立一个有中介的调节模型。方法: 对湖北地区1 970名学生进行体质健康水平测试,并采用问卷法对执行功能水平测试,以语文、数学、英语三门学科成绩的标准分作为学业成绩指标。使用AMOS21.0以及SPSS22.0对数据进行分析。结果: 体质健康水平指标中的有氧耐力、速度、肌肉力量以及柔韧性均与各科学业成绩存在显著正相关;执行功能作为中介变量存在于体质健康水平与学业成绩的关系中,模型拟合程度良好(χ²/df为4.246,NFI为0.98,CFI为0.98,RMSEA为0.041)。此外,该模型还受到年龄的调节作用,与其他因素一起构成了有中介的调节模型。结论: (1)儿童青少年的体质健康水平与其学业成绩间呈正相关,可以对其作出正向预测;(2)执行功能在体质健康水平与学业成绩间起到部分中介作用;(3)年龄在体质健康水平、执行功能、学业成绩的关系间起调节作用。     

中国皮划艇国家二队功能动作筛查的应用研究

运用文献资料法、测试法、问卷调查法、专家访谈法和数理统计法对国家皮划艇青年队进行功能动作筛查测试,根据测试结果为备战2020年奥运会提供数据及理论的支持。通过研究发现:划艇运动员的总分情况整体优于皮艇运动员;大部分运动员髋、膝、踝三关节在单一的运动平面中具有较好的协调和稳定性,但在两个以上的运动平面中完成动作的稳定和控制能力有待提高;运动员的髋关节、肩关节及股四头肌柔韧性存在不平衡现象,左侧链与右侧链在多运动平面中协调稳定性也存在不平衡现象;运动员的损伤率较高,且损伤的主要部位是肩和腰。     

独生子女的行为和性格特点与体育后备人才的关系

独生子女与体育后备人才的关系是独生子女与体育关系研究中的一个最基本的方面。以分析独生子女的行为和性格特点为研究的切入点,从3个方面探讨了独生子女与体育后备人才的关系,对科学地选拔优秀的体育后备人才具有重要的现实意义。     

Learning Benefits of Self-Controlled Knowledge of Results in 10-Year-Old Children

Abstract

The leg strength of 70 college men was measured in a position designed to involve the power thrust of the major muscle groups used in the vertical jump. The subjects then performed a modified Sargent jump that used no arm snap. Although the reliability of all measures was high, individual differences in the ratio of tested strength to body mass showed only a low and nonsignificant correlation with jumping performance. The results are interpreted to support the hypothesis that strength exerted against a dynamometer involves a different neuromotor pattern than strength exerted by the muscles during a movement. Tables of means, variabilities, and intercorrelations are included in the report.     

Reliability and Validity of the Flemish Physical Activity Computerized Questionnaire in Adults

The purpose of this study was to investigate the test-retest reliability and concurrent validity of the Flemish Physical Activity Computerized Questionnaire (FPACQ) in employed/unemployed and retired people. The FPACQ was developed to assess detailed information on several dimensions of physical activity and sedentary behavior over a usual week. A triaxial accelerometer, the RT3 Triaxial Research Tracker (RT3), in combination with a written 7-day activity record, was used as the objective criterion measure. In employed/unemployed people, 2-week test-retest reliability for several activity variables calculated from the FPACQ was good to excellent with intraclass correlations (ICCs) ranging from .67 to .99. In retired people ICCs were lower but, except for time spent eating, still fair to excellent, ranging from .57 to .96. Except for time spent in leisure time activities for men and the average energy expenditure related to sports participation in women, correlations between the RT3 and the FPACQ generally supported the relative validity of the FPACQ for employed/unemployed people (r ranging from .37 to .88). Values for retired people were somewhat lower (r ranging from .15 to .85), but most variables still reached at least moderate correlations. Concerning absolute validity, the FPACQ generally overestimated physical activity and underestimated sedentary behavior compared to the RT3. From this study, it can be concluded that the FPACQ is a reliable and reasonably valid questionnaire for assessing different dimensions of physical activity and sedentary behavior.     

Health-enhancing physical activity and sedentary behaviour in children and adolescents

We provide a wide-ranging review of health-related physical activity in children and adolescents using a behavioural epidemiology framework. In contrast to many other reviews, we highlight issues associated with true sedentary behaviours alongside physically active behaviours. Specifically, we review the evidence concerning the links between physical activity and cardiovascular disease, overweight and obesity, psychosocial measures, type II diabetes, and skeletal health. Although the evidence is unconvincing at times, several factors lead to the conclusion that promoting physical activity in youth is desirable. A review of the prevalence of physical activity and sedentary behaviours shows that many young people are active, but this declines with age. A substantial number are not adequately active for health benefits and current trends in juvenile obesity are a cause for concern. Prevalence data on sedentary behaviours are less extensive but suggest that total media use by young people has not changed greatly in recent years. Most children and adolescents do not exceed recommended daily hours of TV viewing. Physical activity is unrelated to TV viewing. We also identified the key determinants of physical activity in this age group, highlighting demographic, biological, psychological, behavioural, social and environmental determinants. Interventions were considered for school, family and community environments. Finally, policy recommendations are offered for the education, governmental, sport and recreation, health, and mass media sectors.