Association of accelerometer-derived step volume and intensity with hospitalizations and mortality in older adults: A prospective cohort study

Purpose:This study aimed to examine the associations of accelerometer-derived steps volume and intensity with hospitalizations and all-cause mortality in older adults.Methods:This prospective cohort study involved 768 community-dwelling Spanish older adults(78.8±4.9 years,mean±SD;53.9% females)from the Toledo Study for Healthy Aging(2012-2017).The number of steps per day and step cadence(steps/min) were derived from a hip-mounted accelerometer worn for at least 4 days at baseline.Participants we...     

Effects of a remote,YouTube-delivered exercise intervention on young adults’physical activity,sedentary behavior,and sleep during the COVID-19 pandemic:Randomized controlled trial

Background:Public health guidelines have called for innovative and flexible physical activity(PA)intervention strategies to promote PA and health amid the coronavirus disease 2019(COVID-19)pandemic.Therefore,this study’s purpose was to examine the effects of a home-based,YouTube-delivered PA intervention grounded in self-determination theory on young adults’free-living PA,sedentary behavior,and sleep quality(NCT04499547).Methods:Sixty-four young adults(48 females;age=22.8±3.4 years,mean±SD;body mass index=23.1±2.6 kg/m²)were randomized(1:1)into the intervention group,which received weekly aerobic and muscle-strengthening PA videos,or control group,which received weekly general health education videos,for 12 weeks.Our primary outcome was free-living moderate-to-vigorous PA(MVPA)and our secondary outcomes were sedentary behavior,light PA,and sleep quality(measured using ActiGraph accelerometers)along with muscle-strengthening PA frequency,self-determination theory-related motivation(non-regulation,external regulation,introjected regulation,identified regulation,integrated regulation,and intrinsic regulation),and perceived PA barriers(assessed using validated questionnaires).Repeated measures analysis of variances(ANOVAs)examined between-group differences at an adjusted significance level of 0.004 and effect sizes as partial eta-squared(η;).Results:We observed statistically significant interaction effects for MVPA,sleep efficiency,muscle-strengthening PA frequency,non-regulation,integrated regulation,intrinsic regulation,and perceived PA barriers(F(1,62)=10.75-77.67,p<0.001-0.002,η_p²=0.15-0.56)with all outcomes favoring the intervention group.We observed no statistically significant differences in either group for sedentary behavior,light PA,sleep duration,or external,introjected,and identified regulations after 12 weeks(F(1,62)=1.11-3.64,p=0.06-0.61).Conclusion:With national COVID-19 restrictions still in place and uncertainty regarding post-pandemic PA environments and behaviors,a remote,YouTube-delivered PA intervention may help foster clinically meaningful improvements in young adults’free-living MVPA,musclestrengthening PA frequency,sleep efficiency,PA-related intrinsic motivation,and perceived PA barriers.     

A brief history of the Compendium of Physical Activities

<正>The Compendium of Physical Activities (Compendium) was developed to address consistent assignment of physical activity(PA) intensity values used in PA epidemiology research of the association between PA and health outcomes.¹ The known protective effects of PA on incident health outcomes traces to the mid-1900s,with over 50 studies examining coronary heart disease (CHD) as the outcome of interest.     

A clash of fundamental assumptions: Can/should we measure physical literacy?

The special issue of the Journal of Teaching in Physical Education (JTPE)~1 on physical literacy (PL) has provided much needed information about measuring and assessing student learning in terms of the well-defined and yet abstract concept.Multiple authors have elaborated from diverse educational and psychometric perspectives on the development of the construct,the measurement model,and the assessment of the construct.In this attempt,many issues associated with the conception of PL were clarified and insightful information and arguments were brought forward.In this regard,the special issue has moved our understanding of the concept one step further.More importantly,it points to a possibility to actualize the teaching of the concept in physical education (PE).     

A physically active lifestyle is related to a lower level of skin autofluorescence in a large population with chronic-disease (LifeLines cohort)

Background:Physical activity(PA)has substantial health benefits and is important in combatting chronic diseases,which have been associated with elevated levels of advanced glycation endproducts(AGEs).AGEs play a role in the aging process,and an association between PA and AGEs has been reported.We aimed to investigate the relationship between PA and AGE accumulation in a general population and in a population with chronic diseases.Methods:This large cross-sectional population study used data from adult participants in the LifeLines project,with participant information drawn from the LifeLines database as well data from patients with diabetes mellitus or renal and/or cardiovascular diseases.Tissue AGE accumulation was assessed non-invasively by skin-autofluorescence(SAF)using an AGE reader(DiagnOptics Technologies BV,Groningen,the Netherlands).PA was assessed using the short questionnaire to assess health-enhancing physical activity(SQUASH).Multivariate linear regression analyses were adjusted for age,body mass index,sex,and smoking status.Results:Data from 63,452 participants(general population n=59,177,chronic disease n=4275)were analyzed.The general population was significantly younger(43.58±11.77 years,mean±SD)and had significantly lower SAF(1.90±0.42 arbitrary units(AU))compared to the population with chronic disease(age:55.51±12.07 years;SAF:2.27±0.51 AU).In the group with chronic disease,more hours of moderate to vigorous physical activities per week were associated with lower SAF(β=-0.002,95%confidence interval(95%CI):-0.002 to-0.001).For the general population,there was no association between hours of moderate to vigorous activity and SAF(β=3.2×10^-5,95%CI:0.000-0.001,p=0.742).However,there was an association in the general population between total hours of PA per week and SAF(β=4.2×10^-4,95%CI:0.000-0.001,p<0.001),but this association was not found in the chronic disease population(β=-3.2×10^-4,95%CI:-0.001 to 0.000,p=0.347).Conclusion:Our study demonstrates that an inverse relationship exists between PA and AGE accumulation in the population with chronic disease.More hours of moderate to vigorous activity is associated a significantly decreased SAF.More PA is associated a lower SAF,even after for the established predictors(age,body mass index,smoking status,and sex).Our findings could help to promote health and prolong longevity.     

Using compositional data analysis to explore accumulation of sedentary behavior,physical activity and youth health

Purpose:The study aimed to describe youth time-use compositions,focusing on time spent in shorter and longer bouts of sedentary behavior and physical activity(PA),and to examine associations of these time-use compositions with cardiometabolic biomarkers.Methods:Accelerometer and cardiometabolic biomarker data from 2 Australian studies involving youths 7-13 years old were pooled(complete cases with accelerometry and adiposity marker data,n=782).A 9-component time-use composition was formed using compositional data analysis:time in shorter and longer bouts of sedentary behavior;time in shorter and longer bouts of light-,moderate-,or vigorous-intensity PA;and"other time"(i.e.,non-wear/sleep).Shorter and longer bouts of sedentary time were defined as<5 min and>5 min,respectively.Shorter bouts of light-,moderate-,and vigorous-intensity PA were defined as<1 min;longer bouts were defined as≥1 min.Regression models examined associations between overall time-use composition and cardiometabolic biomarkers.Then,associations were derived between ratios of longer activity patterns relative to shorter activity patterns,and of each intensity level relative to the other intensity levels and"other time",and cardiometabolic biomarkers.Results:Confounder-adjusted models showed that the overall time-use composition was associated with adiposity,blood pressure,lipids,and the summary score.Specifically,more time in longer bouts of light-intensity PA relative to shorter bouts of light-intensity PA was significantly associated with greater body mass index z-score(zBMI)(β=1.79;SE=0.68)and waist circumference(β=18.35,SE=4.78).When each activity intensity was considered relative to all higher intensities and"other time",more time in light-and vigorous-intensity PA,and less time in sedentary behavior and moderate-intensity PA,were associated with lower waist circumference.Conclusion:Accumulating PA,particularly light-intensity PA,in frequent short bursts may be more beneficial for limiting adiposity compared to accumulating the same amount of PA at these intensities in longer bouts.     

Biceps femoris long head sarcomere and fascicle length adaptations after 3 weeks of eccentric exercise training

Background:Eccentric exercise increases muscle fascicle lengths;however,the mechanisms behind this adaptation are still unknown.This study aimed to determine whether biceps femoris long head(BFlh)fascicle length increases in response to 3 weeks of eccentric exercise training are the result of an in-series addition of sarcomeres within the muscle fibers.Methods:Ten recreationally active participants(age=27±3 years;mass=70±14 kg;height=174±9 cm;mean±SD)completed 3 weeks of Nordic hamstring exercise(NHE)training on a custom exercise device that was instrumented with load cells.We collected in vivo sarcomere and muscle fascicle images of the BFlh in 2 regions(central and distal)by using microendoscopy and 3 dimension ultrasonography.We then estimated sarcomere length,sarcomere number,and fascicle length before and after the training intervention.Results:Eccentric knee flexion strength increased after the training(15%;p<0.001;η_p²=0.75).Further,we found a significant increase in fascicle length(21%;p<0.001;η_p²=0.81)and sarcomere length(17%;p<0.001;ηp2=0.90)in the distal but not in the central portion of the muscle.The estimated number of sarcomeres in series did not change in either region.Conclusion:Fascicle length adaptations appear to be heterogeneous in the BFlh in response to 3 weeks of NHE training.An increase in sarcomere length,rather than the addition of sarcomeres in series,appears to underlie increases in fascicle length in the distal region of the BFlh.The mechanism driving regional increases in fascicle and sarcomere length remains unknown,but we speculate that it may be driven by regional changes in the pas sive tension of muscle or connective tis sue adaptations.     

Social correlates of sedentary behavior in young people:The UP&DOWN study

Purpose:The aim of the present study was to analyze the associations of youths' sedentary behavior(SB) with parents' and siblings' SB and physical activity(PA),as well as the associations of youths' coparticipation with parents,siblings,and friends in PA and SB with youths' SB.Methods:The sample consisted of 1543 youths(12.02±2.51 years;788 boys) enrolled in the baseline cohort of the UP&DOWN study.SB was assessed by accelerometry and questionnaire.Participants reported the time spent by their parents and siblings watching television,playing videogames,surfing the Internet,sitting/resting,and doing PA.Further,participants reported coparticipation with parents,siblings,and friends in these activities.Linear mixed models,including school and city as random effects,were performed.Results:Parents' television time was positively associated with youths' screen-based SB.Coparticipation with friends in playing videogames(in boys) and in surfing the Internet(in girls) showed a positive association with screen-based SB and a negative association with educational-based SB.Moreover,coparticipation with siblings and friends in PA was inversely associated with accelerometer-based SB in boys and girls.Conclusion:Our results emphasize the important role of social modeling in the development of sedentary lifestyles in youths.Interventions aimed at reducing health risk behaviors in youths could be more effective if they are oriented from a social perspective that involves their families and networks of their closest friends.     

Commentary on "Association of daily sitting time and leisure-time physical activity with body fat among U.S. adults"

<正>In their study,association of daily sitting time and leisure-time physical activity (LTPA) with body fat among U.S.Adults,Liao et al.¹ analyzed data from the 2011-2018 National Health and Examination Survey to examine associations between h/day sitting,meeting (or not meeting) the U.S.Physical Activity Guidelines of≥150 min/week of moderate-and vigorous-intensity LTPA,and combinations of sitting time and LTPA on totaland trunk percent body fat (BF%).     

Bidirectional relationships of physical activity and gross motor skills before and after summer break: Application of a cross-lagged panel model

Background:Gross motor skills are postulated to have a bidirectional relationship with physical activity(PA);however,no study has tested this relationship before and after a summer break.The purpose of this study was to examine the bidirectional relationships between school PA and gross motor skills in children before and after a summer break.Methods:Participants were a sample of 440 children recruited from 3 low-income schools(age=8.9±1.2 years,mean±SD).PA was assessed as average school-day step counts using Yamax DigiWalker pedometers(Yamasa Tokei Keiki,Tokyo,Japan)worn for 5 consecutive school days.Gross motor skills were assessed using the Test for Gross Motor Development,3 rd edition.Data were collected at 2 timepoints:at the end of spring semester(T1)and at the beginning of the subsequent fall semester(T2).An age-and body mass index-adjusted cross-lagged model was employed to relate T1 school step counts with T2 gross motor skills and T1 gross motor skills with T2 school step counts.Results:T1 gross motor skills significantly predicted T2 school step counts(β=0.24,95%confidence interval(95%CI):0.08-0.40,p=0.003);however,Tl school step counts did not predict T2 gross motor skills(β=0.04,95%CI:-0.06 to 0.14,p=0.445).The model explained 35.4%and 15.9%of the variances of T2 gross motor skills and T2 school step counts,respectively.Additional analyses indicated that these relationships were driven primarily by ball skills.Conclusion:The relationship between gross motor skills and school PA was not bidirectional;however,higher gross motor skills,specifically ball skills,predicted higher school PA after a 3-month summer break.     

Competition and Extrinsic Rewards: Effect on Intrinsic Motivation and Attribution

The purpose of the present investigation was to determine the effect of monetary rewards and success/failure on intrinsic motivation and causal attributions of males and females competing on a motor task. Multivariate analysis of variance produced a significant overall main effect for feedback, with subjects exhibiting more intrinsic motivation after success than after failure. The Sex × Feedback interaction (p < .09) indicated that males exhibited more intrinsic motivation than females after success, whereas females displayed more intrinsic motivation than males after failure. Attribution results showed that success was primarily attributed to high ability, high effort, and good luck while failure was attributed to low ability, low effort, and bad luck. Correlational analysis revealed that success was related to high ability, high effort, good luck, and high intrinsic motivation. Conversely, failure was associated with low ability, low effort, bad luck, and low intrinsic motivation. In addition, ability and effort were the causal attributes most related to changes in intrinsic motivation. The relationship between causal attributions and intrinsic motivation is discussed in terms of the self-enhancement hypothesis and Deci's cognitive evaluation theory. Implications for competitive physical activity are drawn.     

内容与方法: 内隐自尊的探索与问题

目的：观察以高脂膳食诱导的C57BL／6J小鼠脂肪肝和血脂的变化以及有氧运动对它们的改善作用。方法：以高脂膳食诱导的脂肪肝小鼠为模型．分析有氧运动20周后脂肪肝及血清TC，TG，HDL—c，LDL-c和VLDL—c水平的变化。结果：H组血清TC、TG、LDL—c水平显著高于其他各组，而VLDL-c显著降低：RE组血清TG、TC、LDL-c的水平显著降低，且与N组没有显著差异；RS组TG、TC、LDL—c有降低的趋势，但显著高于正常对照组；N组血清HDL-c显著低于HS、RS和RE组（P〈0．05），而HS、RS与RE组之间无显著差异；肝脏中脂滴数高脂膳食组（H组）显著高于其他各组，恢复正常膳食不运动组（RS组）显著高于恢复正常膳食结合运动组（RE组），正常对照组（N组）与RE组间无显著差异；脂肪肝的病变程度与TC、TG、LDL-c呈显著正相关，与VLDL—c呈显著负相关，与HDL—c呈正相关，但无显著性。结论：运动与改善膳食结构相结合，对高脂所致的高脂血症和脂肪肝．比单纯的改善膳食结构具有更明显的治疗效果。     

Pre-exercise carbohydrate and fat ingestion: effects on metabolism and performance

A key goal of pre-exercise nutritional strategies is to maximize carbohydrate stores, thereby minimizing the ergolytic effects of carbohydrate depletion. Increased dietary carbohydrate intake in the days before competition increases muscle glycogen levels and enhances exercise performance in endurance events lasting 90 min or more. Ingestion of carbohydrate 3-4 h before exercise increases liver and muscle glycogen and enhances subsequent endurance exercise performance. The effects of carbohydrate ingestion on blood glucose and free fatty acid concentrations and carbohydrate oxidation during exercise persist for at least 6 h. Although an increase in plasma insulin following carbohydrate ingestion in the hour before exercise inhibits lipolysis and liver glucose output, and can lead to transient hypoglycaemia during subsequent exercise in susceptible individuals, there is no convincing evidence that this is always associated with impaired exercise performance. However, individual experience should inform individual practice. Interventions to increase fat availability before exercise have been shown to reduce carbohydrate utilization during exercise, but do not appear to have ergogenic benefits.     

体育产业:概念及其构成的质疑与讨论

“体育产业”作为一个全新的概念,理论界对它的确切定义和产业结构的识别仍处在探讨阶段。本文采用文献资料法,以产业经济学理论为依据,对目前代表性观点进行分析和质疑,并在此基础上提出新的观点和解释。     

Aspiration and Reflection: Sport Historians on Sport History

Abstract

Following the series of Presidential Forum conversation pieces instigated by Kevin Wamsley on the NASSH website, this piece places the context of the collection of comments and criticisms by 29 contributors to this special issue on sport historians reflecting on the field of sport history.     

中国体育体制研究:历史回顾与未来展望

中国体育这一超前于社会其他行业对外开放的领域,内部的改革却相对滞后。对于体育制度层面特别是体制改革的研究,自改革开放后逐渐成为理论研究及实践中的热点问题。体育制度的改革走向如何?突破口在哪里? 文章在对体制研究历史进行简要回顾的基础上,提出一些想法,供讨论。     

Attentional focus and control parameter: effect on throwing pattern and performance

In two separate experiments, this study examined changes in motor pattern and performance accuracy when low-level throwers focused on internal variables, external variables, and/or velocity of throw. In Experiment 1 the task goal was to improve the throwing pattern. In Experiment 2 the task goal was to throw as accurately as possible at a target. The results of Experiment 1 indicated that increasing velocity was most effective for changing the throwing pattern, with external focus more effective than internal focus. The results of Experiment 2 indicated that external focus was the most accurate condition and increasing velocity was most effective for changing the throwing pattern.