步行和日常体力活动能量消耗的推算

目的:研究不同步速下行走时的能量消耗水平,进而推导出根据计步器参数推算步行能耗和一日总能耗的方程,以期为进一步开发计步器功能提供参考依据。方法:研究对象为在校大学生共计30名(男性15名,女性15名)。受试者身体右侧平肚脐锁骨中线处和腋前线交点处分别佩带计步器,在跑台上分别以3.2、4.8、6.4、8.1、9.7 km/h 5种速度步行800 m,记录计步器计数和实际步数,通过间接热量法测试步行代谢情况。佩带计步器一周,记录每日计步器计数,每日填写Bouchard体力活动日记。结论:以不低于正常步速行走时,计步器可以精确记录步数,放置位置不同对步数记录无影响。随着速度加快,步频加快,步幅加大,单位能耗增加。但在完成相同距离步行时,运动强度(速度)不同,总热量消耗不完全一致,能量消耗不仅与单位能耗有关,运动时间也是重要的因素。根据计步器参数推算步行能量消耗和一日总能量消耗的公式分别为:步行能量消耗(kca l)=0.43×身高(cm) 0.57×体重(kg) 0.26×步频(步/m in) 0.92×时间(m in)-108.44。一日能量消耗(kca l)=0.05×一日计步器计数(步) 2213.09×体表面积(m2)-1993.57。     

普通高校群体活动改革理论与实践

运用文献资料、调查访问、问卷调查、数理统计等方法,对大学生余暇时间活动现状、群体活动理念、群体活动的组织管理、体育竞赛的组织与运作和构建群体活动工作网络等方面进行研究.结果表明,大学生余暇时间活动内容呈多元化,体育锻炼被排在次要位置;高校群体活动在组织运作上应围绕四个层面展开,使群体竞赛贯穿全年,实现大学校园里人人崇尚体育,人人追求身心健康,人人关注、人人参与、人人体验、人人享受体育的目标.     

大学生体育锻炼行为动机冲突解释模型研究

目的:研究探索体育锻炼行为动机冲突解释模型.在测试人口学变量调节效应的同时,验证刻板印象和自我意识分别在该模型中的中介解释效应.方法:研究以浙江省5所高校的789名大学生为研究对象,完成动机冲突、刻板印象、自我意识及体育锻炼行为的问卷.运用分层回归分析和3步中介效应验证法进行数据统计分析.结果:1)性别和年级变量在动机冲突对体育锻炼行为的解释过程中不存在调节效应的作用;2)刻板印象变量在大学生体育锻炼行为动机冲突解释模型中,存在不完全的中介效应,其效应值占总效应值的30％,对模型的变异解释率为2％;3)自我意识的公众自我意识维度在该模型中不存在中介效应的作用.但是,个体自我意识的维度在该模型中则具有不完全的中介效应,其解释效应占模型总效应的22％,变异解释率为2.8％.结论:大学生体育锻炼行为动机冲突解释模型成立,其中;刻板印象和个体自我意识分别具有中介解释效应,它们可以影响动机冲突对体育锻炼行为的预测效果.同时,人口学变量在该解释模型中不具有调节效应的作用.     

论综合实践活动课程开发的自然维度

综合实践活动课程是基于现实世界视野对生活的探究与体验,自然世界本身成为课程.超越对自然的役用与膜拜,走向对自然的理解、欣赏与看护,是综合实践活动自然维度开发的基本原则."在自然中"的自然探究、"关于自然"的自然探究和"为了自然"的自然探究是综合实践活动自然维度开发的基本内容.此外,在开发的过程中尚须注意季节的变化、在自然探究中渗透人文精神并引导学生慎重对待探究结论.     

中美基础教育课外体育活动的比较研究

运用文献资料法、访谈法、比较分析法和逻辑法，对中美基础教育课外体育活动的价值取向、政策文件、组织管理、场地设施、运动时间及实施效果进行梳理、分析和比较，从中得出以下启示：要坚持课外体育活动健身育人的价值；学校体育政策要向课外体育活动倾斜，并注重政策的落实；构建课外体育活动的三级体系，促进家校社三方联动；加快社区体育建设，引导体育消费升级；布置体育作业，保证课外运动时间；立足实际问题，让学生从课外体育活动中受益。以邻为镜比较优劣得失，但不能生搬硬套，要从传统体育文化中吸收养分，促进青少年身心健康，促进我国课外体育活动改革与发展。     

Fatigue increases ankle sprain risk in badminton players: A biomechanical study

ABSTRACT

Ankle sprains are the most common injury in regular badminton players and usually occur at the end of a match or training. The purpose of the present study was to examine the influence of fatigue produced by badminton practice on the lower limb biomechanics of badminton players. It was hypothesized that fatigue induces ankle kinematic and lower leg muscle activity changes which may increase the risk of ankle sprain. Ankle kinematics, ankle kinetics and muscles activities of 17 regular badminton players were recorded during lateral jumps before and after an intense badminton practice session. Post-fatigue, ankle inversion at foot strike and peak ankle inversion increased (+2.6°, p = 0.003 and +2.5°, p = 0.005, respectively). EMG pre-activation within 100 ms before foot landing significantly decreased after fatigue for soleus (?23.4%, p = 0.031), gastrocnemius lateralis (?12.2%, p = 0.035), gastrocnemius medialis (?23.3%, p = 0.047) and peroneus brevis (?17.4%, p = 0.036). These results demonstrate impaired biomechanics of badminton players when fatigue increases, which may cause a greater risk of experiencing an ankle sprain injury.     

TPR技术对钒系催化剂供氧活性和数目的研究

本文报导了利用TPR技术研究钒系催化剂的供氧活性和数目,从而阐明了TPD平衡法的可靠性.     

二溴羧基偶氮胂催化光度法测定水中痕量锰

研究了在NH_3．H_2O-NH_4Cl 介质中锰催化 H_2O_2氧化二溴羧基偶氮胂褪色的最佳条件。λ_(max)=565nm，表观摩尔吸光系数为2．6×10~4 L·moL~(-1)·cm~(-1)，线性范围为0～2．1 μg/25 mL。用于水样中痕量锰的测定，结果满意。     

Mediating effects of resistance training skill competency on health-related fitness and physical activity: the ATLAS cluster randomised controlled trial

The purpose of this study was to examine the mediating effect of resistance training skill competency on percentage of body fat, muscular fitness and physical activity among a sample of adolescent boys participating in a school-based obesity prevention intervention. Participants were 361 adolescent boys taking part in the Active Teen Leaders Avoiding Screen-time (ATLAS) cluster randomised controlled trial: a school-based program targeting the health behaviours of economically disadvantaged adolescent males considered “at-risk” of obesity. Body fat percentage (bioelectrical impedance), muscular fitness (hand grip dynamometry and push-ups), physical activity (accelerometry) and resistance training skill competency were assessed at baseline and post-intervention (i.e., 8 months). Three separate multi-level mediation models were analysed to investigate the potential mediating effects of resistance training skill competency on each of the study outcomes using a product-of-coefficients test. Analyses followed the intention-to-treat principle. The intervention had a significant impact on the resistance training skill competency of the boys, and improvements in skill competency significantly mediated the effect of the intervention on percentage of body fat and the combined muscular fitness score. No significant mediated effects were found for physical activity. Improving resistance training skill competency may be an effective strategy for achieving improvements in body composition and muscular fitness in adolescent boys.     

Accelerometer data requirements for reliable estimation of habitual physical activity and sedentary time of children during the early years - a worked example following a stepped approach

This study presents a worked example of a stepped process to reliably estimate the habitual physical activity and sedentary time of a sample of young children. A total of 299 children (2.9 ± 0.6 years) were recruited. Outcome variables were daily minutes of total physical activity, sedentary time, moderate to vigorous physical activity and proportional values of each variable. In total, 282 (94%) provided 3 h of accelerometer data on ≥1 day and were included in a 6-step process: Step-1: determine minimum wear-time; Step-2: process 7-day-data; Step-3: determine the inclusion of a weekend day; Step-4: examine day-to-day variability; Step-5: calculate single day intraclass correlation (ICC) (2,1); Step-6: calculate number of days required to reach reliability. Following the process the results were, Step-1: 6 h was estimated as minimum wear-time of a standard day. Step-2: 98 (32%) children had ≥6 h wear on 7 days. Step-3: no differences were found between weekdays and weekend days (P ≥ 0.05). Step-4: no differences were found between day-to-day variability (P ≥ 0.05). Step-5: single day ICC’s (2,1) ranged from 0.48 (total physical activity and sedentary time) to 0.53 (proportion of moderate to vigorous physical activity). Step-6: to reach reliability (ICC = 0.7), 3 days were required for all outcomes. In conclusion following a 7 day wear protocol, ≥6 h on any 3 days was found to have acceptable reliability. The stepped-process offers researchers a method to derive sample-specific wear-time criterion.