Continuous walking and time- and intensity-matched interval walking: Cardiometabolic demand and post-exercise enjoyment in insufficiently active,healthy adults     

Kate Francis  Tom Williamson  Paul Kelly 《Journal of sports sciences》2021,39(1):23-30

ABSTRACT

We compared cardiometabolic demand and post-exercise enjoyment between continuous walking (CW) and time- and intensity-matched interval walking (IW) in insufficiently active adults. Sixteen individuals (13 females and three males, age 25.3 ± 11.1 years) completed one CW and one IW session lasting 30 min in a randomised-counterbalanced design. For CW, participants walked at a mean intensity of 65–70% predicted maximum heart rate (HR_max). For IW, participants alternated between 3 min at 80% HR_max and 2 min at 50% HR_max. Expired gas was measured throughout each protocol. Participants rated post-exercise enjoyment following each protocol. Mean HR and V˙O₂ showed small positive differences in IW vs. CW (2, 95%CL 0, 4 beat.min^?1; d = 0.23, 95%CL 0.06, 0.41 and 1.4, 95%CL 1.2 ml.kg^?1.min^?1, d = 0.36, 95%CL 0.05, 0.65, respectively). There was a medium positive difference in overall kcal expenditure in IW vs. CW (25, 95%CL 7 kcal, d = 0.58, 95%CL 0.33, 0.82). Post-exercise enjoyment was moderately greater following IW vs. CW (9.1, 95%CL 1.4, 16.8 AU, d = 0.62, 95%CL 0.06, 0.90), with 75% of participants reporting IW as more enjoyable. Interval walking elicits meaningfully greater energy expenditure and is more enjoyable than CW in insufficiently active, healthy adults.  相似文献   

足球比赛的负荷量化-结构、方法和特征     

缪律  史国生  黎涌明 《成都体育学院学报》2020,(2):93-99,106

足球比赛负荷是球员在比赛情景下完成各类动作所承受的物理、生理和心理等方面刺激之和。比赛负荷的量化结构分为外部和内部负荷,外部负荷的量化方法包括人工视频分析技术、自动轨迹追踪技术和全球定位设备,通过球员体能或技术表现的负荷量和强度来评定足球比赛中的行为活动特点,外部负荷特征表现为间歇性运动下频繁变向和短距离变速跑,高比例的中低强度无球跑穿插较少的高强度带球跑。内部负荷的量化方法包括耗氧量、心率和血乳酸等指标的测定,通过上述指标的变化幅度来评定足球比赛中的能量代谢水平;内部负荷特征表现为有氧供能为主、无氧磷酸原和糖酵解供能交替进行。现有研究局限为外部负荷低估了变向运动对足球比赛负荷的影响,内部负荷无法概括正式比赛的供能特征等。未来可尝试在优化量化方法基础上结合内外负荷,从而更精准地量化比赛负荷。  相似文献   

Bio-inspired untethered fully soft robots in liquid actuated by induced energy gradients     

Liang Xiong Lyu  Fen Li  Kang Wu  Pan Deng  Seung Hee Jeong  Zhigang Wu  Han Ding 《国家科学评论(英文版)》2019,6(5):970

Soft robotics with new designs, fabrication technologies and control strategies inspired by nature have been totally changing our view on robotics. To fully exploit their potential in practical applications, untethered designs are preferred in implementation. However, hindered by the limited thermal/mechanical performance of soft materials, it has been always challenging for researchers to implement untethered solutions, which generally involve rigid forms of high energy-density power sources or high energy-density processes. A number of insects in nature, such as rove beetles, can gain a burst of kinetic energy from the induced surface-energy gradient on water to return to their familiar habitats, which is generally known as Marangoni propulsion. Inspired by such a behavior, we report the agile untethered mobility of a fully soft robot in liquid based on induced energy gradients and also develop corresponding fabrication and maneuvering strategies. The robot can reach a speed of 5.5 body lengths per second, which is 7-fold more than the best reported, 0.69 (body length per second), in the previous work on untethered soft robots in liquid by far. Further controlling the robots, we demonstrate a soft-robot swarm that can approach a target simultaneously to assure a hit with high accuracy. Without employing any high energy-density power sources or processes, our robot exhibits many attractive merits, such as quietness, no mechanical wear, no thermal fatigue, invisibility and ease of robot fabrication, which may potentially impact many fields in the future.  相似文献   

Leg amputation side determines performance in curve sprinting: a case study on a Paralympic medalist     

Johannes Funken  Kai Heinrich  Steffen Willwacher  Ralf Müller  Jonas Böcker  Hiroaki Hobara 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(1):75-87

The lower limb kinetics of curve sprinting in amputees are not well described in the literature, particularly with respect to the effect of the side of amputation. This is an issue due to the importance of the knowledge for prosthetic design and classification of athletes. Thus, the aim of this study was to investigate the influence of side of amputation on curve sprinting performance in athletes with a unilateral leg amputation. A three-dimensional motion analysis system (Vicon), four force plates (Kistler) and a modified mathematical human model (ALASKA) were used to compare clockwise and counter clockwise curve sprinting lower limb kinematics and kinetics of a Paralympic medalist with a left-sided knee exarticular amputation. Results reveal that vertical ground reaction force application and total vertical impulse were lower when the affected limb was at the inside of the curve. The unaffected limb showed joint mechanics different to those established for non-amputee athletes and might contribute better to propulsion when being the inside limb. Curve sprinting biomechanics and the ability to attain high radial velocities are directly dependent on the side of amputation relative to the curve direction in a unilateral amputee athlete of highest performance level.  相似文献   

车辆工程专业实践教学系统的改革     

张雨 《中国现代教育装备》2011,(19):46-48,59

讨论了我国汽车产业要求将车辆工程专业内涵定位于新能源汽车的原因;提出了新能源汽车相比于传统内燃机汽车的特点;给出了以新能源汽车为专业内涵的车辆工程专业对其实践教学系统进行改革的思路,介绍了实施改革所做的工作内容。  相似文献   

高等学校专用基金收支与管理初探     

李绍燕 《宁德师专学报(自然科学版)》2001,13(1):47-49

阐述了高校专用基金的财务管理特点及其加强学校专用基金管理的重要性 .结合长期财务管理工作实践 ,初步探讨了高校各项专用基金收支及管理 ,并对实际操作中存在的具体问题提出处理办法  相似文献   

穆旦:"自我"聚积起新诗的能量     

肖严 《钦州学院学报》2005,20(2):18-21

穆旦诗歌充满了不同的自我的声音,展示了人类心灵最为丰富而神秘的一面.以"带电的肉体"和"丰富而且危险"的写作方式直逼当前中国诗歌中"那一团模糊不清的诗意",颠覆了现代诗歌中残留的古典性和传统性,在此之上建立的是一个独异的穆旦世界多重、分裂的现代自我,苦涩的现代感情,人与世界、人与自身之间更加暧昧而复杂的关系.  相似文献   

转型时期的农村宗族及其嬗变——以20世纪下半叶江西为中心     

戴利朝 《江西师范大学学报(哲学社会科学版)》2004,37(2):19-24

20世纪下半叶,受社会变迁、国家权力、村落场域、农民分层等多重因素的交织影响,江西农村宗族的真实面貌及其变迁深深刻上了时代的烙印,但宗族并没有消亡,而始终扎根于农民的观念深处和日常行为中。作为农民群体的一种组织和生活方式,农村宗族亦处在变革与创新之途。  相似文献   

普朗克与早期量子论     

王立  张小安  张辉 《咸阳师范学院学报》2002,17(2):40-43

回顾了量子力学发展初期的重要概念之一的能量子产生的背景及过程。探讨了普朗克大胆创新与守旧思想的主客观原因，以及普朗克对量子力学所做出的杰出贡献。  相似文献   

我国学前教育财政投入的特征与对策研究——基于国际比较的视角     

李芳  祝贺  姜勇 《教育学报》2020,(1):43-54

基于国际比较视角,回顾2006—2016年我国学前教育财政投入的发展,发现:(1)我国学前教育成本分担结构不合理,政府承担比重偏低,家庭负担沉重,社会力量发挥不足;各级政府间投入责任不明确,地区之间投入水平不够均衡。(2)学前教育投入规模不断扩大,但与OECD发达国家仍有较大差距;生均教育经费增长速度较为缓慢,支出绝对值与发达国家相差甚远。(3)经费配置中偏重资本性支出,经常性支出不足;对学前教育质量核心要素的投入不够,教师薪资待遇水平偏低。基于此,应构建“保基本、广覆盖、有质量”的普惠性学前教育公共服务体系,对策如下:一是各级政府应承担投入的主体责任,聚积社会力量,减轻家庭负担,提供“付得起”的学前教育;二是分级分类设立学前教育发展项目,直指处境不利儿童,提供“顾得广”的学前教育;三是调整经费配置结构,关注教师的薪资保障和专业发展,提升学前教育质量,提供“配得齐”的学前教育。  相似文献