高强度间歇运动可改善大鼠的心肺耐力

背景:最大摄氧量(VO2max)是评定心肺耐力及运动能力最直接有效的客观指标,但目前研究中反映大鼠较长时间最大摄氧量变化数据的文章较少,尚未见有关高强度间歇训练对大鼠增龄过程中心肺耐力持续变化影响的相关报道。目的:探讨16周高强度间歇训练对大鼠心肺耐力的改善作用,并通过对29周龄大鼠最大摄氧量持续16周测定,为实验动物训练强度的量化提供数据参考。方法:将28只29周龄雄性Wistar大鼠分为2组:安静对照组大鼠正常饮食生活,无训练;高强度间歇训练组大鼠进行高强度(90%最大摄氧量)、低强度(50%最大摄氧量)的间歇运动,为期16周,每周5次,平均每2周测定最大摄氧量、完成最大摄氧量测试对应的最大跑速变化,并针对2组大鼠最大摄氧量和最大跑速值进行对比及相关分析。实验经北京体育大学运动科学实验伦理委员会批准(2015025)。结果与结论:①29-45周龄增龄过程中最大摄氧量出现下降-上升-下降波动,16周后,高强度间歇训练组大鼠最大摄氧量下降了31.6%,安静对照组大鼠最大摄氧量下降了47.9%,高强度间歇训练组大鼠最大摄氧量显著高于安静对照组(P<0.01);②干预6,8,16周时高强度间歇训练组最大摄氧量下降幅度显著低于安静对照组(P<0.05或P<0.01);③干预4,8周时高强度间歇训练组最大跑速值显著高于安静对照组(P<0.05或P<0.01);④最大摄氧量与最大跑速的相对值呈正相关;⑤结果说明,年龄的增加是大鼠心肺耐力下降的不可逆因素,但高强度间歇训练可延缓心肺耐力下降趋势;高强度间歇训练干预6周后可明显降低大鼠因增龄导致的心肺耐力下降幅度,8周后可有效延缓大鼠因增龄导致的心肺耐力下降;高强度间歇训练干预4周后大鼠最大跑速提高,运动能力增强。     

跑节省化、最大摄氧量评价普通人有氧耐力的效果比较

背景：尽管跑节省化、最大摄氧量在评价竞技运动员耐力上的差异已有定论,但有关普通人耐力水平的评价效果至今少有研究。 目的：比较跑节省化与最大摄氧量在评价普通人群有氧耐力水平的效果。 方法：以63名入伍新兵为测试对象,测定其最大摄氧量、跑节省化和5 km跑成绩。最大摄氧量和跑节省化的测定采用逐级递增负荷运动方式在室内跑台上进行,坡度为0°。最大摄氧量的测定由8.5 km/h的速度逐渐递增,直至力竭,满足最大摄氧量判定标准为止;跑节省化的测定由8.5 km/h的速度增至11.5 km/h并持续稳定3 min,计算最后2 min摄氧量的均值作为跑节省化值。采用Pearson积差相关法分析比较5 km成绩同最大摄氧量、跑节省化之间的关系。 结果与结论：当跑节省化采用相对值表示时,5 km成绩与跑节省化值高度正相关(r=0.797,P=0.000),而与最大摄氧量呈低度负相关(r=-0.317,P=0.056)。另外,当前国民体质监测中常使用的台阶试验、室外800 m/1 000 m跑等方法受到各种因素制约。结果证实,跑节省化在评价普通人群中表达有氧耐力上优于最大摄氧量,简单易行、可靠性高,在国民体质评价中具有明显优势。     

跑鞋与着地方式对跑步损伤的影响

长跑是骨骼肌肉系统损伤发病率最高的运动健身项目之一,与跑鞋和着地方式有很大关系。在百链云图书馆和谷歌学术数据库中检索有关跑鞋和着地方式与跑步损伤关系的生物力学研究,最终选择42篇进行文献综述,发表时间为1981~2016年。跑鞋所宣称的缓冲和动作控制的作用并未得到证实,裸足跑作为更自然的跑步方式得到提倡。前脚掌着地的跑步方式对膝关节的损伤更小,但踝关节和跖骨的负荷较大;后跟着地则相反。因此,跑步者应根据自身情况选择适合的跑步方式。但转变跑步方法对跑步者下肢生物力学特征的影响尚未明确,这方面的研究会对跑步者转变跑步方式提出更好的建议。     

跑步疗法助你健康

<正>跑步时人的两腿不停地转换移动、协调配合,可以提高大脑左右半球的功能和脑细胞的反应速度及灵活性,延缓脑细胞的衰老;跑步运动可以锻炼腿部肌肉的力量及踝、膝、髋、腰等部位关节的灵活性;跑步可以增加机体的摄氧量,锻炼心肺器官的活动机能,提高人体循环系统的能力。因此,目前流行于国外的沙跑、雨跑、水跑等跑步疗法已被广泛应用。下面就向您介绍一下这几种跑步疗法:     

改变步频对无氧阈跑速下能量消耗、表面肌电和步态特征的影响

背景:长跑训练中流行的观点是通过提高步频可以提高跑步效率,这需要多方面的科学评价及研究。目的:通过比较个体无氧阈强度下自选步频与改变步频后机体的心率、摄氧量、表面肌电和步态特征的变化,探究改变步频对跑者产生的影响,为提高跑步效率提供科学策略。方法:选择12名男性马拉松跑步爱好者。在试验开始前,首先通过跑台递增负荷试验进行有氧能力测试,得到跑者的通气无氧阈及无氧阈速度。在正式试验开始后,采用随机交叉设计,在无氧阈跑速下,进行自选步频、自选步频±5%和自选步频±10%跑台测试。使用配对t检验和皮尔逊相关分析等方法对心率、摄氧量、表面肌电和步态特征等指标进行统计分析,探究改变步频后各指标的变化规律。研究方案的实施符合北京体育大学的相关伦理要求,受试者对试验过程完全知情同意。结果与结论:(1)心率和摄氧量:改变步频后,心率显著增加(P <0.01),步幅发生显著变化(P <0.01),自选步频-5%(P <0.05)和自选步频±10%(P <0.01)时摄氧量显著增加;步幅和与摄氧量呈正相关关系(r=0.57,P <0.01),步频/步幅与摄氧量呈负相关关系(r=...     

运动过程中人体“二氧化碳耐受力”与心肺耐力的关联分析

背景：最大摄氧量作为评估心肺耐力的“金标准”,根据其概念的逻辑关系,除心肺功能外,外周组织(肌肉)对氧气的利用能力应作为心肺耐力水平的关键和决定因素。心肺功能水平是人体运动过程中氧气供应的重要保证因素,但或并不能作为氧气利用的“关键因素”。目的：通过评估有氧代谢过程中人体CO₂耐受力,探究其与心肺耐力的关联。方法：在北京5所高校筛选92名健康在校大学生,经受试者知情同意,进行心肺运动试验采集CO₂耐受及心肺耐力评估指标,并进行关联分析。试验经国家体育总局体育科学研究所伦理委员会批准。结果与结论：(1)人体CO₂耐受力指标与最大摄氧量相对值和绝对值存在显著正相关(P <0.01),与身高、体质量和体质量指数存在显著正相关(P <0.01);(2)通过CO₂耐受指标构建的多元线性回归模型可准确解释及预测最大摄氧量的变化(校正R2分别为0.847,0.668,P <0.01),模型验证评价提示预测值与实测值相比差异均无显著性意义(P> 0.05);(3)有氧代谢过程中人体CO     

性别和动作对排球运动员前交叉韧带损伤危险因素的影响

目的 研究性别和动作对排球运动员前交叉韧带（anterior cruciate ligament, ACL） 损伤危险因素的影响。方法 采集排球运动员急停起跳、起跳垂直落地和急停变向跑时的运动生物力学数据,运用蒙特卡罗模拟得到运动员ACL损伤概率和损伤试跳的生物力学参数。采用2×3混合设计的双因素方差分析验证性别和动作对损伤危险因素的影响。结果 不论男女,变向跑ACL损伤危险性最大（P＜0.001）。变向跑和急停起跳时,女子比男子运动员ACL损伤危险更大（P＜0.001）。垂直落地时,男子比女子运动员更易发生损伤（P＜0.001）。排球运动员ACL损伤危险因素均受性别和动作的显著性交互作用（P＜0.001）。结论 变向跑时,男子运动员由于膝关节屈角小、小腿趋于前倾以及足跟着地而增加ACL负荷,女子运动员倾向于由于较大地面反作用力和膝关节伸展力矩而增加损伤风险。膝关节屈角小是运动员急停起跳的主要损伤因素,且男子因素更繁杂。垂直落地时,女子运动员损伤危险因素是地面反作用力、膝关节外翻和伸展力矩及足跟着地等;较小的膝关节屈角是男子运动员损伤危险因素。研究结果可为排球运动员ACL损伤风险评价、个性化损伤预防方案制定、临床与康复治疗等提供依据。     

髌股关节痛业余跑者性别特异的下肢生物力学特征

目的 研究髌股关节痛（patellofemoral pain,PFP）业余跑者性别特异的下肢生物力学特征。方法 选取15名男性和10名女性PFP业余跑者作为实验组,并匹配25名无损伤业余跑者作为对照组。采集所有受试者跑步时的下肢运动学、动力学和表面肌电数据。采用双因素方差分析确定组别与性别对跑步时下肢生物力学特征的影响。结果 男性PFP业余跑者跑步缓冲期最大膝屈角度显著大于对照组;男性和女性PFP业余跑者跑步缓冲期最大髋内收角度显著大于对照组,且女性显著大于男性。结论 不同性别PFP业余跑者在跑步时表现出不同的下肢生物力学特征,PFP临床治疗应具有性别特异性。     

肥胖症患者心肺运动试验指标特点分析

目的探讨肥胖症患者心肺运动试验指标特点,进一步明确其病理生理的变化特征,指导减重训练,预防疾病的发生和发展。方法选择昆明医科大学附属心血管病医院2020年4月至6月肥胖症患者71例(肥胖组),其中男性43例,女性28例;年龄21～71岁,平均年龄49.03岁。同期选择BMI正常者181例(非肥胖组),其中男性107例,女性74例;年龄25～79岁,平均年龄50.88岁。分析心肺运动试验检查数据,统计患者行心肺运动试验过程中的峰值负荷(Load peak)、峰值摄氧量(VO2peak)、峰值千克摄氧量(VO₂/kg)、无氧阈(AT)、峰值摄氧量占预计值的百分比(VO2peak/pre)、峰值代谢当量(Mets peak)、无氧阈时的代谢当量(Mets@AT)、心率储备(HRR)、呼吸储备(BR)、静息心率(HRrest)、最大心率(HRmax)、最大心率占预计值的百分比(HRmax/pre)、1 min心率恢复(HRR-1 min)、最大氧脉搏(VO2/HRmax)、氧脉搏占预计值的百分比、氧通气当量(VE/VO2)、二氧化碳通气当量(VE/VCO2)的值。结果心肺...     

国产功率自行车心肺功能测评的研究

目的研究国产功率自行车进行心肺耐力测评的有效性。方法选择普通大学生18例作为受试者,其中男性12例,女性6例。男性年龄19.55~21.39岁,平均年龄20.25岁;身高167.00~184.00 cm,平均身高175.42 cm;体质量62.30~77.80 kg,平均体质量72.15 kg;体质量指数18.40~25.28,平均体质量指数23.49。女性年龄19.64~21.96岁,平均年龄20.77岁;身高156.00~167.00 cm,平均身高162.00 cm;体质量52.00~65.70 kg,平均体质量53.83 kg;体质量指数17.67~23.56,平均体质量指数20.44。记录静息状态的心率、血乳酸、血压及静息代谢率等指标,利用主成分分析法和回归方程对静息状态体适能进行综合评价。采用50 W/3 min负荷递增,以50 r/min的骑车节律进行实验室最大摄氧量值测试。评判指标和标准包括:最大心率≥180次/分,血乳酸浓度≥8 mmol/L,运动自觉量表(RPE)等级为19~20,测试时间≥9~12 min,最大摄氧量平台。利用PWC170法、Astrand法和YMCA法,进行最大摄氧量的间接测试。结果得到受试者静息身体状况的综合评价值F,并进行了分组,第Ⅰ组,F0,代表男性身体素质较高或者静止时身体状态较佳的一组;第Ⅱ组,F0,代表身体情况欠佳的一组;第Ⅲ组为女性。直接测试法获得的最大摄氧量值,每一位受试者的5个评价指标中至少3个指标均合格,数据有效,且第Ⅰ组受试者的有氧能力评价整体高于第Ⅱ组受试者的有氧能力;说明受试者静息身体状况综合评价指标高,有氧能力也相对较高。最大摄氧量的实测值分别为(41.64±9.99)、(31.93±3.20)mL/(kg·min),属于有氧能力评价中的中档和低档。直接测试法数据与间接测试法中的YMCA法最为接近,贴合度最高;Astrand法估测的最大摄氧量值与实测值相比,差别较大;PWC170法用运动员和普通人来分别预测,存在不灵活性,使预测值偏大或偏小。结论利用此国产功率自行车,进行普通大学生心肺功能数据的直接测试和间接预测,方法合理,得出的数据规律与其他文献表述一致,基本有效,对于此国产功率自行车精确度的验证起到了一定的作用。     

Knee biomechanical factors associated with patellofemoral pain in recreational runners

BackgroundPatellofemoral pain (PFP) is a common injury among runners. Knee biomechanical factors associated with PFP, however, remain unclear. The purpose of this study was to determine possible associations between knee biomechanics and symptoms of PFP in recreational runners.MethodsFifteen male and 15 female recreational runners with PFP were enrolled as the PFP group, 30 matched runners without PFP were recruited as the control group. The PFP group was tested running with and without knee pain, while the control group had only one running test. Reflective marker coordinates and ground reaction force data were collected in each test. Knee kinematics and kinetics during running were reduced and compared between groups (PFP group without knee pain and control group) and between pain conditions (PFP group with knee pain and without knee pain), as well as between sexes.ResultsFemale and male participants with PFP had an increased peak knee valgus angle when running without pain compared to matched controls (P = 0.001), and to themselves when running with pain (P = 0.001). Male participants with PFP also had an increased peak knee flexion angle when running without pain compared to matched controls (P = 0.008), however did not decrease their peak knee flexion angle when running with pain (P = 0.245). No significant main effect of group or pain condition on any peak knee joint moment during running was detected (P ≥ 0.175).ConclusionsIncreased peak knee valgus angle during running appears to be a critical biomechanical factor associated with PFP in recreational runners, while decreasing knee valgus angle during running may be an adaptation to reduce symptoms of PFP. Increased peak knee flexion angle during running appears to be another biomechanical factor associated with PFP that is sex specific for male recreational runners.     

Aftereffects from jogging

After running on a treadmill, runners who attempted to jog in place on solid ground inadvertently jogged forwards. One-legged hopping on the treadmill produced an aftereffect in the same leg, but not in the other leg. This non-transfer suggests a peripheral neural site. Judgments of velocity and slope were affected; running on a backward-moving treadmill made a stationary test treadmill seem to move forwards, and running on an uphill-sloping treadmill made a horizontal test treadmill seem to slope downhill. These aftereffects suggest an automatic gain control process.     

不同地面对跑步下肢运动生物力学的影响

诸多因素会影响跑步运动损伤的发生,其中内在因素包括人体解剖学因素、受伤史、下肢运动生物力学和运动中的神经肌肉控制等,外在因素包括训练方法、跑步鞋、跑步路面等。跑步路面被认为是造成跑步运动损伤发生的重要潜在风险因素之一。总结不同地面对跑步下肢运动学、动力学、神经肌肉调控、运动损伤方面的影响,发现在不同地面跑步时,人体可能通过自身的神经肌肉调节功能进行运动学调整以获得动力学适应,调节下肢刚度以获得相似的冲击负荷。但是目前关于在不同路面上跑步的生物力学变化,多数研究只关注于运动学、动力学和神经肌肉调控中的某一方面,缺乏更进一步具体的三维运动生物力学数据,以及针对这种生物力学调整的具体神经肌肉调控机制。     

基于统计参数映射分析跑鞋跟掌落差对下肢关节负荷的影响

目的 探讨在相同跑速下穿着不同落差跑鞋对下肢关节负荷的影响,为跑鞋设计和跑步者选购跑鞋提供依据。方法 18名男性跑步者分别穿着零落差和10 mm落差跑鞋以(4.0±0.2) m/s速度完成测试,使用红外高速运动捕捉系统和三维测力台同步采集下肢运动学参数和地面反作用力(ground reaction force, GRF)。使用统计参数映射法(statistical parameter mapping, SPM)分析跑鞋跟掌落差对支撑期垂直GRF、下肢关节三维力矩的影响。结果 跑鞋跟掌落差对垂直GRF无影响,对下肢关节部分力矩-时间序列影响显著。与穿着零落差跑鞋相比,穿着10 mm落差跑鞋在27%～38%支撑期髋关节内旋力矩增加,在47%～75%支撑期膝关节伸展力矩增加,在16%～33%、25%～30%、12%～25%支撑期踝关节跖屈力矩、外翻力矩和外旋力矩降低。结论 与穿着零落差跑鞋相比,穿着10 mm落差跑鞋在支撑前期髋关节负荷增加,踝关节负荷降低,在支撑中期膝关节负荷增加。建议跑步者结合自身特点及跑鞋跟掌落差对下肢关节负荷特征的影响,选择适合自己的跑鞋。     

基于一维统计参数映射分析跑者跑步地面反作用力差异

目的通过一维统计参数映射(statistical parametric mapping,SPM)对比分析男、女性跑者及左右侧地面反作用力(ground reaction force,GRF)差异。方法 30名男、女性跑者在测力跑台上以12 km/h速度进行跑步测试,记录连续5个支撑期GRF,采用一维统计参数映射独立样本t检验与配对样本t检验分别对比男、女性跑者及左右侧GRF差异。结果男、女性跑者的垂直平均负荷加载率(vertical average loading rate,VALR)左右侧均存在不对称,且男性跑者左侧VALR显著高于女性,而右侧无显著差异;男女性跑者右侧垂直GRF在蹬离期及横向GRF在落地期存在差异,男、女性跑者左侧横向GRF在落地期及支撑中期存在差异;男性跑者左右侧前后GRF在蹬离期、垂直GRF在落地和蹬离期及横向GRF在落地期均在存在差异;女性跑者左右侧GRF仅在垂直方向的落地期和蹬离期存在差异。结论介绍SPM在GRF数据分析中的应用,阐释相关步骤及原理,对比SPM连续值检验与特征值检验的差异,并讨论参数性SPM与非参数性SPM的差异与特征,为该方法在运动生物力学研究中的应用提供参考。通过对男、女性跑者间及左右侧GRF对比分析发现在落地期、支撑中期及蹬离期等阶段的性别差异及左右侧对称性差异,相关结果为后续进一步探究跑步相关损伤原理及防治措施铺垫基础。     

A Contemporary Approach to Patellofemoral Pain in Runners

Patellofemoral pain (PFP) is among the most common injuries in recreational runners. Current evidence does not identify alignment, muscle weakness, and patellar maltracking or a combination of these as causes of PFP. Rather than solely investigating biomechanics, we suggest a holistic approach to address the causes of PFP. Both external loads, such as changes in training parameters and biomechanics, and internal loads, such as sleep and psychological stress, should be considered. As for the management of runners with PFP, recent research suggested that various interventions can be considered to help symptoms, even if these interventions target biomechanical factors that may not have caused the injury in the first place. In this Current Concepts article, we describe how the latest evidence on education about training modifications, strengthening exercises, gait and footwear modifications, and psychosocial factors can be applied when treating runners with PFP. The importance of maintaining relative homeostasis between load and capacity will be emphasized. Recommendations for temporary or longer-term interventions will be discussed. A holistic, evidence-based approach should consist of a graded exposure to load, including movement, exercise, and running, while considering the capacity of the individual, including sleep and psychosocial factors. Cost, accessibility, and the personal preferences of patients should also be considered.     

Preferred and optimal stride frequency,stiffness and economy: changes with fatigue during a 1-h high-intensity run

Metabolic cost of submaximal running at constant speed is influenced by various factors including fatigue and kinematic characteristics. Metabolic costs typically drift upwards during extended running while stride characteristics often shift away from initial. When non-fatigued, experienced runners naturally optimize stride frequency in a manner that minimizes oxygen uptake. An initial objective was to determine whether runners demonstrate a similar self-optimizing capability when fatigued where stride characteristics have perhaps shifted away from the initial state. A secondary objective involved measurement of vertical and leg stiffness characteristics as a potential explanation for frequency changes with fatigue. We hypothesized that runners decrease stride frequency and stiffness with fatigue while optimizing these characteristics to minimize metabolic cost. Sixteen experienced runners completed a near maximal effort 1-h treadmill run at a constant speed. Preferred and optimal stride frequencies (PSF and OSF) were measured near the beginning and end of the hour run using frequencies ±4 and ±8% around PSF. From vertical force data recorded throughout the run, leg and vertical stiffness were determined. As expected, oxygen uptake significantly increased during the run from 45.9 to 47.4 ml kg⁻¹ min⁻¹ (P = 0.004). There was no difference between preferred and optimal stride frequencies at the beginning or the end of running (P = 0.978), however both PSF and OSF significantly decreased from 1.45 to 1.43 Hz (P = 0.026). All runners self-optimized stride frequency at the beginning and end of one-hour of running despite changes of optimal stride frequency. Stiffness and stride frequency changes were subject specific with some runners exhibiting little to no change. No clear relationship of frequency or stiffness changes to economy was found.     

Patellofemoral joint stress during running in females with and without patellofemoral pain

Patellofemoral pain (PFP) is a common complaint among female runners. The etiology for PFP is frequently associated with increased patellofemoral joint stress (PFJS) and altered hip and knee joint kinematics during running. However, whether PFJS during running is increased among runners with PFP is unknown. The primary aim of this study was to compare PFJS during running among females with and without PFP. We also compared hip and knee transverse plane kinematics during running due to their potential influence on patellofemoral contact area and PFJS. Three dimensional hip and knee running kinematics and kinetics were obtained from 20 females with PFP and 20 females with no pain. Patellofemoral joint stress during running was estimated using patellofemoral contact area and a sagittal plane patellofemoral joint model previously described. Patellofemoral joint stress, PFJS-time integral, and hip and knee transverse plane kinematics at the time of impact peak and peak ground reaction force were compared between groups using a multivariate analysis of variance. The results show that peak PFJS and PFJS-time integral were similar between groups. Peak knee flexion angle and net knee extension moment were not different between groups. However, females with PFP demonstrated hip internal rotation that was 6° greater (P=0.04) when ground reaction forces were greatest. The extent these results are influenced by compensations for pain is unclear. However, if increased PFJS contributes to the etiology or exacerbation of PFP, interventions to minimize altered transverse plane hip kinematics may be indicated among runners who demonstrate this characteristic.     

The effect of plyometric training on distance running performance

Previous research has reported that plyometric training improves running economy (RE) and ultimately distance-running performance, although the exact mechanism by which this occurs remains unclear. This study examined whether changes in running performance resulting from plyometric training were related to alterations in lower leg musculotendinous stiffness (MTS). Seventeen male runners were pre- and post-tested for lower leg MTS, maximum isometric force, rate of force development, 5-bound distance test (5BT), counter movement jump (CMJ) height , RE, V˙O_2max, lactate threshold (Th_la), and 3-km time. Subjects were randomly split into an experimental (E) group which completed 6 weeks of plyometric training in conjunction with their normal running training, and a control (C) group which trained as normal. Following the training period, the E group significantly improved 3-km performance (2.7%) and RE at each of the tested velocities, while no changes in V˙O_2max or Th_la were recorded. CMJ height, 5BT, and MTS also increased significantly. No significant changes were observed in any measures for the C group. The results clearly demonstrated that a 6-week plyometric programme led to improvements in 3-km running performance. It is postulated that the increase in MTS resulted in improved RE. We speculate that the improved RE led to changes in 3-km running performance, as there were no corresponding alterations in V˙O_2max or Th_la. Electronic Publication