Senior men’s pacing profiles at the IAAF World Cross Country Championships

Abstract

The aim of this study was to describe pacing profiles used by senior men competing in the World Cross Country Championships. Lap times were collated for 1273 competitors across 10 races. Each individual’s lap times were expressed as a percentage of the eventual winner’s lap times, and athletes were grouped according to finishing position. Most athletes started the race by following the pace set by the leaders but slowed relative to the winner with each successive lap. The gold medallists were faster than the other medallists only after the final lap (P < 0.001). Most athletes who dropped out (61%) had completed the first lap within 105% of the winner’s lap time. The medallists used a strategy of running close to the front from an early stage, but did not separate themselves from other top 15 finishers until halfway, with the eventual medal positions decided even closer to the finish. Athletes finishing further down had positive pacing profiles relative to the winner, possibly because of early fatigue caused by a relatively quick first lap. Athletes should note that a patient approach during the early stages can benefit not only the mass field but also those who aim to win a medal.     

Relationships between highly skilled golfers’ clubhead velocity and force producing capabilities during vertical jumps and an isometric mid-thigh pull

Whilst previous research has highlighted significant relationships between golfers’ clubhead velocity (CHV) and their vertical jump height and maximum strength, these field-based protocols were unable to measure the actual vertical ground reaction force (vGRF) variables that may correlate to performance. The aim of this study was to investigate relationships between isometric mid-thigh pull (IMTP), countermovement jump (CMJ), squat jump (SJ) and drop jump (DJ) vGRF variables and CHV in highly skilled golfers. Twenty-seven male category 1 golfers performed IMTP, CMJ, SJ and DJ on a dual force platform. The vertical jumps were used to measure positive impulse during different stretch-shortening cycle velocities, with the IMTP assessing peak force (PF) and rate of force development (RFD). Clubhead velocity was measured using a TrackMan launch monitor at a golf driving range. Pearsons correlation coefficient analyses revealed significant relationships between peak CHV and CMJ positive impulse (r = 0.788, p < 0.001), SJ positive impulse (r = 0.692; p < 0.001), DJ positive impulse (r = 0.561, p < 0.01), PF (r = 0.482, p < 0.01), RFD from 0–150 ms (r = 0.343, p < 0.05) and RFD from 0–200 ms (r = 0.398, p < 0.05). The findings from this investigation indicate strong relationships between vertical ground reaction force variables and clubhead velocity.     

Mood state monitoring of training and recovery in elite kayakers

Abstract

Eleven elite kayakers performed an identical weekly training schedule each week during a 3-week training-camp. The Profile of Mood States (POMS) inventory (“right now” instructions) was completed before and after selected workouts each week to assess both training-induced mood disturbances and the extent of recovery following short and long rest. The ratio of POMS vigour to POMS fatigue scores was used as an “energy index”. Energy index scores were compared with ratings of perceived exertion (RPE) to address the size of the training load. Performance measures were obtained during the first and last week. The results showed that the energy index decreased (p<0.01) throughout the camp and did not return to initial values following either the short (one night) or long rest (two nights and one day). Performance measures and RPE remained unaffected throughout training, as did the POMS depression scores, indicating that the athletes experienced an overreached state but did not develop staleness. Our results suggest that repeated evaluation using POMS fatigue, vigour, and depression scores during periods of intensified training may help prevent athletes from becoming severely overreached and reduce the likelihood of staleness.     

An elite endurance athlete's recovery from underperformance aided by a multidisciplinary sport science support team

Abstract

Overload training resulting in an overreached state is common in elite sports, and if undetected can develop into an overtraining syndrome. This risk is accentuated by the lack of reliable measures of overreaching. Coaches and scientists therefore have to use a combination of tests in the monitoring process. This article presents a case study of the recovery from underperformance of a young elite endurance athlete and the work of a multidisciplinary sport science support team. When it was determined that the athlete's performance had deteriorated, and that this was due solely to the stress of training, training load was radically reduced for a period of 14 days. A combination of physiological, biochemical, and psychological measurements were then used to monitor the recovery process. The purpose of this article is to describe how coaches and sport science teams can help in monitoring training and recovery in practical settings, allowing detection of the early signs of overreaching before a more serious overtraining syndrome develops.     

Effects of Altered Stride Lengths on Ratings of Perceived Exertion during Running

Abstract

The purpose of this study was to determine the effects of stride length variations on ratings of perceived exertion (RPEs) in experienced recreational runners. Twenty-eight male college students were randomly divided into equal-sized treatment and control groups. The treatment group performed five 15 min altered stride length runs, each separated by a minimum of 48 hr. The five trials involved running with a freely chosen stride length (FCSL) and a FCSL altered by +14%, +7%, ?14%, and ?7%. The control group was utilized to monitor changes in subjects' RPEs as a result of practice effects developed through repeated bouts of treadmill running. Results revealed that the treatment group's local and general RPEs for the over striding runs (+14%, +7%) were significantly greater (p < .01) than RPEs recorded during the FCSL run. Additionally, there was a marginally significant difference (p < .05) in local RPEs between the FCSL run and the extreme understriding run (?14%). Analysis of variance on the control group's RPE data suggests that neither local nor general RPEs changed significantly in repeated FCSL runs across the six-week testing period. The results of this study suggest that experienced recreational runners perceive differences in exertion accompanying changes in stride length.     

Acute effects of whole-body vibrations on balance,maximal force and perceived exertion: Vertical platform versus oscillating platform

Abstract

To investigate the effects of acute whole body vibration (WBV) intervention on body balance, neuromuscular performance and perceived exertion two types of vibration platforms were compared: vertical platform (VP) and oscillating platform (OP). Forty-four healthy college students (35 men and nine women) were exposed on different days to two types of WBV platforms (VP and OP). Electromyography activity (EMG) of six muscle groups was recorded while standing in squat position on the vibrating platform during five 1-min sets. Balance, maximal voluntary isometric contraction (MVIC), and rating of perceived exertion (RPE) were recorded immediately after the WBV exposure. The OP protocol induced a significantly higher change in balance than VP protocol, as shown by variations in displacement area of the centre of pressure (+25.5% versus –5.5% for OP and VP, respectively). Moreover, RPE scores were significantly higher during OP than VP (+13.2%; P<0.05). No changes were observed concerning MVIC. WBV exposure induces changes in static body balance, these changes being larger when the vibratory stimulus is provided by an OP in comparison to a VP. Moreover, the perceptual response is higher with the OP. Aspects related to direction of vibration or amplitude could explain this acute effect.     

Experimenter Effects in Exercise Tolerance Testing: The Race and Gender of the Tester and the Tester/Subject Relationship

Abstract

Two studies examined the effects of the experimenter on heart rate (HR), rating of perceived exertion (RPE), and time to voluntary exhaustion on a graded treadmill test in college students. The first study determined the effects of the gender and race of the tester on black and white subjects of both sexes. Four testers (black female—BFT, white female—WFT, black male—BMT, and white male—WMT) tested 5 subjects of each gender and race. Differences based on gender and race were determined by a 2 × 2 × 2 × 2 ANOVA. The second study dealt with the tester/subject relationship. One tester tested 20 subjects. Ten were his friends (5 males, 5 females) and 10 (5 males, 5 females) did not know him. Differences were determined by 2 × 2 ANOVA. In both studies, the female subjects had poorer performance than the males. HR during moderate and heavy exercise was not affected by the race and gender of the tester or the tester/subject relationship. For time to exhaustion, white female subjects (WFS) exercised longer when being tested by a female but black female subjects (BFS) had a longer total time with male testers. Significant interactions occurred for HR at rest and at various times during light work for both studies. There were also significant interactions for RPE at various stages of light, moderate and heavy exercise for both studies. For subjects unaccustomed to exercise testing, it appears that the effects of the race and gender of the tester and the tester/subject relationship predominate at rest and during light work. Fewer effects are observed during moderate and heavy work. Many of the results in these studies are consistent with societal roles and expectations for males and females, blacks and whites. A consistent testing environment can minimize the influence of extrinsic testing variables.     

大运动量训练时自由式摔跤运动员应激激素变化的探讨

观察了大运动量训练期8名自由式摔跤运动员应激激素、焦虑水平及主观强度感的变化。研究过程中,每周安排11次大运动量训练,共进行2次实验,每次3个取样点(运动前、即刻和次日晨)。结果显示,两次取样时期次日晨ACTH水平较运动后即刻明显降低;C水平在第二次取样运动后即刻水平和次日晨水平明显高于运动前的,并且该时期运动后即刻C水平也明显高于第一次取样时期运动后即刻水平;E水平在第二次取样运动后即刻水平明显高于第一次取样运动后即刻的,且次日晨该激素水平也明显高于第一次取样次日晨的;血浆β-END水平在第二次取样运动后即刻水平明显高于运动前,也高于第一次取样运动后即刻,第二次取样次日晨该激素水平均低于运动前和运动后即刻水平,同时低于第一次取样次日晨的;血清NE水平变化与β-END水平变化类似;而RPE等级和焦虑水平在两次测试中呈现出运动后即刻水平高于运动前和次日晨的趋势,但不明显;RPE等级与诸多应激激素之间存在着弱相关关系。这预示着,在运动员身体机能评定工作中欲采用简单易行的显示身体机能的外部指标来表现不易测到的内部变化还需努力。     

主观用力感觉在预测心脏康复适宜运动度中的作用

目的:探讨主观用力感觉(RPE)在预测急性期后心梗患者(PMIP)对运动的生理和临床反应中的作用,这将有利于适宜运动强度的制定。方法:46名服用β阻断剂的男性PMIP(年龄60.9±7.5岁)5,5名未服用β阻断剂的男性PMIP(年龄63.6±7.3岁)在活动跑台上进行递增负荷实验,终止实验的标准依美国运动医学会的指南(ACSM)或病人的主观要求。运动中每30 s测量一次摄氧量(VO2)和通气量(VE)、每3 min记录一次心率(HR),血乳酸(BL)和主观用力感觉(RPE),并连续监测12导心电图。结果:两组病人在VO2,BL,VE和ST段降低与RPE的关系方面无显著差异(P>0.05)。然而,在运动实验过程中,两组病人在心率方面有显著差异(P<0.01)。无论是服用还是未服用β阻断剂的PMIP,RPE达到13都是其运动中有氧代谢向无氧代谢过渡的转折点。结论:基于以上结果,建议PMIP在运动心脏康复中感觉到\"稍费力\"时即不应再加大运动强度。     

Effect of fatigue on reaction time,response time,performance time,and kick impact in taekwondo roundhouse kick

Reaction time and response time are considered important abilities and can potentially affect combat performance. This study investigated the effect of a specific fatigue protocol on reaction time, response time, performance time, and kick impact. Seven male athletes reported to the laboratory on two different days. During day one, athletes performed a specific progressive taekwondo test, and on day two, a protocol for determining reaction time, response time, performance time, and kick impact before and after a time to exhaustion test at an intensity level corresponding to the maximal kick frequency obtained during the specific progressive taekwondo test. Muscle activation from rectus femoris and kick impact of the preferred limb were assessed. No differences were observed for response time and performance time. However, kick impact decreased (43 ± 27 to 13 ± 10 g, p < 0.01) while reaction time increased (145 ± 51 to 223 ± 133 ms, p < 0.05). Moderate correlation was observed between kick impact and response time (r = 0.565; p < 0.01), and kick impact and performance time (r = 0.494; p < 0.05). Results indicate that coaches and athletes may use taekwondo training programmes on coordination-based exercises leading to improve response time and to reduce fatigue effects in order to improve technique effectiveness and enhance the possibilities of scoring in a competitive situation.     

sRPE监控优秀越野滑雪运动员训练负荷的应用研究

目的:基于我国某越野滑雪专业队伍连续观测累积的主客观负荷数据,检验sRPE表征不同类型(强度及持续时长)训练课负荷的可靠性并探讨其训练应用。方法:以我国某越野滑雪国家集训队10名一级以上水平运动员为实验对象,分别采集273节不同类型训练课的强度、时长、运动员sRPE和教练员的sRPE推测值(C-sRPE),采用回归分析等统计学方法进行数据分析。结果:(1)sRPE与TRIMP之间相关性显著(r=0.68,P<0.001),其中LIT组sRPE与TRIMP呈强相关(r=0.70,P<0.001),MIT与HIT组sRPE与TRIMP呈中等程度相关(r=0.46、r=0.31,P<0.001);(2)在LIT组三种不同时间长度样本中(0~60 min、60~120 min和120~180 min),sRPE与TRIMP均有较强的相关关系且差异较小,(r=0.70、r=0.67、r=0.69,P<0.001);(3)不同强度训练的sRPE与C-sRPE皆有非常显著的相关性(P<0.001),且配对样本T检验不具有显著差异(P<0.05);(4)C-sRPE和sRPE的差值与训练强度之间有显著的正相关关系(P<0.05)。结论与建议: sRPE表征耐力训练课负荷可靠,用于LIT训练课最优。在sRPE与TRIMP的换算关系方面,LIT的持续时间不会影响换算关系,但HIT训练课的换算关系与其他强度有差异。教练员对运动员的sRPE估计准确,但对LIT和HIT的估计有相反的偏差。建议将测量教练员C-sRPE的流程融入队伍的管理机制中,用于校准教练员对运动员主观负荷的判断,此外谨慎使用sRPE记录高强度训练课负荷。