Altitude and wind effects on long jump performance with particular reference to the world record established by Bob Beamon

An analysis of long jump performance, including both the approach and aerial phases, is applied to Bob Beamon's legendary leap at the Mexico City Olympic Games of 1968. It is shown that the combined effects of altitude and wind assistance yielded an increment in the length of the jump of about 31 cm, compared to a corresponding jump at sea level under still air conditions. The main factor is shown to be the increased sprinting speed attained under favourable conditions of wind and altitude.     

The effects of wind and altitude in the 400-m sprint

In this paper I use a mathematical model to simulate the effect of wind and altitude on men's and women's 4400-m race performances. Both wind speed and direction were altered to calculate the effect on the velocity profile and the final time of the sprinter. The simulation shows that for a constant wind velocity, changing the wind direction can produce a large variation in the race time and velocity profile. A wind of velocity 2 m x s(-1) is generally a disadvantage to the 400-m runner but this is not so for all wind directions. Constant winds blowing from some directions can provide favourable conditions for the one-lap runner. Differences between the running lanes can be reduced or exaggerated depending on the wind direction. For example, a wind blowing behind the runner in the back straight increases the advantage of lane 8 over lane 1. Wind conditions can change the velocity profile and in some circumstances produce a maximum velocity much later than is evident in windless conditions. Lower air density at altitude produces a time advantage of around 0.06 s for men (0.07 s for women) for each 500-m increase in elevation.     

The effects of wind and altitude in the 400-m sprint

In this paper I use a mathematical model to simulate the effect of wind and altitude on men's and women's 400-m race performances. Both wind speed and direction were altered to calculate the effect on the velocity profile and the final time of the sprinter. The simulation shows that for a constant wind velocity, changing the wind direction can produce a large variation in the race time and velocity profile. A wind of velocity 2 m?·?s^?1 is generally a disadvantage to the 400-m runner but this is not so for all wind directions. Constant winds blowing from some directions can provide favourable conditions for the one-lap runner. Differences between the running lanes can be reduced or exaggerated depending on the wind direction. For example, a wind blowing behind the runner in the back straight increases the advantage of lane 8 over lane 1. Wind conditions can change the velocity profile and in some circumstances produce a maximum velocity much later than is evident in windless conditions. Lower air density at altitude produces a time advantage of around 0.06 s for men (0.07 s for women) for each 500-m increase in elevation.     

Data-driven quantification of the effect of wind on athletics performance

So far, the relationship between wind and athletics performance has been studied mainly for 100 m sprint, based on simulation of biomechanical models, requiring several assumptions. In this study, this relationship is quantified empirically for all five horizontal jump and sprint events where wind is measured, with freely available competition results. After systematic scraping several elite and sub-elite results sites, the obtained results (n?=?150,169) were filtered and matched to athletes. A quadratic mixed effects model with athlete and season as random effects was applied to express the influence of wind velocity on performance in each event. Whether this effect differs with performance level was investigated by applying the model on subgroups based on performance level. In the fitted quadratic model, the linear coefficients were significant (p?p?p?=?.138). A 2.0?m?s^?1 tail wind provides an average advantage of 0.125, 0.140 and 0.146?s for the 100, 200 and 100/110 m hurdles, respectively, and an advantage of 0.058 and 0.102 m for long jump and triple jump, respectively. Performance level had a significant effect on the wind influence only for 100 m (p??1 tail wind than elite athletes (～10?s). Practical formulas are presented for each event. These can easily be used correct results for wind speed, allowing better talent scouting and championship selection. This study demonstrates the efficacy of answering scientific questions empirically, through freely available data.     

Enhanced jump performance when providing augmented feedback compared to an external or internal focus of attention

Factors such as an external focus of attention (EF) and augmented feedback (AF) have been shown to improve performance. However, the efficacy of providing AF to enhance motor performance has never been compared with the effects of an EF or an internal focus of attention (IF). Therefore, the aim of the present study was to identify which of the three conditions (AF, EF or IF) leads to the highest performance in a countermovement jump (CMJ). Nineteen volunteers performed 12 series of 8 maximum CMJs. Changes in jump height between conditions and within the series were analysed. Jump heights differed between conditions (P < 0.001), resulting in best performance with AF (32.04 ± 7.11 cm), followed by EF (31.21 ± 6.67 cm) and IF (30.77 ± 6.87 cm). Significantly different (P < 0.001) within-series effects of higher jump heights at the end of the series in AF (+1.60%) and lower jump heights at the end of the series in EF (?1.79%) and IF (?1.68%) were observed. Muscle activity did not differ between conditions. The differences between conditions and within the series provide evidence that AF leads to higher performance and better progression within one series than EF and IF. Consequently, AF seems to outperform EF and IF when maximising jump height.     

模拟4800m低氧环境训练的适应效果研究

目的:对20名平原受试者进行为期3周递增性低氧训练,测试其低氧训练前后模拟海拔4 800m(PO2为10.4%～10.8%)时血清抗利尿激素(AVP)和醛固酮(ALD)的变化,并结合AMS评分、心率和血压,探讨递增性低氧训练对模拟高海拔低氧环境的适应效果。方法:阶段1:受试者于模拟海拔4 800m低氧环境中急性暴露6 h,以60rpm、80 W的定量负荷仰卧蹬车20 min,LLS量表评价AMS,测试低氧暴露过程中的HR和BP,低氧结束时的血清AVP和ALD;阶段2:进行3周递增性低氧训练后,再重复阶段1的测试。结果:低训后模拟海拔4 800m低氧环境下,AMS评分大于等于3分的人数由9人降到2人;运动时的心率明显低于低训前;急性低氧暴露6h,血清AVP和ALD均较常氧值显著下降;低训3周后再次低氧暴露,血清AVP和ALD与常氧值相比较,均无显著差异。结论:递增性低氧训练有助于增强机体对低氧的习服。     

Mood responses to athletic performance in extreme environments

Competition at elite level can require athletes to perform optimally in extreme environmental conditions. This review focuses on mood responses in such conditions and proposes practical guidelines for those working with athletes. Different environments are considered, including altitude and extreme heat and cold. Performing in extreme heat, cold or at altitude can produce a stress response characterized by increased negative mood and relatively poor performance. Positive adaptations to extreme conditions can be accelerated, but the rate of adaptation appears to be highly individualized. Monitoring mood responses to training under normal conditions provides a basis for identifying the psychological effects of extreme conditions. It is suggested that practitioners carefully monitor the interplay between vigour, fatigue and depressed mood. Reductions in vigour and increases in fatigue are normal responses to hard training, but other aspects of mood disturbance, especially symptoms of depressed mood - however small - may be indicative of a maladaptive response, and practitioners should consider intervening when such symptoms first appear.     

Mood responses to athletic performance in extreme environments

Competition at elite level can require athletes to perform optimally in extreme environmental conditions. This review focuses on mood responses in such conditions and proposes practical guidelines for those working with athletes. Different environments are considered, including altitude and extreme heat and cold. Performing in extreme heat, cold or at altitude can produce a stress response characterized by increased negative mood and relatively poor performance. Positive adaptations to extreme conditions can be accelerated, but the rate of adaptation appears to be highly individualized. Monitoring mood responses to training under normal conditions provides a basis for identifying the psychological effects of extreme conditions. It is suggested that practitioners carefully monitor the interplay between vigour, fatigue and depressed mood. Reductions in vigour and increases in fatigue are normal responses to hard training, but other aspects of mood disturbance, especially symptoms of depressed mood--however small--may be indicative of a maladaptive response, and practitioners should consider intervening when such symptoms first appear.     

The effect of exercise-induced muscle damage on isometric and dynamic knee extensor strength and vertical jump performance

In this study, we assessed the effect of exercise-induced muscle damage on knee extensor muscle strength during isometric, concentric and eccentric actions at 1.57 rad · s -1 and vertical jump performance under conditions of squat jump, countermovement jump and drop jump. The eight participants (5 males, 3 females) were aged 29.5 - 7.1 years (mean - s ). These variables, together with plasma creatine kinase (CK), were measured before, 1 h after and 1, 2, 3, 4 and 7 days after a bout of muscle damaging exercise: 100 barbell squats (10 sets 2 10 repetitions at 70% body mass load). Strength was reduced for 4 days ( P ? 0.05) but no significant differences ( P > 0.05) were apparent in the magnitude or rate of recovery of strength between isometric, concentric and eccentric muscle actions. The overall decline in vertical jump performance was dependent on jump method: squat jump performance was affected to a greater extent than countermovement (91.6 - 1.1% vs 95.2 - 1.3% of pre-exercise values, P ? 0.05) and drop jump (95.2 - 1.4%, P ? 0.05) performance. Creatine kinase was elevated ( P ? 0.05) above baseline 1 h after exercise, peaked on day 1 and remained significantly elevated on days 2 and 3. Strength loss after exercise-induced muscle damage was independent of the muscle action being performed. However, the impairment of muscle function was attenuated when the stretch-shortening cycle was used in vertical jumping performance.     

对我国跳高项目制胜因素的分析

运用文献资料调研、比较分析和逻辑归纳等方法，通过对我国男女跳高项目的训练特点进行归纳分析，认为：对原有项目特征的突破性认识，继而在训练方法、手段上不断创新，是我国男女跳高项目一度崛起的重要因素；在特定的历史条件下，有创新则兴，无创新则衰是我国男女跳高项目发展的客观规律。     

The effect of exercise-induced muscle damage on isometric and dynamic knee extensor strength and vertical jump performance

In this study, we assessed the effect of exercise-induced muscle damage on knee extensor muscle strength during isometric, concentric and eccentric actions at 1.57 rad x s(-1) and vertical jump performance under conditions of squat jump, countermovement jump and drop jump. The eight participants (5 males, 3 females) were aged 29.5+/-7.1 years (mean +/- s). These variables, together with plasma creatine kinase (CK), were measured before, 1 h after and 1, 2, 3, 4 and 7 days after a bout of muscle damaging exercise: 100 barbell squats (10 sets x 10 repetitions at 70% body mass load). Strength was reduced for 4 days (P< 0.05) but no significant differences (P> 0.05) were apparent in the magnitude or rate of recovery of strength between isometric, concentric and eccentric muscle actions. The overall decline in vertical jump performance was dependent on jump method: squat jump performance was affected to a greater extent than countermovement (91.6+/-1.1% vs 95.2+/-1.3% of pre-exercise values, P< 0.05) and drop jump (95.2+/-1.4%, P< 0.05) performance. Creatine kinase was elevated (P < 0.05) above baseline 1 h after exercise, peaked on day 1 and remained significantly elevated on days 2 and 3. Strength loss after exercise-induced muscle damage was independent of the muscle action being performed. However, the impairment of muscle function was attenuated when the stretch-shortening cycle was used in vertical jumping performance.     

速度滑冰运动员高原训练效果的研究

通过对国家速度滑冰集训队和解放军冰上基地运动员高原训练前后肺活量、气体代谢、能量代谢、酶活性、血乳酸等生理生化指标进行测试,旨在探索高原训练对速滑运动员机体代谢水平的影响及所产生的生物学效应,为高原训练和比赛提供科学依据。研究发现,高原训练后能量代谢活跃,高原训练前后测值显示差异较大,酶活性指标改变不明显。高原训练对运动员机体产生应激作用较大,可以作为提高速滑运动员竞技能力的有效方法,在应用过程中还要根据受试者个体差异合理安排训练计划。     

跳深练习中弹性能量利用的实验研究

运用Vicon运动影像捕捉分析系统,对运动训练专业二级运动员原地纵跳、半蹲跳及不同高度下落跳深动作进行采集与三维重构,运用V3D系统完成身体质心位置坐标计算。依据肌肉收缩理论,借鉴前人对肌肉弹性能利用的计算方法,对受试者不同高度下落跳深的弹性能利用率进行测试分析。结果表明:一般水平的运动员跳深练习中肌肉弹性能利用率,随着下落高度的增加,表现出"增大—峰值—下降"的单峰波特征,最大利用率大约出现在40 cm的下落高度;原地纵跳练习的肌肉弹性能利用率与跳深练习的最大利用率相接近;仅就肌肉弹性能的利用方面,原地纵跳是一种较好的训练方法。     

试析姚向斌1995至1996学年训练过程

正确认识和深刻领会跳远运动项目特点结合训练客观条件、选手实际状况,找准训练突破口,合理选择针对性强的若干专项训练手段与方法,同时始终贯穿在训练过程中,是提高跳远专项水平的有效途径。训练方法、手段的设计与运用必须围绕跳远技术作结构和功能,尽可能使手段在动作方向、动作速度、动作幅度、动作用力顺序等因素与专项技术动作特点相符*充分体现了“手段专项模似化”的训练原则。     

Quantifying the effects of load carriage and fatigue under load on sacral kinematics during countermovement vertical jump with IMU-based method

We present a method for quantifying sacral kinematics during countermovement jumping (CMJ) using an inertial measurement unit (IMU). The IMU-derived sacral kinematic trajectories reproduced motion capture acceleration, velocity, and displacement to within mean (standard deviation) differences of 0.024 (0.088) m/s², 0.023 (0.026) m/s, and 0.003 (0.032) m, respectively, across 252 jumps performed by 14 subjects. The method also quantified differences in maximum sacral displacement to within 1 % and differences in maximum propulsive velocity to within 0.7 % of motion capture estimates. This builds upon existing IMU-based methods for quantifying jump performance, which do not provide sacral kinematic trajectories. The utility of this method is demonstrated by its ability to discriminate jump performance metrics across a diverse subject population. In particular, we found that 21 participants adopted multiple strategies to maximize jump height in unloaded and loaded fresh conditions, but converged to a common strategy when jumping fatigued and under load. Changes in kinematic parameters were evident across conditions, and several changes were significantly associated with changes in jump performance (i.e., height). These parameters include changes in the depth of the countermovement, duration of the propulsive phase and maximum propulsive velocity. Collectively, these results point toward the future use of this method in naturalistic environments and for multiple objectives including biomechanical performance assessment and tracking, fatigue assessment, and jump training.     

体育院校女子三级跳远教学研究

在论述女子三级跳远运动发展的基础上，对女子三级跳远教学进行了回顾和研究。认为无论从教学实践看，还是从女生从事三级跳远学习和训练的创伤情况看，在高等体育专业教学中开设女子三级跳远是可行的。最后针对女子三级跳远教学的特点进行了教法提示     

Performance environment and nested task constraints influence long jump approach run: a preliminary study

The purpose of the study was to investigate possible changes at step pattern and technical performance of the long jump approach run in seven young long jumpers by modifying the performance environment (long jump runway versus track lane) and the nested actions (run-through with take-off versus complete long jump). Our findings suggest that the step pattern and technical aspects of the approach run are affected by environmental context and nested task constraints. In terms of environmental context, it appears that practising the training routine of run-through followed by take-off on the long jump runway allows athletes to simulate competition conditions in terms of step regulation and technical efficacy. The task of run-through followed by take-off on the track lane failed to initiate visual perception, step regulation and technical efficiency at the steps preceding the instant of take-off. In terms of nested task constraints, when run-ups were followed by jump for distance instead of only a take-off, a higher level of consistency was achieved and step regulation was based on perception–action coupling. Practising long jump run-up accuracy at a setting not containing the informational elements of the performance environment fails to develop the key elements of the skill.     

模拟交替低氧训练对大鼠心肌相关生理生化指标的影响

模拟高原训练是能够避免高原训练弊端,最大程度激发机体生理潜能,提高运动员竞技水平的有效方法。本研究尝试从设计交替训练的海拔高度着手,通过应用人工低压氧舱模拟高原训练方法,建立固定海拔2500m、4000m以及2500m～4000m交替低氧训练的动物模型,通过应用生理和生化方法对大鼠心肌相关指标进行检测及研究分析,探讨不同海拔及交替海拔训练条件下大鼠心肌抗氧化能力、有氧代谢能力等的变化,从而为运动员高——高交替训练提供参考。实验以雄性Wister大鼠为实验对象,以递增负荷跑台训练方式建立动物训练模型。将筛选后的大鼠随机分为：常氧运动组、2500m低氧运动组、4000m低氧运动组、交替低氧运动组,每组8只。第1周到第4周各组分别以不同的跑台训练模型进行训练,下高原后第5天以25m／min的速度跑至力竭。全部断头处死后,取心肌组织,分别测试各组大鼠心肌中SOD、MDA、SDH、LDH、Ca^2＋-ATP酶活性的变化。实验结果表明：经过4周不同海拔低氧递增负荷跑台训练及下高原后4天的训练,交替低氧运动组大鼠心肌各指标,如SOD、SDH、Ca^2＋-ATP酶活性均高于其他各组,MDA低于其他各组,LDH活性组间无显著性变化。说明交替低氧训练既可以维持较高海拔的低氧刺激,又可以减少过高海拔造成的损伤,有利于机体恢复。     

A variable drag coefficient,spatially extended numerical model of hammer throws and new wind tunnel data on current hammers

The maximum distance a hammer can be thrown depends on its mass, length and aerodynamic drag, meaning that record hammer throws performed before and after a rule change (for example, if the minimum mass is changed) cannot be compared directly. However, if all factors affecting the flight of a hammer are fully understood, and the range travelled by a hammer thrown with a given initial speed, angle and release height can be predicted, records thrown under different rules can be compared. In this work, a numerical model is developed, which includes the effects of atmospheric pressure, altitude, Coriolis Effect, gravitational variation, wind speed, ambient temperature, linear drag, torsional drag, hammer size and hammer orientation. It is based on the model of Mizera and Horvath (J Biomech 35:785–796, 2002). Two refinements are made: the drag coefficient varies with Reynolds number, and the hammer is represented as a spatially extended object with nonzero moment of inertia. New wind tunnel data on the drag of the three main components of the hammer (ball, cable and handle) are presented. This data are incorporated into the model which is then used to predict throws made at the IAAF 2011 World Athletics Championships (Daegu, Korea). The model is shown to be capable of predicting to within 1 % the distance of hammer throws where the air density, latitude, release height, release angle and release velocity are known. It is more accurate than numeric and analytic models which assume a constant drag coefficient. This may be because it does not require the user to choose the drag coefficient and automatically uses an appropriate drag coefficient regardless of conditions. With a good biomechanical model or good assumptions about release speeds, throws with different implements can be compared to compare records thrown before and after rule changes. Further work is needed to develop a biomechanical model capable of predicting the release speed an athlete can achieve with a range of different implements.     

Effects of Additional Load on the Occurrence of Bilateral Deficit in Counter-Movement and Squat Jumps

ABSTRACT

Purpose: A vertical jump (VJ) is a common task performed in several sports, with the height achieved correlated to skilled performance. Loaded VJs are often used in the training of recreational and professional athletes. The bilateral deficit (BLD), which refers to the difference between the heights achieved by a bilateral jump and the sum of two unilateral jumps, has not been reported for loaded jumps and the findings for unloaded jumps are inconclusive. The purpose of this study was threefold: (a) to quantify and compare BLD in countermovement (CMJ) and squat jumps (SJ), (b) to explore the effects of an additional 10% of body weight (BW) load on the BLD in both CMJ and SJ, and (c) examine the relationship between magnitude of BLD and jump performance in both jumps and conditions. Methods: Forty participants (22 for CMJ and 18 for SJ) performed a bilateral jump and unilateral jumps on each leg with and without an added load equivalent to 10% of each participant’s bodyweight. Results: BLD was evident in all conditions, with CMJ BLD values nearly double those for the SJ. The extra load did not affect the magnitude of BLD. BLD had a significant correlation with unilateral jump height, expect for the 110%BW SJ. Conclusions: BLD is present in SJs and CMJs at both loaded and unloaded conditions. The SJs have about half of the BLD observed in CMJs regardless of additional load. Participants who had higher single leg jumps seemed to also have higher BLDs, but there was no evidence of association between the bilateral jump height and BLD.