Canoe slalom – competition analysis reliability

The aim of this study was to assess intra-observer and inter-observer reliability of data gathered from a lapsed-time time–motion analysis of canoe slalom competition. The data were collected using a definition set developed in conjunction with elite canoe slalom coaches. Competition runs from four national-standard paddlers in a national selection race were analysed in random order three times by three observers. For each run, observers identified various events specific to canoe slalom, including time taken between gates, touched and missed gates, turn times, major and minor avoidance, rolls, paddle in and out of water times, and stroke classification. The error of measurement was determined for each of these variables. For time taken between gates and turn times, the error was ≤ 0.21 and ≤ 0.39 s for intra-observer and inter-observer analysis, respectively. The error for stroke in and out of water times was ≤ 0.08 and ≤ 0.13 s for intra-observer and inter-observer analysis, respectively. Analysis of stroke classification identification for intra-observer comparisons revealed that 91% of the time identical stroke identification occurred. Inter-observer analysis revealed identical stroke identification was achieved 81% of the time. These reliability data compare favourably with previous time–motion analysis in other sports using fewer variables.     

Canoe slalom competition analysis

The aim of this study was to quantify the differences between groups of elite canoe slalom athletes based on the class they paddle in and the strategies they use in competition. Canoe and kayak footage was recorded using three cameras and analysed using lapsed-time time-motion analysis. Analysis was undertaken on the ten fastest competition runs for men's kayak and canoes and women's kayak for the 22-gate semi-final/final course at the 2005 canoe slalom world championships. Comparison between the categories of paddlers revealed that despite canoe paddlers taking significantly (P < or = 0.05) fewer strokes than kayak paddlers, they were not significantly slower than men's single kayak paddlers with respect to their run times and only significantly slower between 4 of 22 gates. Results revealed also that paddlers using different turn strategies (spin vs. pivot) had significantly (P < or = 0.05) different split times for the gates before and after the execution of the manoeuvre. For a paddler this means that their individual strategy could be analysed and compared with those of others to determine if alternate strategies would be beneficial to their performance.     

Canoe slalom competition analysis

The aim of this study was to quantify the differences between groups of elite canoe slalom athletes based on the class they paddle in and the strategies they use in competition. Canoe and kayak footage was recorded using three cameras and analysed using lapsed-time time–motion analysis. Analysis was undertaken on the ten fastest competition runs for men's kayak and canoes and women's kayak for the 22-gate semi-final/final course at the 2005 canoe slalom world championships. Comparison between the categories of paddlers revealed that despite canoe paddlers taking significantly (P ≤ 0.05) fewer strokes than kayak paddlers, they were not significantly slower than men's single kayak paddlers with respect to their run times and only significantly slower between 4 of 22 gates. Results revealed also that paddlers using different turn strategies (spin vs. pivot) had significantly (P ≤ 0.05) different split times for the gates before and after the execution of the manoeuvre. For a paddler this means that their individual strategy could be analysed and compared with those of others to determine if alternate strategies would be beneficial to their performance.     

皮划艇激流回旋的项目特点认识与分析

皮划艇激流回旋运动是我国在1999年新引进的奥运会竞技运动项目,经过短短的7年多时间的摸索和奋斗,中国皮划艇激流回旋项目在短时间内取得了让世界激流界惊讶的进步和发展．虽然取得了不小的进步,但我们对于该项目特点和规律的认识还是比较有限．笔者有幸作为国家队教练员见证和参与了中国国家激流队的进步和发展。通过对国家队和四川队以及在国外的见到的优秀世界级运动员的训练的总结与分析,总结出皮划艇激流回旋是以依靠自身体能和借助水能控制船为目的的,以无氧代谢供能为主的智能性技巧类竞速项目。     

Morphological characteristics of Olympic slalom canoe and kayak paddlers

Abstract

Sidney and Shephard (1973) were the first to report on the morphology of slalom paddlers and characterized them as having “a substantial standing height and lean body mass, good general muscle development with particular emphasis on the leg muscles”. The purpose of this study was to analyse the morphological characteristics of Olympic slalom kayak and canoe paddlers to determine whether they possess unique physique or structural characteristics that provide an advantage for their sport. Thirty-one male and 12 female slalom paddlers were measured using a battery of 36 anthropometric dimensions in the 15-day period before competition at the 2000 Olympic Games. Male slalom paddlers were older, lighter, shorter, and leaner than previously reported slalom paddlers and had similar height and weight to a reference population of non-athletes. Compared with Olympic sprint paddlers, male slalom paddlers were older, lighter and shorter, and had similar body fat and almost identical proportionality characteristics. Female slalom paddlers were taller, lighter, older, and less fat than those reported previously. They were taller and lighter than the reference population of non-athletes and of similar age and height but lighter and leaner than the Olympic sprint paddlers. While a high brachial index was reported for both male and female slalom paddlers, the Best male paddlers (those ranked in the top 10 placings) were more compact, had smaller proportional hip girth, and showed a tendency for smaller proportional hip breadth but a larger proportional waist girth than the Rest (those not ranked in the top 10 placings). Changes to the technical aspect of the events and to competition rules and the nature and approach to training were explored as possible reasons for some of these differences. We outline the contribution this research makes to talent identification and highlight the need for further research.     

我国极限激流项目教练员对训练特征认知研究

极限皮划艇激流回旋是新兴运动,探索运动项目的训练特征是提高竞技水平的基础,提高教练员对训练特征的认知水平是形成正确训练理念的前提。研究运用运动训练学理论,采用文献资料法、问卷调查法和逻辑分析法对我国极限皮划艇激流回旋项目教练员对训练特征的认知进行调查研究,得出结论:绝大部分教练员对极限皮划艇激流回旋项目的技术、战术、体能和心理训练特征的认知符合项目的运动特征和竞赛特征;近4成教练员对该项目训练理念的认知不够清晰;我国极限皮划艇激流回旋项目运动员专项化训练水平较低。建议:加强项目供能结构等的基础研究;加强该项目运动员的专项化训练程度,以尽快提高竞技水平。     

伦敦奥运会激流回旋皮划艇决赛信息比较分析

运用文献资料法、数理统计法和对比分析法对伦敦奥运会激流回旋男子单人皮艇、女子单人皮艇、男子单人划艇和男子双人划艇决赛的国家、最终成绩、运动员的年龄、身高与体重等有关信息进行了研究,认为当前激流回旋世界格局依然是欧洲主导,但分布较广;世界优秀运动员年龄及形态数据为国内选材提供了参考;男子双人划艇竞争最为激烈,其次是男子单人皮艇。     

The development of a reliable amateur boxing performance analysis template

Abstract

The aim of this study was to devise a valid performance analysis system for the assessment of the movement characteristics associated with competitive amateur boxing and assess its reliability using analysts of varying experience of the sport and performance analysis. Key performance indicators to characterise the demands of an amateur contest (offensive, defensive and feinting) were developed and notated using a computerised notational analysis system. Data were subjected to intra- and inter-observer reliability assessment using median sign tests and calculating the proportion of agreement within predetermined limits of error. For all performance indicators, intra-observer reliability revealed non-significant differences between observations (P > 0.05) and high agreement was established (80–100%) regardless of whether exact or the reference value of ±1 was applied. Inter-observer reliability was less impressive for both analysts (amateur boxer and experienced analyst), with the proportion of agreement ranging from 33–100%. Nonetheless, there was no systematic bias between observations for any indicator (P > 0.05), and the proportion of agreement within the reference range (±1) was 100%. A reliable performance analysis template has been developed for the assessment of amateur boxing performance and is available for use by researchers, coaches and athletes to classify and quantify the movement characteristics of amateur boxing.     

我国优秀皮划艇激流回旋运动员体能诊断与训练对策研究

以中国皮划艇激流回旋队9名国际健将级运动员为研究对象,对其最大摄氧量、心率、乳酸、卧推与卧拉的最大力量（1RM）及力量耐力（40% 1RM,120 s）、静水300 m直线速度、静水8 km长划等指标进行测试,采用SPSS25.0对测试结果进行描述统计,并与世界优秀选手相关体能指标进行比较,诊断我国优秀激流回旋运动员体能问题,并提出相应训练对策。结果表明,我国优秀激流回旋运动员有氧能力、专项力量、基础速度与专项速度不同程度落后于国际优秀选手。为提升我国优秀激流回旋运动员体能水平,建议采用水上与陆上相结合的有氧训练方法发展运动员有氧能力,提高全年有氧训练比例,科学安排有氧训练的负荷量与强度;采用陆上基础力量训练发展运动员上肢爆发力、力量耐力与躯干稳定性力量,采用水上专项力量训练发展运动员划桨的峰值桨力与功率;既要重视运动员静水划船的基础速度,也要强化其高强度、高速度的激流专项竞速能力。     

Concurrent validity and test-retest reliability of a global positioning system (GPS) and timing gates to assess sprint performance variables

There has been no previous investigation of the concurrent validity and reliability of the current 5 Hz global positioning system (GPS) to assess sprinting speed or the reliability of integrated GPS-accelerometer technology. In the present study, we wished to determine: (1) the concurrent validity and reliability of a GPS and timing gates to measure sprinting speed or distance, and (2) the reliability of proper accelerations recorded via GPS-accelerometer integration. Nineteen elite youth rugby league players performed two over-ground sprints and were simultaneously assessed using GPS and timing gates. The GPS measurements systematically underestimated both distance and timing gate speed. The GPS measurements were reliable for all variables of distance and speed (coefficient of variation [CV] = 1.62% to 2.3%), particularly peak speed (95% limits of agreement [LOA] = 0.00 ± 0.8 km · h(-1); CV = 0.78%). Timing gates were more reliable (CV = 1% to 1.54%) than equivalent GPS measurements. Accelerometer measurements were least reliable (CV = 4.69% to 5.16%), particularly for the frequency of proper accelerations (95% LOA = 1.00 ± 5.43; CV = 14.12%). Timing gates and GPS were found to reliably assess speed and distance, although the validity of the GPS remains questionable. The error found in accelerometer measurements indicates the limits of this device for detecting changes in performance.     

国家队激流回旋运动员肩关节脱位的分析研究

通过对国家队激流回旋运动员损伤状况的检查和治疗发现 ,肩关节脱位发生率比较高 ,女性高于男性 ;肩关节脱位与肩周围软组织损伤密切相关 ;“爱斯基摩翻滚”是导致肩关节脱位的主要技术动作。据此 ,提出了 4项建议     

The validity and reliability of a novel app for the measurement of change of direction performance

ABSTRACT

The aim of the present investigation was to analyze the validity and reliability of a novel iPhone app (CODTimer) for the measurement of total time and interlimb asymmetry in the 5 + 5 change of direction test (COD). To do so, twenty physically active adolescent athletes (age = 13.85 ± 1.34 years) performed six repetitions in the COD test while being measured with a pair of timing gates and CODTimer. A total of 120 COD times measured both with the timing gates and the app were then compared for validity and reliability purposes. There was an almost perfect correlation between the timing gates and the CODTimer app for the measurement of total time (r = 0.964; 95% Confidence interval (CI) = 0.95–1.00; Standard error of the estimate = 0.03 s.; p < 0.001). Moreover, non-significant, trivial differences were observed between devices for the measurement of total time and interlimb asymmetry (Effect size < 0.2, p > 0.05). Similar levels of reliability were observed between the timing gates and the app for the measurement of the 6 different trials of each participant (Timing gates: Intraclass correlation coefficient (ICC) = 0.651–0.747, Coefficient of variation (CV) = 2.6–3.5%; CODTimer: ICC = 0.671–0.840, CV = 2.2–3.2%). The results of the present study show that change of direction performance can be measured in a valid, reliable way using a novel iPhone app.     

国家皮划艇激流回旋集训队膳食状况调查

以国家皮划艇激流回旋集训队运动员为研究对象,应用称重法进行连续5个训练日膳食调查。结果显示,该队整体水平上总能量、碳水化合物摄入不足,脂肪摄入过多且动物性脂肪摄入比例过高;晚餐能量分配比例略高于推荐值;食物实际消耗量与推荐消耗量存在明显的差别,如水果类、畜肉类、蛋类、奶类摄入过多,而谷类、淀粉类和水产类摄入明显不足;维生素的摄入量与推荐供给量相比较有参差不齐的现象。     

Reliability and validity of depth camera 3D scanning to determine thigh volume

Gross thigh volume is a key anthropometric variable to predict sport performance and health. Currently, it is either estimated by using the frustum method, which is prone to high inter-and intra-observer error, or using medical imaging, which is expensive and time consuming. Depth camera 3D-imaging systems offer a cheap alternative to measure thigh volume but no between-session reliability or comparison to medical imaging has been made. This experiment established between-session reliability and examined agreement with magnetic resonance imaging (MRI). Forty-eight male cyclists had their thigh volume measured by the depth camera system on two occasions to establish between-session reliability. A subset of 32 participants also had lower body MRIs, through which agreement between the depth camera system and MRI was established. The results showed low between-session variability (CV = 1.7%; Absolute Typical Error = 112 cm³) when measuring thigh volume using the depth camera system. The depth camera systematically measured gross thigh volume 32.6cm³ lower than MRI. These results suggest that depth camera 3D-imaging systems are reliable tools for measuring thigh volume and show good agreement with MRI scanners, providing a cheap and time-saving alternative to medical imaging analysis.     

The validation of a swimming turn wall-contact-time measurement system: a touchpad application reliability study

The effectiveness of the swimming turn is highly influential to overall performance in competitive swimming. The push-off or wall contact, within the turn phase, is directly involved in determining the speed the swimmer leaves the wall. Therefore, it is paramount to develop reliable methods to measure the wall-contact-time during the turn phase for training and research purposes. The aim of this study was to determine the concurrent validity and reliability of the Pool Pad App to measure wall-contact-time during the freestyle and backstroke tumble turn. The wall-contact-times of nine elite and sub-elite participants were recorded during their regular training sessions. Concurrent validity statistics included the standardised typical error estimate, linear analysis and effect sizes while the intraclass correlating coefficient (ICC) was used for the reliability statistics. The standardised typical error estimate resulted in a moderate Cohen’s d effect size with an R² value of 0.80 and the ICC between the Pool Pad and 2D video footage was 0.89. Despite these measurement differences, the results from this concurrent validity and reliability analyses demonstrated that the Pool Pad is suitable for measuring wall-contact-time during the freestyle and backstroke tumble turn within a training environment.     

A comparison of time-motion and technical–tactical variables between age groups of female judo matches

Abstract

The aim of the study was to verify differences between age groups of female judo matches in time-motion and technical–tactical analysis. The sample was composed of pre-cadet (13–14 years, n = 148), cadet (15–16 years, n = 228), junior (17–19 years, n = 104) and senior (>20 years, n = 237) groups. The time-motion indicators consisted of total combat time, standing combat time, displacement without contact, gripping time, total time of techniques, groundwork combat time and pause time, per match and by each combat/pause cycle. Technical and tactical variables were also collected. The one-way analysis of variance and a post hoc test were conducted, P ≤ 0.05. Cadets, with a median of 7 (2, 12), had a number of combat/pause cycles different from junior, with 3 (1, 8.5). Regarding time-motion per match and per cycle, senior had longer total combat time, standing combat time and gripping time than other groups. Senior presented lower frequency of leg techniques than pre-cadet, cadet and junior. Time-motion and technical–tactical variables effects in female judo athletes emphasise the difference between seniors and other groups.     

Reliability and stability of anthropometric and performance measures in highly-trained young soccer players: effect of age and maturation

Abstract

The purpose of this study was to assess both short-term reliability and long-term stability of anthropometric and physical performance measures in highly-trained young soccer players in relation to age and maturation. Data were collected on 80 players from an academy (U13–U18, pre- (n = 14), circum- (n = 32) and post- (n = 34) estimated peak height velocity, PHV). For the reliability analysis, anthropometric and performance tests were repeated twice within a month. For the stability analysis, these tests were repeated 12 times over a 4-year period in 10 players. Absolute reliability was assessed with the typical error of measurement, expressed as a coefficient of variation (CV). Relative reliability and long-term stability were assessed using the intraclass correlation coefficient (ICC). There was no clear age or maturation effect on either the CVs or ICCs: e.g., Post-PHV vs. Pre-PHV: effect size = –0.37 (90% confidence limits (CL):-1.6;0.9), with chances of greater/similar/lower values of 20/20/60%. For the long-term stability analysis, ICCs varied from 0.66 (0.50;0.80) to 0.96 (0.93;0.98) for 10-m sprint time and body mass, respectively. The short-term reliability of anthropometry and physical performance measures is unlikely to be affected by age or maturation. However, some of these measures are unstable throughout adolescence, which questions their usefulness in a talent identification perspective.     

Canoe slalom boat trajectory while negotiating an upstream gate

The aim of this study was to determine how the path chosen by elite slalom paddlers influences the time taken to negotiate an upstream gate. Six trials for international men's single kayak (MK1) (n = 11) and single canoe (C1) (n = 6) paddlers were digitized for a left-hand upstream gate. Results revealed that the absolute variability of paddlers increased as their total time increased (r = 0.594), but the coefficient of variation remained constant. There was a strong correlation (r = 0.89, each individual trial; r = 0.93, mean total time for each participant) between boat trajectory and the total time. The MK1 and C1 paddlers used similar strategies to negotiate an upstream gate. There were significant differences (P < 0.05) between the boat trajectory of the fastest and slowest paddlers (average distance between paddler's head and the inside pole). These results suggest that to achieve a faster upstream gate performance, paddlers should concentrate on the distance between their head and the inside pole. However, there would be an optimal distance beyond which any further reduction in the distance would impede technique and performance.     

Quantifying instantaneous performance in alpine ski racing

Abstract

Alpine ski racing is a popular sport in many countries and a lot of research has gone into optimising athlete performance. Two factors influence athlete performance in a ski race: speed and the chosen path between the gates. However, to date there is no objective, quantitative method to determine instantaneous skiing performance that takes both of these factors into account. The purpose of this short communication was to define a variable quantifying instantaneous skiing performance and to study how this variable depended on the skiers' speed and on their chosen path. Instantaneous skiing performance was defined astime loss per elevation difference dt/dz, which depends on the skier's speed v(z), and the distance travelled per elevation difference ds/dz. Using kinematic data collected in an earlier study, it was evaluated how these variables can be used to assess the individual performance of six ski racers in two slalom turns. The performance analysis conducted in this study might be a useful tool not only for athletes and coaches preparing for competition, but also for sports scientists investigating skiing techniques or engineers developing and testing skiing equipment.     

Quantifying instantaneous performance in alpine ski racing

Alpine ski racing is a popular sport in many countries and a lot of research has gone into optimising athlete performance. Two factors influence athlete performance in a ski race: speed and the chosen path between the gates. However, to date there is no objective, quantitative method to determine instantaneous skiing performance that takes both of these factors into account. The purpose of this short communication was to define a variable quantifying instantaneous skiing performance and to study how this variable depended on the skiers' speed and on their chosen path. Instantaneous skiing performance was defined as time loss per elevation difference dt/dz, which depends on the skier's speed v(z), and the distance travelled per elevation difference ds/dz. Using kinematic data collected in an earlier study, it was evaluated how these variables can be used to assess the individual performance of six ski racers in two slalom turns. The performance analysis conducted in this study might be a useful tool not only for athletes and coaches preparing for competition, but also for sports scientists investigating skiing techniques or engineers developing and testing skiing equipment.