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1.
Dinghy sailors lean their upper body over the windward side of the boat (‘hiking’) to keep the boat’s balance and maximise its speed. Sustaining the hiking position is essential for competitive performance and this study examined sport-specific differences of muscles relevant for hiking in elite sailors. Knee extensor muscle strength as well as trunk muscle strength, muscle endurance and muscle thickness were assessed in elite dinghy sailors (n = 15) and compared to matched, non-sailing controls (n = 15). Isometric extensor strength was significantly higher in sailors at 60° (+14%) but not at 20° knee flexion. Sailors showed significantly higher trunk flexor (but not extensor) strength under isometric (+18%) and eccentric (+11%) conditions, which was associated to greater muscle thickness (rectus abdominis +40%; external oblique +26%) and higher endurance for ventral (+66%) and lateral (+61%) muscle chains compared to non-sailors. Greater muscles thickness and the particular biomechanical requirements to maintain the hiking position may drive the increases in isometric and eccentric muscle strength as well as ventral and lateral trunk endurance. The current findings identified sport-specific muscle function differences and provide performance benchmarks for muscle strength and endurance in elite sailors.  相似文献   

2.
‘A tribute to Dr J. Rogge’ aims to systematically review muscle activity and muscle fatigue during sustained submaximal quasi-isometric knee extension exercise (hiking) related to Olympic dinghy sailing as a tribute to Dr Rogge’s merits in the world of sports. Dr Jacques Rogge is not only the former President of the International Olympic Committee, he was also an orthopaedic surgeon and a keen sailor, competing at three Olympic Games. In 1972, in fulfilment of the requirements for the degree of Master in Sports Medicine, he was the first who studied a sailors’ muscle activity by means of invasive needle electromyography (EMG) during a specific sailing technique (hiking) on a self-constructed sailing ergometer. Hiking is a bilateral and multi-joint submaximal quasi-isometric movement which dinghy sailors use to optimize boat speed and to prevent the boat from capsizing. Large stresses are generated in the anterior muscles that cross the knee and hip joint, mainly employing the quadriceps at an intensity of 30–40% maximal voluntary contraction (MVC), sometimes exceeding 100% MVC. Better sailing level is partially determined by a lower rate of neuromuscular fatigue during hiking and for ≈60% predicted by a higher maximal isometric quadriceps strength. Although useful in exercise testing, prediction of hiking endurance capacity based on the changes in surface EMG in thigh and trunk muscles during a hiking maintenance task is not reliable. This could probably be explained by the varying exercise intensity and joint angles, and the great number of muscles and joints involved in hiking.

Highlights

  • Dr Jacques Rogge, former president of the International Olympic Committee and Olympic Finn sailor, was the first to study muscle activity during sailing using invasive needle EMG to obtain his Master degree in Sports Medicine at the Ghent University.

  • Hiking is a critical bilateral and multi-joint movement during dinghy racing, accounting for >60% of the total upwind leg time. Hiking generates large stresses in the anterior muscles that cross the knee and hip joint.

  • Hiking is considered as a quasi-isometric bilateral knee extension exercise. Muscle activity measurements during sailing, recorded by means of EMG, show a mean contraction intensity of 30-40% maximal voluntary contraction with peaks exceeding 100%.

  • Hiking performance is strongly related to the development of neuromuscular fatigue in the quadriceps muscle. Since maximal strength is an important determinant of neuromuscular fatigue during hiking, combined strength and endurance training should be incorporated in the training program of dinghy sailors.

  相似文献   

3.
Physical fitness and muscular strength are important performance factors for Olympic class sailors, but the physical demands vary greatly between yacht classes, and limited information is available regarding the physical demands for the different crew positions. In the present paper, strength and aerobic capacity data from elite Olympic sailors are presented and compared with previous findings. Furthermore, a system for classification of Olympic class sailors is suggested. Peak aerobic capacity (peak oxygen uptake, VO(2peak)) and maximal isometric and isokinetic muscle strength of the knee extensors and flexors were assessed, together with the hamstring/quadriceps strength ratio (H/Q ratio). Peak aerobic capacity (ml O(2) . min(-1) . kg(-2/3)) was as follows: males - static hikers (n = 5) 215, s = 7; dynamic hikers (n = 8) 252, s = 17; trapezing helmsmen (n = 6) 234, s = 15; trapezing crew (n = 10) 239, s = 16; females - dynamic hikers (n = 6) 194, s = 16; trapezing crew (n = 2) 200, s = 13. Strength data for hikers, presented as peak moments (normalized to body weight) obtained during eccentric, isometric, and concentric contraction (Nm . kg(-1)) respectively were as follows: males - quadriceps: 3.66 (s = 0.68), 3.97 (s = 0.66), 1.82 (s = 0.34); hamstrings: 1.93 (s = 0.22), 1.38 (s = 0.41), 1.05 (s = 0.21); females - quadriceps: 3.84 (s = 0.71), 3.81 (s = 0.58), 1.60 (s = 0.28); hamstrings: 1.75 (s = 0.23), 1.10 (s = 0.16), 0.84 (s = 0.13). The peak moment based H/Q ratios for slow eccentric and concentric contractions were 0.42 (s = 0.11) and 0.39 (s = 0.04) for males and 0.43 (s = 0.06) and 0.39 (s = 0.04) for females respectively. Elite Olympic class sailors demonstrated high VO(2peak) values comparable to those observed in other non-endurance sports. The strength data revealed very high quadriceps strength for hikers, which is likely a result of the high muscle forces encountered during sailing, and a low H/Q ratio. To ensure optimal knee joint stabilization during sailing and other training activities, it is suggested that hikers should counter this strength imbalance by performing additional strength training for the hamstrings muscle group.  相似文献   

4.
In this study, we tested the hypothesis that elite dinghy sailing is a whole-body, dynamic, repeated-effort sport, and that increased heart rate and oxygen consumption reflect its dynamic element. Six elite male Laser sailors (mean age 19.7 years, s = 1.82; height 1.81 m, s = 0.03; body mass 78.0 kg, s = 4.1) performed a cycle ergometer test to volitional exhaustion to determine peak oxygen uptake (VO(2peak)) and a simulated 30-min upwind leg sail on a specially constructed Laser sailing ergometer. The simulation protocol was based on video analysis of previous Laser World Championships. Expired gases were collected in Douglas bags, heart rate recorded at rest and after every 5 min, and pre- and post-simulation capillary blood samples taken for blood lactate analysis. Results were analysed with a one-way analysis of variance. Mean VO(2peak) was 4.32 l . min(-1) (s = 0.16). Mean simulation VO(2) was 2.51 l . min(-1) (s = 0.24) and peaked at 2.58 l . min(-1) (s = 0.25) during the 5th minute. Mean simulation heart rate was 156 beats . min(-1) (s = 8), peaking during the final minute at 160 beats . min(-1) (s = 10). These results suggest that, unlike pseudo-isometric static hiking, elite dinghy sailing demands a substantial proportion (58%VO(2peak), s = 5.6) of aerobic capacity.  相似文献   

5.
Laser sailors have to tolerate fatiguing contractions of the lower-body muscles for prolonged periods. The aims of the present study were (1) to evaluate the difference between top-ranked and club sailors, in their capacity to resist fatigue during sustained isometric and maximal power exercise, and (2) to examine the relationships between the above parameters and performance on a Laser simulator and competitive racing performance according to the national ranking list. Eight Greek nationally ranked Laser sailors were compared with eight club sailors. Each sailor performed: (a) an effort to the limit of tolerance on the Laser simulator, (b) an effort to the limit of tolerance of isometric endurance for the right leg on an isokinetic dynamometer, and (c) a Wingate test of maximal lower-body anaerobic power on a cycle ergometer. In the nationally ranked sailors, isometric endurance time (mean 160 s, s = 50) and endurance time on the Laser simulator (1381 s, s = 1354) were significantly (P < 0.05) longer than in the club sailors (101 s, s = 29 and 565 s, s = 367, respectively), whereas the final minute heart rate (in both groups: 149 beats . min(-1), s = 22) and the mean arterial pressure (nationally ranked sailors: 129 mmHg, s = 16; club sailors: 120 mmHg, s = 21) on the Laser simulator were not different between groups. During the Wingate test, the nationally ranked sailors had a significantly lower index of fatigue (42%, s = 5) than the club sailors (49%, s = 6). Isometric endurance time was significantly correlated with the Wingate index of fatigue (r = -0.73; P < 0.001). The nationally ranked sailors' mean and maximal anaerobic powers were significantly correlated with their national ranking positions (r = -0.83 and -0.71, respectively). It is suggested that isometric endurance and anaerobic power are well-developed in Laser class sailors and may influence their sailing performance. Furthermore, compared with club sailors, the nationally ranked sailors are able to sustain the same intensity of lower-limb isometric contractions for much longer with similar cardiovascular responses.  相似文献   

6.
Following preliminary indications that in some individuals arm exercise enhanced rather than reduced simultaneous leg endurance, ten young men and women performed three forms of intermittent work to volitional exhaustion, under duty cycles of 45 s work, 15 s rest. The protocols were as follows: (A) knee extensions at 30% maximum voluntary contraction (MVC); (B) 30% MVC knee extensions combined with arm cranking at 130% of their own lactate threshold; (C) combined 30% MVC knee extensions and arm cranking at 20% of their own lactate threshold. Heart rate, oxygen uptake (VO(2)), and blood lactate concentration were among the variables recorded throughout. All physiological indicators of demand were substantially higher in protocol B than in protocols A or C [heart rate: (A) 154 beats . min(-1), (B) 171 beats . min(-1), (C) 150 beats . min(-1); VO(2): (A) 11.9 ml . kg(-1) . min(-1), (B) 21.7 ml . kg(-1) . min(-1), (C) 14.2 ml . kg(-1) . min(-1); blood lactate concentration: (A) 3.3 mmol . l(-1), (B) 5.1 mmol . l(-1), (C) 2.8 mmol . l(-1)], yet there were no significant differences (P > 0.05) in the endurance times between the three conditions [(A) 11.43 min, (B) 11.1 min, (C) 10.57 min] and seven participants endured longest in protocol B. Results from protocol (C) cast doubt on explanations in terms of psychological distraction. We suggest that lactic acid produced by the arms is shuttled to the legs and acts there either as a supplementary fuel source or as an antagonist to the depressing effects of increased potassium concentration.  相似文献   

7.
邱俊  陈文鹤 《体育科研》2009,30(1):57-61
有氧耐力是人体从事耐力性运动的重要能力一，最大摄氧量是客观评价人体心肺功能的一项综合生理指标。本文对有氧耐力的重要测试指标最大摄氧量和无氧阈在有氧耐力评价中的作用及其影响因素进行了综合分析，并梳理了有氧耐力训练的新方法。耐力性项目的连动成绩与最大摄氧量关系紧密，而无氧阀在评定有氧耐力水平、制订有氧耐力训练强度等许多方面亦具有较强的指导意义。有氧耐力训练在很多项目训练中占有重要地位，掌握科学的有氧耐力训练方法对提高运动员的专项竞技水平起着关键性作用。  相似文献   

8.
In this study, we wished to determine whether the observed reduction in quadriceps muscle oxygen availability, reported during repetitive bouts of isometric exercise in simulated sailing efforts (i.e. hiking), is because of restricted muscle blood flow. Six national-squad Laser sailors initially performed three successive 3-min hiking bouts followed by three successive 3-min cycling tests sustained at constant intensities reproducing the cardiac output recorded during each of the three hiking bouts. The blood flow index (BFI) was determined from assessment of the vastus lateralis using near-infrared spectroscopy in association with the light-absorbing tracer indocyanine green dye, while cardiac output was determined from impedance cardiography. At equivalent cardiac outputs (ranging from 10.3±0.5 to 14.8±0.86 L · min(-1)), the increase from baseline in vastus lateralis BFI across the three hiking bouts (from 1.1±0.2 to 3.1±0.6 nM · s(-1)) was lower (P = 0.036) than that seen during the three cycling bouts (from 1.1±0.2 to 7.2±1.4 nM · s(-1)) (Cohen's d: 3.80 nM · s(-1)), whereas the increase from baseline in deoxygenated haemoglobin (by ～17.0±2.9 μM) (an index of tissue oxygen extraction) was greater (P = 0.006) during hiking than cycling (by ～5.3±2.7 μM) (Cohen's d: 4.17 μM). The results suggest that reduced vastus lateralis muscle oxygen availability during hiking arises from restricted muscle blood flow in the isometrically acting quadriceps muscles.  相似文献   

9.
Abstract

This study aimed to determine indicators of sailing performance in 2 (age) groups of youth sailors by investigating the anthropometric, physical and motor coordination differences and factors discriminating between elite and non-elite male optimist sailors and young dynamic hikers. Anthropometric measurements from 23 optimist sailors (mean ± SD age = 12.3 ± 1.4 years) and 24 dynamic youth hikers (i.e. Laser 4.7, Laser radial and Europe sailors <18 years who have to sail the boat in a very dynamic manner, due to a high sailor to yacht weight ratio) (mean ± SD age = 16.5 ± 1.6 years) were conducted. They performed a physical fitness test battery (EUROFIT), motor coordination test battery (Körperkoordinationstest für Kinder) and the Bucket test. Both groups of sailors were divided into two subgroups (i.e. elites and non-elites) based on sailing expertise. The significant differences, taking biological maturation into account and factors discriminating between elite and non-elite optimist sailors and dynamic hikers were explored by means of multivariate analysis of covariance and discriminant analysis, respectively. The main results indicated that 100.0% of elite optimist sailors and 88.9% of elite dynamic hikers could be correctly classified by means of two motor coordination tests (i.e. side step and side jump) and Bucket test, respectively. As such, strength- and speed-oriented motor coordination and isometric knee-extension strength endurance can be identified as indicators of sailing performance in young optimist and dynamic youth sailors, respectively. Therefore, we emphasise the importance of motor coordination skill training in optimist sailors (<15 years) and maximum strength training later on (>15 years) in order to increase their isometric knee-extension strength endurance.  相似文献   

10.
The aim of this study was to investigate the effects of extensive endurance training (15-25 h per week) on the development of maximal oxygen uptake (VO2 max) in boys from puberty. Maximal oxygen uptake was measured a number of times each year from the age of puberty and for the next 6-9 years in seven young male elite cross-country skiers. Mean VO2 max was measured as 76.3 and 80.1 ml kg-1 min-1 at the ages of 14 and 15 years respectively. Despite the fast rate of growth during puberty, maximal aerobic power showed seasonal variations from the age of 14, reaching a plateau at the age of 15, whereas VO2 max (ml kg-2/3 min-1) increased continuously. It is concluded that, during puberty, boys probably attain significant increases in VO2 max when appropriate amounts of endurance training are undertaken.  相似文献   

11.
The purpose of this study was to compare changes in aerobic condition, strength, and muscular endurance following 8 weeks of endurance rowing alone or in combination with weight-training. Twenty-two elite rowers were assigned to (1) rowing (n = 10, 250-270 km · week?1) or (2) rowing (n = 12, 190-210 km · week?1) plus four weight-training sessions each week. Pre and post mean and standardized effect-size (ES) differences in aerobic condition (watts at 4 mmol · L?1) and strength (isometric pull, N), prone bench-pull (6-repetition maximum, 6-RM), 5- and 30-repetition leg-press and 60-repetition seated-arm-pull (J, performed on a dynamometer) normalized by body mass and log-transformed were analysed, after adjusting for gender. The standardized differences between groups were trivial for aerobic condition (ES [±90% CI] = 0.15; ±0.28, P = 0.37) and prone bench-pull (ES = 0.27; ±0.33, P = 0.18), although a moderate positive benefit in favour of rowing only was observed for the seated-arm-pull (ES = 0.42; ±0.4, P = 0.08). Only the weight-training group improved isometric pull (12.4 ± 8.9%, P < 0.01), 5-repetition (4.0 ± 5.7%, P < 0.01) and 30-repetition (2.4 ± 5.4%, P < 0.01) leg-press. In conclusion, while gains in aerobic condition and upper-body strength were comparable to extensive endurance rowing, weight-training led to moderately greater lower-body muscular-endurance and strength gains.  相似文献   

12.
Physiological characteristics of America's Cup sailors   总被引：2，自引：0，他引：2  
The aim of this study was to assess the physiological profile of America's Cup grinders and mastmen, by measuring energy expenditure during sailing and assessing their aerobic and anaerobic fitness. The study focused on estimating the energy used during grinding activity, by measuring oxygen uptake (VO(2)) during sail setting in real sailing conditions. In the laboratory, using an arm-cranking ergometer, we measured VO(2peak) during an incremental maximal exercise test and total energy expended during the effort and recovery phases of an all-out test that simulated grinding activity, in six grinders and mastmen and ten sailors of the same crew. Total energy used during grinding corresponded to 45% (s = 9) and 51% (s = 5) of that used in the all-out test (234 kJ, s = 21.7) for tacks and gybes, respectively. In both grinding activity and the all-out test, VO(2) increased during and after the effort. The "VO(2) top value" was 53% (s = 8.6), 68% (s = 5.5), and 78% (s = 3.1) of VO(2peak) (4.7 l . min(-1), s = 0.43) in tacks, gybes, and the all-out test, respectively. During fast sequences of grinding activity, the "VO(2) top value" reached 65% (s = 7.1) VO(2peak) in tacks and 91% (s = 3.3) VO(2peak) in gybes. Our results suggest that grinders and mastmen are characterized by a high anaerobic capacity but their performance can be improved by powering aerobic fitness, to increase this energy contribution to all-out efforts and to guarantee fast recovery when grinding activity is repeated with short rest intervals.  相似文献   

13.
曹洪宇  李军 《冰雪运动》2010,32(2):6-8,31
有氧训练是提高优秀女子速滑1000m运动员速度耐力的基础,良好的速度耐力基础是提高运动员比赛成绩的关键。研究发现我国优秀女子速滑1000m运动员在比赛600～1000m段落降速较国外运动员明显,表明速度耐力不足是运动成绩不佳的重要原因之一。提出改变训练理念,通过控制有氧训练的强度、有氧训练的比例、有氧训练的质量有效掌握有氧训练的负荷;采用风阻式速度滑冰专项能力训练器、高住低训等新的训练方法、手段,提高我国优秀女子速滑1000m运动员的有氧能力。  相似文献   

14.
ABSTRACT

The study assesses the test–retest reliability of movement and physiological measures during a simulated rugby match that employed activities performed in a stochastic order. Twenty male rugby players (21.4 ± 2.1 y) completed two trials of a 2 × 23 min rugby movement simulation protocol during which the order of events was performed in a stochastic order, with 7–10 days between trials. Movement characteristics, heart rate (HR), RPE, maximum voluntary contraction (MVC), voluntary activation (VA%) of the quadriceps, Stroop test and subjective task load rating (NASA-TLX) were measured. The most reliable measures of external load was relative distance (typical error [TE] and CV% = 1.5–1.6 m min?1 and 1.4–1.5%, respectively), with all other movement characteristics possessing a CV% <5%. The most reliable measure of internal load, neuromuscular function and perceptual measures were for %HRmax (TE and CV% = 1.4–1.7% and 1.4–2.1%, respectively), MVC before (TE and CV% = 10.8–14.8 N·m and 3.8–4.6%, respectively), and average RPE (TE and CV% = 0.5–0.8 AU and 3.6–5.5%, respectively). The Stroop test, NASA-TLX and blood lactate produced the least reliable measures (CV% >5%). Future studies can confidently examine changes in several perceptual, neuromuscular, physiological and movement measures related to rugby activity using stochastic movements.  相似文献   

15.
研究目的 :探讨了 mt DNA D- loop多态性与澳大利亚自行车运动员的 VO2 max及优异耐力成绩的关系。研究结果 :前期研究发现虽然运动员组和对照组 VO2 max有显著性差异 ,但 mt DNA D- loop的多态性在两组的分布频率没有显著性差异  相似文献   

16.
游泳运动训练的生理、生化监控方法研究   总被引：8，自引：1，他引：7  
采用实验测试法对国家游泳队运动员的生理生化监控方法进行研究。研究表明：游泳运动员血液生化指标的评价参考范围也表现出一定的性别和5个级别差异性；科学的高原训练计划可以提高运动员的有氧代谢能力；无氧酵解能力训练手段对不同优秀游泳运动员有着不同的影响；同一种磷酸原供能训练方法并非可以同时适合于不同的运动员；相同负荷训练后运动员成绩越好、恢复心率越快，则表明运动员机能状况越佳；单一生理生化指标并不能完全监控游泳周（阶段）训练后的恢复情况。  相似文献   

17.
Previous studies have reported strong correlations between 5-km performance times and maximal oxygen uptake (VO2 max) and also for running speeds equivalent to blood lactate concentrations of 4 mM. However, there is little information on the physiological responses of individuals during races over this distance. Therefore, the aim of the present study was to measure the physiological and metabolic responses of endurance trained male (n = 8) and female (n = 8) runners during a 5-km time trial using an instrumented treadmill. Performance times were 18.77 +/- 1.27 min for the men and 21.80 +/- 1.98 min for the women (P less than 0.01). The corresponding times on the athletics track were 17.68 +/- 0.39 min for the men (P less than 0.05) and 20.70 +/- 2.16 min for the women (N.S.). During the treadmill time trials, both the men and women were able to utilize approximately 90% VO2 max, 82% VE max, 98% HR max and produce similar concentrations of blood lactate. Although the physiological and metabolic responses of these endurance-trained men and women to 5-km treadmill running were similar, the faster running times recorded by the men in this study were the result of their higher VO2 max values.  相似文献   

18.
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。  相似文献   

19.
高水平耐力运动员高强度间歇训练的生理机制   总被引：2，自引：0，他引：2  
张勇  李之俊 《体育科研》2005,26(5):66-69
次最大强度训练对经过长期训练的高水平耐力运动员的运动成绩和相关生理指标的提高作用甚少。研究发现通过高强度的间歇训练(HIT)可以提高他们的运动成绩。但是,关于高水平耐力运动员 HIT 的相关生理机制并不十分清楚。本文就高水平耐力运动员高强度间歇训练的相关生理机制的研究进展加以总结和展望。  相似文献   

20.
In 19 elite schoolboy rowers, the relationships between anthropometric characteristics, metabolic parameters, strength variables and 2000-m rowing ergometer performance time were analysed to test the hypothesis that a combination of these variables would predict performance better than either individual variables or one category of variables. Anthropometric characteristics, maximal oxygen uptake (VO2max), accumulated oxygen deficit, net efficiency, leg strength and 2000-m rowing ergometer time were measured. Body mass, VO2max and knee extension correlated with 2000-m performance time (r= -0.41, -0.43 and -0.40, respectively; P< 0.05), while net efficiency and accumulated oxygen deficit did not. Multiple-regression analyses indicated that the prediction model using anthropometric variables alone best predicts performance (R = 0.82), followed by the equation comprising body mass, VO2max and skinfolds (R = 0.80). Although the regression equations increased the predictive power from that obtained using single variables, the hypothesis that a prediction model consisting of variables from different physiological categories would predict performance better than variables from one physiological category was not supported.  相似文献   

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