浅谈400米运动员的速度耐力训练

运用文献资料法和数据统计分析法,对我国部分优秀运动员400米的速度耐力训练进行研究。研究认为,在400米跑这一径赛项目中,发展速度与发展速度耐力是提高该项目成绩的两大关键,也是训练实践中要解决的核心问题。本文以运动生理学、运动生物化学为依据,结合运动训练理论与方法,对发展速度耐力这一问题进行分析,并提出了400米跑中发展速度耐力的有效方法和手段。     

Intensity of exercise recovery,blood lactate disappearance,and subsequent swimming performance

Abstract

The aim of this study was to examine the effects of active versus passive recovery on blood lactate disappearance and subsequent maximal performance in competitive swimmers. Fourteen male swimmers from the University of Virginia swim team (mean age 20.3 years, s = 4.1; stature 1.85 m, s = 2.2; body mass 81.1 kg, s = 5.6) completed a lactate profiling session during which the speed at the lactate threshold (V_LT), the speed at 50% of the lactate threshold (V_LT.5), and the speed at 150% of the lactate threshold (V_LT1.5) were determined. Participants also completed four randomly assigned experimental sessions that consisted of a 200-yard maximal-effort swim followed by 10 min of recovery (passive, V_LT.5, V_LT, V_LT1.5) and a subsequent 200-yard maximal effort swim. All active recovery sessions resulted in greater lactate disappearance than passive recovery (P < 0.0001 for all comparisons), with the greatest lactate disappearance associated with recovery at V_LT (P = 0.006 and 0.007 vs. V_LT.5 and V_LT1.5 respectively) [blood lactate disappearance was 2.1 mmol · l^?1 (s = 2.0), 6.0 mmol · l^?1 (s = 2.6), 8.5 mmol · l^?1 (s = 1.8), and 6.1 mmol · l^?1 (s = 2.5) for passive, V_LT.5, V_LT, and V_LT1.5 respectively]. Active recovery at V_LT and V_LT1.5 resulted in faster performance on time trial 2 than passive recovery (P = 0.005 and 0.03 respectively); however, only active recovery at V_LT resulted in improved performance on time trial 2 (TT₂) relative to time trial 1 (TT₁) [TT₂?TT₁: passive +1.32 s (s = 0.64), V_LT.5+1.01 s (s = 0.53), V_LT?1.67 s (s = 0.26), V_LT1.5?0.07 s (s = 0.51); P < 0.0001 for V_LT). In conclusion, active recovery at the speed associated with the lactate threshold resulted in the greatest lactate disappearance and in improved subsequent performance in all 14 swimmers. Our results suggest that coaches should consider incorporating recovery at the speed at the lactate threshold during competition and perhaps during hard training sessions.     

Differences in distal lower extremity tissue masses and mass ratios exist in athletes of sports involving repetitive impacts

Abstract

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.     

App for the calculation of blood lactate markers

A new free app is available for the objective analysis of the blood lactate response to incremental exercise developed using Open-source R software.     

短跑运动的耐力素质机理及影响因素研究

短跑运动员运动成绩的提高主要取决于专项技术训练和一般身体素质训练的水平,短跑中的耐力素质也十分重要,教练员只有充分认识到耐力素质的重要性,才能更好地制定出科学的训练计划。通过文献资料法和综合分析法,对短跑耐力素质训练的生理机制及影响因素进行了综合论述与分析,以期为短跑的科学训练提供理论依据。     

Education in the Chinese national sport system: experiences of professional wushu athletes

Abstract

Within the Chinese national sport system, the government provides resources and funding to train athletes from a young age to become high-performance competitors. Though athletes are well supported to excel in their sport, during their years of intense physical training, athletes generally receive little to no formal education to prepare them for life outside of sport. The sacrifice of forgoing formal education to compete in elite level sport is not uncommon for athletes within centralized sporting systems and has been widely documented; however, there is little research that focuses on the impact of the team’s educational systems from the perspective of the athletes. To add to the growing body of research in this area, the authors utilized in-depth interviews to examine professional wushu athletes’ education experiences whilst training on their team. Thematic analysis of the findings revealed that athletes who committed themselves to sport training in the Chinese national system had to negotiate a number of factors related to time, motivation, social influences, and resources when it came to education and academia. Findings highlight the ways in which these athletes experience and come to terms with limited academic opportunities, preparation and support from their team and the training environment.     

我国优秀男子散打运动员身体功能训练研究

探讨身体功能训练在我国优秀男子散打运动员的应用实践效果,采用随机对照实验设计对我国24名优秀男子散打运动员进行为期16周、每周3次、每次60 min的身体功能训练。结果显示:(1)在基本运动能力方面,实验组在平板支撑、仰卧脚撑瑞士球平板支撑、悬吊侧卧平板支撑(左和右两侧)、单腿站平衡垫、瑞士球静蹲、坐位体前屈7项指标上较对照组有非常显著性改善(P<0.01);(2)在一般运动能力方面,实验组在400 m跑、单足4级跳、立卧撑3项指标上较对照组有显著性提高(P<0.05),在Illinois跑、高翻、卧推、深蹲等4项指标上较对照组有非常显著性提升(P<0.01);(3)在专项运动能力方面,实验组在10 s冲拳、10 s侧踹2项指标上较对照组有显著性提高(P<0.05),在30 s变向击打靶、30 s夹背摔假人、单次鞭腿击打力量、10 s腿法击打力量、10 s拳腿组合击打力量5项指标上较对照组有非常显著性提升(P<0.01)。结果表明:优秀男子散打运动员实验组的身体功能训练方案相对于对照组传统力量训练方案,强化了运动员的核心稳定性,优化了动作模式,加强了核心力量及其传输效率,对发展散打运动员的身体功能效果更佳。     

Physiological and metabolic responses of wheelchair athletes in different racing classes to prolonged exercise

The aims of this study were to examine and compare selected physiological and metabolic responses of wheelchair athletes in two paraplegic racing classes [T3: n?=?8 (lesion levels T1–T7; paraplegics); T4: n?=?9 (lesion levels below T7; paraplegics)] to prolonged exercise. In addition, we describe the responses of three tetraplegic athletes [T2: n?=?3 (lesion levels C6/C7: tetraplegics)]. Twenty athletes completed 90?min of exercise at 75% [Vdot]O_2peak on a motorized treadmill adapted for wheelchairs. The mean (±s) heart rates of the T3 and T4 racing classes were 165±2 and 172±6 beats?·?min^?1, respectively. For the T4 racing class, heart rate gradually increased during the test (P?<0.05), whereas for the T3 racing class, heart rate reached a plateau after an initial increase. The mean heart rate of the tetraplegics was 114±3 beats?·?min^?1. The T3 and T4 classes exhibited similar respiratory exchange ratios, plasma lactate and glucose concentrations throughout the test. For both the T3 and T4 racing class, free fatty acid, glycerol, ammonia, urea and potassium concentrations had increased from resting values by the end of the test (P?<0.05). In conclusion, the results of this study suggest that endurance-trained wheelchair athletes are able to maintain velocities equivalent to the same relative exercise intensity (75% [Vdot]O_2peak) for prolonged periods irrespective of lesion level.     

Changes in energy availability across the season in Division I female soccer players

Abstract

Low energy availability [(energy intake – exercise expenditure)/kg lean body mass], a component of the Female Athlete Triad, has been associated with menstrual disturbances and low bone mass. No studies have examined the energy availability of athletes across a season. The purpose of this study was to assess the prevalence of, and what contributes to, low energy availability in Division I female soccer players across a season. Nineteen participants aged 18–21 years (mean [Vdot]O_2max: 57.0 ± 1.0 mL · kg^?1 · min^?1) were studied during the pre, mid, and post season. Mean energy availability was overall lowest at mid season, and lower at mid than post season (35.2 ± 3.7 vs. 44.5 ± 3.7 kcal · kg^?1 lean body mass, P = 0.009). Low energy availability (<30 kcal · kg^?1 lean body mass) was observed in 5/19 (26.3%), 5/15 (33.3%), and 2/17 (11.8%) of participants during the pre, mid, and post season. Dietary energy intake was lower mid (P = 0.008) and post season (P = 0.022) than it was pre season (pre: 2794 ± 233 kcal · day^?1; mid: 2208 ± 156 kcal · day^?1; post: 2161 ± 143 kcal · day^?1). Exercise energy expenditure decreased significantly (P ≤ 0.001) over time (pre: 819 ± 57 kcal · day^?1; mid: 642 ± 26 kcal · day^?1; post: 159 ± 28 kcal · day^?1). Low energy availability was due to lower dietary energy intake at lunch during pre season (P = 0.014) and during lunch and dinner during mid season (P ≤ 0.030). Energy availability was inversely related to body dissatisfaction (r = ?0.62, P = 0.017) and drive for thinness (r = ?0.55, P = 0.041) during mid season. Although most Division I female soccer players are not at risk for low energy availability, a concerning proportion exhibited low energy availability at pre or mid season. Further studies are needed to explore strategies to prevent and monitor low energy availability in these athletes.     

对我国优秀短距离速滑运动员力量耐力的研究--运用"最大力量能力阈"评价力量耐力水平的试验

运用“最大力量能力阈”的测试方法,对国内10名男子和10名女子优秀短距离速滑运动员的力量耐力进行测试与研究。建立了力量的检测与评价平台,从负荷重量与运动速度两个方面综合评价运动员的力量素质能力。从力量素质的结构上发现了我国速滑运动员存在的问题,提出了在保持最大力量和快速力量的基础上优先发展“力量耐力”,特别是“速度力量耐力”的力量训练指导思想。通过1年多的实施已显示出明显的效果。对备战2006年冬季奥运会的重点运动员进行了系统测试和专门指导,获得了显著的训练效果。     

优秀运动员"运动寿命"解析

界定了运动寿命的概念，分析了运动寿命与年龄、竞赛成绩的关系以及影响运动寿命的因素。     

青年女子摔跤运动员无氧代谢能力的变化特点

为了探讨优秀青年女子自由式摔跤运动员无氧代谢能力纵向变化特点,以北京体育大学竞技体校女子摔跤队13名优秀青年运动员为研究对象,采用Wingate834E功率自行车对其无氧代谢能力进行为期3年的测试和分析。测试共进行了三次,测试时间分别安排在2008、2009和2010年全国青年女子自由式摔跤锦标赛的准备期第二阶段(专门准备期),测试对象为同一组运动员。结果发现:1)随着年龄和训练年限的增长,反映运动员无氧代谢能力的各项指标均得到不同程度提高,其中,PP(最大无氧功率)、AP(平均功率)和T-SP(维持最大功率的时间)这三项指标得到显著提高(P<0.05、P<0.01);2)T-AP和T-SP(达到和维持最大功率时间)这两项指标的变异系数(CV%)较高,表明无论优秀青年女子摔跤运动员竞技水平的高低,其无氧代谢能力都具备较高的储备和提升空间。     

Prediction of performance by heart rate-derived parameters in recreational runners

We investigated whether heart rate (HR)-derived parameters are accurate performance predictors in endurance recreational runners. One hundred thirty recreational athletes completed an incremental running test (4´running + 1´rest). After each stage, we recorded HR, % of maximum HR (%HRmax), and blood lactate. We also assessed HR after each recovery period, and calculated lactate and HR recovery thresholds and HR deflection point. We tested these parameters for associations with running performance, as measured by peak treadmill speed (PTS) and personal best International Association of Athletics Federations (IAAF) score. The %HRmax at 14.5 km·h^?1 correlated with PTS (r = ?0.92), and IAAF score (rho = ?0.80). The magnitudes of the correlations of lactate-related parameters with PTS (|r| = 0.84 to 0.86) or IAAF score (|rho| = 0.70 to 0.77) in absolute values were slightly lower. The correlations detected between other HR-derived parameters and running performance were weaker (|r or rho| = 0.24 to 0.70). Regression models identified %HRmax at 14.5 km·h^?1 as the strongest predictor of both PTS (β = ?0.72) and IAAF score (β = ?0.72). Consequently, tests based on %HRmax may provide a non-invasive and inexpensive alternate method for predicting the performance of these athletes.     

有氧训练--提高我国耐力项目运动水平的关键

“耐力”是我国运动员普遍欠缺的素质，是造成我国体能类运动项目长期落后于世界水平的主要原因。忽视有氧训练，过于强调以提高运动员“乳酸耐受能力”为目标的高强度无氧训练，是我国大部分耐力项目训练中普遍存在的问题。研究结果表明，不能简单地将比赛的能量代谢特点作为指导长期运动训练、培养耐力能力的惟一依据，不同的代谢途径是一个有机整体，应当从机体“适应理论”的角度，从负荷对机体的正、负两方面的影响考虑耐力的训练。当前有氧训练已有了很大变化，有氧训练与力量和技术训练的密切结合是耐力训练的一个重要发展趋势。     

Identification of critical intensity from a single lactate measure during a 3-min,submaximal cycle-ergometer test

We tested the hypothesis that critical intensity in cycling can be determined from a single delta blood lactate in the third minute of a submaximal cycle ergometer trial. Fourteen healthy young men performed four to six constant-power-output trials on a cycle ergometer to the limit of tolerance. Critical intensity was calculated via a linear model and subsequently validated. Lactate was measured at baseline and at 3 min from exercise onset. Delta lactate was the difference between these measures. Based on individual trials, we obtained the delta lactate–% validated critical intensity relationship and thereafter an estimate of critical intensity was computed. Validated and estimated critical intensity were compared by effects sizes, paired-sample t-test and Bland–Altman analysis. Delta lactate was a linear function of the intensity of exercise, expressed as % validated critical intensity (R² = 0.89). Estimated critical intensity was not different from (d = 0.03, P = 0.98) and highly correlated with (R² = 0.88) validated critical intensity. The bias between measures was 0.03 W (≠0) with a precision of 7 W. The results suggest that critical intensity in cycling can be accurately and precisely determined from delta lactate during a sub-maximal trial and so provides a practical and valid alternative to direct determination.     

运用积分肌电阈评定赛艇运动员有氧耐力的研究

文章报道了江西省赛艇运动员的积分肌电阈均值,指出赛艇运动员的积分肌电阈与乳酸无氧阈、3000米耐力跑成绩,以及6分钟划船测功计全力划行的平均功率,都呈高度相关;同时,发现优秀选手组,不仅在3000米耐力跑成绩和6分钟划船测功计全力划行的平均功率上高于一般选手组,而且在积分肌电阈值上,也高于一般选手组。说明运用积分肌电阈评定赛艇运动员的有氧耐力是可行的。     

Upper and lower thresholds of fat-free mass index in a large cohort of female collegiate athletes

ABSTRACT

Fat-free mass index (FFMI) is a height-adjusted metric of fat-free mass which has been suggested as a useful method of body composition assessment in athletic populations. The purpose of this study was to determine sport-specific FFMI values and the natural upper threshold of FFMI in female athletes. 372 female collegiate athletes (Mean±SD; 20.03±1.55 years, 167.55±7.50 cm, 69.46±13.04 kg, 24.18±5.48% bodyfat) underwent body composition assessment via dual-energy x-ray absorptiometry. FFMI was adjusted to height via linear regression and sport-specific reference values were determined. Between-sport differences were identified using one-way ANOVA with Tukey post-hoc tests. Average FFMI was 18.82±2.08 kg/m²; height-adjusted values were not significantly different (p<0.05) than unadjusted values. FFMI in rugby athletes (20.09±2.23 kg/m²) was found to be significantly higher (p<0.05) than in gymnastics (18.62±1.12 kg/m²), ice hockey (17.96±1.04 kg/m²), lacrosse (18.58±1.84 kg/m²), swim & dive (18.16±1.67 kg/m²), and volleyball (18.04±1.13 kg/m²). FFMI in cross country (16.56±1.14 kg/m²) and synchronized swimming (17.27±1.47 kg/m²) was significantly lower (p<0.05) than in Olympic weightlifting (19.69±1.98 kg/m²), wrestling (19.15±2.47 kg/m²), and rugby. The upper threshold for FFMI in female athletes (97.5^th percentile) was 23.90 kg/m². These results can be used to guide personnel decisions and assist with long-term body composition, training, and nutritional goals.     

优秀男子跆拳道运动员后横踢技术动作的表面肌电特征研究

研究目的:选取国家队优秀男子跆拳道运动员的后横踢技术动作进行肌电分析,揭示跆拳道运动员的用力特征。研究方法:运用美国产Noraxon表面肌电遥测系统对14名国家跆拳道队男子运动员进行测试,并根据后横踢技术特点,分别选取了三组肌肉进行测试。研究结果:1)从肌肉的激活顺序来看,以左侧竖脊肌、左侧胫骨前肌最先发力,但与此同时,右侧的胫骨前肌和腓肠肌也同时被激活;2)从肌力特征来看,右侧肌群的肌力值相对较大,在整个的后横踢技术动作中占有绝对的优势,相比之下,左侧肌群肌力较小,并且肌肉的募集能力相对较低(40%以下);3)在肌电的持续时间上,左侧肌群持续时间相对较短(0.20s以下),右侧肌群持续时间较长,表明它们是主要做功肌群,但左侧半腱半膜肌无论是在肌力动员方面(46.8%),还是在积分肌电方面(326.00uv.s),或是在激活顺序(0.06s)和持续时间上(0.70s),都表现出非常高地贡献作用。研究结论:由于左侧和右侧具有同时肌肉放电的现象,因此,训练中在加强左侧支撑用力的同时,应逐步提高运动员动作腿的起动速度训练,并加强右侧主动肌和拮抗肌的用力效果。此外,应特别关注左侧半腱半膜肌等肌肉的力量训练。     

跑节省化、无氧阈和最大摄氧量评价篮球运动员有氧能力的比较研究

以天津商务职业学院24名男篮球队员为研究对象,通过跑台测试、因子分析法等,采用跑节省化、无氧阈和最大摄氧量对篮球运动员进行评价分析。结果显示:篮球运动员跑节省化的修正值在第一公因子中载荷最大,在第二、第三公因子中跑节省化相关指标的载荷量处于相对重要位置,在第四公因子中只有跑节省化时通气量;跑节省化、无氧阈和最大摄氧量三指标在评价篮球运动员有氧耐力时,跑节省化指标优势明显。提示:跑节省化可以作为评价篮球运动员有氧耐力的首选指标。     

Expert-level classification of ventilatory thresholds from cardiopulmonary exercising test data with recurrent neural networks

Abstract

First and second ventilatory thresholds (VT₁ and VT₂) represent the boundaries of the moderate-heavy and heavy-severe exercise intensity. Currently, VTs are primarily detected visually from cardiopulmonary exercise test (CPET) data, beginning with an initial data screening followed by data processing and statistical analysis. Automated VT detection is a challenging task owing to the high signal to noise ratio typical of CPET data. Recurrent neural networks describe a machine learning form of Artificial Intelligence that can be used to uncover complex non-linear relationships between input and output variables. Here we proposed detection of VTs using a single neural network classifier, trained with a database of 228 laboratory CPET data. We tested the neural network performance against the judgement of 7 couples of board-certified exercise-physiologists on 25 CPET tests. The neural network achieved expert-level performances across the tasks (mean absolute error was 9.5% (r?=?0.79) and 4.2% (r?=?0.94) for VT₁ and VT₂, respectively). Estimation errors are compatible with the typical error of the current gold standard visual methodology. The neural network demonstrated VT detecting and exercise intensity level classifying at a high competence level. Neural networks could potentially be embedded in CPET hardware/software to extend the reach of exercise physiologists beyond their laboratories.