体育项目中的训练与过度训练特征

目的:多种症状都支持对过度训练(OT)的探查。测量血清尿素(SU)和血清肌氨酸激酶(CK)值,除了对优秀运动员进行诊断和分析之外,也用于对运动员日常训练状态进行监控。因此,我们将根据不同运动员,同一运动员的不同状态,对这些指标的意义进行检验。方法:测试时象为具有国际水平的赛艇运动员,所有数据均来自于对这些运动员训练过程的测试。结果:6981例血清尿素测试样本(男运动员717人,女运动员285人)表明, 数据呈现出一种轻微不对称的正态分布态势(男运动员80％,5～7mmol·L-1;女运动员75％, 4～6mmol·L-1)。女运动员的数值比男运动员约低1．5mmol·L-1,个体差异较大,因此以 8．3mmol·L-1(男运动员)和7．0mmol·L-1(女运动员)作为判断运动员过度训练的固定阈值是不可靠的。在运动训练中,肌氨酸激酶(CK)也已被作为判定肌肉紧张的重要参数进行检测和评价。2790例肌氨酸激酶测试样本(男运动员497人,女运动员350人)显示,数据的频率分布为不对称的正态分布,在100—250U·L-1的区域内具有明显偏向高值区域的趋势,在250～ 350U·L-1和1000～2000U·L-1范围内分布频数明显升高。男运动员的最高值为3000U·L- 1,女运动员最高值为1150U·L-1,个体差异显著。血清肌氨酸激酶水平长期较低的运动员显示出小的数值变化;血清肌氨酸激酶水平长期较高的运动员在数值上显示出显著的变化波动。结论:这两个参数也许都有助于从大量样本中测定个人数值基准线。对这两个参数的测量至少应该在标准条件下每3天进行一次。如果在一段时间的训练(2—4天)后同时观察到参数数值显著升高和训练耐受力降低,则表明机体的分解／合成代谢活动或训练耐受力不足的可能性升高。     

赛前强化训练和比赛对优秀女子赛艇运动员免疫系统机能的影响

通过对河南省参加2005年全国春季锦标赛的12名优秀女子赛艇运动员4周大运动量训练和比赛的跟踪调查，观察大运动量训练和比赛对其机体免疫机能的影响。结果显示：赛艇运动员机体的CD4及CD4D／CD。在比赛后显著下降、NK细胞显著上升、补体C4明显上升，而免疫球蛋白的变化不一。提示在对运动员免疫系统机能进行监测时，需同时监测免疫球蛋白、补体及T淋巴细胞亚群和NK细胞指标。     

Estimating fat-free mass in elite-level male rowers: a four-compartment model validation of laboratory and field methods

The purpose of this study was to investigate the accuracy of fat-free mass (FFM) estimates from two-compartment (2C) models including air displacement plethysmography (ADP), ultrasound (US), near-infrared interactance (NIR), and the Jackson and Pollock skinfold equation (SKF) against a criterion four-compartment (4C) model in elite male rowers. METHODS: Twenty-three elite-level male rowers (mean± SD; age 24.6 ± 2.2 years; stature: 191.4 ± 7.2 cm; mass: 87.2 ± 11.2 kg) participated in this investigation. All body composition assessments were performed on the same day in random order, except for hydrostatic weighing (HW), which was measured last. FFM was evaluated using a 4C model, which included total body water from bioimpedance spectroscopy, body volume from HW, and total body bone mineral via dual-energy X-ray absorptiometry. The major findings of the study were that the 2C models evaluated overestimated FFM and should be considered with caution for the assessment of FFM in elite male rowers. Future studies should use multiple-compartment models, with measurement of TBW and bone mineral content, for the estimation of FFM.     

Sleep and stress hormone responses to training and competition in elite female athletes

Stress hormone and sleep differences in a competition versus training setting are yet to be evaluated in elite female team-sport athletes. The aim of the current study was to evaluate salivary cortisol and perceptual stress markers during competition and training and to determine the subsequent effects on sleep indices in elite female athletes. Ten elite female netball athletes (mean?±?SD; age: 23?±?6 years) had their sleep monitored on three occasions; following one netball competition match (MATCH), one netball match simulation session (TRAIN), and one rest day (CONTROL). Perceived stress values and salivary cortisol were collected immediately pre- (17:15 pm) and post-session (19:30 pm), and at 22:00 pm. Sleep monitoring was performed using wrist actigraphy assessing total time in bed, total sleep time (TST), efficiency (SE%), latency, sleep onset time and wake time. Cortisol levels were significantly higher (p?p?p?相似文献   

Fluid balance and hydration assessment during the weight-stable preparation phase in elite youth boxers

This study investigated (i) the prevalence of hypohydration and (ii) association between urinary indices of hydration status and confounding factors (e.g., urine protein content, water intake) in elite youth boxers during their weight-stable phase before competition. Sixteen national champion boxers (all male, 17 ± 1 y) were measured on 3 occasions (baseline, day 3, day 10), 30-day prior to competition. Body mass, total body water, urine specific gravity (USG), osmolality (UOSM) and total protein content (TPC) were evaluated to determine hydration status and fluid balance. Overall macronutrient and water intake were assessed using dietary records. Both UOSM and USG increased from day 3 to day 10 by 16% and 0.4% (P < 0.001), despite athletes being in their weight-stability period, and regardless of ad libitum fluid intake. Hypohydration was universally prevalent among all athletes on both test days with USG: 1.027 ± 0.003 g · mL^?1 and UOSM: 1035 ± 108 mOsmol · kg^?1. An inverse association between mean UOSM values and mean water intake was observed (R = ?0.52, P = 0.04), while TPC was not associated with any urinary dehydration markers (USG, P = 0.51; UOSM, P = 0.61). The present outcomes find that the most prevalent urinary dehydration markers used to classify hydration status in competition exhibit large variability, even during weight-stable periods.     

Hormonal and psychological adaptation in elite male rowers during prolonged training

In this study, we examined possible hormonal and psychological changes in elite male rowers during a 24-week preparatory period. Eleven elite male rowers were tested on seven occasions over the 6-month training season. Fasting testosterone, growth hormone, cortisol, and creatine kinase activity, together with perceived recovery-stress state were evaluated after a day of rest. Maximal oxygen consumption (VO2max) was determined before and after the training period. Training was mainly organized as low-intensity prolonged training sessions. Significant increases in VO2max (from 6.2 +/- 0.5 to 6.4 +/- 0.6 l x min(-1)) were observed as a result of training. The overall perceived recovery-stress index did not change during the preparatory period. Standardized recovery and stress scores changed during the course of training in comparison with pre-training values. When basal hormone concentrations were compared with the first measurement, significant changes in testosterone and cortisol were observed together with changes in mean weekly training volume. Basal testosterone (r = 0.416; P = 0.010) and cortisol (r = 0.527; P = 0.001) were related to mean weekly training volume. Basal growth hormone did not change during the training. Changes in creatine kinase activity demonstrated similar pattern with changes in mean weekly training volume. The overall perceived recovery-stress index was related to testosterone, cortisol, growth hormone, and creatine kinase activity (r > 0.299; P < 0.015). Our findings indicate that testosterone and cortisol are more sensitive to changes in training volume than either growth hormone or perceived recovery-stress state in elite rowing training. Increases in these stress hormone concentrations represent a positive adaptation to current training load. Significant relationships between hormonal and perceived recovery-stress state suggest that metabolic and psychological changes should be carefully monitored to avoid a negative effect on the training status of elite rowers.     

Inspiratory muscle training effects on oxygen saturation and performance in hypoxemic rowers: Effect of sex

ABSTRACT

Exercise-induced arterial hypoxemia (EIAH) has been consistently reported in elite endurance athletes. This study examined the effects of an inspiratory muscle training protocol (IMT) on resting pulmonary function, end-exercise arterial oxygen saturation and performance in hypoxemic rowers. Twenty male and sixteen female well-trained hypoxemic rowers were divided into four groups: IMT-male, control-male, IMT-female and control-female. The IMT groups, additionally to the regular training, performed IMT (30 min/day, 5 times/week, 6 weeks). Before and after training, groups underwent an incremental rowing test, a 2000-m time trial and a 5-min “all-out” race. IMT increased respiratory strength in the IMT-male (135 ± 31 vs. 180 ± 22 cmH₂O) and IMT-female (93 ± 19 vs. 142 ± 22 cmH₂O) (P < 0.05). The IMT-female group exhibited lower EIAH and improved rowing performance in the 2000-m time trial (487 ± 32 vs. 461 ± 34 sec) and in the 5-min “all-out” test (1,285 ± 28 vs. 1,310 ± 36m) (P < 0.05). IMT protocol improved performance in IMT-male only in the 5-min test (1,651 ± 31 vs. 1,746 ± 37m) (P < 0.05). IMT may be a useful tool for increasing respiratory strength and enhancing performance in hypoxemic rowers, especially for women.

Abbreviations: EIAH: Exercise-induced arterial hypoxemia; IMT: inspiratory muscle training protocol; PaO2: partial pressure of arterial oxygen; SaO2: arterial oxyhemoglobin saturation; VO2max: maximal oxygen consumption; [(A-a)DO2]: alveolar-to-arterial oxygen difference; VA/Q: ventilation-perfusion inequality/mismatching; PImax: maximal inspiratory pressure; BMI: body mass index; BSA: body surface area; FVC: vital capacity; FEV1: forced expiratory volume in 1 sec; VCin: vital capacity; MVV12: maximal voluntary ventilation in 12 sec     

Psychological characteristics of male gymnasts: Differences between competitive levels

The purpose of this study was to examine whether any differences exist in the cognitive and behavioural strategies of gymnasts competing at different elite levels. Thirty‐eight male gymnasts competing at different competitive levels in an Australian gymnastic championship completed a standardized questionnaire prior to the first day of the competition. The questionnaire focused on a number of psychological factors that may affect both training and competition. Using both t‐tests and simple discriminant function analysis, it was revealed that gymnasts competing at different elite levels could be distinguished on the basis of two psychological factors, psychological recovery and self‐confidence, as well as the behavioural measure, training hours. Specifically, gymnasts competing at higher elite levels versus those at lower elite levels, were better able to recover from their competitive mistakes, were more confident and trained longer per week.     

优秀赛艇运动员赛前调控的方法

借鉴现代运动训练理论，依据赛艇运动的基本特征和赛艇运动训练的基本规律，对赛艇运动员赛前调控训练中影响调控的主要因素、训练时间与内容、训练负荷、手段方法，从理论上进行了分析与探讨。     

优秀中长跑运动员赛前训练血尿素氮( BUN) 变化特征分析

为了探索优秀中长跑运动员赛前训练身体机能评定的方法,对22名优秀中长跑运动员赛期训练过程中的血尿素氮(BUN)指标进行检测和分析。结果发现,血尿素氮(BUN)是反映中长跑运动员赛前训练运动负荷的敏感指标;优秀中长跑运动员血尿素氮(BUN)的基础值为(6.40±0.62)mmol/L;男女运动员血尿素氮(BUN)的运动值有显著性差异,基础值和恢复值两项指标都没有显著性差异,未见训练年限对血尿素氮(BUN)有影响;提出了适于优秀中长跑运动员周运动量的评价标准,在今后的实际训练中,可根据不同对象个体差异进行适当调整。     

The effect of two different 18-week walking programmes on aerobic fitness,selected blood lipids and factor XIIa

Abstract

The purpose of this project was to evaluate the utility of low- and high-repetition maximum (RM) strength tests used to assess rowers. Twenty elite heavyweight males (age 23.7 ± 4.0 years) performed four tests (5 RM, 30 RM, 60 RM and 120 RM) using leg press and seated arm pulling exercise on a dynamometer. Each test was repeated on two further occasions; 3 and 7 days from the initial trial. Per cent typical error (within-participant variation) and intraclass correlation coefficients (ICCs) were calculated using log-transformed repeated-measures data. High-repetition tests (30 RM, 60 RM and 120 RM), involving seated arm pulling exercise are not recommended to be included in an assessment battery, as they had unsatisfactory measurement precision (per cent typical error > 5% or ICC < 0.9). Conversely, low-repetition tests (5 RM) involving leg press and seated arm pulling exercises could be used to assess elite rowers (per cent typical error ≤ 5% and ICC ≥ 0.9); however, only 5 RM leg pressing met criteria (per cent typical error = 2.7%, ICC = 0.98) for research involving small samples (n = 20). In summary, low-repetition 5 RM strength testing offers greater utility as assessments of rowers, as they can be used to measure upper- and lower-body strength; however, only the leg press exercise is recommended for research involving small squads of elite rowers.     

Critical velocity: A predictor of 2000-m rowing ergometer performance in NCAA D1 female collegiate rowers

Abstract

The aims of this study were to examine the use of the critical velocity test as a means of predicting 2000-m rowing ergometer performance in female collegiate rowers, and to study the relationship of selected physiological variables on performance times. Thirty-five female collegiate rowers (mean ± s: age 19.3 ± 1.3 years; height 1.70 ± 0.06 m; weight 69.5 ± 7.2 kg) volunteered to participate in the study. Rowers were divided into two categories based on rowing experience: varsity (more than 1 year collegiate experience) and novice (less than 1 year collegiate experience). All rowers performed two continuous graded maximal oxygen consumption tests (familiarization and baseline) to establish maximal oxygen uptake ([Vdot]O_2max), peak power output, and power output at ventilatory threshold. Rowers then completed a critical velocity test, consisting of four time-trials at various distances (400 m, 600 m, 800 m, and 1000 m) on two separate days, with 15 min rest between trials. Following the critical velocity test, rowers completed a 2000-m time-trial. Absolute [Vdot]O_2max was the strongest predictor of 2000-m performance (r = 0.923) in varsity rowers, with significant correlations also observed for peak power output and critical velocity (r = 0.866 and r = 0.856, respectively). In contrast, critical velocity was the strongest predictor of 2000-m performance in novice rowers (r = 0.733), explaining 54% of the variability in performance. These findings suggest the critical velocity test may be more appropriate for evaluating performance in novice rowers.     

上海汉族优秀耐力运动员ACE基因I/D多态性与最大有氧能力(VO2max)的关联研究

采用PCR和breath by breath方法，对上海汉族55名优秀游泳运动员、60名优秀赛艇运动员和85名汉族普通人的ACE基因I／D多态性和VO2max进行检测。结果显示：1）上海汉族优秀游泳和赛艇运动员ACE基因的基因型和等位基因频率与上海和成都地区汉族普通人组无明显差异（P〉0．05）；与Caucasian人群相比，均存在非常显著性差异（P〈0．0001），表现出明显的民族和地区的差异性；游泳和赛艇项目健将和一级运动员间的基因型和等位基因频率分布，存在明显差异（P〈0．05）；游泳运动员水平越高，Ⅱ型所占比例就越高，赛艇运动员中水平越高，ID型的比例越大；2）不同基因型的游泳运动员的VO2max、VO2max／kg、VCO2max、VEmax、O2-plusemax、Wmax和Tmax等指标，均表现为Ⅱ型〉DD型〉ID型，Ⅱ型明显优于ID型（P〈0．05～0．01），而赛艇运动员则表现为ID型〉Ⅱ型〉DD型，ID明显优于DD型（P〈0．05～0．01）。结果提示，游泳项目中具有Ⅱ基因型或Ⅰ等位基因的运动员，赛艇项目中具有ID基因型或Ⅰ等位基因的运动员，可能属于运动训练敏感的高反应群体，经过多年系统科学的训练，具有成为优秀运动员的可能。ACE基因I／D多态性可作为运动训练和选材中高敏感的、非常重要的遗传标记之一。     

The effect on heart rate variability of acclimatization to a humid,hot environment after a transition across five time zones in elite junior rowers

Abstract

The aim of this study was to examine the simultaneous effect on heart rate variability (HRV) of acclimatization to a hot, humid environment and a transition of five time zones in elite junior rowers. Thirteen rowers (12 males and 1 female) participated in the study. Each rower was monitored during training camps in temperate and in humid, hot conditions before and during the Junior Rowing World Championship. All participants recorded the lengths of high-intensity training sessions, and R-R (the time between the R peaks of consecutive QRS complexes) intervals were measured every morning after awakening. Compared with baseline values taken during training before the transition to the new time zone and climate, HRV indices during first 3 days of acclimatization remained unchanged. On the fourth and fifth days of acclimatization, significant decreases in measures of heart rate variability in the standing position were observed. Beginning from the sixth day of acclimatization and for all subsequent days, the HRV indices, while standing, returned to baseline values and were not significantly different from baseline. Despite this, there were no significant changes in HRV measures in a supine position until the eighth day of acclimatization. R-R intervals decreased and mean heart rate increased significantly (P<0.001) during days 8–10 of acclimatization. In conclusion, major physiological adaptation of HRV indices in the standing position during acclimatization to a humid, hot environment, with a transition across five time zones, occurs within the first 5 days in elite athletes before returning to baseline. Indices of heart rate variability in the supine position correlate with the length of high-intensity training sessions on the previous day.     

上海汉族优秀耐力运动员ACE基因I/D多态性与最大有氧能力(O_2max)的关联研究

采用PCR和breath by breath方法,对上海汉族55名优秀游泳运动员、60名优秀赛艇运动员和85名汉族普通人的ACE基因I/D多态性和V。O2max进行检测。结果显示1)上海汉族优秀游泳和赛艇运动员ACE基因的基因型和等位基因频率与上海和成都地区汉族普通人组无明显差异(P>0.05);与Caucasian人群相比,均存在非常显著性差异(P<0.0001),表现出明显的民族和地区的差异性;游泳和赛艇项目健将和一级运动员间的基因型和等位基因频率分布,存在明显差异(P<0.05);游泳运动员水平越高,II型所占比例就越高,赛艇运动员中水平越高,ID型的比例越大;2)不同基因型的游泳运动员的O2max、O2max/kg、CO2max、Emax、O2-plusemax、Wmax和Tmax等指标,均表现为II型>DD型>ID型,II型明显优于ID型(P<0.05~0.01),而赛艇运动员则表现为ID型>II型>DD型,ID明显优于DD型(P<0.05~0.01)。结果提示,游泳项目中具有II基因型或I等位基因的运动员,赛艇项目中具有ID基因型或I等位基因的运动员,可能属于运动训练敏感的高反应群体,经过多年系统科学的训练,具有成为优秀运动员的可能。ACE基因I/D多态性可作为运动训练和选材中高敏感的、非常重要的遗传标记之一。     

Reference power values for the jump squat exercise in elite athletes: A multicenter study

ABSTRACT

The present study aimed to provide reference values for lower-limb muscle power assessed during the incremental jump squat (JS) test in elite athletes (i.e., professional athletes competing at international level). We pooled data from all JS tests performed by elite athletes of different sports in two high-performance centres between 2015 and 2019, and computed reference values (i.e., terciles) for mean power (MP), mean propulsive power (MPP), and peak power (PP). Reference values were obtained from 684 elite athletes (458 male and 226 female) of 16 different sports (boxing, judo, karate, fencing, taekwondo, wrestling, basketball, soccer, futsal, handball, rugby union, badminton, tennis, long distance running, triathlon, and sprinting). Significant differences (p < 0.001) were found between male and female athletes for MP (7.47 ± 1.93 and 6.15 ± 1.68 W·Kg^?1, respectively), MPP (10.50 ± 2.75 and 8.63 ± 2.43 W·Kg^?1), and PP (23.64 ± 6.12 and 19.35 ± 5.49 W·Kg^?1). However, the velocity at which these power measures was attained seemed to be independent of sex (~0.95, 1.00 and 2.00 m·s^?1 for mean, mean propulsive, and peak velocity, respectively) and homogeneous across different sport disciplines (coefficient of variation <10%). These data can be used to classify athletes’ power capabilities, and the optimum velocity ranges provided here could be useful for training purposes.     

Game movement demands and physical profiles of junior,senior and elite male and female rugby sevens players

To inform recruitment, selection, training and testing of male and female rugby sevens players game running movement patterns and physical characteristics were quantified across junior, senior, and elite playing levels. Anthropometric and physical testing (40 m sprint, vertical jump, Yo-Yo IR1) occurred prior to players’ national championships or international tournaments (n = 110 players), while game movements were obtained via GPS (n = 499 game files). The game movements of male players were similar across playing levels except for number of impacts >10 g which were 2 to 4-fold higher in elite (25.0 ± 11.2 impacts · game^?1; mean ± SD), than junior (6.3 ± 3.5) and senior (11.8 ± 6.6) players. In men, there were fewer substantial correlations between on- and off-field measures which may reflect similar physical attributes across playing levels, and that other (strength, technical or tactical) factors may better differentiate these players. In females, elite players had more favourable on- and off-field performance measures than juniors and seniors, with moderate to strong correlations between on- and off-field variables. Female players should benefit from additional fitness training, while male players need to balance fitness with other technical and tactical factors.     

Differences in body composition and risk of lifestyle-related diseases between young and older male rowers and sedentary controls

Abstract

The aim of this cross-sectional study was to compare body composition and risk factors of lifestyle-related diseases between young and older male rowers and sedentary controls. Healthy males aged 19–73 years participated in the study, and were divided into four groups: 26 young rowers, 24 senior rowers, 23 young sedentary controls, and 22 senior sedentary controls. Total and regional lean soft tissue, fat mass, and bone mineral density were measured using dual-energy X-ray absorptiometry. The HDL-cholesterol of senior rowers (67.4 ± 13.4 mg · dl^?1) was significantly (P < 0.05) higher than that of senior sedentary controls (59.2 ± 11.9 mg · dl^?1), while HDL-cholesterol was similar in senior rowers and young rowers (66.1 ± 10.8 mg · dl^?1). Arm, leg, and trunk lean soft tissue mass were significantly higher in senior rowers (5.6 ± 0.6 kg, 18.2 ± 1.8 kg, and 27.3 ± 3.2 kg respectively) than in senior sedentary controls (5.1 ± 0.4 kg, 16.3 ± 1.4 kg, and 24.6 ± 1.7 kg respectively; P < 0.05). Bone mineral density was also significantly higher in senior rowers than in senior sedentary controls (ribs, lumbar spine, and pelvic segments; P < 0.05). We conclude that age-related increases in the risk of lifestyle-related diseases, such as osteoporosis and sarcopenia, are attenuated in male rowers. These results suggest that regular rowing exercise may have a positive influence in the prevention of lifestyle-related diseases in older Japanese people.     

Relative shank to thigh length is associated with different mechanisms of power production during elite male ergometer rowing

The effect of anthropometric differences in shank to thigh length ratio upon timing and magnitude of joint power production during the drive phase of the rowing stroke was investigated in 14 elite male rowers. Rowers were tested on the RowPerfect ergometer which was instrumented at the handle and foot stretcher to measure force generation, and a nine segment inverse dynamics model used to calculate the rower's joint and overall power production. Rowers were divided into two groups according to relative shank thigh ratio. Time to half lumbar power generation was significantly earlier in shorter shank rowers (p = 0.028) compared to longer shank rowers, who showed no lumbar power generation during the same period of the drive phase. Rowers with a relatively shorter shank demonstrated earlier lumbar power generation during the drive phase resulting from restricted rotation of the pelvic segment requiring increased lumbar extension in these rowers. Earlier lumbar power generation and extension did not appear to directly affect performance measures of the short shank group, and so can be attributed to a technical adaptation developed to maximise rowing performance.