上海男子体操运动员青春发育状况的调查研究

通过对上海男子体操运动员青春发育状况调查和下丘脑——垂体——性腺轴功能检查,进一步探讨大负荷、高难度运动训练对男子少年体操运动员青春发育的影响。结果显示;(1)上海男子体操运动员青春发育明显延迟。(2)实验运动员性腺轴功能差,其主要原因是下丘脑分泌LHRH功能受抑制。     

上海男子体操运动员青春发育状况的调查研究

通过对上海男子体操运动员青春发育状况调查和下丘脑——垂体——性腺轴功能检查,进一步探讨大负荷、高难度运动训练对男子少年体操运动员青春发育的影响。结果显示;(1)上海男子体操运动员青春发育明显延迟。(2)实验运动员性腺轴功能差,其主要原因是下丘脑分泌LHRH功能受抑制。     

花样滑冰运动员的控制训练

1 制定多年训练计划的基本原则 制定多年训练计划要考虑下列几点:花样滑冰运动员达到最高技术水平的平均年限,出现最好成绩的年龄,开始专门训练的年龄。花样滑冰运动员达到最高技术水平需9—10年。首次出现好成绩的年龄为单人滑:男子16±1.9岁,女子15±2.1岁;成绩下降的年龄为男子17.7±1岁,女子17.6±1.8     

对女子体操训练启蒙年龄的研究

女子体操训练习练启蒙年龄，在不同的年代，有过不同的看法。本文立足于九十年代体操发展的水平、从人体生长发育的规律、体操教学训练大纲的要求、运动员初出成绩的年龄出发，分析探讨女子体操启蒙训练的最佳年龄。     

我国 12～14 岁少年女子体操运动员专项身体素质训练的研究

查阅有关身体素质训练的相关文献,对国内的知名体操专家及教练员问卷调查有关女子体操运动员在12-14岁年龄专项身体素质训练相关问题,并对调查结果进行测试检验,统计分析制定出此年龄段女子体操运动员专项身体素质等级划分标准,进而提出运动员专项身体素质训练的内容和科学控制负荷量.     

女子体操运动员肘关节损伤的原因与预防

本文以11-17岁女子体操运动员为研究对象探讨肘关节损伤的规律及预防措施,为制订科学的训练计划提供依据。1.创伤原因与机理1.1年龄和训练年限的原因体操运动员开始专项训练的年龄越来越小,她们本身的身体发育尚未成熟,运动支撑器官还很软弱,力量、耐力等身体素质比成年运动员差,与高难度,大强度的现代体操训练要求不相适应。随着年     

对女子体操运动员启蒙训练的研究

优秀的体操运动员必须经过启蒙训练,一般年龄都在男子5-6岁,女子4—5岁。启蒙训练必须经过4个阶段：首先是运动员的选材,其次是培养运动员对项目的兴趣和爱好,第三是进行科学的意识培养训练,最后是进行专业技术教学。     

谈青少年体操运动员的选材

1．青少年体操运动员选材的特点 1．1早期选材是体操运动的重要特征 现代竞技体操项目经过不断地发展，逐渐呈现出运动员低龄化的特点，特别是女子运动员在13、14岁登上世界大赛领奖台的不胜枚举。由于比赛年龄小，则开始训练的年龄必然更小，目前各国女子体操运动员的开始训练年龄已经提前到6、7岁，甚是更早。     

我国10～11岁女子体操运动员力量素质指标筛选及发展标准

采用文献资料法、专家调查法和数理统计法等,对我国32名10～11岁女子体操运动员力量素质进行研究,筛选出对10～11岁女子体操运动员专项成绩有显著影响的力量素质指标,运用灰色关联方法确定力量素质指标的权重系数,建立10～11岁女子体操运动员力量素质发展的理想标准值,为科学调控10～11岁女子体操运动员力量训练,最优控制力量训练过程提供参考。     

女子体操运动员训练中的误区——控制体重

有关文献资料研究,证明控体重,特别对少年女体操运动员而言实为训练中的误区,危害尤甚。控制体重之法不可取。在此简要论述其危害。一、女子体操运动员的合理营养运动员要出成绩,就必须进行大运动量训练。现在我国女子体操每周一般进行9次约36小时左右的训练,而且早操还不计算在内。如此之大的训练运动量,必然消耗大量的能量。此外,正常     

Protective role of 17-β-estradiol towards IL-6 leukocyte expression induced by intense training in young female athletes

Abstract

Exercise performed at a competitive level could deeply modify the immune system and the cytokine response of athletes. In this report, we demonstrated that young elite female artistic gymnasts (n = 16; age: 9–15 years) showed an increase of interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α) mRNA expression in blood mononuclear cells (PBMCs), in comparison to girls performing the same sport at a recreational level (n = 16; age: 10–15 years). The increase of IL-6 and TNF-α mRNAs appeared to be directly linked to the intensity and duration of the training. Moreover, in elite athletes engaged in artistic gymnastics or in synchronised swimming (n =34; age: 9–15 years), IL-6 gene expression appeared to be modulated by the levels of circulating oestrogens: pre-pubertal athletes (n = 20; age: 11 ± 1 years) revealed a higher increase in IL-6 than pubertal athletes (n = 14; age: 14 ± 1.6 years). In pre-pubertal athletes, body mass index (BMI) percentile was inversely correlated with the increase of both IL-6 and TNF-α. The consequence of these events was the shift of the cytokine profile towards a pro-inflammatory status. These modifications, induced by training performed at an elite level, might negatively affect the growth of female children athletes.     

Low energy availability and low body fat of female gymnasts before an international competition

Abstract

The purpose of the present study was to evaluate dietary intake and body composition of elite rhythmic gymnastics (RG) athletes prior to a competition event. Sixty-seven rhythmic gymnasts (18.7 ± 2.9 years old) of high performance level, with 36.6 ± 7.6 h of training/week were evaluated in order to collect training and competition data, medical and gynaecological history, detailed dietary intake and body composition before an international competition. The majority of the participants (n = 40; 59.7%) had already menstruated, but age of menarche was delayed (15.3 ± 1.3 years) and all revealed menstrual irregularities. Gymnasts' body mass (48.4 ± 4.9 kg) and body mass index (BMI; 17.4 ± 1.1 kg/m²) were below the normal for age, and height (1.66 ± 0.05 m) was normal or even slightly above normal for age. Body fat was 9.0 ± 2.0% with no significant differences between age strata. Gymnasts exhibited low energy availability (EA; 31.5 ± 11.9 kcal/kg fat-free mass (FFM)/day). The average carbohydrate and protein intakes were 5.1 ± 2.3 g/kg/day and 1.6 ± 04 g/kg/day, which correspond to 51.4 ± 7.2% and 16.9 ± 3.4% of total energy intakes, respectively; average fat contribution was 33.0 ± 5.3%. Low intakes of pantothenic acid, folate and vitamins D, E and K and of minerals, including calcium, iron and magnesium were reported. Intakes of thiamine, riboflavin, niacin, vitamins A, B-6, B-12, C and manganese and zinc were above-adequate (P < 0.05). Low EA, low body fat and micronutrient deficiencies are common among RG.     

Performance characteristics of Parkour practitioners: Who are the traceurs?

Parkour is a modern physical activity that consists of using the environment, mostly urban, as a playground of obstacles. The aims of this study were (i) to investigate age, anthropometric and training characteristics of Parkour practitioners, called ‘traceurs’ and (ii) to assess jump performances and muscular characteristics of traceurs, compared to those of gymnasts and power athletes. The mean age of the population of traceurs studied (n?=?130) was 19.4?±?4.3 years, women represented 12.4% of the total field and mean training volume was 8.1?±?0.5?hours/week. Vertical and long jump performances were analysed on smaller samples of participants (four groups, n?=?15 per group); and eccentric (?90°?s^?1, ?30°?s^?1), concentric (30°?s^?1, 90°?s^?1) and isometric knee extensors torques were evaluated by means of an isokinetic dynamometer. Traceurs showed greater (P?P?P?P?相似文献   

Superior short-term learning effect of visual and sensory organisation ability when sensory information is unreliable in adolescent rhythmic gymnasts

Rhythmic gymnasts specialise in dynamic balance under sensory conditions of numerous somatosensory, visual, and vestibular stimulations. This study investigated whether adolescent rhythmic gymnasts are superior to peers in Sensory Organisation test (SOT) performance, which quantifies the ability to maintain standing balance in six sensory conditions, and explored whether they plateaued faster during familiarisation with the SOT. Three and six sessions of SOTs were administered to 15 female rhythmic gymnasts (15.0 ± 1.8 years) and matched peers (15.1 ± 2.1 years), respectively. The gymnasts were superior to their peers in terms of fitness measures, and their performance was better in the SOT equilibrium score when visual information was unreliable. The SOT learning effects were shown in more challenging sensory conditions between Sessions 1 and 2 and were equivalent in both groups; however, over time, the gymnasts gained marginally significant better visual ability and relied less on visual sense when unreliable. In conclusion, adolescent rhythmic gymnasts have generally the same sensory organisation ability and learning rates as their peers. However, when visual information is unreliable, they have superior sensory organisation ability and learn faster to rely less on visual sense.     

Carbohydrate intake and training efficacy – a randomized cross-over study

Carbohydrate (CHO) availability during endurance exercise seems to attenuate exercise-induced perturbations of cellular homeostasis and might consequently diminish the stimulus for training adaptation. Therefore, a negative effect of CHO intake on endurance training efficacy seems plausible. This study aimed to test the influence of carbohydrate intake on the efficacy of an endurance training program on previously untrained healthy adults. A randomized cross-over trial (8-week wash-out period) was conducted in 23 men and women with two 8-week training periods (with vs. without intake of 50g glucose before each training bout). Training intervention consisted of 4x45 min running/walking sessions/week at 70% of heart rate reserve. Exhaustive, ramp-shaped exercise tests with gas exchange measurements were conducted before and after each training period. Outcome measures were maximum oxygen uptake (VO_2max) and ventilatory anaerobic threshold (VT). VO_2max and VT increased after training regardless of CHO intake (VO_2max: Non-CHO 2.6 ± 3.0 ml*min^?1*kg^?1 p = 0.004; CHO 1.4 ± 2.5 ml*min^?1*kg^?1 p = 0.049; VT: Non-CHO 4.2 ± 4.2 ml*min^?1*kg^?1 p < 0.001; CHO 3.0 ± 4.2 ml*min^?1*kg^?1 p = 0.003). The 95% confidence interval (CI) for the difference between conditions was between +0.1 and +2.1 ml*min^?1*kg^?1 for VO_2max and between ?1.2 and +3.1 for VT. It is concluded that carbohydrate intake could potentially impair the efficacy of an endurance training program.     

Poor precompetitive sleep habits,nutrients’ deficiencies,inappropriate body composition and athletic performance in elite gymnasts

This study aimed to evaluate body composition, sleep, precompetitive anxiety and dietary intake on the elite female gymnasts’ performance prior to an international competition. Sixty-seven rhythmic gymnasts of high performance level were evaluated in relation to sport and training practice, body composition, sleep duration, daytime sleepiness by the Epworth Sleepiness Scale (ESS), sleep quality by the Pittsburgh Sleep Quality Index (PSQI), precompetitive anxiety by the Sport Competition Anxiety Test form A (SCAT-A) and detailed dietary intake just before an international competition. Most gymnasts (67.2%) suffered from mild daytime sleepiness, 77.6% presented poor sleep quality and 19.4% presented high levels of precompetitive anxiety. The majority of gymnasts reported low energy availability (EA) and low intakes of important vitamins including folate, vitamins D, E and K; and minerals, including calcium, iron, boron and magnesium (p?p?=?.001), sport practice (p?=?.024), number of daily training hours (p?=?.000), number of hours of training/week (p?=?.000), waist circumference (WC) (p?=?.008) and sleep duration (p?=?.005). However, it was negatively correlated with WC/hip circumference (p?=?.000), ESS (p?=?.000), PSQI (p?=?.042), SCAT-A (p?=?.002), protein g/kg (p?=?.028), EA (p?=?.002) and exercise energy expenditure (p?=?.000). High performance gymnasts presented poor sleep habits with consequences upon daytime sleepiness, sleep quality and low energy availability.     

Fluid and electrolyte balance in elite male football (soccer) players training in a cool environment

There are few data in the published literature on sweat loss and drinking behaviour in athletes training in a cool environment. Sweat loss and fluid intake were measured in 17 first-team members of an elite soccer team training for 90 min in a cool (5°C, 81% relative humidity) environment. Sweat loss was assessed from the change in body mass after correction for the volume of fluid consumed. Sweat electrolyte content was measured from absorbent patches applied at four skin sites. Mean (?± s) sweat loss during training was 1.69?±?0.45 l (range 1.06?-?2.65 l). Mean fluid intake during training was 423?±?215 ml (44?-?951 ml). There was no apparent relationship between the amount of sweat lost and the volume of fluid consumed during training (r ² = 0.013, P = 0.665). Mean sweat sodium concentration was 42.5?±?13.0 mmol?·?l^?1 and mean sweat potassium concentration was 4.2?±?1.0 mmol?·?l^?1. Total salt (NaCl) loss during training was 4.3?±?1.8 g. The sweat loss data are similar to those recorded in elite players undergoing a similar training session in warm environments, but the volume of fluid ingested is less.     

Body composition and inflammatory markers in pubertal girls: Comparison between athletes and non-athletic controls

Various inflammation parameters are increased with childhood obesity, but few comparable data are found in lean growing athletes. This study aims to characterize differences in 12 simultaneously measured inflammatory parameters between pubertal rhythmic gymnasts (RG) and untrained controls (UC), and to examine the relationship between body composition and inflammatory markers. Sixty 10–12-year-old girls were divided into RG (n?=?30) and UC (n?=?30). Fat mass (FM) and fat free mass (FFM) were measured by dual-energy X-ray absorptiometry. Leptin and 12 inflammatory parameters (interleukin [IL]-2, IL-4, IL-6, IL-8, IL-10, vascular endothelial growth factor, interferon-gamma [IFN-γ], tumor necrosis factor-alpha, IL-1α, IL-1β, monocyte chemotactic protein-1 and epidermal growth factor) were measured from fasting blood samples. No differences were seen in 12 inflammatory markers between studied groups. As expected, leptin (RG: 2.4?±?1.1; UC: 7.6?±?4.2?ng?ml^?1) and FM (RG: 7.3?±?2.3; UC: 11.8?±?5.1?kg) were lower (p?<?.05) in RG compared to UC. In the whole group of lean pubertal girls, 69.0% of the variability in body FM was determined by leptin, and 11.2% of the variability in body FFM was explained by IFN-γ. In conclusion, measured 12 inflammatory biomarkers were not different between RG and UC, despite lower leptin and FM in RG. In lean pubertal girls, IFN-γ was independently associated with FFM, and leptin with FM.     

Evaluation of pre-game hydration status,heat stress,and fluid balance during professional soccer competition in the heat

Abstract

In this study, we assessed initial hydration status (stadium arrival urine specific gravity), fluid balance (pre- and post-game nude body weight, fluid intake, urine collection), and core temperature changes (pre-game, half-time, post-game) during a professional soccer game. We monitored 17 male players (including goalkeepers) between arrival at the stadium and the end of the game (3 h), playing at 34.9°C and 35.4% relative humidity, for an average wet bulb globe temperature (WBGT) heat stress index of 31.9°C. Data are reported as mean±standard deviation (range). Initial urine specific gravity was 1.018±0.008 (1.003–1.036); seven players showed urine specific gravity ≥ 1.020. Over the 3 h, body mass loss was 2.58±0.88 kg (1.08–4.17 kg), a dehydration of 3.38±1.11% body mass (1.68–5.34% body mass). Sweat loss was 4448±1216 ml (2950–6224 ml) versus a fluid intake of 1948±954 ml (655–4288 ml). Despite methodological problems with many players, core temperatures ≥ 39.0°C were registered in four players by half-time, and in nine players by the end of the game. Many of these players incurred significant dehydration during the game, compounded by initial hypohydration; thermoregulation may have been impaired to an extent we were unable to measure accurately. We suggest some new recommendations for soccer players training and competing in the heat to help them avoid substantial dehydration.     

Asymmetry analysis of the arm segments during forward handspring on floor

Asymmetry in gymnastics underpins successful performance and may also have implications as an injury mechanism; therefore, understanding of this concept could be useful for coaches and clinicians. The aim of this study was to examine kinematic and external kinetic asymmetry of the arm segments during the contact phase of a fundamental skill, the forward handspring on floor. Using a repeated single subject design six female National elite gymnasts (age: 19?±?1.5 years, mass: 58.64?±?3.72?kg, height: 1.62?±?0.41?m), each performed 15 forward handsprings, synchronised 3D kinematic and kinetic data were collected. Asymmetry between the lead and non-lead side arms was quantified during each trial. Significant kinetic asymmetry was observed for all gymnasts (p?相似文献