清华大学跳水队优秀运动员有氧代谢能力测试分析

目的:测试分析有潜力的学生跳水运动员的有氧代谢能力。方法:清华大学跳水队优秀跳水运动员9名,年龄13~15岁,采用递增负荷试验,运用心肺功能测试系统对运动员有氧能力进行测试与分析,测试过程中监测心率和心电图。结果:男运动员VO2max和VO2max/kg显著高于女运动员(P<0.01),男运动员无氧阈时的VO2和VO2/kg、%VO2max、HR、氧脉搏也显著高于女运动员(P<0.01)。结果提示:男运动员有氧能力显著优于女运动员,男子运动员所能承受的运动负荷与潜能大于女子,表明在13~15岁这个年龄阶段的优秀学生跳水运动员的有氧代谢能力存在性别差异,但整体水平还较弱,故训练中应给予重视,以保证长时间、大强度高难度动作的重复训练和比赛中技术水平的稳定发挥。     

优秀龙舟运动员尿液~1H NMR代谢组学研究

目的:应用1H NMR代谢组学方法对优秀龙舟运动员尿液代谢特征进行分析,结合尿常规进行全面、系统的训练监控。方法:于集训期间及比赛前后连续5次收集运动员晨尿,采用1H NMR的代谢组学方法结合尿常规检测,运用多元统计分析和t检验对实验数据进行分析。结果:(1)与安静时相比,男、女运动员尿液p H值、尿蛋白(PRO)和红细胞(BLD)阳性检出率分别在训练期和比赛后具有显著性变化(P<0.05),特别是集训1周和集训2周时。(2)与安静时相比,男运动员在不同训练期和比赛后尿液中乳酸、谷氨酸、丙氨酸、谷氨酰胺、二甲胺和柠檬酸含量均显著增加,而苯乙酰甘氨酸则明显下降(P<0.05);女运动员尿液中牛磺酸含量显著增加,苯乙酰甘氨酸同样显著下降(P<0.05)。运动员尿液代谢组学指标主要在集训1周、比赛次日和恢复1周时变化明显。不同性别运动员尿液共有7种代谢物含量存在显著性差异(P<0.05)。结论:(1)龙舟运动能够引起运动员机体内与糖、氨基酸代谢相关的代谢物发生显著改变,运用1H NMR的代谢组学技术实现对运动员无损伤的训练监控可行。(2)不同性别运动员尿液代谢组学信息存在差异,可能由于训练负荷安排和运动员机能状态不同所致。(3)龙舟运动员尿液代谢组学信息比尿常规信息能更加敏感和全面地反映运动员机能状态,对运动性疲劳和过度训练的监控和早期诊断可能更有优势。     

儿童青少年运动员锌的营养、代谢与日供给量的探讨

本文为了解儿童青少年运动员的锌营养状况并从中探讨其日供给量,以北京市业余体校的156名8—16岁的儿童青少年运动员为对象(男75、女81人),进行了(1)膳食锌摄入量(采用膳食锌实测法和食物称重—食物成分表计算法)、血清锌和发锌水平检测;(2)运动员在运动与不运动情况下锌平衡状态的测定;(3)运动员在补充不同量锌强化食品三个月前后的血清和发锌水平变化等研究。初步提出儿童青少年运动员膳食锌的日供给量应比一般不运动的儿童青少年高;6—10岁者为15—20mg/d,10—18岁者为20—25mg/d。     

2周低住高练对游泳运动员心肺功能和有氧运动能力的影响

目的:探讨2周低住高练(LoHi)对游泳运动员心肺功能及其有氧运动能力的影响。方法:15名游泳运动员进行为期2周的LoHi训练(模拟海拔2500m),分别在训练前后采用自行车递增负荷力竭运动测试各项气体代谢指标和有氧运动能力。结果:2周LoHi训练后,(1)同等负荷下男运动员VO2/kg低于训练前,第5min50s时相差最大(-21.8%),最大摄氧量平台(VO2/kgmaxPD)持续时间延长了1min;女运动员自第6min后,VO2/kg值与训练前差值逐渐加大,第12min30s时达到最大(-14.5%),VO2/kgmaxPD持续时间缩短了1min30s;(2)男女运动员R值总体上均处于略微下降的趋势,R=1标志点出现时间明显延后。男运动员从R>1到力竭的时间延长,女运动员则缩短;(3)男运动员fb值在中低负荷阶段略高于训练前,女运动员只在10min50s到13min10s阶段低于训练前。不同负荷阶段,男运动员HR值始终低于训练前。训练后女运动员在第5min后HR值略低于训练前。结论:2周LoHi训练提高了男子游泳运动员对负荷的适应能力,表现为一般有氧运动能力和高负荷状态下的无氧耐力水平提高,但女子运动员的运动能力未见明显改善,表现出一定的性别差异。     

儿童青少年运动员铁营养状况及其影响因素的研究

对北京575名共13个项目的儿童青少年运动员(其中男299人、女276人,年龄在6—26岁)进行了铁营养状况及有关影响因素的系列研究。主要结果:1.儿童青少年运动员的贫血检出率,>14岁组男女的贫血率分别是22.5%和36.9%,≤14岁组男女分别是30.9%和57.9%;分析了运动员缺铁与多种因素有关研究结果提示青少年运动员在系统训练期铁供给量应比一般静态生活者高。作者提出:采用猪血球粉(含有血红蛋白铁)研制成复方血片和全血片治疗运动员缺铁性贫血,一个月后可使Hb提高0.8—1.0g/dL。     

营养干预措施对优秀女子赛艇运动员营养摄入和体成分的影响

目的:通过监测赛艇运动员膳食摄入和生理生化指标变化,制定营养补充方案,调整其膳食结构。方法:采用称重法对9名女子赛艇运动员进行膳食营养调查,根据调查结果及训练实际制定营养补充方案,监测和分析营养干预前后膳食营养状况、身体成分和血红蛋白的变化。结果:营养干预后,运动员的能量、宏量营养素、维生素和矿物质的摄入量均达到推荐量的85%以上。运动员体重从73.6kg恢复到74.3kg(P<0.05),瘦体重达到峰值,同时体脂百分比维持在正常水平,未见显著变化。此外,运动员血红蛋白水平从131.3g/L增加到146.1g/L(P<0.05)。结果表明,科学营养干预改善了运动员的营养状况,使其体重和血红蛋白水平处于理想范围,为切实保障训练和比赛奠定了基础。     

武警某部战士膳食营养素与体成分的相关性

 目的 探讨武警某部战士膳食与体成分的关系,为进一步提供科学的膳食结构和强化战士体能水平打下理论基础。方法 整群选择武警某部137名战士作为调查对象,采用三日称重法对其食堂伙食供应情况连续调查,计算其能量及三大营养素摄入情况;采用人体成分分析仪测定体成分,包括身体总水分、肌肉量、体脂百分比、内脏脂肪面积和腰臀比,采用多元回归分析食物能量及三大营养素与体成分之间的关联。结果 调研的战士每日膳食能量摄入量为3591.5 kcal,蛋白质、脂肪和碳水化合物的摄入量分别为(98.6±18.2)g、(138.9±24.1)g和(484.8±78.2)g;调查对象的身体总水分为(38.5±7.2)kg,肌肉量为(43.7±10.7)kg,体脂百分比为(17.6±5.3)%,内脏脂肪面积为(58.6±14.2)cm²,腰臀比为(81.0±15.2)%。饮食蛋白质摄入量与身体总水分和肌肉量呈正相关,脂肪摄入量与体脂百分比、内脏脂肪面积呈正相关(P<0.05),碳水化合物摄入量与体脂百分比和腰臀比呈负相关(P<0.05)。结论 饮食结构与战士体成分关系密切,应适当调整基层部队的膳食结构,对于降低体脂百分比、提高运动能力、保障军人身体健康具有重要意义。     

自由式滑雪空中技巧国家队运动员不同训练时期部分生理生化指标监测

目的:对自由式滑雪空中技巧项目国家队运动员不同训练时期的部分生理生化指标进行监测与分析,为科学训练提供参考依据。方法:在不同训练时期,监测自由式滑雪空中技巧项目国家队运动员的体温、血压、心率、血红蛋白、血尿素、血清肌酸激酶、反应时和闪光融合频率等指标。结果:陆训期和雪上训练期比较,运动员的血红蛋白、尿素氮、血清肌酸激酶等指标均出现了不同程度的变化,其中雪上期男运动员的血尿素、女运动员的血清肌酸激酶显著升高,女运动员的心率下降显著,男女运动员的反应时均显著延长。结果为调整训练安排提供了参考依据。     

牛初乳对优秀赛艇运动员强化耐力训练期免疫功能的影响

目的:探讨牛初乳对长时间强化耐力训练后运动员免疫功能抑制的调节作用。方法:将15名国家健将级赛艇男运动员随机分为运动对照组和牛初乳组。两组运动员同时进行30天内容相同的运动训练,训练期间牛初乳组以15g/d的剂量补充牛初乳。训练期前及训练期后分别测定各组运动员的各项免疫指标。结果:强化耐力训练期后,牛初乳组淋巴细胞数量明显增加,并显著高于运动对照组(P<0.001);CD3+T细胞和CD4+/CD8+比值维持在训练前正常水平,但均显著高于对照组(P<0.01);训练期后,牛初乳组血清球蛋白水平显著高于运动对照组(P<0.01),血清白蛋白及A/G比值却明显低于对照组(P<0.05)。强化耐力训练期后,牛初乳组与运动对照组中性粒细胞、巨噬细胞、IgA和IgG均无显著性差异。结论:强化耐力训练期补充牛初乳能有效防止强化耐力训练期后CD4+/CD8+比值的下降、淋巴细胞数量的减少及血清球蛋白含量的降低。提示牛初乳具有良好的维持机体免疫功能自稳态的作用,有助于防止长时间大强度耐力训练后运动员机体免疫功能的下降。     

采用Feisher判别分析评估铁、铜、锌比值与运动性贫血的关系

<正> 对广东省体校304名(男182名、女122名)正常训练的青少年运动员的Hb进行了测定,然后对其中37名贫血运动员(男15,女12)及43名正常运动员发中Fe、Cu、Zn含量进行了测定,结果发现:贫血运动员发中Fe、Cu含量明显低于正常运动员的(P<0.01),Zn的含量无明显差异;贫血运动员发中Fe/Cu值与正常运动员的没有明显差异,而Fe/     

Balance ability and athletic performance

The relationship between balance ability and sport injury risk has been established in many cases, but the relationship between balance ability and athletic performance is less clear. This review compares the balance ability of athletes from different sports, determines if there is a difference in balance ability of athletes at different levels of competition within the same sport, determines the relationship of balance ability with performance measures and examines the influence of balance training on sport performance or motor skills. Based on the available data from cross-sectional studies, gymnasts tended to have the best balance ability, followed by soccer players, swimmers, active control subjects and then basketball players. Surprisingly, no studies were found that compared the balance ability of rifle shooters with other athletes. There were some sports, such as rifle shooting, soccer and golf, where elite athletes were found to have superior balance ability compared with their less proficient counterparts, but this was not found to be the case for alpine skiing, surfing and judo. Balance ability was shown to be significantly related to rifle shooting accuracy, archery shooting accuracy, ice hockey maximum skating speed and simulated luge start speed, but not for baseball pitching accuracy or snowboarding ranking points. Prospective studies have shown that the addition of a balance training component to the activities of recreationally active subjects or physical education students has resulted in improvements in vertical jump, agility, shuttle run and downhill slalom skiing. A proposed mechanism for the enhancement in motor skills from balance training is an increase in the rate of force development. There are limited data on the influence of balance training on motor skills of elite athletes. When the effectiveness of balance training was compared with resistance training, it was found that resistance training produced superior performance results for jump height and sprint time. Balance ability was related to competition level for some sports, with the more proficient athletes displaying greater balance ability. There were significant relationships between balance ability and a number of performance measures. Evidence from prospective studies supports the notion that balance training can be a worthwhile adjunct to the usual training of non-elite athletes to enhance certain motor skills, but not in place of other conditioning such as resistance training. More research is required to determine the influence of balance training on the motor skills of elite athletes.     

Extreme sports: injuries and medical coverage

Extreme sports (including in-line skating, snowboarding, mountain bicycling, extreme skiing, rock climbing, indoor tackle football, kickboxing, skateboarding, and ultra-endurance racing) are growing in popularity. Often these sports are designed to expose athletes to greater thrills and risks than are found in traditional sporting activities. Despite this increased risk of injury, athletes competing in these sports often have little or no formal medical coverage. This article reviews what is known about this emerging area of sports medicine to assist physicians in preparing for medical coverage of these athletes and their competitions.     

Incidence of exercise-induced bronchospasm in Olympic winter sport athletes

PURPOSE: The purpose of this project was to determine the incidence of exercise-induced bronchospasm (EIB) among U.S. Olympic winter sport athletes. METHODS: Subjects included female and male members of the 1998 U.S. Winter Olympic Team from the following sports: biathlon, cross-country ski, figure skating, ice hockey, Nordic combined, long-track speedskating, and short-track speedskating. Assessment of EIB was conducted in conjunction with an "actual competition" (Olympic Trials, World Team Trials, World Cup Event, U.S. National Championships) or a "simulated competition" (time trial, game), which served as the exercise challenge. Standard spirometry tests were performed preexercise and at 5, 10, and 15 min postexercise. An athlete was considered EIB-positive based on a postexercise decrement in FEV1 > or = 10%. RESULTS: For the seven sports evaluated on the 1998 U.S. Winter Olympic Team, the overall incidence of EIB across all sports and genders was 23%. The highest incidence of EIB was found in cross-country skiers, where 50% of the athletes (female = 57%; male = 43%) were diagnosed with EIB. Across the seven sports evaluated, the prevalence of EIB among the female and male athletes was 26% and 18%, respectively. Among those individuals found to be EIB-positive were athletes who won a team gold medal, one individual silver medal, and one individual bronze medal at the Nagano Winter Olympics. CONCLUSIONS: These data suggest that: 1) EIB is prevalent in several Olympic winter sports and affects nearly one of every four elite winter sport athletes; 2) the winter sport with the highest incidence of EIB is cross-country skiing; 3) in general, EIB is more prevalent in female versus male elite winter sport athletes; and 4) athletes may compete successfully at the international level despite having EIB.     

Propulsive and gliding phases in four cross-country skiing techniques.

The purpose of this study was to compare the relative durations of the propulsive and gliding phases between three skating techniques (1-skate, 2-skate, and offset) and the diagonal stride technique in elite cross-country skiers. Nine skiers of provincial and national level were videotaped with a Panasonic AG 170 camera. The camera speed was set at 30 frames.s-1 and the shutter speed at 1/500 s. The athletes were asked to ski at approximately 80% of their maximal skiing speed on a flat (50 m long) and on an uphill course (35 m long, 5 degrees grade). The relative propulsive phases of the skating techniques were significantly longer than those of the diagonal stride. The relative gliding phases were also longer with the skating techniques. In addition, velocities obtained while skiing with the diagonal stride were about 16% slower than those attained with the skating techniques, principally related to the longer cycle lengths observed with the skating techniques, while cycle rates were quite similar between all four techniques. The results of this study suggest that the longer relative phases of propulsion with the skating techniques may explain the greater speed attained with these techniques in comparison with the diagonal stride.     

Bone mineral density of olympic-level female winter sport athletes

PURPOSE: To compare areal bone mineral density (aBMD) of female winter sport athletes to healthy controls of similar age and body mass index (BMI). METHODS: Areal BMD (g x cm(-2)) of the whole body, lumbar spine (L2-L4), and right proximal femur were assessed by dual energy x-ray absorptiometry in athletes (N = 40; age: 26.1 +/- 5.7 yr; ht: 165.6 +/- 0.1 cm; wt: 63.0 +/- 6.5 kg; BMI: 23.0 +/- 1.9 kg x m(-2)) involved in speed skating (N = 9), snowboarding (N = 13), freestyle skiing (N = 3), biathlon (N = 8), bobsleigh, skeleton, luge (N = 7), and controls (N = 21; age: 26.0 +/- 5.1 yr; ht: 165.8 +/- 0.1 cm; wt: 62.8 +/- 5.9 kg; BMI: 22.9 +/- 1.3 kg x m(-2)). RESULTS: Using independent t-tests, athletes had lower fat mass, percent body fat, and higher lean mass than controls (P < 0.001). Areal BMD was higher in athletes than controls for all skeletal sites (P 相似文献   

Changes in glutamine and glutamate concentrations for tracking training tolerance

PURPOSE: The purpose was to monitor high-performance athletes throughout training macrocycles and competitions and examine the changes in plasma glutamine (Gm) and glutamate (Ga) concentrations in order to develop a model of tolerance to training. METHODS: Plasma glutamine and glutamate concentrations of 52 National team athletes (31 male and 21 female) divided into male and female groups of speed skating, swimming, and cross-country skiing were measured in an early season rested condition to determine highest Gm and lowest Ga concentrations and over 2-4 macrocycles, which included heavy training to establish lowest Gm and highest Ga concentrations. RESULTS: In the rested condition, there were no differences within and between the male and female groups, excluding five athletes (OTA) who became overtrained in heavy training. The mean (+/-SD) Gm concentration was 585 +/- 54 micromol x L(-1), Ga concentration 101 +/- 16 micromol x L(-1), and Gm/Ga ratio 5.88 +/- 0.84 micromol x L(-1). The OTA had a significantly higher Ga concentration of 128 +/- 16 micromol x L(-1) and lower Gm/Ga ratio of 4.43 +/- 0.49 micromol x L(-1) than all the other groups. In heavy training, there was a significant decrease (P < 0.05) in Gm concentration to 522 +/- 53 micromol x L(-1), significant increase in Ga concentration to 128 +/- 19 micromol x L(-1) and significant decrease in Gm/Ga ratio to 4.15 +/- 0.57 micromol x L(-1). The OTA Gm concentration of 488 +/- 31 micromol x L(-1) was significant lower than only the male speed skating and swimming groups. However, the Ga concentration of 171 +/- 17 micromol x L(-1) and Gm/Ga ratio of 2.88 +/- 0.27 micromol x L(-1) were significantly higher and lower respectively than all other groups. CONCLUSIONS: Based on the changes in Gm and Ga concentration under different training conditions, we propose an athlete tolerance to training model where glutamine concentration reflects tolerance to volume of work and glutamate concentration reflects tolerance to high intensity training. We suggest that the Gm/Ga ratio may globally represent overall tolerance to training.     

Comparison between the physiological response to roller skiing and in-line skating in biathletes

PURPOSE: Roller skiing is frequently used in Nordic disciplines during the off-season periods. Recently, in-line skating has become a potential alternative. In the present study, the responses of heart rate, oxygen uptake, respiratory exchange ratio, and lactic acid concentration to roller skiing and in-line skating were compared in competitive biathletes. METHODS: Eight male subjects performed three tests with both devices on a hilly outdoor track. They were requested to adjust their speed in such a way that the following criteria were met: intensity 1, lactate concentration about 2 mmol x L(-1); intensity 2, lactate concentration about 4 mmol x L(-1); AND intensity 3, maximal speed. RESULTS: Though the subjects were not experienced in-line skaters, all managed to adjust the required intensities. This was achieved through increased velocities during in-line skating. Independent of the exercise intensity the differences in speed ranged between 1.0 and 1.4 m x s(-1). The relationships between lactic acid concentration, oxygen uptake, respiratory exchange ratio, and heart rate were not influenced by the test device. The respiratory exchange ratio amounted to 0.88, 0.95, and 1.02 for intensities 1 to 3, respectively. CONCLUSIONS: These results show that in-line skating can be regarded as an alternative to roller skiing for off-seasonal training in Nordic disciplines. A potential advantage of in-line skating is that aerobic training intensities can be obtained at competitive velocities.     

Injuries among World Cup ski and snowboard athletes

There is little information available on injuries to World Cup skiers and snowboarders. The aim of this study was to describe and compare the injury risk to World Cup athletes in alpine skiing, freestyle skiing, snowboarding, ski jumping, Nordic combined and cross country skiing. We performed retrospective interviews with the International Ski Federation (FIS) World Cup athletes from selected nations during the 2006–2007 and 2007–2008 winter seasons and recorded all acute injuries occurring during the seasons. We interviewed 2121 athletes and recorded 705 injuries. There were 520 (72%) time‐loss injuries and 196 (28%) severe injuries (absence >28 days). In freestyle skiing, alpine skiing and snowboarding, there were 27.6, 29.8 and 37.8 time‐loss and 14.4, 11.3 and 13.8 severe injuries per 100 athletes per season, respectively. In Nordic combined, ski jumping and cross country skiing, there were 15.8, 13.6 and 6.3 time‐loss and 3.3, 5.6 and 0.7 severe injuries per 100 athletes per season, respectively. In conclusion about 1/3 of the World Cup alpine, freestyle and snowboard athletes sustain a time‐loss injury each season, while the risk is low in the Nordic disciplines. A particular concern was the high proportion of severe injuries observed among alpine, freestyle and snowboard athletes, which is in contrast to most other sports.     

Characterization of the Patient Population in a Sports Medicine Facility

In brief: This article presents a statistical portrait of the injuries seen over a five-year period at a large sports medicine facility that serves primarily recreational athletes. About half of the 10,271 injuries treated were caused by overuse. Overuse problems exceeded acute injuries in running, tennis, figure skating, and aerobic dance, while acute injuries were more common in skiing, basketball, football, and soccer. The knee was the anatomic area most often injured in all of the major sports. The prevalence of overuse injuries indicates the importance of instructing patients in prevention methods.     

A social cognitive approach to burnout in elite athletes

The purpose of this study was to investigate athlete burnout from a social-cognitive perspective by examining the relationship between social cognitive motivational variables at the start of a season and signs of burnout in elite athletes at the end of the season. Participants were 141 (F=60, M=81) elite winter sport athletes competing in Alpine skiing, Biathlon, Nordic Combined, Nordic skiing, and Speed skating. Participants completed a comprehensive motivation assessment package at the start of the season and a further burnout inventory at season's end. Results indicated that motivational dispositions, measures of the achievement climate, perceived ability and dimensions of perfectionism were associated with burnout in a conceptually consistent manner. Furthermore, the elite athletes could be grouped into two motivational profiles based on variables measured at the start of the season, one being adaptive and the other maladaptive. At season's end, the two different motivational profiles yielded distinctively different responses on an inventory assessing signs of burnout. The current findings strengthen the claim that burnout in elite athletes may not simply be "motivation gone awry" as Gould has suggested, but an inevitable consequence of exhibiting a maladaptive motivational profile.