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1.
运动与氨代谢关系的研究进展   总被引：1，自引：0，他引：1  
运动中机体氨代谢增强。氨的主要来源：短时间高强度运动为骨骼肌的嘌呤核苷酸循环，长时间力竭性运动主要与骨骼肌大量摄取支链氨基酸有关。运动强度递增及长时间力竭运动，骨骼肌产氨增多。短时间力竭运动血氨与血乳酸的浓度呈正相关。运动性疲劳的产生亦与运动后高血氨水平密切相关。因此，血氨可以用作评定运动负荷的强度和量度、运动员机体的机能状态、疲劳程度及运动训练程度的有效指标。  相似文献   

2.
Abstract

There are no studies available that portray insulin sensitivity and β-cell function in ageing sprint-trained athletes. We compared male young and master sprint-trained athletes to endurance-trained and untrained individuals. We hypothesised that ageing sprint-trained athletes would preserve insulin sensitivity and β-cell function at a level similar to that of endurance-trained peers and better than in untrained individuals. We showed the associations between age and parameters derived from the updated Homeostasis Model Assessment (HOMA2 model) in 52 sprint-trained track and field athletes (aged 20?90 years), 85 endurance runners (20?80 years) and 55 untrained individuals (20?70 years). Fasting glucose, fasting insulin, insulin sensitivity and β-cell function were not associated with age in sprint-trained athletes. These variables remained relatively stable across a wide range of age and comparable to those observed in endurance-trained athletes. In contrast, the untrained group showed considerable age-related increase in fasting insulin and β-cell activity and a strong decrease in insulin sensitivity compared to both athletic groups. HOMA2 parameters were significantly related to maximal oxygen in the combined group of participants. In summary, chronic training based on a “sprint model” of physical activity, that contains mixed exercise, seems to be effective in maintaining normal insulin sensitivity with ageing.  相似文献   

3.
通过对田径运动员心理能量和运动性疲劳分析，得出心理能量和运动性疲劳存在一定的相关性。根据二者的相关性，运动员在比赛中进行有效的心理调控，并且加强心理方面的训练，减少比赛中心理疲劳和生理疲劳。  相似文献   

4.
The idea that dietary supplements can improve athletic performance is popular among athletes. The use of antioxidant supplements is widespread among endurance athletes because of evidence that free radicals contribute to muscle fatigue during prolonged exercise. Furthermore, interest in vitamin D supplementation is increasing in response to studies indicating that vitamin D deficiency exists in athletic populations. This review explores the rationale for supplementation with both antioxidants and vitamin D and discusses the evidence to support and deny the benefits of these dietary supplements. The issue of whether athletes should use antioxidant supplements remains highly controversial. Nonetheless, at present there is limited scientific evidence to recommend antioxidant supplements to athletes or other physically active individuals. Therefore, athletes should consult with their health care professional and/or nutritionist when considering antioxidant supplementation. The issue of whether athletes should supplement with vitamin D is also controversial. While arguments for and against vitamin D supplementation exist, additional research is required to determine whether vitamin D supplementation is beneficial to athletes. Nevertheless, based upon the growing evidence that many athletic populations are vitamin D deficient or insufficient, it is recommended that athletes monitor their serum vitamin D concentration and consult with their health care professional and/or nutritionist to determine if they would derive health benefits from vitamin D supplementation.  相似文献   

5.
跆拳道运动项目的比赛特点决定了它属于激烈的对抗性比赛项目,是集力量、速度、耐力和协调性等诸多身体素质的综合,日常训练要求对运动员要求高强度、高密度、高负荷的大运动量的训练,极易导致运动员出现运动性疲劳的状况,从而影响运动员日常训练和比赛的成绩.文章主要研究跆拳道运动员运动性疲劳产生的机理以及通过合理休息、营养学、物理疗法、心理治疗等多种消除运动性疲劳的方法,为跆拳道运动员构建出一套完善的立体式恢复方法,为跆拳道运动员运动性疲劳的恢复提供极其重要的理论依据  相似文献   

6.
Energy balance and body composition in sports and exercise   总被引：2，自引：0，他引：2  
Many athletes, especially female athletes and participants in endurance and aesthetic sports and sports with weight classes, are chronically energy deficient. This energy deficiency impairs performance, growth and health. Reproductive disorders in female athletes are caused by low energy availability (defined as dietary energy intake minus exercise energy expenditure), perhaps specifically by low carbohydrate availability, and not by the stress of exercise. These reproductive disorders can be prevented or reversed by dietary supplementation in compensation for exercise energy expenditure without any moderation of the exercise regimen. Energy balance is not the objective of athletic training. To maximize performance, athletes strive to achieve an optimum sport-specific body size, body composition and mix of energy stores. To pursue these objectives, athletes need to manage fat, protein and carbohydrate balances separately, but it is impractical for athletes to monitor these balances directly, and appetite is not a reliable indicator of their energy and macronutrient needs. To guide their progress, athletes need to eat by discipline and to monitor specific, reliable and practical biomarkers of their objectives. Skinfolds and urinary ketones may be the best biomarkers of fat stores and carbohydrate deficiency, respectively. Research is needed to identify and validate these and other markers.  相似文献   

7.
Twelve endurance athletes and six power athletes performed fatiguing isokinetic knee flexions/extensions. Isokinetic torque was recorded during the exercise. Isometric torque, cortisol and lactate responses, electromyographic (EMG) mean power frequency, average rectified value, and conduction velocity were analysed before and after the isokinetic exercise to determine correlations between electrophysiological variables and mechanical performances and/or blood concentrations of biomarkers in the two groups of athletes. The EMG variables were estimated from signals recorded from the vastus lateralis in both voluntary and electrically elicited isometric contractions. Power athletes recorded higher values than endurance athletes for the following variables: pre-exercise isometric maximal voluntary contraction (MVC), isokinetic MVC, rate of mechanical fatigue during isokinetic contractions, pre - post exercise variations and recovery times of conduction velocity and mean power frequency, and lactate concentrations. Moreover, conduction velocity overshooting was observed in endurance athletes during the recovery phase after exercise. The correlation analyses showed that the higher the rate of mechanical fatigue, the higher the lactate production and the reduction in conduction velocity due to the exercise.  相似文献   

8.
ABSTRACT

This study tested the effect of 8-week endurance and resistance training programmes on cardiovascular stress responses, life stress, and coping. Fifty-two untrained but healthy female students were randomised to an 8-week endurance training, an 8-week resistance training, or a wait list control group. Before and after the training intervention, we assessed the groups’ cardiorespiratory fitness (VO2max test), self-reported life stress, coping strategies and cardiovascular reactivity to and recovery from a standardised laboratory stressor. Both endurance and resistance training programmes caused physiological adaptation in terms of increased VO2max after the intervention. For stress and coping parameters, participants in the training groups improved cardiovascular recovery from stress and reported having less stress in their everyday life after the intervention than participants in the control group, while the two training groups did not differ from each other. We did not find any significant differences in heart rate reactivity and coping strategies between the study groups. These results partly support that exercise training has stress-reducing benefits regardless of the type of exercise. Both endurance and resistance exercise activities may be effectively used to improve stress regulation competence while having less impact on changing specific coping strategies.  相似文献   

9.
咖啡因作为一种功能增进营养补剂,广泛应用于耐力运动员的训练和竞赛中。通过系统梳理探讨摄入咖啡因对耐力运动员计时赛、恒定负荷运动和递增负荷运动至力竭3种类型运动表现影响的相关研究,总结咖啡因对耐力运动员运动表现的影响规律,以期为我国教练员和运动员优化营养补剂方案提供理论依据。结果显示,自行车、中长跑及赛艇等耐力运动员多以胶囊形式摄入低中高剂量咖啡因（3~9 mg/kg）来提高耐力运动表现,但对于不同类型运动表现的有效剂量及作用机制存在差异。另外,咖啡因与其他营养补剂混合摄入的效果以及咖啡因不同摄入方式、性别差异、基因组别、安慰剂效应等对其功能增进效果的影响是咖啡因研究领域未来的发展方向。  相似文献   

10.
运动性肌肉疲劳的表面肌电非线性信号特征   总被引：13，自引：3，他引：10  
王健  方红光  杨红春 《体育科学》2005,25(5):39-43,64
研究目的在于探讨不同强度等长运动诱发肌肉疲劳过程中s EMG非线性信号变化特征及其与肌肉运动耐力的关系。10名青年大学生志愿者参加本次实验。采用4 0 %、6 0 %和80 %MVC强度的等长运动试验诱发肱二头肌疲劳,同步采集该肌肉s EMG信号并进行非线性C(n)和% DET和线性MPF分析。研究发现1)肌肉疲劳过程中s EMG信号的MPF和C(n)呈单调递减型变化,而% DET呈单调递增型变化;2 )不同强度运动负荷诱发肌肉疲劳过程中MPF、C(n)和% DET变化率具有明显的运动强度依赖性并与肌肉耐力运动成绩高度相关;3)以% DET变化率反映运动性肌肉疲劳的敏感度明显高于MPF和C(n)。  相似文献   

11.
Abstract

Concurrent training (the combination of endurance exercise to resistance training) is a common practice for athletes looking to maximise strength and endurance. Over 20 years ago, it was first observed that performing endurance exercise after resistance exercise could have detrimental effects on strength gains. At the cellular level, specific protein candidates have been suggested to mediate this training interference; however, at present, the physiological reason(s) behind the concurrent training effect remain largely unknown. Even less is known regarding the optimal nutritional strategies to support concurrent training and whether unique nutritional approaches are needed to support endurance and resistance exercise during concurrent training approaches. In this review, we will discuss the importance of protein supplementation for both endurance and resistance training adaptation and highlight additional nutritional strategies that may support concurrent training. Finally, we will attempt to synergise current understanding of the interaction between physiological responses and nutritional approaches into practical recommendations for concurrent training.  相似文献   

12.
Maximal strength training with a focus on maximal mobilization of force in the concentric phase improves endurance performance that employs a large muscle mass. However, this has not been studied during work with a small muscle mass, which does not challenge convective oxygen supply. We therefore randomized 23 adult females with no arm-training history to either one-arm maximal strength training or a control group. The training group performed five sets of five repetitions of dynamic arm curls against a near-maximal load, 3 days a week for 8 weeks. This training increased maximal strength by 75% and improved rate of force development during both strength and endurance exercise, suggesting that each arm curl became more efficient. This coincided with a 17-18% reduction in oxygen cost at standardized submaximal workloads (work economy), and a 21% higher peak oxygen uptake and 30% higher peak load during maximal arm endurance exercise. Blood flow assessed by Doppler ultrasound in the axillary artery supplying the working biceps brachii and brachialis muscles could not explain the training-induced adaptations. These data suggest that maximal strength training improved work economy and endurance performance in the skeletal muscle, and that these effects are independent of convective oxygen supply.  相似文献   

13.
目的观察耐力训练和一次性力竭运动对大鼠骨骼肌线粒体通透性转换孔(mitochondrial permeability transi-tion pore,MPTP)相关因素及细胞凋亡的影响。方法 24只大鼠随机分为3组:对照组(C组)、耐力训练组(T组)和一次性力竭组(E组)。T组进行无负重游泳训练,6次/周,共6周,训练时间从每天45 min逐渐增加到90 min;E组正常笼内饲养6周后进行一次力竭性游泳运动。通过紫外分光光度仪检测MPTP的开放;Western blot检测细胞色素c(Cyt c)的释放;RT-PCR检测Bcl-2和Bax mRNA;双光束紫外分光光度仪检测线粒体Ca2+的转运。结果与对照组相比:(1)T组线粒体吸光度值和Ca2+的转运量无显著性变化,Cyt c的释放量与Bax mRNA的表达显著减少,Bcl-2 mRNA的表达显著增加;(2)E组线粒体吸光度值显著减少,Cyt c释放量及Ca2+转运量显著增加,Bcl-2mRNA表达显著下降,Bax mRNA表达显著增强。结论 耐力运动可能通过上调Bcl-2/Bax基因表达,减少Cyt c释放,稳定MPTP开放,从而减少细胞凋亡;一次性力竭运动可能通过下调Bcl-2/Bax基因表达,MPTP异常开放,增加Cyt c和Ca2+释放,促进细胞凋亡。  相似文献   

14.
Abstract

The barbell back squat is commonly used by athletes participating in resistance training. The barbell squat is typically performed using standard athletic shoes, or specially designed weightlifting footwear, although there are now a large number of athletes who prefer to squat barefoot or in barefoot-inspired footwear. This study aimed to determine how these footwear influence 3-D kinematics and muscle activation potentials during the barbell back squat. Fourteen experienced male participants completed squats at 70% 1 rep max in each footwear condition. 3-D kinematics from the torso, hip, knee and ankle were measured using an eight-camera motion analysis system. In addition, electromyographical (EMG) measurements were obtained from the rectus femoris, tibialis anterior, gastrocnemius, erector spinae and biceps femoris muscles. EMG parameters and joint kinematics were compared between footwear using repeated-measures analyses of variance. Participants were also asked to subjectively rate which footwear they preferred when performing their squat lifts; this was examined a chi-squared test. The kinematic analysis indicated that, in comparison to barefoot the running shoe was associated with increased squat depth, knee flexion and rectus femoris activation. The chi-squared test was significant and showed that participants preferred to squat barefoot. This study supports anecdotal evidence of athletes who prefer to train barefoot or in barefoot-inspired footwear although no biomechanical evidence was found to support this notion.  相似文献   

15.
Carbohydrate ingestion before and during endurance exercise delays the onset of fatigue (reduced power output). Therefore, endurance athletes are recommended to ingest diets high in carbohydrate (70% of total energy) during competition and training. However, increasing the availability of plasma free fatty acids has been shown to slow the rate of muscle and liver glycogen depletion by promoting the utilization of fat. Ingested fat, in the form of long-chain (C 16-22 ) triacylglycerols, is largely unavailable during acute exercise, but medium-chain (C 8-10 ) triacylglycerols are rapidly absorbed and oxidized. We have shown that the ingestion of medium-chain triacylglycerols in combination with carbohydrate spares muscle carbohydrate stores during 2 h of submaximal (< 70% VO 2 peak) cycling exercise, and improves 40 km time-trial performance. These data suggest that by combining carbohydrate and medium-chain triacylglycerols as a pre-exercise supplement and as a nutritional supplement during exercise, fat oxidation will be enhanced, and endogenous carbohydrate will be spared. We have also examined the chronic metabolic adaptations and effects on substrate utilization and endurance performance when athletes ingest a diet that is high in fat (> 70% by energy). Dietary fat adaptation for a period of at least 2-4 weeks has resulted in a nearly two-fold increase in resistance to fatigue during prolonged, low- to moderate-intensity cycling (< 70% VO 2 peak). Moreover, preliminary studies suggest that mean cycling 20 km time-trial performance following prolonged submaximal exercise is enhanced by 80 s after dietary fat adaptation and 3 days of carbohydrate loading. Thus the relative contribution of fuel substrate to prolonged endurance activity may be modified by training, pre-exercise feeding, habitual diet, or by artificially altering the hormonal milieu or the availability of circulating fuels. The time course and dose-response of these effects on maximizing the oxidative contribution of fat for exercise metabolism and in exercise performance have not been systematically studied during moderate- to high-intensity exercise in humans.  相似文献   

16.
目的旨在探讨耐力运动预激活增强效应的研究进展,从生理学表现和研究方法方面为耐力项目运动训练方案设计提供理论依据。方法检索、整理和分析耐力运动预激活增强效应相关的文献。结果和结论预激活增强效应的生理机制为肌球蛋白调节轻链磷的酸化及神经肌肉特征的变化;预激活增强效应可用于优化耐力运动热身方案,提升运动成绩;耐力运动引发的神经肌肉特征变化可用于调节耐力运动中外周疲劳所带来的负面影响。未来的研究应进一步明确各专项的热身方案,在耐力训练或竞赛中的作用,最大限度地发挥预激活增强效应在各专项运动中的用作,热身活动中最佳的负荷强度也需进一步地研究,便于研究者们更好地探究用以提升运动成绩的训练方案。  相似文献   

17.
“Core” exercise is a basic part of many physical training regimens with goals ranging from rehabilitation of spine and knee injuries to improving athletic performance. Core stiffness has been proposed to perform several functions including reducing pain by minimising joint micro-movements, and enhancing strength and speed performance. This study probes the links between a training approach and immediate but temporary changes in stiffness. Passive and active stiffness was measured on 24 participants; 12 having little to no experience in core training (inexperienced), and the other 12 being athletes experienced to core training methods; before and after a 15 min bout of isometric core exercises. Passive stiffness was assessed on a “frictionless” bending apparatus and active stiffness assessed via a quick release mechanism. Short-term isometric core training increased passive and active stiffness in most directions for both inexperienced and experienced participants, passive left lateral bend among experienced participants being the exception (P < 0.05). There was no difference between the inexperienced and experienced groups. The results confirm that the specific isometric training exercise approach tested here can induce immediate changes in core stiffness, in this case following a single session. This may influence performance and injury resilience for a brief period.  相似文献   

18.
目的：观察穴位敷贴缓解运动性疲劳的效果及对运动成绩的影响。方法：将20名足球运动员随机分为穴位敷贴组和空白对照组,穴位敷贴组采用药物贴对受试者神阙穴、气海穴、足三里穴进行敷贴,对照组采用安慰贴对受试者上述穴位进行敷贴。对两组受试者进行主观感觉疲劳程度评分（RPE）、运动心情评价（POMS）、情绪状态总估价（TMD）;检测受试者血乳酸和血氨浓度;记录受试者8 00 m全力跑成绩。结果：穴位敷贴可减轻受试者主观疲劳感觉,与治疗前相比,显著降低RPE值（P〈0.01）;穴位敷贴可缓解运动员因疲劳而产生的消极情绪,降低TMD分值,与治疗前相比有统计学差异（P〈0.05）。穴位敷贴可升高运动后4 min机体血乳酸（P〈0.05）和血氨浓度（P〈0.05）,降低运动后20 min机体血乳酸（P〈0.05）及血氨浓度（P〈0.05）,显著提高受试者8 00 m跑成绩（P〈0.01）。结论：穴位敷贴可减轻运动员的主观疲劳感觉,缓解运动员因运动疲劳而产生的消极情绪,促进运动员机体内血乳酸和血氨的代谢,提高运动员耐缺氧能力,进而缓解运动性疲劳临床症状,促进运动性疲劳的恢复,提高运动成绩。  相似文献   

19.
Muscular strength, endurance, and rate of fatigue were studied in populations of various ages actively engaged in strength and endurance training, as compared with those not engaged in such activities. The strength and fatigability of the elbow flexor muscles were studied for 62 subjects at the ages of 20 (n = 11 active, 10 inactive), 35 (n = 11 active, 10 inactive), and 50 (n = 10 active, 10 inactive) years, tested within 2 years of the appropriate age. They performed a 6-min bout of maximal rhythmic contractions of the dominant arm at a rate of 30 contractions per min. Force applied to the transducer was converted into electrical activity and transmitted to a recorder, where differences in mean values for initial strength, final strength, absolute endurance, and relative endurance were examined for significance. Rates of fatigue and the fatigue curves were also obtained for each group. Results revealed significantly less muscular strength, absolute endurance, and relative endurance as the age of the subjects increased, but no significant difference for age was found in final strength at the conclusion of the exercise bout. Significant differences were found between active and inactive subjects in initial strength, final strength, and absolute endurance in favor of the active subjects. No significant interaction between activity level and age was found for any of the dependent variables. The rates of fatigue were similar for all ages except for the inactive 20-year-old subjects, whose rate of fatigue was markedly slower than that found for all other groups of subjects.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

20.
笔者通过对普通小学生男生和男游泳运动员进行90min踏车功量计上50％Vo2max的持续性定量负荷运动,观察血清中芳香族氨基酸和支链氨基酸水平的变化。结果表明:两组芳香族氨基酸/支链氨基酸和色氨酸/支链氨基酸的比值升高,提出存在运动性中枢疲劳的物质基础;同时,在色氨酸/支链氨基酸的比值上,专业游泳组显著低于学生组,可能与它们对支链氨基酸的依赖程度的差异有关。结论:长期耐力训练对缓解由于长时间运动的芳香族氨基酸变化所引起的运动性中枢疲劳有适应性变化。  相似文献   

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