“个体乳酸阈”与“无氧阈”术语之比较

本文通过参阅大量的文献资料，对“无氧阈”与“个体乳酸阈”两个术语进行了比较、分析，同时论述了“无氧阈”术语之不足，提出了以“个体乳酸阈”一词替代“无氧阈”一词。     

不同无氧阈评价方法的比较研究

通过不同的无氧阈检测方法检测无氧阈指标出现的时间顺序,并对出现无氧阈时各相关指标进行相关性分析,以探讨不同无氧阈之间的关系。让8名赛艇运动员在ConceptⅡ风轮式赛艇测功仪上进行递增负荷测试,每级负荷3 min,直至力竭,同时测试每级负荷后的血乳酸,全程记录肌电以及气体代谢量,并做相关分析。结果表明：1）肌电阈、通气阈和乳酸阈3种无氧阈指标出现的时间依次为8 min 58 s、9 min 22 s和9 min 48 s;2）肌电阈、通气阈和乳酸阈依次出现的时间差均不超过30 s,并且通气阈和乳酸阈之间无显著性差异（P〉0.05）。3种无氧阈依次出现的原因是快肌纤维的快速动员引起了乳酸急剧增加,进而在转运到血液中时首先引起酸碱缓冲对的中和,当强度进一步增加时,产生的乳酸大大超过了乳酸的清除能力,进而引起血乳酸急剧增加。     

心率控制法在赛艇训练中的应用

对山东女子赛艇运动员在第八届全运会赛前训练各阶段进行多项生理生化指标同步测试,以个体无氧阈指标为依据制定训练计划,以个体无氧阈对应心率为指标控制训练强度。即：以个体无氧阈对应心率时强度来发展最大有氧耐力,以高于个体无氧阈对应心率时强度来发展无氧耐力,以阶段性血乳酸测试来进一步修正训练计划。结果各训练阶段都达到了预期训练目的,并取得了理想成绩。说明无氧阈心率控制法不失为赛艇训练的一种简便易行的有效方法。     

试析无氧阈强度训练帮助提高训练水平的生理机制

通过血乳酸浓度的测试，控制无氧阔强度训练，检验无氧闽强度训练的效果，并分析无氧阈强度训练后，训练水平提高的生理机制。     

两种无氧阈测试法在赛艇运动中应用的比较研究

采用两种不同的无氧阈测试方法(乳酸法和Conconi法)对赛艇运动员进行测试,并比较其结果的相关性。结果表明:其无氧阈血乳酸值无显著性差异,无氧阈心率存在显著性差异,心率之间的差异有可能是由最大乳酸稳定状态下的个体乳酸阈最大速度引起的,在赛艇训练中以Conconi测试的心率拐点作为无氧阈训练的评定指标更有利于运动员有氧耐力水平的提高。     

高等级速滑运动员无氧阈的测定

速度滑冰运动员的无氧阈是运动员训练的重要依据之一。采用测定潮末呼出气CO_2峰值的方法来测定无氧阈,并对潮末呼出气中CO_2峰值与无氧阈的关系进行了分析。     

EMGFT评定无氧阈的可行性研究

运用Matsumoto测定EMGFT的方法对青少年足球运动员EMGFT进行测试,目的在于验证肌电阈稳定性;检验EMGFT与LAT、VAT、HRT的相关性;探讨EMGFT无损伤测定无氧阈方法的可行性。方法:递增负荷实验确定LAT、VAT、HRT;肌电阈实验确定EMGFT。结果:EMGFT稳定性实验,两次均值分别为151.08±10.52 W、153.56±12.93 W,r=0.95(P<0.001),组间无显著性差异(P>0.05);以VO2为参数,EMGFT、LAT、VAT、HRT均值分别为2481±463ml/min、2507±501ml/min、2580±474ml/min、2610±517ml/min,EMGFT分别与LAT、VAT、HRT相关性检验r=0.97(P<0.001)、r=0.91(P<0.001)、r=0.76(P<0.05),配对样本t检验P>0.05、P>0.05、P<0.05;以功率为参数,EMGFT、LAT、VAT、HRT均值分别为157±20 W、158±20 W、162±21 W、162±26 W,相关性检验r=0.96(P<0.001)、r=0.93(P<0.001)、r=0.71(P<0.05),配对样本t检验P>0.05、P>0.05、P<0.05。结论:应用Matsumoto肌电无氧阈方法能很好地确定EMGFT,稳定性较好;EMGFT与LAT、VAT呈高度相关,出现时间顺序依次为EMGFT→LAT→VAT,EMGFT略早于LAT和VAT,呈一定的规律性,表明EMGFT可以用于检测无氧阈,具有无损伤、简单、易测等优点;HRT检测无氧阈不稳定,说明HRT不宜作为无氧阈的评定指标。     

最大乳酸稳定状态下足球运动员康科尼测试中个体无氧阈最大速度的选取及可靠性研究

研究目的 :1)应用场地康科尼测试方法寻找足球运动员个体无氧阈最大速度的可行性 ;2 )分析康氏测试心率拐点与乳酸阈拐点对应的个体无氧阈最大速度之间的关系 ;3)测定最大乳酸稳定状态 ( ML SS) ,验证康氏测试个体无氧阈最大速度的可靠性。结果证明 ,在康氏测试中 85 %受试者都出现心率拐点 ,完成距离最短者心率拐点偏左、中长者居中、最长者偏右 ,相对应的乳酸阈速度正好低于心率拐点速度一个等级 ,但该两种速度之间并未出现不规则变化差异 ,且高度相关。选取康氏测试心率拐点速度进行 2 4 min匀速运动受试者平均乳酸值显示最大乳酸稳定状态 ( ML SS) ,表明可用于个体无氧阈最大速度 ,但大于 180次 / m in的心率拐点速度即已超过本人的个体无氧阈最大速度     

无氧阈强度在短距离游泳项目中的应用及训练监控

采用无氧阈强度在游泳训练中作为训练强度不仅可以评定有氧强度,而且是选择无氧强度的重要方法。游泳项目中无氧能力和有氧能力是一个相互利用,互为提高的过程。有氧和无氧训练应该从机能整体性原则去认识,片面的将其分离必然使训练计划制定和强度的安排产生指导性错误。     

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。     

现代五项运动员不同距离游泳时的血乳酸阈值等几项指标的对比研究

本文对现代五项运动员在100m、200m、300m游泳后进行血乳酸测试36人次，对乳酸阈值、乳酸阈强度、极限乳酸值和斜率4项指标作对比分析得出：乳酸阈值不随距离的变化而改变（P＞0．05），乳酸阈强度、乳酸水平与距离长短成正比，阈值后曲线斜率与距离的长短成反比。     

近乳酸阈30公里跑对血尿素氮含量的影响

25名男子马拉松运动员以接近本人乳酸阈30公里跑前后血尿素氮含量进行了测定。运动前清晨、运动后即刻和运动后次日清晨血尿素氮水平分别为19.7±5.1、25.3±4.9(P<0.05)和20.6±4.3(mg％)。其中有7名运动后血素氮含量不但显著升高,而且恢复缓慢直至运动后第三天清晨仍然偏高,对这种非适应型运动员本文提出必须通过调整性训练才能防止慢性疲劳的继续发展。     

优秀女子赛艇运动员奥运会赛前乳酸阈曲线变化规律的研究

以中国队参加2004年雅典奥运会女子公开级八人单桨有舵手项目运动员为研究对象,观察在赛艇大周期训练过程中,定期测定定量负荷后血乳酸、身体成分等指标;定期应用赛艇测功仪进行多级负荷及2 000m测试,利用乳酸阈功率及乳酸功率曲线等对训练效果进行实时分析和评价。结果:在整个训练周期中,女子公开级运动员的体重没有显著性变化(P>0.05),在整个训练周期内,平均乳酸阈功率显著性提高(P<0.01);2 000m测试成绩显著性提高(P<0.05)。结论:功率-乳酸、功率-心率曲线,乳酸阈功率曲线可以对运动员的训练效果进行有效的实时分析和评价;运动训练使女子公开级运动员的平均乳酸阈功率有显著性提高。     

综述个体乳酸阈的研究进程

本文通过利用文献资料法对个体乳酸阈方面相关资料进行了详细地查阅和阅读,综述了个体乳酸阈的研究进程并发现多数文献对个体乳酸阈的研究侧重于个体间的比较,缺少个体自身的比较以及自身的跟踪测试;一直以来都是通过个体乳酸阈值合理安排运动训练,但很少有实验验证哪种运动训练方法对提高个体乳酸阈值更为有效。     

Active recovery intervals restore initial performance after repeated sprints in swimming*

The purpose of this study was to examine the effects of active recovery (AR) and passive recovery (PR) using short (2-min) and long (4-min) intervals on swimming performance. Twelve male competitive swimmers completed a progressively increasing speed test of 7?×?200-m swimming repetitions to locate the speed before the onset of curvilinear increase in blood lactate concentration (LT₁). Subsequently, performance time of 6?×?50-m sprints was recorded during four different conditions: (i) 2-min PR (PR-2), (ii) 4-min PR (PR-4), (iii) 2-min AR (AR-2) and (iv) 4-min AR (AR-4) intervals. Blood lactate concentration was measured before the first and after the last 50-m repetition. AR was applied at an intensity corresponding to LT₁. Performance as indicated by the time needed to complete 6?×?50-m sprints was impaired after AR-4 compared to PR-4 (AR-4: 28.65?±?1.04, PR-4: 28.17?±?0.72?s; mean% difference: MD% ±s; ±90% confidence limits: 90%CL, 1.71?±?3.01%; ±1.43%, p?=?.01) but was not different between AR-2 compared to PR-2 conditions (AR-2: 28.68?±?0.85, PR-2: 28.69?±?0.82 s; MD%: 0.03?±?1.61%; 90%CL?±?0.77%, p?=?.99). Performance in sprint-6 was improved after AR compared to PR independent of interval duration (AR: 28.55?±?0.81, PR: 29.01?±?1.03?s; MD%: 1.52?±?2.61%; 90%CL?±?1.2%; p?=?.03). Blood lactate concentration was lower after AR-4 compared to PR-4 but did not differ between AR-2 and PR-2 conditions. In conclusion, AR impaired performance after a 4-min but not after a 2-min interval. A better performance during sprint-6 after AR could be attributed to a faster metabolic recovery or anticipatory regulatory mechanisms towards the end of the series especially when adequate 4-min active recovery interval is applied.     

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.     

Cardiorespiratory responses to exercises of equal relative intensity distributed between the upper and lower body

Abstract

The aim of this study was to compare the ‘anaerobic threshold’ (AnT) of subjects determined during a continuous 2‐min incremental exercise test until exhaustion and the ‘maximal lactate steady‐state’ (BLaSs_max) determined during prolonged exercise at constant loads corresponding to the subjects’ AnT and/or 5–25% above and below it. Seventeen subjects performed an incremental exercise test and 1–5 prolonged exercise tests on a cycle ergometer until exhaustion at intervals of 1 week, and work rates, oxygen uptake (VO₂) values and brachial venous blood lactate (BLa) levels were measured. It was proposed that when exercising at a constant workload below AnT, BLa would fall after having reached its peak; at the level of AnT, BLa reaches maximal steady‐state (BLaSs_max); and above AnT, BLa increases continuously. Altogether, in 34 of 45 tests with a constant workload between 80 and 125% AnT, BLa values were as expected. In those cases in which BLaSs_max was reached, BLa increased on average by 3.8 mM from resting levels. This increase was 2.0 mM greater than that seen between resting levels and AnT during incremental exercise. There was no correlation between BLa values at BLaSs_max and at AnT, both when expressed as an increase in BLa (ABLa) and absolute BLa concentration. Altogether, 81% of the variation in BLa concentration at BLaSs_max could be explained by the subjects’ age, the percentage of slow‐twitch fibres and BLa levels at rest. The AnT and BLaSs_max did not differ significantly, and these values were correlated (r = 0.83). Together, AnT and age accounted for 85% of the variation seen in BLaSs_max. The BLaSs_max did not correlate with AnT when fixed at a BLa concentration of 4 mM (AnT_4mM). The three hypotheses tested in this study were confirmed, and the present results demonstrate that AnT correlates with BLaSs_max. The few exceptions to anticipated BLa kinetics were small in magnitude and could be explained by physiological variations.