高原（2260m）女子公路自行车运动员的通气无氧阈、乳酸阈和最大氧耗量的研究

采用实验室递增负荷运动试验和运动现场血乳酸的测定,研究了高原（２２６０ｍ）女子公路自行车运动员的通气无氧阈、乳酸阈及最大氧耗量。结果发现,通气无氧阈时的氧耗量为２．０３ｌ／ｍｉｎ,功率为１３１．４Ｗ;乳酸阈（以运动速度表示）为３３．０ｋｍ／ｈ。通气无氧阈时对应的心率（１３７次／ｍｉｎ）低于乳酸阈的心率（１５３次／ｍｉｎ）。最大氧耗量的绝对值（２．８ｌ／ｍｉｎ）和相对值（４７．４ｍｌ／ｋｇ．ｍｉｎ）分别比平原运动员低２２．２％和２２．９％,但与平原运动员高原训练期间的测试值（２．８ｌ／ｍｉｎ）比较,高原与平原运动员最大氧耗量的差异消失。在相同氧耗量（２．８ｌ／ｍｉｎ）条件下运动时,高原运动员完成的功率（２５１Ｗ）低于平原运动员（２７４Ｗ）。     

逐级递增负荷踏车试验测定最大耗氧量和无氧阈的重复性

本文目的旨在研究在逐级递增负荷踏车试驻中测定最大耗氧量和无氧阈的重复性。21名运动员各完成三次重复性递增负荷踏车试验。通过与Apple Ⅱ_E计算机辅助联机的Jaeger EOS自动分析系统,根据通气和气体交换参数的变化,对无氧阈及最大耗氧量进行无创性测定。结果表明,采用递增负荷踏车试验测定最大耗氧量时,有必要对不熟悉试验程序的受试者进行重复测定以提高准确性,无创性测定无氧阈具有令人满意的重复性,多次重复测定将可提高无氧阈测定的准确性。     

高原（2260m）女子公路自行车运动员的通气无氧阈,乳酸阈和最大氧…

采用实验室递增负荷运动试验和运动现场血乳酸的测定,研究了高原（２２６０ｍ）女子公路自行车运动员的通气无氧阈,乳酸阈及最大氧耗量,结果发现,通气无氧阈时的氧耗量为２．０３１／ｍｉｎ,功率为１３１．４Ｗ乳酸阈（以运动速度表示）为３３．０ｋｍ／ｈ。通气无氧时对应的心率（１３７次／ｍｉｎ）低于乳酸阈的心率（１５３次／ｍｉｎ）。最大氧耗量的绝对值（２．８１／ｍｉｎ）和相对值（４７．４ｍｌ／ｋｇ．ｍｉｎ）分别     

高原青少年最大有氧能力的研究

采用自行车递增负荷运动试验,对青海西宁地区(海拔2260m)86名13～16岁男女中学生的最大摄氧量,无氧阈以及血氧饱和度等指标进行了测定。结果表明,高原青少年的最大摄氧量较低,而无氧阈则较高。血氧饱和度随负荷增加逐渐降低,在接近极限负荷时迅速下降,提示高原低氧是限制最大运动能力的主要因素。无氧阈较高说明高原青少年组织细胞利用氧的能力提高,这是对高原低氧环境长期适应的结果。     

急性低氧对耐力运动员无氧代谢阈值的影响

通过观察急性低氧对耐力运动员无氧代谢阈值的影响,探讨了急性低氧对耐力运动员体力活动能力的影响,并分析与上述影响强弱有关的若干可能因素。18名青年耐力运动员分别吸入21％O_2(常氧对照)和12.8％O_2(急性低氧),进行逐级递增体力负荷运动,直至最大耐受量。观察运动期间每分通气量、氧耗量、二氧化碳排出量、动脉血氧饱和度、心率和氧脉搏,并测定无氧代谢阈值。结果表明,急性低氧使耐力运动员的无氧代谢阈值明显降低。各个体无氧代谢阈值的降低程度分别与该个体动脉血氧饱和度以及氧脉搏的降低程度呈正相关。急性低氧下无氧代谢阈值降低提示了体力活动能力的削弱,而低氧下心肺代偿功能较弱以及动脉血氧饱和度较低者,其体力活动能力的削弱较明显。     

少年足球运动员运动性疲劳后的差异代谢物筛选*

目的: 探索少年足球运动员在运动性疲劳后的差异代谢物变化。方法: 以12名男性少年足球运动员(14～16岁)为试验对象,用功率自行车建立包含有氧运动和无氧运动的训练模型:完成6 min 150 W负荷、60～65 r/min的踏骑运动和30 s的负荷按照测试者体重而设定的最大速度踏骑运动,中间休息1 min,重复运动3组,组间休息3 min;测定运动员每组运动后的最大摄氧量值和平均无氧功率值,采集运动训练前后的尿液样本,利用气相-质谱联用(GC-MS)法检测尿液样本,通过数据库筛选潜在的差异代谢物。结果: 与运动前相比较,少年足球运动员运动疲劳后的平均无氧功率显著下降(P＜0.05),筛选出25个差异代谢物,其中3个代谢物显著升高(P＜0.05,0.01),22个代谢物显著降低(P＜0.05,0.01);上述差异代谢物的相关代谢通路归属为甘氨酸-丝氨酸-苏氨酸代谢、三羧酸循环、酪氨酸代谢、氮代谢和甘油磷酯代谢通路。结论: 少年足球运动员发生运动性疲劳后,机体的代谢物:肌氨酸、L-别苏氨酸、肌酸、丝氨酸、琥珀酸、柠檬酸、4-羟基苯乙酸、羟胺和乙醇胺产生明显的变化,上述差异代谢物可作为少年足球运动员疲劳评价的指标。     

不同训练频率对最大吸氧量和左室功能及亚极量运动能力的影响

采用间歇和持续训练相结合的方法,纵向观察13周不同频率的训练对最大吸氧量、左室功能和亚极量运动能力的影响。结果提示,采用持续和间歇训练相结合的方法并用相同的强度进行训练,其训练频率只影响最大吸氧量和左室功能增进进程的速度,而不影响它们的最终程度;亚极量运动能力受训练频率的影响,频率高,亚极量运动能力提高的幅度亦大,对最大吸氧量、左室功能和亚极量运功能力的同步观察结果表明,最大吸氧量与左室功能密切相关,而Vo_(2max)、左室功能与亚极量运功能力并不完全同步,当训练引起最大吸氧量、左室功能达到最大适应后,其亚极量运动能力仍可继续提高。     

Fatmax和AT强度运动干预对中老年糖尿病前期人群糖和骨质代谢的影响

为探究最大脂肪氧化强度(fatmax)和无氧阈强度(AT)运动干预对糖尿病前期人群糖和骨质代谢的影响,本研究选取73名中老年糖尿病前期人群为受试者进行随机分组,分别分为最大脂肪氧化强度运动组(F组,25人)、无氧阈强度运动组(A组,25人)、对照组(C组,23人),并对所有受试者进行前测(身体成分,骨密度,生长激素分泌指标,骨质代谢指标,胰岛素敏感性指标),前测结束后24 h内分别对F组进行最大脂肪氧化强度测试;对A组进行无氧阈强度测试,前测结束48 h后开始为期36周的运动干预,运动干预结束后再对所有受试者进行后测。研究发现,以C组作为参照,F组、A组经过36周两种强度运动干预后,体重指数(BMI)、体脂率、腰臀比、葡萄糖耐量(OGT)、胰岛素抵抗指数(HOMA-IR)、抵抗素(resistin)水平的后测数据显著低于前测数据(p0.05);血清生长激素(GH)水平、类胰岛素一号增长因子(IGF-1)水平、血清骨钙素(BGP)水平的后测数据显著高于前测数据(p0.05)。相比C组,A组经过36周无氧阈强度运动干预后,股骨颈骨密度、大转子骨密度、Ward's三角区骨密度、腿部肌力的后测数据显著高于前测数据(p0.05);F组经过36周最大脂肪氧化强度运动干预后,股骨颈骨密度、大转子骨密度、Ward's三角区骨密度、腿部肌力后测数据高于前测数据但是未达到显著性差异(p0.05)。研究数据表明长期采用最大脂肪氧化强度或无氧阈强度运动均可有效改善中老年糖尿病前期人群的糖和骨质代谢,并且无氧阈强度运动对骨质代谢具有更好的改善效果。     

赛艇运动员重大比赛前不同训练阶段无创微循环相关指标变化初步研究

目的:探讨不同训练负荷结构下赛艇运动员无创微循环指标变化特点,为进一步完善无创微循环指标在运动员机能状态监控中的应用提供参考与借鉴。方法:2013年7月国家青年赛艇队作了世界青年锦标赛的最后备战训练,整个备战训练分为强度训练期及接下来的调整期,强度训练期主要以500 m、1000 m专项速度练习为主,其训练强度较大,而调整期主要以有氧长划为主,训练强度较小;以8名女性赛艇运动员为研究对象,应用Peri Flux System5000系列激光多普勒血流仪对8名运动员早晨空腹安静、坐位状态下右臂肱二头肌隆起最高处微循环相关指标进行测试,其中强度训练期结束时及接下来的调整期结束时各测试一次,通过对两个阶段无创微循环相关指标变化特点分析,进而对运动员竞技状态作出判断。结果:除运动血细胞浓度(Concentration of moving blood cells,CMBC),调整期微循环血流灌注量(Microcirculatory blood perfusion,MBP)、血细胞平均运行速度(Average velocity of blood cells,AVBC)、经皮氧分压(Transcutaneous oxygen pressure,Tcp O2)均明显高于强度训练期(P<0.05)。结论:不同训练负荷下无创微循环相关指标呈现出不同的变化特点,低强度负荷下无创微循环相关指标呈现出上升趋势,而高强度负荷下则呈现下降趋势。     

无氧代谢阈值与竞走比赛成绩的关系

本文旨在研究无氧代谢阈值与竞走比賽成绩的相关性,并比较无氧代谢阈值和最大氧耗在与比赛成绩相关程度上的差别。受试者为8名男竞走运动员和12名女竞走运动员。他们的无氧代谢阈值和最大氧耗在竞走比赛前的8至7天内测定,无氧代谢阈值用逐级增加负荷量期间气体交换参数的改变特征加以判定。结果表明,男女运动员的无氧代谢阈值以单位体重氧耗量表示分别为38.4±6。3和31.7±8.9毫升/公斤/分,最大氧耗分别为64.5±7.8和53.3±8.9毫升/公斤/分。无氧代谢阈值无论与男子50公里或女子5公里和10公里竞走比赛成绩均呈现了明显相关,相关系数(r)分别为-0.866(P<0.01),-0.863(P<0.01)和-0.674(P<0.05);然而,最大氧耗仅与女子5公里比赛成绩有相关性联系(r=-0.672,P<0.05)。结果提示,无氧代谢阈值较之最大氧耗更能反映各个体的竞走比赛能力,它可能是一个评估和预测竞走比赛水平的生理学指标。     

A comparison of the oxygen consumption/body weight relationship obtained during submaximal exercise on a bicycle ergometer and on a treadmill.

It is widely accepted that the relationship between oxygen consumption and body weight obtained during exercise on a bicycle ergometer differs from that obtained during treadmill walking. Experimental evidence to support this claim is lacking. To examine this difference a group of subjects (body weight 41--81 kg) undertook a predetermined level of submaximal exercise on a bicycle ergometer and a treadmill. Oxygen consumption was measured in a steady state at rest (i.e. sitting on the bicycle ergometer and standing on the treadmill) and during the two modes of exercise. A significant positive correlation between oxygen consumption and body weight was obtained under all four conditions of measurement. At rest the two regression lines did not differ in slope or elevation. During exercise the slope and the elevation of the line obtain from treadmill walking were significantly greater than from bicycle ergometer exercise. The 'metabolic cost' of bicycle ergometer exercise, (Vo2 during exercise--V02 at rest), showed no significant correlation with body weight. In contrast, there was a significant positive correlation during walking. It is suggested that these differences have arisen due to a different proportion of the total body weight supported by the subject in the two forms of exercise.     

Oxygen uptake kinetics and time to exhaustion in cycling and running: a comparison between trained and untrained subjects

The objective of the present study was to compare pulmonary gas exchange kinetics (VO2 kinetics) and time to exhaustion (Tlim) between trained and untrained individuals during severe exercise performed on a cycle ergometer and treadmill. Eleven untrained males in running (UR) and cycling (UC), nine endurance cyclists (EC), and seven endurance runners (ER) were submitted to the following tests on separate days: (i) incremental test for determination of maximal oxygen uptake (VO2max) and the intensity associated with the achievement of VO2max (IVO2max) on a mechanical braked cycle ergometer (EC and UC) and on a treadmill (ER and UR); (ii) all-out exercise bout performed at IVO2max to determine the time to exhaustion at IVO2max (Tlim) and the time constant of oxygen uptake kinetics (tau). The tau was significantly faster in trained group, both in cycling (EC = 28.2 +/- 4.7s; UC = 63.8 +/- 25.0s) and in running (ER = 28.5 +/- 8.5s; UR = 59.3 +/- 12.0s). Tlim of untrained was significantly lower in cycling (EC = 384.4 +/- 66.6s vs. UC; 311.1 +/- 105.7 s) and higher in running (ER = 309.2 +/- 176.6 s vs. UR = 439.8 +/- 104.2 s). We conclude that the VO2 kinetic response at the onset of severe exercise, carried out at the same relative intensity is sensitive to endurance training, irrespective of the exercise type. The endurance training seems to differently influence Tlim during exercise at IVO2max in running and cycling.     

Influence of plasma catecholamines on the lactate threshold during graded exercise

This investigation examined the relationship among plasma catecholamines, the blood lactate threshold (TLa), and the ventilatory threshold (TVE) in highly trained endurance athletes. Six competitive cyclists and six varsity cross-country runners performed a graded exercise test via two different modalities: treadmill running and bicycle ergometry. Although maximal oxygen consumption (VO2 max) did not differ significantly for the cyclists for treadmill running and cycling (64.6 +/- 1.0 and 63.5 +/- 0.4 ml O2.kg-1-min-1, respectively), both TLa and TVE occurred at a relatively earlier work load during the treadmill run. The opposite was true for the runners as TLa and TVE appeared at an earlier percent of VO2max during cycling compared with treadmill running (60.0 +/- 1.7 vs. 75.0 +/- 4.0%, respectively, TLa). The inflection in plasma epinephrine shifted in an identical manner and occurred simultaneously with that of TLa (r = 0.97) regardless of the testing protocol or training status. Although a high correlation (r = 0.86) existed for the shift in TVE and TLa, this relationship was not as strong as was seen with plasma epinephrine. The results suggest that a causal relationship existed between the inflection in plasma epinephrine and TLa during a graded exercise test. This association was not as strong for TVE and TLa.     

Step ergometry: is it task-specific training?

Maximal exercise responses were measured before and after 10 weeks of training in two groups of men, one trained on a treadmill (n = 12) and the other on a step ergometer (n = 9); the groups were pre- and post-tested on both machines to examine the specificity of the training modes. Training for both groups consisted of 3 days week-1, 30 min day-1, progressing to 50 min day-1, at an intensity of 75%-80% heart rate maximum reserve. Pre-training maximal oxygen uptake (VO2max) was significantly higher on the treadmill for both groups (X = 8.5%). VO2max increased 6.9% on the treadmill (P less than 0.05) and 6.9% (P greater than 0.05) on the step ergometer after treadmill training. The small increases may be attributed to the specificity of the testing protocols used to elicit VO2max. Significant (P less than 0.01) increases in VO2max were found for both modalities after step-ergometry training (treadmill = 11.8%; step ergometer = 23.2%). These increases resulted in equal post-test VO2max values (4.05 l min-1; 51 ml kg-1 min-1) on the step ergometer and treadmill. The significant increases in VO2max found for both modalities after step-ergometry training shows that (1) step ergometry is an effective training modality, and (2) its effects can be measured on the treadmill and therefore it is not task-specific training.     

Effects of standing cycling and the use of toe stirrups on maximal oxygen uptake

Twenty-eight subjects (6 normal men, 14 distance runners, and 8 rowers) were tested for maximal oxygen uptake (VO2max) and associated physiological measures during bicycle ergometer exercise with toe stirrups while standing (BEts) and during treadmill exercise (TM). Correlation between BEts VO2max and TM VO2max was high (r = 0.901, p less than 0.05). No significant difference existed between the two VO2max values (60.3 +/- 8.9 vs. 60.5 +/- 9.7 ml.kg-1.min-1; n = 28). No differences were found even when three different subgroups were separately compared. It is concluded that the higher VO2max elicited during BEts as compared with normal sitting cycling may be attributed to the increased muscle blood flow and/or involvement of a larger muscle mass, the latter being partly evidenced by the observation of greater electromyographic activity during BEts.     

Maximal aerobic capacity for repetitive lifting: comparison with three standard exercise testing modes

A multi-stage, repetitive lifting maximal oxygen uptake (VO2max) test was developed to be used as an occupational research tool which would parallel standard ergometric VO2max testing procedures. The repetitive lifting VO2max test was administered to 18 men using an automatic repetitive lifting device. An intraclass reliability coefficient of 0.91 was obtained with data from repeated tests on seven subjects. Repetitive lifting VO2max test responses were compared to those for treadmill, cycle ergometer and arm crank ergometer. The mean +/- SD repetitive lifting VO2max of 3.20 +/- 0.42 l.min-1 was significantly (p less than 0.01) less than treadmill VO2max (delta = 0.92 l.min-1) and cycle ergometer VO2max (delta = 0.43 l.min-1) and significantly greater than arm crank ergometer VO2max (delta = 0.63 l.min-1). The correlation between repetitive lifting oxygen uptake and power output was r = 0.65. VO2max correlated highly among exercise modes, but maximum power output did not. The efficiency of repetitive lifting exercise was significantly greater than that for arm cranking and less than that for leg cycling. The repetitive lifting VO2max test has an important advantage over treadmill or cycle ergometer tests in the determination of relative repetitive lifting intensities. The individual curves of VO2 vs. power output established during the multi-stage lifting VO2max test can be used to accurately select work loads required to elicit given percentages of maximal oxygen uptake.     

Crossmodal session rating of perceived exertion response at low and moderate intensities

Session rating of perceived exertion (SRPE) permits global effort estimations after an exercise bout and has shown promise for evaluating training load. However, factors mediating SRPE are not well understood. The purpose of this study was to compare SRPE between cycling and treadmill exercise at low and moderate intensities. In a counterbalanced order, male subjects (n = 7) completed a VO2max trial on a cycle ergometer and a motor-driven treadmill. Then, participants completed trials at 50 and 75% mode-specific VO2max on a cycle ergometer (BK75, BK50) and a treadmill (TM75, TM50) to achieve ～ 400-kcal energy expenditure per trial. Acute RPE (i.e., during exercise) at 5 minutes, midway, and test termination were recorded with SRPE (20-minutes postexercise) expressed as overall (SRPEO), legs (SRPEL), and breathing also recorded were heart rate (HR) and change in rectal temperature (ΔTrec). Significance was accepted at p ≤ 0.05. Repeated-measures analysis of variance revealed significantly greater SRPE for higher intensities within each mode. Crossmodal comparisons also show a higher SRPE at moderate (75% VO2max) intensities [SRPEO] = BK75: 7.6 ± 1.0, TM75: 6.9 ± 1.3) vs. lower (50% VO2max) intensities (BK50: 4.6 ± 1.4, TM50: 4.6 ± 1.1). Within modes, SRPE corresponded well with ΔTrec and HR. Acute RPE was linked with intensity and drifted upward across time. Results indicated that overall and differentiated SRPEs are magnified with exercise intensity with the corresponding disruption in internal environment potentially mediating subjective responses. From a practical application standpoint, SRPE provides a subjective assessment for immediate evaluation of daily training. Results indicate that, when using SRPE to monitor training, consideration should be given to responses across differing exercise modes.     

A prediction equation for indirect assessment of anaerobic threshold in male distance runners

The predictability of anaerobic threshold (AT) from maximal aerobic power, distance running performance, chronological age, and total running distance achieved on the treadmill (TRD) was investigated in a sample of 53 male distance runners, 17-23 years of age. The dependent variable was oxygen uptake (Vo2) at which AT was detected (i.e. Vo2 @ AT). A regression analysis of the data indicated Vo2 @ AT could be predicted from the following four measurements with a multiple R = 0.831 and a standard error of the estimate of 2.66 ml . min-1 . kg-1: Vo2max (67.9 +/- 5.7 ml . min-1 . kg-1), 1,500-m running performance (254.5 +/- 14.2 s), TRD (6.82 +/- 1.13 km), and age (19.4 +/- 2.2 years). When independent variables were limited to Vo2max (X1) and 1,500-m running performance (X2) for simpler assessment, a multiple R = 0.806 and a standard error of the estimate of 2.76 ml . min-1 . kg-1 were computed. A useful prediction equation with this predictive accuracy was considered to be Vo2 @ AT = 0.386X1 - 0.128X2 + 57.11. To determine if the prediction equation developed for the 53 male distance runners could be generalized to other samples, cross-validation of the equation was tested, using 21 different distance runners, 17-22 years of age. A high correlation (R = 0.927) was obtained between Vo2 AT predicted from the above equation and directly measured Vo2 @ AT. It is concluded that the generalized equation may be applicable to young distance runners for indirect assessment of Vo2 @ AT.