The effect of training on aerobic power characteristics of young cross‐country skiers

The influences of growth, training and various training methods were investigated by analysing long‐term training effects in young cross‐country and biathlon skiers (n = 129). Some athletes (n = 49) were studied six times in three years and some at least once a year during a four year period (n = 48). During three summer training periods skiers emphasized either intensive training or distance training or continued to train normally. The results indicated that maximal oxygen uptake (VO₂ max) and heart volume increased between 15 and 20 years of age and the most significant changes in heart volume were observed between 16 and 18 years of age. International level skiers were able to increase their VO₂ max and heart volume even after 20 years of age. Anaerobic threshold (AT, ml kg^‐1 min^‐1) increased like VO₂ max but when expressed as a percentage of VO₂ max, the AT was similar in every age group over 16 years of age. Intensive training at the intensity of anaerobic threshold or higher was observed to be most effective in producing improvements in VO₂ max. Low‐intensity distance training was more effective in producing improvements in anaerobic threshold.     

运动对无氧阈、最大吸氧量的影响与心功能的关系

两年游泳系统训练后,男女运动员ＶＯ２ｍａｘ绝对值和相对值都无显著性变化,无氧阈明显提高。表明,ＡＴ的显著改善并不需要ＶＯ２ｍａｘ明显提高。训练后,ＡＴ和心泵血功能都有显著性提高,并且ＣＯ与ＡＴ的相关比ＣＯ与ＶＯ２ｍａｘ相关更为密切,提示,ＡＴ提高与心泵血功能变化有关,心功能可能是影响ＡＴ的重要因素。训练使心脏舒张功能得以改善,这是心脏对运动的又一适应。     

Development of maximal oxygen uptake in young elite male cross-country skiers: a longitudinal study.

The aim of this study was to investigate the effects of extensive endurance training (15-25 h per week) on the development of maximal oxygen uptake (VO2 max) in boys from puberty. Maximal oxygen uptake was measured a number of times each year from the age of puberty and for the next 6-9 years in seven young male elite cross-country skiers. Mean VO2 max was measured as 76.3 and 80.1 ml kg-1 min-1 at the ages of 14 and 15 years respectively. Despite the fast rate of growth during puberty, maximal aerobic power showed seasonal variations from the age of 14, reaching a plateau at the age of 15, whereas VO2 max (ml kg-2/3 min-1) increased continuously. It is concluded that, during puberty, boys probably attain significant increases in VO2 max when appropriate amounts of endurance training are undertaken.     

HiHiLo训练法与LoHiLo训练法对女子跆拳道运动员有氧代谢能力影响的比较

探讨HiHiLo训练法与LoHiLo训练法对提高女子跆拳道运动员有氧代谢能力的影响。结果表明:HiHiLo组无氧阈功率指标显著性上升,AT功率平均水平上升了8.24%,RPE指标在各时间点均显著性降低,心率指标无显著性影响,血乳酸指标从150~240W时段显著性降低,.VO2max指标显著性升高,升高幅度达5.37%;LoHiLo组无氧阈功率指标无显著变化,上升幅度为6.24%,RPE指标只有在150~240W两个时间点有显著性降低,其他时间点无显著性,心率指标无显著性,血乳酸指标无显著性,.VO2max指标无显著性,降低了1.08%。结果提示:在提高跆拳道女运动员有氧代谢能力上,HiHi-Lo训练法较LoHiLo训练法更加有效。     

高中生“阳光长跑”无氧阈心率强度控制干预效果 王

目的通过实验研究建立青少年“阳光长跑”个体适宜强度(无氧阈心率)回归方程,以改变目前全国青少年“阳光长跑”中强度随意的现状。方法以我国X市3所(A、B、C)中学的高中生为样本,按随机抽样原则从中抽取研究对象,分2个阶段进行研究。①从3所中学高中各年级中抽取男、女生共593名,通过实验测试获得基础数据,以文献资料法和专家法筛选出的指标为自变量、无氧阈心率为因变量,建立个体无氧阈心率回归方程。②来自3所中学高二年级的学生(共204名),分别以3种模式[按照无氧阈心率强度(基于所建立的个体无氧阈心率回归方程)监控、不按强度但严格监控、不监控自主式]完成“阳光长跑”,12周后,比较实验前后3所中学高中生最大摄氧量(VO2max)、基础心率指标的变化情况。结果3所中学高中生按不同模式完成长跑后,其基础心率均未出现降低现象(P均大于0.05);A中学男、女生VO2max均出现不同程度增长现象(t=2.804,P<0.01;t=2.831,P<0.01);B中学女生VO2max出现一定程度增长现象(t=2.337,P<0.05),男生则未出现增长现象(t=0.574,P>0.05);C中学男、女生VO2max均未出现增长现象(P均大于0.05)。结论①所建立的高中生个体无氧阈心率回归方程可用于指导该群体在长跑中的适宜强度调节;②通过实证研究提出针对性建议,有助于“阳光长跑”的可持续性开展。     

有氧代谢能力与耐力项目训练中运动强度的选择

全面阐述了有氧代谢能力的概念，提出了最大摄氧量、无氧阈、最大摄氧量平台的持续时间都应是耐力训练的目标。在此基础上讨论了发展此3项目标应采用的训练强度。     

Physiological effects of altitude training on elite male cross-country skiers.

Seven elite male cross-country skiers trained for 3 weeks at an altitude of 1900 m. Haemoglobin concentration ([Hb]), haematocrit (Hct) (obtained from venous blood), maximal oxygen uptake (VO2 max) and energy expenditure during a standard submaximal workload were measured before and after training at altitude, and 1 year later while training at sea level (control). Both [Hb] and Hct increased significantly, and the skiers with the lowest initial [Hb] and Hct experienced the largest increases during training at altitude. The increase in blood lactate (BLa) concentration (using haemolysed capillary blood) during a standard submaximal exercise test was significantly lower after training at altitude than before it or 1 year later (control). A significant correlation was found between the magnitude of increase in [Hb] and Hct and the difference in the lactate response to the standard submaximal workload pre- and post-altitude training. Although VO2 max remained unchanged, lower BLa concentration during the submaximal test probably reflects an improved ability to exercise at higher submaximal workloads shortly after training at altitude compared with pre-altitude training. It is suggested that subjects with low initial [Hb] and Hct improve their aerobic performance capacity most during altitude training.     

不同无氧阈测定方法比较及其在中长跑训练中的应用

本文比较了各种无氧阈测值:通气阈(VT),4mmol乳酸阈(LT_4),血乳酸开始升高(LT_(OBLA)),个体无氧阈(IAT),血乳酸最大稳态(maxLass)和心率拐点(HRd)。发现各测值之间高度相关,但是maxLass与其它测值之间存在不同程度的差异,为AT在训练中的应用提供了有价值的生理依据。继而探讨了LT_4百分比强度对控制中长跑训练,改善运动员肌肉氧化代射能力,提高运动成绩的意义。     

有氧耐力的测试指标和训练方法研究新进展

有氧耐力是人体从事耐力性运动的重要能力一,最大摄氧量是客观评价人体心肺功能的一项综合生理指标。本文对有氧耐力的重要测试指标最大摄氧量和无氧阈在有氧耐力评价中的作用及其影响因素进行了综合分析,并梳理了有氧耐力训练的新方法。耐力性项目的连动成绩与最大摄氧量关系紧密,而无氧阀在评定有氧耐力水平、制订有氧耐力训练强度等许多方面亦具有较强的指导意义。有氧耐力训练在很多项目训练中占有重要地位,掌握科学的有氧耐力训练方法对提高运动员的专项竞技水平起着关键性作用。     

Combined metabolic gas analyser and dGPS analysis of performance in cross-country skiing

The purpose of this study was to provide a more detailed analysis of performance in cross-country skiing by combining findings from a differential global positioning system (dGPS), metabolic gas measurements, speed in different sections of a ski-course and treadmill threshold data. Ten male skiers participated in a freestyle skiing field test (5.6 km), which was performed with dGPS and metabolic gas measurements. A treadmill running threshold test was also performed and the following parameters were derived: anaerobic threshold, threshold of decompensated metabolic acidosis, respiratory exchange ratio = 1, onset of blood lactate accumulation and peak oxygen uptake (VO2peak). The combined dGPS and metabolic gas measurements made detailed analysis of performance possible. The strongest correlations between the treadmill data and final skiing field test time were for VO2peak (l x min(-1)), respiratory exchange ratio = 1 (l x min(-1)) and onset of blood lactate accumulation (l x min(-1)) (r = -0.644 to - 0.750). However, all treadmill test data displayed stronger associations with speed in different stretches of the course than with final time, which stresses the value of a detailed analysis of performance in cross-country skiing. Mean oxygen uptake (VO2) in a particular stretch in relation to speed in the same stretch displayed its strongest correlation coefficients in most stretches when VO2 was presented in units litres per minute, rather than when VO2 was normalized to body mass (ml x kg(-1) x min(-1) and ml x min(-1) x kg(-2/3)). This suggests that heavy cross-country skiers have an advantage over their lighter counterparts. In one steep uphill stretch, however, VO2 (ml x min(-1) x kg(-2/3)) displayed the strongest association with speed, suggesting that in steep uphill sections light skiers could have an advantage over heavier skiers.     

中长跑运动员赛前训练的调控研究

运用实验法对参加全国第七届大学生运动会的江苏省大学生中长跑运动员和参加第十届全运会江苏队中长跑运动员的赛前训练期间的生理学指标进行跟踪测定、评价，对训练进行了调控。研究表明：用心率、心功能指数、尿蛋白、最大吸氧量、无氧功率、斯坦格试验与汉契试验、无氧闽等指标评定中长跑运动员赛前的机能状态有较强的实用性和针对性，但需结合项目的特点和训练实际，加强监控和调控，进行综合分析；中长跑赛前训练安排应以专项素质为主，突出速度和速度耐力的训练，速度力量在中长跑项目赛前训练要给予重视，负荷的安排是赛前训练的关键。     

Prediction of energy expenditure from heart rate monitoring during submaximal exercise

The aims of this study were to quantify the effects of factors such as mode of exercise, body composition and training on the relationship between heart rate and physical activity energy expenditure (measured in kJ x min(-1)) and to develop prediction equations for energy expenditure from heart rate. Regularly exercising individuals (n = 115; age 18-45 years, body mass 47-120 kg) underwent a test for maximal oxygen uptake (VO2max test), using incremental protocols on either a cycle ergometer or treadmill; VO2max ranged from 27 to 81 ml x kg(-1) x min(-1). The participants then completed three steady-state exercise stages on either the treadmill (10 min) or the cycle ergometer (15 min) at 35%, 62% and 80% of VO2max, corresponding to 57%, 77% and 90% of maximal heart rate. Heart rate and respiratory exchange ratio data were collected during each stage. A mixed-model analysis identified gender, heart rate, weight, V2max and age as factors that best predicted the relationship between heart rate and energy expenditure. The model (with the highest likelihood ratio) was used to estimate energy expenditure. The correlation coefficient (r) between the measured and estimated energy expenditure was 0.913. The model therefore accounted for 83.3% (R2) of the variance in energy expenditure in this sample. Because a measure of fitness, such as VO2max, is not always available, a model without VO2max included was also fitted. The correlation coefficient between the measured energy expenditure and estimates from the mixed model without VO2max was 0.857. It follows that the model without a fitness measure accounted for 73.4% of the variance in energy expenditure in this sample. Based on these results, we conclude that it is possible to estimate physical activity energy expenditure from heart rate in a group of individuals with a great deal of accuracy, after adjusting for age, gender, body mass and fitness.     

Relationship of running economy, ventilatory threshold, and maximal oxygen consumption to running performance in high school females

The purpose of the study was to relate three determinants of distance running success, (a) maximal oxygen consumption (VO2max), (b) ventilatory threshold (VT), and (c) running economy (RE), to actual running time in a 5-km race (ART). Twenty-four female runners (M age = 15.9 years) from four high school teams that competed at the Massachusetts All-State 5-km Cross Country Championship Meet and placed 1st, 7th, 19th, and 20th were tested in the laboratory. The mean VO2max of these runners was 61.7 ml.kg-1.min-1, HRmax 201 b.min-1, VEmax 100 L.min-1, and RER 1.10. The VT occurred at 79% of the VO2max, and HR of 184 b.min-1 (92% of HRmax). The velocity at VT (vVT) and velocity at VO2max (vVO2max) was correlated with ART, r(22) = .78 and .77 (p less than .001), respectively. The VO2 at VT and at maximal exercise was correlated with ART by r(22) = -.66 and -.69 (p less than .001), respectively. The VO2 at 215 m.min-1 (8 mph) was poorly related to ART, r(22) = -.05, p greater than .05. It was concluded that either of the derived variables vVT and vVO2max appear to explain significant variation in distance running performance among adolescent female cross country runners.     

短期高强度训练对优秀篮球运动员有氧耐力的影响

为了调查短期高强度训练对篮球运动员有氧耐力的影响 ,对 2 0名 (男、女各 10名 )优秀篮球运动员 ,进行跑台渐增负荷运动直到力竭为止。同时测定气体代谢最大吸氧量 (VO2max)、通气量 (VE)、血乳酸(BLa)、心率 (HR)、血睾酮 (T)、皮质醇 (Cor)及血红蛋白 (Hb)。结果为 :1)短期高强度训练期后男、女两组无氧阈 (AT)值与训练前相比较均有显著性差异 (P <0 .0 5 ) ,但VO2max却未有显著性差异 ;2 )短期高强度训练期后男、女两组Hb值与训练前相比较均有显著性差异 (P <0 .0 5 ) ,而T、Cor在训练期前后却未有显著性差异。其结果表明 ,短期高强度训练并不能提高VO2max,而AT却明显提高。提示可采用AT值作为反映篮球运动员有氧耐力的指标。     

The multistage 20 metre shuttle run test for aerobic fitness

A maximal multistage 20 m shuttle run test was designed to determine the maximal aerobic power of schoolchildren, healthy adults attending fitness class and athletes performing in sports with frequent stops and starts (e.g. basketball, fencing and so on). Subjects run back and forth on a 20 m course and must touch the 20 m line; at the same time a sound signal is emitted from a prerecorded tape. Frequency of the sound signals is increased 0.5 km h-1 each minute from a starting speed of 8.5 km h-1. When the subject can no longer follow the pace, the last stage number announced is used to predict maximal oxygen uptake (VO2max) (Y, ml kg-1 min-1) from the speed (X, km h-1) corresponding to that stage (speed = 8 + 0.5 stage no.) and age (A, year): Y = 31.025 + 3.238 X - 3.248A + 0.1536AX, r = 0.71 with 188 boys and girls aged 8-19 years. To obtain this regression, the test was performed individually. Right upon termination VO2 was measured with four 20 s samples and VO2max was estimated by retroextrapolating the O2 recovery curve at time zero of recovery. For adults, similar measurements indicated that the same equation could be used keeping age constant at 18 (r = 0.90, n = 77 men and women 18-50 years old). Test-retest reliability coefficients were 0.89 for children (139 boys and girls 6-16 years old) and 0.95 for adults (81 men and women, 20-45 years old).(ABSTRACT TRUNCATED AT 250 WORDS)     

Heart rate,blood lactate concentration and estimated energy expenditure in a semi-professional rugby league team during a match: a case study

The aim of this study was to examine heart rate, blood lactate concentration and estimated energy expenditure during a competitive rugby league match. Seventeen well-trained rugby league players (age, 23.9 +/- 4.1 years; VO2max, 57.9 +/- 3.6 ml x kg(-1) x min(-1); height, 1.82 +/- 0.06 m; body mass, 90.2 +/- 9.6 kg; mean +/- s) participated in the study. Heart rate was recorded continuously throughout the match using Polar Vantage NV recordable heart rate monitors. Blood lactate samples (n = 102) were taken before the match, after the warm-up, at random stoppages in play, at half time and immediately after the match. Estimated energy expenditure during the match was calculated from the heart rate-VO2 relationship determined in laboratory tests. The mean team heart rate (n = 15) was not significantly different between halves (167 +/- 9 vs 165 +/- 11 beats x min(-1)). Mean match intensity was 81.1 +/- 5.8% VO2max. Mean match blood lactate concentration was 7.2 +/- 2.5 mmol x l(-1), with concentrations for the first half (8.4 +/- 1.8 mmol x l(-1)) being significantly higher than those for the second half (5.9 +/- 2.5 mmol x l(-1)) (P<0.05). Energy expenditure was approximately 7.9 MJ. These results demonstrate that semi-professional rugby league is a highly aerobic game with a considerable anaerobic component requiring high lactate tolerance. Training programmes should reflect these demands placed on players during competitive match-play.     

Effects of endurance training on transient oxygen uptake responses in cyclists

The aim of this study was to determine the alterations in oxygen uptake kinetics following endurance training in previously trained athletes. Sixteen competitive cyclists completed 8 weeks of supervised endurance cycle training. Ventilatory threshold, maximal oxygen uptake (VO2max), oxygen uptake kinetics and simulated 40-km time-trial tests were performed three times over a 4-week period before training, and then after 4 and 8 weeks of training. The protocol for measuring oxygen uptake kinetics consisted of three square-wave increments from unloaded cycling to a power output of 78 W followed by a single increment from 78 to 156 W. No significant differences in any variables were observed over the pre-training period. The ventilatory threshold and VO2max increased, and the time for 40 km decreased (P < 0.05) with training. Shorter VO2 time constants and lower heart rates were observed during the protocol for measuring oxygen uptake kinetics (same absolute power output) post-training. These results indicate that oxygen uptake kinetics may be improved with endurance training in previously trained athletes.     

The multi-stage fitness test as a predictor of endurance fitness in wheelchair athletes

The aims of this study were two-fold: (1) to consider the criterion-related validity of the multi-stage fitness test (MSFT) by comparing the predicted maximal oxygen uptake (.VO(2max)) and distance travelled with peak oxygen uptake (VO(2peak)) measured using a wheelchair ergometer (n = 24); and (2) to assess the reliability of the MSFT in a sub-sample of wheelchair athletes (n = 10) measured on two occasions. Twenty-four trained male wheelchair basketball players (mean age 29 years, s = 6) took part in the study. All participants performed a continuous incremental wheelchair ergometer test to volitional exhaustion to determine .VO(2peak), and the MSFT on an indoor wooden basketball court. Mean ergometer .VO(2peak) was 2.66 litres . min(-1) (s = 0.49) and peak heart rate was 188 beats . min(-1) (s = 10). The group mean MSFT distance travelled was 2056 m (s = 272) and mean peak heart rate was 186 beats . min(-1) (s = 11). Low to moderate correlations (rho = 0.39 to 0.58; 95% confidence interval [CI]: -0.02 to 0.69 and 0.23 to 0.80) were found between distance travelled in the MSFT and different expressions of wheelchair ergometer .VO(2peak). There was a mean bias of -1.9 beats . min(-1) (95% CI: -5.9 to 2.0) and standard error of measurement of 6.6 beats . min(-1) (95% CI: 5.4 to 8.8) between the ergometer and MSFT peak heart rates. A similar comparison of ergometer and predicted MSFT .VO(2peak) values revealed a large mean systematic bias of 15.3 ml . kg(-1) . min(-1) (95% CI: 13.2 to 17.4) and standard error of measurement of 3.5 ml . kg(-1) . min(-1) (95% CI: 2.8 to 4.6). Small standard errors of measurement for MSFT distance travelled (86 m; 95% CI: 59 to 157) and MSFT peak heart rate (2.4 beats . min(-1); 95% CI: 1.7 to 4.5) suggest that these variables can be measured reliably. The results suggest that the multi-stage fitness test provides reliable data with this population, but does not fully reflect the aerobic capacity of wheelchair athletes directly.     

Effect of 6 weeks of endurance training on the lactate minimum speed

The aim of this study was to assess the sensitivity of the lactate minimum speed test to changes in endurance fitness resulting from a 6 week training intervention. Sixteen participants (mean +/- s: age 23+/-4 years; body mass 69.7+/-9.1 kg) completed 6 weeks of endurance training. Another eight participants (age 23+/-4 years; body mass 72.7+/-12.5 kg) acted as non-training controls. Before and after the training intervention, all participants completed: (1) a standard multi-stage treadmill test for the assessment of VO2max, running speed at the lactate threshold and running speed at a reference blood lactate concentration of 3 mmol x l(-1); and (2) the lactate minimum speed test, which involved two supramaximal exercise bouts and an 8 min walking recovery period to increase blood lactate concentration before the completion of an incremental treadmill test. Additionally, a subgroup of eight participants from the training intervention completed a series of constant-speed runs for determination of running speed at the maximal lactate steady state. The test protocols were identical before and after the 6 week intervention. The control group showed no significant changes in VO2max, running speed at the lactate threshold, running speed at a blood lactate concentration of 3 mmol x l(-1) or the lactate minimum speed. In the training group, there was a significant increase in VO2max (from 47.9+/-8.4 to 52.2+/-2.7 ml x kg(-1) x min(-1)), running speed at the maximal lactate steady state (from 13.3+/-1.7 to 13.9+/-1.6 km x h(-1)), running speed at the lactate threshold (from 11.2+/-1.8 to 11.9+/-1.8 km x h(-1)) and running speed at a blood lactate concentration of 3 mmol x l(-1) (from 12.5+/-2.2 to 13.2+/-2.1 km x h(-1)) (all P < 0.05). Despite these clear improvements in aerobic fitness, there was no significant difference in lactate minimum speed after the training intervention (from 11.0+/-0.7 to 10.9+/-1.7 km x h(-1)). The results demonstrate that the lactate minimum speed, when assessed using the same exercise protocol before and after 6 weeks of aerobic exercise training, is not sensitive to changes in endurance capacity.