Nichols J F, Phares S L, Buono M J
Department of Exercise & Nutritional Sciences, San Diego State University, CA 92182-0171, USA.
Int J Sports Med. 1997 Aug;18(6):458-63. doi: 10.1055/s-2007-972664.
The blood lactate response to graded exercise and its relationship to performance in the field was examined in highly competitive female master cyclists. Thirteen women, age 47.5+/-2.2yr (mean+/-SE), all of whom were United States Cycling Federation (USCF) competitors, underwent laboratory testing for aerobic capacity (VO2max) and lactate threshold (LT), and field testing for performance in 13.5 km and 20 km time-trials. The mean VO2max of the subjects (50.6+/-2.7 ml x kg(-1) x min[-1]) was approximately 10% higher than that previously reported for other age-matched female athletes and correlated moderately (r=-0.67) with age. Maximal heart rate was unrelated to age (r=-0.25, p>0.05). Blood lactate concentration (BLC) while time-trialing was significantly higher than that at the LT (2.86+/-0.17 mmol x l[-1]) for both the 13.5 km (7.59 mmol x l(-1), p < 0.0001), and the 20 km trials (6.99 mmol x l(-1), p<0.002). The LT occurred at a mean power output of 168+/-11.3 W and 66% of VO2max. The VO2 corresponding to a BLC of 4.0 mmol x l(-1) (LT4) was 72% of VO2max. As expected, time-trial performance was highly correlated with VO2max (r=-0.85); however, regression analysis indicated that power output at the lactate threshold was the best laboratory predictor of performance (13.5 km: r2 = 0.83; 20 km: r2 = 0.78). Relative to maximal heart rate, heart rate at LT (88% HRmax) was significantly (p<0.05) lower than time-trial heart rate (92-94% HRmax). The cyclists in this study have higher aerobic capacities and maximal heart rates than those previously reported for other age-matched female athletes and are able to cycle for extended periods at blood lactate concentrations significantly higher than those at the lactate threshold. Traditional methods of exercise prescription, particularly when using age-estimates of maximal heart rate, underestimate training intensities required to be above the LT in female master cyclists.
在极具竞争力的女性成年自行车运动员中，研究了分级运动时的血乳酸反应及其与实际骑行表现的关系。13名年龄为47.5±2.2岁（均值±标准误）的女性，均为美国自行车联合会（USCF）的参赛者，接受了有氧能力（最大摄氧量，VO2max）和乳酸阈（LT）的实验室测试，以及13.5公里和20公里计时赛的实际骑行表现测试。受试者的平均最大摄氧量（50.6±2.7毫升·千克⁻¹·分钟⁻¹）比之前报道的其他年龄匹配的女性运动员高出约10%，且与年龄呈中度相关（r = -0.67）。最大心率与年龄无关（r = -0.25，p>0.05）。在13.5公里（7.59毫摩尔·升⁻¹，p < 0.0001）和20公里计时赛（6.99毫摩尔·升⁻¹，p<0.002）中，计时赛时的血乳酸浓度（BLC）均显著高于乳酸阈时的浓度（2.86±0.17毫摩尔·升⁻¹）。乳酸阈出现在平均功率输出为168±11.3瓦时，此时为最大摄氧量的66%。血乳酸浓度为4.0毫摩尔·升⁻¹（LT4）时对应的最大摄氧量为最大摄氧量的72%。正如预期的那样，计时赛表现与最大摄氧量高度相关（r = -0.85）；然而，回归分析表明，乳酸阈时的功率输出是表现的最佳实验室预测指标（13.5公里：r² = 0.83；20公里：r² = 0.78）。相对于最大心率，乳酸阈时的心率（88%HRmax）显著低于计时赛时的心率（92 - 94%HRmax）（p<0.05）。本研究中的自行车运动员比之前报道的其他年龄匹配的女性运动员具有更高的有氧能力和最大心率，并且能够在血乳酸浓度显著高于乳酸阈浓度的情况下长时间骑行。传统的运动处方方法，尤其是在使用最大心率的年龄估计值时，会低估成年女性自行车运动员达到高于乳酸阈训练强度所需的强度。
