Impellizzeri Franco, Sassi Aldo, Rodriguez-Alonso Manuel, Mognoni Piero, Marcora Samuele
Laboratorio di Fisologia, Sport Service MAPEI, Castellanza, Varese, Italy.
Med Sci Sports Exerc. 2002 Nov;34(11):1808-13. doi: 10.1097/00005768-200211000-00018.
This study was designed to quantify and describe the intensity profile of cross-country mountain-biking races using heart rate (HR) recorded during competitions.
Nine mountain bikers participated in four cross-country circuit races of international and national levels. Each cyclist was tested before the competitions to determine lactate threshold (LT), the onset of blood lactate accumulation (OBLA4), and the relationship between percentage of maximum HR and percentage of VO(2max).
To control for intersubject variability, only the five off-road cyclists who completed all four competitions were included in the statistical analysis. The four races' mean absolute and relative time expressed in percentage of race duration (147 +/- 15 min) spent in the EASY(ZONE) (HR below LT) were 27 +/- 16 min and 18 +/- 10%, in the MODERATE(ZONE) (HR between LT and OBLA4) were 75 +/- 19 min and 51 +/- 9%, and in the HARD(ZONE) (HR above OBLA4) were 44 +/- 21 min and 31 +/- 16%. The average HR was 171 +/- 6 beats x min(-1), corresponding to 90 +/- 3% of maximum (84 +/- 3% of VO(2max).
This study shows that cross-country events are conducted at very high intensity, especially at the start of the race. Coaches must take into account the distribution of the effort and the high exercise intensity characteristic of mountain-biking cross-country events when prescribing specific training programs.
本研究旨在利用比赛期间记录的心率（HR）对越野山地自行车比赛的强度分布进行量化和描述。
九名山地自行车运动员参加了四项国际和国家级别的越野巡回赛。每位自行车运动员在比赛前进行测试，以确定乳酸阈（LT）、血乳酸开始积累点（OBLA4）以及最大心率百分比与最大摄氧量百分比（VO₂max）之间的关系。
为控制个体间差异，仅将完成所有四项比赛的五名单车越野运动员纳入统计分析。四项比赛中，在轻松区（HR低于LT）花费的平均绝对时间和以比赛时长百分比表示的相对时间（147±15分钟）分别为27±16分钟和18±10%，在中等区（HR在LT和OBLA4之间）分别为75±19分钟和51±9%，在困难区（HR高于OBLA4）分别为44±21分钟和31±16%。平均心率为171±6次·分钟⁻¹，相当于最大值的90±3%（VO₂max的84±3%）。
本研究表明，越野赛事强度很高，尤其是在比赛开始时。教练在制定具体训练计划时，必须考虑到越野山地自行车赛事的用力分布和高运动强度特点。
