Billat L V, Koralsztein J P
Laboratoire STAPS, University of Paris 12, Créteil, France.
Sports Med. 1996 Aug;22(2):90-108. doi: 10.2165/00007256-199622020-00004.
In 1923, Hill and Lupton pointed out that for Hill himself, 'the rate of oxygen intake due to exercise increases as speed increases, reaching a maximum for the speeds beyond about 256 m/min. At this particular speed, for which no further increases in O2 intake can occur, the heart, lungs, circulation, and the diffusion of oxygen to the active muscle-fibres have attained their maximum activity. At higher speeds the requirement of the body for oxygen is far higher but cannot be satisfied, and the oxygen debt continuously increases'. In 1975, this minimal velocity which elicits maximal oxygen uptake (VO2max) was called 'critical speed' and was used to measure the maximal aerobic capacity (max Eox), i.e. the total oxygen consumed at VO2max. This should not be confused with the term 'critical power' which is closes to the power output at the 'lactate threshold'. In 1984, the term 'velocity at VO2max' and the abbreviation 'vVO2max' was introduced. It was reported that vVO2max is a useful variable that combines VO2max and economy into a single factor which can identify aerobic differences between various runners or categories of runners. vVO2max explained individual differences in performance that VO2max or running economy alone did not. Following that, the concept of a maximal aerobic running velocity (Vamax in m/sec) was formulated. This was a running velocity at which VO2max occurred and was calculated as the ratio between VO2max (ml/kg/min) minus oxygen consumption at rest, and the energy cost of running (ml/kg/sec). There are many ways to determine the velocity associated with VO2max making it difficult to compare maintenance times. In fact, the time to exhaustion (tlim) at vVO2max is reproducible in an individual, however, there is a great variability among individuals with a low coefficient of variation for vVO2max. For an average value of about 6 minutes, the coefficient of variation is about 25%. It seems that the lactate threshold which is correlated with the tlim at vVO2max can explain this difference among individuals, the role of the anaerobic contribution being significant. An inverse relationship has been found between tlim at vVO2max and VO2max, and a positive one between vVO2max and the velocity at the lactate threshold expressed as a fraction of vVO2max. These results are similar for different sports (e.g. running, cycling, kayaking, swimming). It seems that the real time spent at VO2max is significantly different from an exhaustive run at a velocity close to vVO2max (105% vVO2max). However, the minimal velocity which elicits VO2max, and the tlim at this velocity appear to convey valuable information when analysing a runner's performance over 1500m to a marathon.
1923年，希尔和卢普顿指出，对希尔本人而言，“因运动导致的摄氧率随速度增加而上升，在速度超过约256米/分钟时达到最大值。在这个特定速度下，摄氧量无法进一步增加，此时心脏、肺、循环系统以及氧气向活跃肌纤维的扩散均已达到最大活动水平。在更高速度下，身体对氧气的需求远高于此但无法得到满足，氧债持续增加”。1975年，这个引发最大摄氧量（VO₂max）的最小速度被称为“临界速度”，并被用于测量最大有氧能力（max Eox），即VO₂max时消耗的总氧量。这不应该与“临界功率”这一术语相混淆，临界功率更接近“乳酸阈”时的功率输出。1984年，引入了“VO₂max时的速度”这一术语及其缩写“vVO₂max”。据报道，vVO₂max是一个有用的变量，它将VO₂max和经济性结合为一个单一因素，能够识别不同跑步者或不同类别跑步者之间的有氧差异。vVO₂max解释了VO₂max或单独的跑步经济性无法解释的个体成绩差异。在此之后，制定了最大有氧跑步速度（以米/秒为单位的Vamax）的概念。这是VO₂max出现时的跑步速度，计算方法是VO₂max（毫升/千克/分钟）减去静息耗氧量，再除以跑步的能量消耗（毫升/千克/秒）。有多种方法来确定与VO₂max相关的速度，这使得比较维持时间变得困难。事实上，在vVO₂max时的力竭时间（tlim）对于个体是可重复的，然而，个体之间存在很大差异，vVO₂max的变异系数较低。对于约6分钟的平均值，变异系数约为25%。似乎与vVO₂max时的tlim相关的乳酸阈可以解释个体之间的这种差异，无氧贡献的作用显著。已发现vVO₂max时的tlim与VO₂max之间呈负相关，vVO₂max与以vVO₂max的分数表示的乳酸阈速度之间呈正相关。这些结果在不同运动项目（如跑步、骑自行车、皮划艇、游泳）中相似。似乎在VO₂max时实际花费的时间与以接近vVO₂max（105% vVO₂max）的速度进行的力竭性跑步有显著差异。然而，引发VO₂max的最小速度以及该速度下的tlim在分析跑步者1500米到马拉松的成绩时似乎能传达有价值的信息。
