Several authors have defined velocities which may, as a group, be described as the velocity associated with VO2max. Although several names, definitions, and abbreviations have been introduced, in this paper we shall use vVO2max for them all. These vVO2max have been reported to be an indicator of performance in distance running events. However, protocols for data collection and definitions used in the calculation of vVO2max have differed between studies. The purpose of this investigation was to compare values of vVO2max obtained using five definitions that have been described in the literature. vVO2max was determined in 22 women track athletes as (a) the speed at which VO2max was attained in a speed-incremented 0%-slope treadmill test, (b) the highest speed in the test that could be sustained for 1 min, (c) the ratio of VO2max to the oxygen cost of submaximal running (C), (d) the ratio of (VO2max - VO2 at rest) to (C - VO2 at rest), and (e) the velocity determined by extrapolation of the submaximal velocity:VO2 relationship. Results of ANOVA suggested that there were significant differences among the values derived using the different methods (F4.84 = 7.80, P < 0.001). Correlations among the various pairs of values ranged from 0.68 to 1.00. It is concluded that there are five distinct parameters described by the five definitions. The value of each of these parameters is influenced by VO2max and the energy cost of running. In theory, three of the parameters have an anaerobic component; two do not.