The purpose of this study was to evaluate the rationale for using the velocity associated with VO2max (vVO2max) and the time that vVO2max can be sustained (tMAX) in exercise prescription. Six male runners performed a 0%-slope incremental treadmill test to determine their VO2max (61.6 +/- 9.1 ml x kg(-1) x min(-1)) and the velocity at which it was elicited (vVO2max; 271 +/- 18 m x min(-1)). Then, they performed exhaustive tests at vVO2max and at 92% of vO2max. VO2max in these tests (4.56 +/- 0.55 and 4.57 +/- 0.50 l x min(-1)) were not different from the incremental value (4.31 +/- 0.83 l x min(-1)). At vVO2max, VO2max was attained after 299 +/- 74 s and sustained for 32 +/- 41 s. At 92% of vVO2max, it took longer to attain VO2max (491 +/- 156 s), but it was sustained longer (130 +/- 66 s). Since no athlete reached VO2max in the first 60% of the runs, the results did not provide a rationale to support the recommendation that athletes train at vVO2max for a fixed percentage of tMAX when the goal in the training session is to maintain VO2max.