The purpose of this study was to characterise the relationship between running velocity and the time for which a subject can run at maximal oxygen uptake (VO2max), (tlimVO2max). Seven physical education students ran in an incremental test (3-min stages) to determine VO2max and the minimal velocity at which it was elicited (vVO2max). They then performed four all-out running tests on a 200-m indoor track every 2 days in random order. The mean times to exhaustion tlim at 90%, 100%, 120% and 140% vVO2max were 13 min 22 s (SD 4 min 30 s), 5 min 47 s (SD 1 min 50 s), 2 min 11 s (SD 38 s) and 1 min 12 s (SD 18 s), respectively. Five subjects did not reach VO2max in the 90% vVO2max test. All the subjects reached VO2max in the runs at 100% vVO2max. All the subjects, except one, reached VO2max in the runs at 120% vVO2max. Four subjects did not reach VO2max in the 140% vVO2max test. Time to achieve VO2max was always about 50% of the time to exhaustion irrespective of the intensity. The time to exhaustion-velocity relationship was better fitted by a 3- than by a 2-parameter critical power model for running at 90%, 100%, 120%, 140% vVO2max as determined in the previous incremental test. In conclusion, tlimVO2max depended on a balance between the time to attain VO2max and the time to exhaustion tlim. The time to reach VO2max decreased as velocity increased. The tlimVO2max was a bi-phasic function of velocity, with a peak at 100% vVO2max.