It is commonly admitted that time-to-exhaustion corresponds to about six minutes for an exercise performed at an intensity allowing eliciting 100% of the VO2max. Although many works have tried to identify the limiting factors in time-to-exhaustion at VO2max by investigating energetic or metabolic parameters, the determinants underlying this performance key factor remain unclear. The purpose of this study will be to address this question through a neuromuscular approach. Our hypothesis will be that a neuromuscular invariant could explain exercise breakout in subjects performing a maximal exercise up to volitional exhaustion. 11 physically trained subjects got involved in this study. Each of them had to perform in a random order 2 pedalling exercises designed to elicit 100% of their individual VO2max, separated by 1 week recovery. Each exercise was lead up to exhaustion. The first one was performed at a constant power corresponding to the maximal aerobic power (MAP). During the second one, external power output initially corresponded to the MAP, but was secondarilly adjusted so that VO2 remains maximal despite decreased load. Neuromuscular testings were performed before and immediately after each exercise in order to assess neuromuscular fatigue generated by each condition. Power output during exercise performed at a variable load was modelized in regard to MAP, power at individual anaerobic threshold and time-to-exhaustion at MAP. Time-to-exhaustion significantly increased in variable load condition. Neuromuscular fatigue was not significantly different between the two conditions. Constant neuromuscular fatigue between the two conditions suggests that this parameter could play a key role in volitional exhaustion during maximal exercise. It seems possible to dramatically increase time-to-exhaustion at VO2max. This result could be of interest in field performance training. VO2max could be elicited at a submaximal external power output, what could be an important result in field rehabilitation. Further investigation is required to better understand underlying mechanisms in fatigue during maximal metabolic load.