The aim of the study was to examine whether 1) the power output attained in the last 30 s of a 3-min all-out test (P (end)) correlates with the power output at maximal lactate steady state (P (MLSS)) and whether 2) peak oxygen uptake (VO (2peak)) can be obtained from a 3-min all-out test in well-trained cyclists. 18 cyclists (23±3 years; 186.1±6.9 cm; 79.1±8.2 kg; VO (2peak): 63.2±5.2 mL · kg (-1) · min (-1)) performed a ramp test, a 3-min all-out test and several submaximal constant 30 min-workload tests at +15, 0, -15, -30, -45, -60,-75, -90 W of P (end) to obtain P (MLSS). P (MLSS) was significantly lower compared to P (END) ( P<0.001; mean difference: 54±18 W) with a high correlation (r=0.93; R (2)=0.87; P<0.001) but great intra-individual variability (15-90 W). There were no mean differences between the ramp-VO (2peak) and 3-min all-out cycling VO (2peak) ( P=0.29; mean difference: 133±514 mL · min (-1)) showing significant correlation (r=0.60; R (2)=0.37; P=0.006) but great intra-individual variability (1 057-1 312 mL · min (-1)). We therefore suggest that in well-trained cyclists a 3-min all-out test is 1) not sufficient to obtain P (MLSS) and 2) should not be applied to assess VO (2peak).