The efficacy of the self-paced V̇O _2max test to measure maximal oxygen uptake in treadmill running

The novel self-paced, cycle-based maximal oxygen uptake (V̇O_2max) test (SPV) has been shown to produce higher V̇O_2max values than standard graded exercise test (GXT) protocols. This study sought to ascertain whether these observations would also be apparent in a self-paced, treadmill-based test design. Fourteen trained male runners performed a standard GXT on a motorised treadmill and a self-paced V̇O_2max test on a nonmotorised treadmill in a counter-balanced design. The GXT included a plateau verification and was designed to last between 8 and 12 min. The self-paced test included 5×2 min stages and allowed participants to set their own running speed based on fixed increments in rating of perceived exertion. Significantly higher V̇O_2max values (t_[13] = 3.71, p = 0.003) were achieved in the self-paced test (64.4 ± 7.3 mL·kg^-1.min^-1) compared with the GXT (61.3 ± 7.3 mL·kg^-1.min^-1), and 13 of the 14 participants achieved the same or higher V̇O_2max values in the self-paced test. Higher (p = 0.01) maximum heart rates were observed in the GXT (191 ± 10 beats·min^-1 vs. 187 ± 7 beats·min^-1), but no differences were observed in any other recorded variables. The self-paced V̇O_2max test may provide a more valid means of measuring V̇O_2max than the GXT and suggests that a V̇O₂ plateau during a GXT does not always signify achievement of a definitive V̇O_2max. These results provide further support that self-paced V̇O_2max testing produces higher values for maximal oxygen uptake.