Methods 16 untrained subjects completed a self-paced VO_2max protocol (SPV) and a traditional VO_2max test in a counter-balanced, crossover design. The SPV used incremental ‘clamps’ of ratings of perceived exertion (RPE) over 5 × 2-min stages (10-min duration) while allowing subjects to vary their power output (PO) according to the required RPE.

Results Subjects achieved significantly higher (p < 0.05) VO_2max values (40 ± 10 ml/kg/min vs 37 ± 8 ml/kg/min) and peak POs (273 ± 58 W vs 238 ± 55 W) in the SPV. Higher VO_2max values were observed in the SPV even when a plateau (VO₂–time slope <0.05 l/min) occurred in the traditional test. No differences were found between any other measured physiological variable (minute ventilation, heart rate and respiratory exchange ratio).

Conclusions As SPV is a closed-loop test (10-min duration) that allows subjects to self-pace their work rate, it disregards the need for experimenters to estimate starting work rates, stage lengths and increments in order to bring about volitional exhaustion in 8–10 min. The observation that the SPV may also elicit higher VO_2max values than a traditional test warrants further research in this area and its consideration as standard measure to elicit VO_2max.