Verification trials can create the illusion of VO2max in addition to contributing to confirming the attainment of VO2max

This study examined whether constant-workload verification trials performed at intensities below, at, and above the ramp-incremental peak mechanical power output (PPO) contribute to confirming maximal oxygen uptake (V̇O2max). Methods: Fifteen trained to well-trained male cyclists (V̇O2max: 63.6±5.6 mL·kg-1·min-1) completed maximal ramp testing followed by seven randomized verification trials (80–110% PPO at 5% intervals) on separate days. Differences in V̇O2 responses were analyzed using linear mixed-effects models. Effect size was calculated using Hedges’ g. The peak V̇O2 attained during the verification trials was expressed relative to the ramp-derived V̇O2max and classified as lower (105%). Results: The peak V̇O2 values at 80%, 105%, and 110% PPO were significantly lower than ramp-derived V̇O2max (p < 0.05), whereas no significant differences were observed at 85%, 90%, and 95% PPO. Effect sizes were small at 85–95% PPO (Hedges’ g = 0.29–0.32), medium at 100–105% PPO (Hedges’ g = 0.63–0.66), and large at 80% and 110% PPO (Hedges’ g = 1.21–1.34). Of 105 verification trials, 83 were within ±5% of ramp V̇O2max, 20 were lower (mainly at 80% and 110% PPO), and two exceeded ramp V̇O2max (at 85% and 95% PPO). Conclusions: Although verification trials did not meaningfully contribute to the verification of V̇O2max, trials performed at 85–95% PPO provided the best chances of confirming V̇O2max in trained individuals. Interpretation of verification trials relative to ramp-derived PPO is protocol dependent, which may limit generalizability across different ramp designs.