Cabuk R; Ondokuz Mayis University, Samsun, Turkiye
Alp E; Murias JM; Karsten B

Scandinavian Journal of Medicine & Science in Sports. 36(2):e70226,
2026 Feb.

This study examined whether constant-workload verification trials
performed at intensities below, at, and above the ramp-incremental peak
power output (PPO) contribute to confirming maximal oxygen uptake
(VO2max). Fifteen trained to well-trained male cyclists (VO2max: 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 VO2 responses were analyzed using linear
mixed-effects models. Effect size was calculated using Hedges’ g. The peak
VO2 attained during the verification trials was expressed relative to the
ramp-derived VO2max and classified as lower (< 95%), within normal
variability (95%-105%), or higher (> 105%). The peak VO2 values at 80%,
105%, and 110% PPO were significantly lower than ramp-derived VO2max (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, 81 were within
+/-5% of ramp VO2max, 22 were lower (mainly at 80% and 110% PPO), and two
exceeded ramp VO2max (at 85% and 95% PPO). Although verification trials
did not meaningfully contribute to the verification of VO2max, trials
performed at 85%-95% PPO provided the best chances of confirming VO2max in
trained individuals. Interpretation of verification trials relative to
ramp-derived PPO is protocol dependent, which may limit generalizability
across different ramp designs.