Methodological considerations for the determination of VO2max in healthy men

Purpose A square-wave verification bout to confirm maximal oxygen uptake ( V ˙ O 2max ) from a graded exercise test (GXT) has been recommended. This study ascertained if a verification bout is necessary to determine V ˙ O 2max in moderately trained men. Methods Ten men (24 ± 4 years) completed familiarization and two treadmill GXTs, followed by a submaximal verification bout to determine V ˙ O 2GXT and V ˙ O 2verification (highest V ˙ O 2 from each testing method). After completing the GXT, subjects rested for 5 min then performed a verification bout at 90% speed and 50% incline at termination of the GXT. The analyses included a 2-way repeated-measures ANOVA, intra-class correlation coefficients (ICC 2,1 ), standard errors of the measurement (SEM), minimal differences (MD), and coefficients of variation (CoV). Results There was no test (test 1 vs test 2) × method (GXT vs verification) interaction ( p = 0.584), or main effect for test ( p = 0.320), but there was a main effect for method ( p = 0.011). The V ˙ O 2GXT (50.9±3.0 mL·kg −1 ·min −1 ) was greater than V ˙ O 2verification (46.9 ± mL·kg −1 ·min −1 ). The V ˙ O 2GXT (ICC = 0.988, SEM = 1.0 mL·kg −1 min −1 , MD = 2.9 mL kg −1 min −1 , CoV = 2.03%) and V ˙ O 2verification (ICC = 0.976, SEM = 1.0 mL·kg −1 min −1 , MD = 2.7 mL·kg −1 ·min −1 , CoV = 2.03%) demonstrated “excellent” reliability. No subject exceeded the MD for V ˙ O 2GXT test–retest or for V ˙ O 2verification test–retest, but 50% of subjects had a V ˙ O 2GXT that was greater than the V ˙ O 2verification (> MD). Conclusion While V ˙ O 2GXT and V ˙ O 2verification demonstrated excellent reliability, V ˙ O 2GXT from a stand-alone GXT provided higher estimates of V ˙ O 2 and, therefore, should be considered V ˙ O 2max . The lack of test–retest differences in V ˙ O 2GXT above the MD indicated that subjects achieved their highest V ˙ O 2 ( V ˙ O 2max ) from a standalone GXT. Therefore, the verification bout may not be required to confirm V ˙ O 2max in this population.