Methodological considerations for the determination of VO2max in healthy men

Purpose A square-wave verification bout to confirm maximal oxygen uptake ((V) over dot O-2max) from a graded exercise test (GXT) has been recommended. This study ascertained if a verification bout is necessary to determine(V) over dot 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) over dot O-2GXT and (V) over dot O-2verification (highest (V) over dot 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 (ICC2,1), standard errors of the measurement (SEM), minimal differences (MD), and coefficients of variation (CoV). Results There was no test (test 1 vs test 2) x 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) over dot O-2GXT (50.9 +/- 3.0 mL.kg(-1).min(-1)) was greater than (V) over dot O-2verification (46.9 +/- mL.kg(-1). min(-1)). The (V) over dot 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) over dot 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) over dot O-2GXT test-retest or for (V) over dot O-2verification test-retest, but 50% of subjects had a (V) over dot O-2GXT that was greater than the (V) over dot O-2verification (> MD). Conclusion While (V) over dot O-2GXT and (V) over dot O-2verification demonstrated excellent reliability, (V) over dot O-GXT(2) from a stand-alone GXT provided higher estimates of (V) over dot O-2 and, therefore, should be considered (V) over dot O-2max. The lack of test-retest differences in (V) over dot O-2 GXT above the MD indicated that subjects achieved their highest (V) over dot O-2 ((V) over dot O-2max) from a standalone GXT. Therefore, the verification bout may not be required to confirm(V) over dot O-2max in this population.