Severe-intensity constant-work-rate cycling indicates that ramp incremental cycling underestimates ⩒o2max in a heterogeneous cohort of sedentary individuals

Abstract

In the absence of a ⩒o 2-work-rate plateau, debate continues regarding the best way to verify that the peak ⩒o 2 achieved during incremental exercise (⩒o 2peak) is the "true ⩒o 2max ." Oftused "secondary criteria" have been questioned in conjunction with the contention that a severe-intensity constant-work-rate "verification bout" should be considered the "gold standard." The purpose of this study was to compare the ⩒o 2peak during ramp incremental cycling (RAMP-INC) by a heterogeneous (with respect to body composition and sex) cohort of sedentary individuals with the ⩒o 2peak during severe-intensity constant-work-rate cycling (CWR) performed after RAMP-INC at the highest work rate achieved. A secondary purpose was to determine the degree to which traditional and newly-proposed age-dependent secondary criteria (RER, HR) identified RAMP-INC which CWR confirmed were characterized by a submaximal ⩒o 2peak. Thirty-five healthy male (n = 19: 33.4 ± 6.3 yrs) and female (26.8 ± 3.6 yrs) sedentary participants performed RAMP-INC followed by CWR. The ⩒o 2peak values from the two tests were correlated (r = 0.96; p < 0.01; mean CV = 24%); however, ⩒o 2peak for CWR was significantly greater (29.6 ± 7.2 v. 28.6 ± 6.8 mL�min-1 �kg-1 ; p < 0.01) with a mean bias of 0.98 mL�min-1 �kg-1 (z =-2.9, p < 0.01). Both traditional and newly-proposed criterion values for RER were achieved during RAMP-INC by 33 of 35 participants (including 21 of 23 who registered a higher ⩒o 2peak on CWR). The traditional HR criterion value was achieved on only seven tests (three of which were confirmed to be characterized by a submaximal ⩒o 2peak) while use of less stringent newly-proposed criteria resulted in acceptance of an additional seven tests of which five were confirmed to be submaximal. Severe-intensity CWR to limit of tolerance indicates that RAMP-INC underestimates ⩒o 2max in sedentary individuals and both traditional and newly-proposed secondary criteria are ineffective for identifying such tests.

Is a verification phase useful for confirming maximal oxygen uptake in apparently healthy adults? A systematic review and meta-analysis

“…However, sub-group analyses revealed that while maximal VO 2 in the CPET was higher than that attained in the verification phase for participants with moderate and high cardiorespiratory fitness, the opposite was true for those with lower cardiorespiratory fitness. Similar findings have been reported by Arad et al [ 55 ], indicating that cardiorespiratory fitness level may be a key moderator of the differences between the highest VO 2 values attained in the CPET and verification phase. A plausible explanation is that individuals with low cardiorespiratory fitness are more susceptible to stopping early during the CPET due to fatigue-associated symptoms [ 29 ], which would tend to result in lower VO 2 values.…”

“…Six of the 54 meta-analyzed studies reported significant mean differences between the highest VO 2 values observed in the CPET and verification phase [ 25 , 55 , 56 , 68 , 87 , 95 ]. Astorino and DeRevere [ 56 ], for example, observed significantly higher mean VO 2max values by 0.03 and 0.04 L/min during the CPET than in the verification phase for two samples of participants heterogeneous for cardiorespiratory fitness.…”

Utility of Verification Testing to Confirm Attainment of Maximal Oxygen Uptake in Unhealthy Participants: A Perspective Review

“…As far as the intensity of VER, 2 studies used a submaximal protocol [ 16 , 26 ], 15 studies used supramaximal work rates ranging from 105–115% PPO or above maximal TM velocity, and 3 studies [ 12 , 26 , 27 ] used workloads equivalent to PPO. Eight studies included specific criteria to identify differences in VO 2 max between protocols which were developed through reliability testing or predicted changes in VO 2 for the change in work rate.…”

“…Results from 13 of 19 studies [ 5 , 9 , 10 , 11 , 12 , 13 , 23 , 24 , 25 , 28 , 29 , 30 , 33 ] revealed no significant difference in mean VO 2 max between protocols, although in 7 of these studies [ 9 , 10 , 12 , 13 , 25 , 28 , 29 ], individual participants revealed meaningfully higher VO 2 max (≥3% higher) with VER compared to GXT. Nevertheless, in six studies [ 14 , 22 , 26 , 27 , 31 , 32 ] the VER-derived VO 2 max was significantly higher than GXT, with participants’ VO 2 max ranging from 19–40 mL/kg/min. In one study in cancer patients [ 21 ], VER-derived VO 2 max was significantly lower than from GXT.…”

Verification-phase tests show low reliability and add little value in determining V̇O2max in young trained adults

“…However, the values of these criteria vary considerably between participants [ 10 ] and are affected by the exercise protocol used [ 11 ]. Consequently, even if rather high and age-adjusted secondary exhaustion criteria are used an underestimation of cannot be excluded [ 12 ].…”