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

PLoS One. 2020 Jul 6;15(7):e0235567. doi: 10.1371/journal.pone.0235567. eCollection 2020.

Abstract

In the absence of a ⩒o2-work-rate plateau, debate continues regarding the best way to verify that the peak ⩒o2 achieved during incremental exercise (⩒o2peak) is the "true ⩒o2max." Oft-used "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 ⩒o2peak during ramp incremental cycling (RAMP-INC) by a heterogeneous (with respect to body composition and sex) cohort of sedentary individuals with the ⩒o2peak 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 ⩒o2peak. 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 ⩒o2peak values from the two tests were correlated (r = 0.96; p < 0.01; mean CV = 24%); however, ⩒o2peak 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 ⩒o2peak on CWR). The traditional HR criterion value was achieved on only seven tests (three of which were confirmed to be characterized by a submaximal ⩒o2peak) 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 ⩒o2max in sedentary individuals and both traditional and newly-proposed secondary criteria are ineffective for identifying such tests.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bicycling / physiology*
  • Cohort Studies
  • Female
  • Humans
  • Male
  • Oxygen Consumption*
  • Sedentary Behavior*
  • Work*

Grants and funding

Financial support for the parent study from which the present data were extracted was provided in full by ICAHN School of Medicine at Mount Sinai Hospital (heretofore, “funder”). Other than financial support and an official yearly approval by its Institutional Review Board, funder had no role in study design, data collection/analysis, decision to publish and/or preparation of the manuscript. Avigdor D. Arad, Kaitlyn Bishop, Deena Adimoolam and Jeanine B. Albu were salaried employees of funder during the period of data collection for this study. Fred J. DiMenna received payment from funder as a consultant (independent contractor).