title: A test to establish maximum O2 uptake despite no plateau in the O2 uptake response to ramp incremental exercise.
abstract: The O2 uptake (Vo2) response to ramp incremental (RI) exercise does not consistently demonstrate plateau-like behavior at the limit of tolerance, and hence the requirements for a maximum Vo2 commonly are not met, despite apparent maximum effort. We sought to determine whether an appended step exercise (SE) test at a work rate greater than that achieved in a preceding ramp test would establish the plateau criterion. Seven healthy male adults performed RI cycle ergometry (20 W/min) to the limit of tolerance, followed by 5-min recovery (20 W) and then an SE test at 105% (RISE-105) of the final work rate (WRpeak) achieved during RI. Five of these subjects also performed an RI test followed by SE at 95% WRpeak (RISE-95). Vo2 was measured breath by breath using a turbine and mass spectrometer. The average of the final 15 s of RI or SE was used to establish respective Vo2 peaks. When Vo2 peak was approached, a constant Vo2 value (e.g., a plateau) was not discernable during any RI or SE component of the tests. Although the WRpeak [mean (SD)] was higher during the SE portion [359 W (SD 31)] than during the RI portion [341 W (SD 29)] of the RISE-105, the peak Vo2 was not different [SE, 4.30 l/min (SD 0.51); RI, 4.33 l/min (SD 0.52); P=0.49; n=7]. Similarly, in the RISE-95 test, WRpeak was 310 W (SD 31) for the SE portion and 326 W (SD 32) for the RI portion, yet the peak Vo2 values were not different [SE, 4.12 l/min (SD 0.53); RI, 4.11 l/min (SD 0.48); P=0.78; n=5]. The lack of notable difference between the Vo2 peaks established at different WRpeak values in our RISE protocols provides the plateau criterion for verification of maximum Vo2 in a single test session, even when the data response profiles do not themselves evidence a plateau.
authors.affiliation: Department of Physiology, St. George's Hospital Medical School, London, UK. h.b.rossiter@leeds.ac.uk
authors.forename: H B
authors.initials: HB
authors.lastname: Rossiter
authors.forename: J M
authors.initials: JM
authors.lastname: Kowalchuk
authors.forename: B J
authors.initials: BJ
authors.lastname: Whipp
mesh_terms: D000328:Adult; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D005082:Physical Exertion / Q000502:physiology; D012129:Respiratory Function Tests