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Abstract

Graded exercise testing (GXT), per a cycle-ergometer (CE), offers safety and monitoring advantages over treadmill (TM) GXT. Unfortunately, CE-VO2max and some other cardiorespiratory (CR) variables are frequently lower than TM-GXT values. It has been difficult to compare TM and CE-GXT values. However, it was hypothesized that standing towards the conclusion of the CE-GXT (Stand-CE) might increase CE values to those equal to TM-GXT. If Stand-CE and TM-GXT CR values were equal, Stand-CE-GXT could become the method of choice for GXT for the general population. The purpose of this investigation was to investigate the effect of Stand-CE on CR variables. An intentionally diverse sample (N = 34, 24 males and 10 females, aged 18-54 y, with VO2max values 25-76 ml/kg/min) representing the general population participated. Volunteers completed two GXT trials, one per TM (Bruce protocol) and the other per a MET-TM-matched CE-GXT where initially-seated participants stood and pedaled after their respiratory exchange ratio (RER) reached 1.0. Eighteen participants underwent a third MET-TM-matched trial where they remained seated throughout GXT (Sit-CE). Trials were counter-balanced with at least 48 h between GXT. There were significant statistical differences (p < 0.05) between TM and Stand-CE per matched-samples T-test (N = 34) on the following variables: VEmax (TM = 115 + 24.4 l/min, Stand-CE = 99.4 + 28.1), VCO2max (TM = 4.26 + 0.9 l/min, Stand-CE = 3.56 + 0.84), VO2max (TM = 44.9 + 9.1 ml/kg/min, Stand-CE = 39.3 + 9.0), METSmax (TM = 12.8 + 2.6 METS, Stand-CE = 11.2 + 2.5), and HRmax (TM = 175 + 13 bpm, Stand-CE = 166 + 12). One-way repeated measures ANOVA (N = 18) demonstrated no statistical differences between all trials: VEmax (TM = 112.8 + 25.3 l/min, Stand-CE = 102.3 + 25.2, Sit-CE = 107.3 + 33.1), VCO2max (TM = 4.17 + 0.99 l/min, Stand-CE = 3.62 + 0.80, Sit-CE = 3.55 + 0.83), VO2max (TM = 47.1 + 9.8 ml/kg/min, Stand-CE = 42.0 + 9.0, Sit-CE = 43.3 + 8.9), METSmax (TM = 13.5 + 2.8 METS, Stand-CE = 12.0 + 2.6, Sit-CE = 12.4 + 2.5), and HRmax (TM = 176 + 13 bpm, Stand-CE = 171 + 12, Sit-CE = 173 + 11). Results of this investigation suggest that TM-GXT CR values are larger than Stand-CE, and Stand-CE values are not different from Sit-CE. Future studies will test validity of these findings per gender, aerobic training status, in populations that are highly-skilled with TM and CE (tri-athletes), children, the elderly, and diseased populations.

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