Translating Ramp V˙O2 into Constant Power Output: A Novel Strategy that Minds the Gap.

Abstract

This study aimed to model the dissociation in the V˙O2/power output (PO) relationship between ramp incremental (RI) and constant work rate (CWR) exercise and to develop a novel strategy that resolves this gap and enables an accurate translation of the RI V˙O2 response into a constant PO. Nine young men completed two RI tests (30 and 15 W·min) and CWR tests at seven intensities across exercise intensity domains. The V˙O2/PO relationship for RI and CWR exercise was modeled, and the dissociation was compared in terms of PO. The accuracy of three translation strategies was tested in the moderate-intensity (i.e., zone 1) and heavy-intensity (i.e., zone 2) domain. Strategy 1 comprised a simple mean response time correction, whereas strategies 2 and 3 accounted for the loss of mechanical efficiency in zone 2 by applying an extra correction that was based on, respectively, the difference between s2 - CWR and s2 - ramp and the ratio s2/s1. For all intensities, differences in PO were found between CWR and RI exercise (P < 0.001). Overall, these differences were smaller for the 15-W·min compared with the 30-W·min protocol (P = 0.012). Strategy 1 was accurate for PO selection in zone 1 (bias = 0.4 ± 7.3 W), but not in zone 2 (bias = 17.1 ± 15.9 W). Only strategy 2 was found to be accurate for both intensity zones (bias = 2.2 ± 14.2 W) (P = 0.107). This study confirmed that a simple mean response time correction works for PO selection in the moderate-intensity but not in the heavy-intensity domain. A novel strategy was tested and validated to accurately prescribe a constant PO based on the RI V˙O2 response in a population of young healthy men.