A single-session testing protocol to determine Critical Power and W’

Abstract

Purpose Critical power (CP), and the finite capacity to perform work above CP (W'), can be determined using a 3-min "all-out" cycling test (3MT). This protocol requires two laboratory visits: an incremental exercise test, followed by a 3MT on a separate day. The purpose of this study was to establish whether an incremental exercise test and a 3MT performed during a single laboratory visit can be used to accurately determine CP and W'. Methods Twelve participants completed two experimental protocols: (1) Combined protocol: an incremental exercise test followed by a 3MT, with 20 min of recovery between exercise bouts; and (2) Independent protocol: the conventional 3MT protocol, performed on a separate day. Results CP determined from the Combined (254 ᠱ17 W) and Independent (256 ᠱ18 W) protocols were not different (p = 0.40). Similarly, W' was not different (p = 0.96) between the Combined (13.7 ᠳ.9 kJ) and Independent (13.7 ᠴ.5 kJ) protocols. Linear regression revealed a strong level of measurement agreement between the protocols for CP and W', evidenced by high R 2 values (=0.85) and marginal standard errors of the estimates (CP = 5 W; W' = 1.81 kJ). Conclusion A Combined protocol, consisting of an incremental exercise test followed by a 3MT, provides an accurate and valid method to determine an individual's CP and, to a lesser extent, W'. Furthermore, this protocol permits the measurement of the gas-exchange threshold and peak O2 uptake and, consequently, the moderate, heavy, and severe exercise-intensity domains may be defined within a single exercise-testing session.