Purpose: To investigate a new power-to-body-mass (BM) ratio 3-min all-out cycling test (3MT(%BM)) for determining critical power (CP) and finite work capacity above CP (W').
Methods: The gas-exchange threshold (GET), maximal oxygen uptake (VO2max), and power output evoking VO2max (W(peak)) and GET (W(GET)) for cycle ergometry were determined in 12 participants. CP and W' were determined using the original "linear factor" 3MT (3MT(rpm^2)) and compared with CP and W' derived from a procedure, the 3MT(%BM), using the subject's body mass and self-reported physical activity rating (PA-R), with values derived from linear regression of the work-time model and power-inverse-time model (1/time) data from 3 separate exhaustive square-wave bouts.
Results: The VO2max, VO(2GET), W(peak), and W(GET) values estimated from PA-R and a non-exercise-regression equation did not differ (P > .05) from actual measurements. Estimates of CP derived from the 3MT(%BM) (235 ± 56 W), 3MT(rpm^2) (234 ± 62 W), work-time (231 ± 57 W), and 1/time models (230 ± 57 W) did not differ (F = 0.46, P = .72). Similarly, estimates of W' between all methods did not differ (F = 3.58, P = .07). There were strong comparisons of the 3MT(%BM) to 1/time and work-time models with the average correlation, standard error of the measurement, and CV% for critical power being .96, 8.74 W, and 4.64%, respectively.
Conclusion: The 3MT(%BM) is a valid, single-visit protocol for determining CP and W'.