The effect of the oxygen uptake-power output relationship on the prediction of supramaximal oxygen demands

Aim. The aim of this study was to investigate the relationship between oxygen uptake ( VO2) and power output at intensities below and above the lactate threshold (LT) in cyclists; and to determine the reliability of supramaximal power outputs linearly projected from these relationships. Methods. Nine male cyclists (mean ± standard deviation age: 41 ± 8 years; mass: 77 ± 6 kg, height: 1.79 ± 0.05 m and VO2max: 54 ± 7 mL∙kg-1∙min-1) completed two cycling trials each consisting of a step test (10 × 3 min stages at submaximal incremental intensities) followed by a maximal test to exhaustion. The lines of best fit for VO2 and power output were determined for: the entire step test; stages below and above the LT, and from rolling clusters of five consecutive stages. Lines were projected to determine a power output predicted to elicit 110% peak VO2. Results. There were strong linear correlations (r ≥ 0.953; P < 0.01) between VO2 and power output using the three approaches; with the slope, intercept, and projected values of these lines unaffected (P ≥ 0.05) by intensity. The coefficient of variation of the predicted power output at 110% VO2max was 6.7% when using all ten submaximal stages. Conclusion. Cyclists exhibit a linear VO2 and power output relationship when determined using 3 min stages, which allows for prediction of a supramaximal intensity with acceptable reliability.