Reliability and validity of an incremental cadence cycle VO2max testing protocol for trained cyclists

Cycle tests for maximal oxygen uptake (O_2max) have traditionally used incremental resistance protocols (RP) at a constant cadence. The purpose of this study was to evaluate whether an incremental cadence protocol (CP) using a constant resistance relative to gross body mass was as reliable and valid in eliciting O_2max as RP in trained cyclists. Ten male recreational cyclists aged 25.2 ± 6.8 years completed two CP and one RP trials in a randomized order over a 3-week period. The CP started at a workload of 2.75 W per kg body mass, with the cadence increased by 10 rpm each minute from 70 rpm. The RP started from 125 W with workload increased 25W each minute with a constant cadence of 90 rpm. The results showed no significant differences between the CP (mean of the two CP trials) and RP for peak O₂ (3.9 ± 0.6 vs. 4.0 ± 0.8 L·min⁻¹), peak ventilation (140.5 ± 22.8 vs. 143.0 ± 27.1 L·min⁻¹) and post-exercise blood lactate (11.4 ± 2.1 vs. 11.9 ± 1.6 mmol·L⁻¹), while peak heart rate (183.9 ± 10.5 vs. 187.5 ± 11.4 beats·min⁻¹) and peak workload (319.9 ± 60.2 vs. 375.1 ± 67.3W) were significantly less for the CP than the RP. For the two CP trials, the intraclass correlation coefficient for test-retest reliability was 0.96, the technical error of measurement (TEM) was 0.17 L·min⁻¹, and the relative TEM was 4.35%. The results indicate that the CP is equally effective in eliciting O_2max as the RP and is a reliable method of measuring O_2max in trained recreational cyclists.