Variations in Ramp Slope Affect the Prediction of W´ from a Single Incremental Test.

PURPOSE The purpose of this study was to assess the suitability of ramp incremental (RI) tests with different ramp slopes to predict the work capacity above critical power (CP), which is termed W´. We hypothesized that RI tests with higher slopes would underestimate W´, whereas RI tests with lower slopes would provide accurate estimates.

METHODS Thirteen healthy young men (23 ± 3 yr, 180 ± 7 cm, 71.8 ± 5 kg) performed a maximal RI test (30 W·min-1), followed by three to five constant work rate (CWR) tests to conventionally determine CP and W´CWR. Additionally, they performed a slow and fast RI test (10 and 50 W·min-1, respectively). W´ estimated from the RI tests was calculated as the work perfomed above CP and referred to as W´R30, W´R10 and W´R50. Each RI test was performed until exhaustion, after which a power output (PO) above CP was imposed, which was also maintained until exhaustion to calculate the remaining W´ after the RI test (W´+), resulting in total W´ values (W´T_R30, W´T_R10, W´T_R50).

RESULTS W´R30 (p = 0.018), W´R10 (p = 0.006) and W´R50 (p < 0.001) significantly underestimated W´CWR. W´T_R30 (p = 0.671), W´T_R10 (p = 0.072), W´T_R50 (p = 0.264) were not different from W´CWR but exhibited a substantial variability.

CONCLUSIONS W´ determination from a RI test results in an underestimation compared to values obtained with traditional CWR methodology, irrespective of the imposed ramp slope. Although adding a supra-CP work bout immediately following termination of the RI test may reduce this difference, substantial variability in W´ estimation remains.