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

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 a higher slope would underestimate W´, whereas RI tests with a lower slope would provide accurate estimates.

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 performed 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 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 , and W´ T_R50 ).

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), and W´ T_R50 ( P = 0.264) were not different from W´ CWR but exhibited a substantial variability.

W´ determination from a RI test resulted in an underestimation compared with values obtained from traditional CWR tests, irrespective of the imposed ramp slope. Although the addition of a supra-CP work bout immediately after termination of the RI test may reduce this underprediction, substantial variability in W´ estimation remain.