Ramp-incremented and RPE-clamped test protocols elicit similar VO_2max values in trained cyclists

The present study compared the efficacy of ramp incremented and ratings of perceived exertion (RPE)-clamped test protocols for eliciting maximal oxygen uptake (VO_2max).

Sixteen trained cyclists (age 34 ± 7 years) performed a ramp-incremented protocol and an RPE-clamped protocol 1 week apart in a randomized, counterbalanced order. The RPE-clamped protocol consisted of five, 2-min stages where subjects self-selected work rate and pedal cadence to maintain the prescribed RPE. After completing both test protocols subjects were asked which they preferred.

The mean ± SD test time of 568 ± 72 s in the ramp protocol was not significantly different to the 600 ± 0 s in the RPE-clamped protocol (mean difference = 32 s; p = 0.09), or was the VO_2max of 3.86 ± 0.73 L min⁻¹ in the ramp protocol significantly different to the 3.87 ± 0.72 L min⁻¹ in the RPE-clamped protocol (mean difference = 0.002 L min⁻¹; p = 0.97). Furthermore, no significant differences were observed for peak power output (p = 0.21), maximal minute ventilation (p = 0.97), maximal respiratory exchange ratio (p = 0.09), maximal heart rate (p = 0.51), and post-test blood lactate concentration (p = 0.58). The VO_2max attained in the preferred protocol was significantly higher than the non-preferred protocol (mean difference = 0.14 L min⁻¹; p = 0.03).

The RPE-clamped test protocol was as effective as the ramp-incremented protocol for eliciting VO_2max and could be considered as a valid alternative protocol, particularly where a fixed test duration is desirable.