Does RCP predict cycling performance?

Purpose. The purpose of this study was to determine whether RCP (respiratory compensation point) (W∙kg-1) and the magnitude of change of POpeak before versus after high-intensity exercise (i.e., “fatigue resistance”) predict time trial performance, as well as the relative importance of other variables, such as V̇O2peak and cycling economy. Methods. 28 healthy trained competitive male cyclists performed the step-ramp-step protocol twice, before and after, a 19.2 km time trial. All trials were performed on their own bike mounted on a smart trainer. Results. A significant decrease was observed between pre-trial (PRE) and post-trial (POST) measurements across all physiological variables except lactate threshold and V̇O2peak. A significant correlation was identified between time trial finishing time and V̇O2peak (ml∙kg∙min-1) (r2= 0.24; p < 0.05) and RCP (W∙kg-1) (r2= 0.58; p < 0.001). Fatigue resistance (as measured by ΔPOpeak) did not correlate with cycling performance. RCP (W∙kg-1) emerged to be the most robust predictor among other independent variables, including V̇O2peak (in mL∙kg⁻¹∙min), cycling economy (mL∙kg⁻¹∙W⁻¹∙min⁻¹) and ∆POpeak (W∙kg-1) (p < 0.001). Conclusions. RCP (W∙kg-1) independently correlated with time trial finishing time and was the strongest predictor of cycling performance out of all four variables.