Slower cycling cadence results in a reduction in the V̇O₂ slow component without changes in performance fatigability

This study investigated the fatigue hypothesis of the V̇O₂ slow component (V̇O₂SC), specifically whether performance fatigability is a necessary condition for the development of the V̇O₂SC during high-intensity cycling exercise. Nine recreationally active males performed two incremental tests (50 and 110 rpm) to determine gas exchange threshold (GET) and V̇O₂max. On four subsequent visits, they completed constant work-rate (CWR) exercises (1 × 3 min and 2 × 8 min) at 50%Δ, followed by a 5 s isokinetic all-out sprint at 120 rpm to determine peak power (PP). The V̇O₂SC was significantly greater at 110 rpm (316 ± 128 mL·min⁻¹) than at 50 rpm (208 ± 125 mL·min⁻¹) (P = 0.032; ES = 0.97). Performance fatigability was similar between cadence conditions (PP3min: -12% vs. -9%, P = 0.409; PP8min: -16% vs. -11%, P = 0.149 for 50 and 110 rpm, respectively; interaction ES = 0.07). No significant correlation between PP changes and V̇O₂SC was observed at either cadence. The present findings do not support a direct causal relationship between performance fatigability and V̇O₂SC amplitude, at least during high-intensity exercise performed at different pedal cadences.