Caffeine blunts RPE estimations but effects on selected cycling cadence are unclear. Purpose This study examined influence of caffeine on cycling cadence with intensities prescribed at RPE 4 and 7 (OMNI Scale). Methods College-aged (20.5 ± 2.0 y) male and female volunteers ( n = 15) (VO 2 peak = 40.3 ± 4.0,) completed a maximal cycling test followed by trials where they adjusted cadence (CAD) (clamped resistances) to produce overall feelings equivalent to RPE 4 (RPE4) and RPE 7 (RPE7) (10 min each) following caffeine (CAF) (6 mg·kg − 1 ·min − 1 ) and placebo (PLA) (counterbalanced) ingestion. Participants were blinded to cadence during production trials. Results Repeated measures ANOVA showed a significant main effect (trial) for CAD (CAF ~ 4 rev·min − 1 faster) for RPE4 but no significance for RPE7. Main effect for heart rate (HR) was not significant for RPE4 but significant for RPE7 (CAF ~ 4 b·min − 1 higher). Main effects showed mean VO 2 significantly higher (~ 1.5–2 ml·kg − 1 ·min − 1 ) for CAF for RPE4 and RPE7. Using a calculated least significant difference (5 rev·min − 1 ) positive responses were observed for five individuals (33%) for RPE4 and 3 individuals (20%) for RPE7. No negative (significantly slower cadences) responses were observed. RER in select trials suggested increased reliance on free fatty acid for CAF in responders. Conclusions Mean results show a mild effect of CAF on cadence selection during RPE production. However, assessing individual results more effectively clarifies ergogenic responses. Future research should identify factors responsible for diverse responses to caffeine during exercise.
Full Text via ClinicalKey