Caffeine ingestion, affect and perceived exertion during prolonged cycling

Caffeine's metabolic and performance effects have been widely reported. However, caffeine's effects on affective states during prolonged exercise are unknown. Therefore, this was examined in the present study. Following an overnight fast and in a randomised, double-blind, counterbalanced design, twelve endurance trained male cyclists performed 90 min of exercise at 70% VO2 max 1 h after ingesting 6 mg kg−1BM of caffeine (CAF) or placebo (PLA). Dimensions of affect and perceived exertion were assessed at regular intervals. During exercise, pleasure ratings were better maintained (F(3,38) = 4.99, P < 0.05) in the CAF trial compared to the PLA trial with significantly higher ratings at 15, 30 and 75 min (all P < 0.05). Perceived exertion increased (F(3,28) = 19.86, P < 0.01) throughout exercise and values, overall, were significantly lower (F(1,11) = 9.26, P < 0.05) in the CAF trial compared to the PLA trial. Perceived arousal was elevated during exercise but did not differ between trials. Overall, the results suggest that a moderate dose of CAF ingested 1 h prior to exercise maintains a more positive subjective experience during prolonged cycling. This observation may partially explain caffeine's ergogenic effects.

► We examined the influence of pre-exercise caffeine ingestion on affect and RPE.
► Caffeine ingestion prior to a prolonged bout of cycling maintained pleasure ratings.
► Effort perceptions were reduced following a moderate caffeine dose.
► Prolonged exercise elevated perceived arousal but caffeine exerted no effect.
► Exercise-supplementation studies should move beyond a focus on effort sense.