December 18, 2019

Caffeine alters RPE-based intensity production

T W Langford et al, 2019. Caffeine alters RPE-based intensity production, International Journal of Exercise Science, Volume 12 (6)


This study examined effects of caffeine (CAF) on power output (PO) selection and associated physiological responses during cycling at moderate and high intensities prescribed by RPE (0-10 scale). Participants (n = 9) (VO2peak: 55.4 ± 6.32 mL · kg-1 · min-1) cycled for 20 min at RPE4 and 20 min at RPE7 separated by 10 min recovery following caffeine (CAF) (6 mg · kg-1) and placebo (PLA) ingestion. PO, HR, serum lactate [La], VO2, VE, and RER were recorded every 5 min. Session RPE (S-RPE) was recorded following 10 min recovery. Repeated-measures ANOVA’s, 2 (trial) x 4 (time pt), showed significantly greater PO during RPE4 for CAF (130 ± 23 W) vs PLA (112 ± 26 W) and during RPE7 (CAF: 165 ± 37 vs PLA: 143 ± 41 W). Overall HR, VO2, and VE were significantly greater for CAF vs PLA during RPE7. RER for RPE4 and RPE7 were not significantly different (CAF vs PLA). Overall [La] was significantly greater for CAF during RPE4 (CAF: 2.32 ± 0.94 vs PLA: 1.73 ± 1.09) and RPE7 (CAF: 3.22 ± 1.44 vs PLA: 2.22 ± 1.49). Paired T-tests for S-RPE revealed no significant difference for RPE4 (CAF: 4.0 ± 0.5 vs PLA: 3.7 ± 0.5) or RPE7 (CAF: 7.1 ± 0.3 vs PLA: 6.9 ± 0.6) despite greater PO for CAF. Although individual responses varied, the current study indicates caffeine ingestion results in elevated self-selected PO with significant systematic changes in associated physiological responses particularly at a higher intensity (RPE7).

Modtag nyhedsbrev

Ja tak, jeg vil gerne modtage nyhedsbrev, når der er noget nyt om kaffe og helbred.