Vol 12, Issue 6

Caffeine Alters RPE-Based Intensity Production

August 15, 2019 - By 

Authors

Tyler Langford, Middle Tennessee State University
Eric O’Neal, ekoneal@crimson.ua.edu
Eric M. Scudamore, expired
Samantha Johnson, Middle Tennessee State University
Caitlin Stevenson, Harding University
Veronika Pribyslavska, Arkansas State University
Matt Green, The University of North Alabama
International Journal of Exercise Science 12(6): 412-424, 2019. 
DOI: 10.70252/PGTB4943

Abstract

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).

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