BACKGROUND: Ergogenic effects of caffeine (CAF) ingestion have been observed in different cycling exercise modes, and have been associated with alterations in ratings of perceived exertion (RPE). However, there has been little investigation of maximal oxygen uptake (VO2MAX) test outcomes. AIM: This study aimed to verify whether CAF may reduce RPE, thereby improving maximal incremental test (MIT) outcomes such as VO2MAX, time to exhaustion and peak power output (WPEAK). METHODS:Nine healthy individuals performed three MITs (25 W/min until exhaustion) in a random, counterbalanced fashion after ingestion of CAF, placebo perceived as caffeine (PLA), and no supplementation (baseline control). VO2 was measured throughout the test, while RPE was rated according to overall and leg effort sensations. The power output corresponding to submaximal (RPE = 14 according to the 6-20 Borg scale) and maximal RPE was recorded for both overall (O-RPE14 and O-RPEMAX) and leg RPE (L-RPE14 and L-RPEMAX). RESULTS:VO2MAX did not change significantly between MITs; however, CAF and PLA increased time to exhaustion (↑ ∼18.7% and ∼17.1%, respectively; p < .05) and WPEAK (↑ ∼13.0% and ∼11.8%, respectively; p < .05) when compared with control. When compared with control, CAF ingestion reduced submaximal and maximal overall and leg RPEs, the effect being greater in maximal (likely beneficial in O-RPEMAX and L-RPEMAX) than submaximal RPE (possibly beneficial in O-RPE14 and L-RPE14). Similar results were found when participants ingested PLA. CONCLUSIONS: Compared with control, CAF and PLA improved MIT performance outcomes such as time to exhaustion and WPEAK, without altering VO2MAX values. CAF effects were attributed to placebo.
RCT Entities:
BACKGROUND: Ergogenic effects of caffeine (CAF) ingestion have been observed in different cycling exercise modes, and have been associated with alterations in ratings of perceived exertion (RPE). However, there has been little investigation of maximal oxygen uptake (VO2MAX) test outcomes. AIM: This study aimed to verify whether CAF may reduce RPE, thereby improving maximal incremental test (MIT) outcomes such as VO2MAX, time to exhaustion and peak power output (WPEAK). METHODS: Nine healthy individuals performed three MITs (25 W/min until exhaustion) in a random, counterbalanced fashion after ingestion of CAF, placebo perceived as caffeine (PLA), and no supplementation (baseline control). VO2 was measured throughout the test, while RPE was rated according to overall and leg effort sensations. The power output corresponding to submaximal (RPE = 14 according to the 6-20 Borg scale) and maximal RPE was recorded for both overall (O-RPE14 and O-RPEMAX) and leg RPE (L-RPE14 and L-RPEMAX). RESULTS: VO2MAX did not change significantly between MITs; however, CAF and PLA increased time to exhaustion (↑ ∼18.7% and ∼17.1%, respectively; p < .05) and WPEAK (↑ ∼13.0% and ∼11.8%, respectively; p < .05) when compared with control. When compared with control, CAF ingestion reduced submaximal and maximal overall and leg RPEs, the effect being greater in maximal (likely beneficial in O-RPEMAX and L-RPEMAX) than submaximal RPE (possibly beneficial in O-RPE14 and L-RPE14). Similar results were found when participants ingested PLA. CONCLUSIONS: Compared with control, CAF and PLA improved MIT performance outcomes such as time to exhaustion and WPEAK, without altering VO2MAX values. CAF effects were attributed to placebo.
Authors: Alexandre C Marques; Alison A Jesus; Bruna M Giglio; Ana C Marini; Patrícia C B Lobo; João F Mota; Gustavo D Pimentel Journal: Nutrients Date: 2018-05-23 Impact factor: 5.717
Authors: Akbar Shabir; Andy Hooton; George Spencer; Mitch Storey; Olivia Ensor; Laura Sandford; Jason Tallis; Matthew F Higgins Journal: Nutrients Date: 2019-09-25 Impact factor: 5.717
Authors: Flavio O Pires; Carlos A S Dos Anjos; Roberto J M Covolan; Eduardo B Fontes; Timothy D Noakes; Alan St Clair Gibson; Fernando H Magalhães; Carlos Ugrinowitsch Journal: Front Physiol Date: 2018-08-17 Impact factor: 4.566