Effect of creatine plus caffeine supplements on time to exhaustion during an incremental maximum exercise
European Journal of Sport Science Volume 12, Issue 4, 2012 pages 338-346 Chia Lun Lee
This study investigated the effects of acute caffeine ingestion following short-term creatine supplementation on an incremental cycling to exhaustion task. Twelve active males performed the task under three conditions: baseline condition (BASE, no ergogenic aid), creatine plus caffeine condition (CRE + CAF), and creatine with placebo condition (CRE + PLA).
Following the establishment of BASE condition, participants were administered CRE + CAF (0.3 g·kg−1·day−1 of creatine for 5 days followed by 6 mg·kg−1 of caffeine 1 h prior to testing) and CRE + PLA (0.3 g·kg−1·day−1 of creatine for 5 days followed by 6 mg·kg−1 of placebo 1 h prior to testing) in a double-blind, randomized crossover and counterbalancing protocol. No significant differences were observed in relative maximal oxygen consumption ([Vdot]O2max) (51.7±5.5, 52.8±4.9 and 51.3±5.6 ml·kg−1·min−1 for BASE, CRE + CAF and CRE + PLA, respectively; P>0.05) and absolute [Vdot]O2max (3.6±0.4, 3.7±0.4 and 3.5±0.5 l·min−1 for BASE, CRE + CAF and CRE + PLA, respectively; P>0.05).
Blood samples indicated significantly higher blood lactate and glucose concentrations in the CRE + CAF among those in the BASE or CRE + PLA condition during the test (P<0.05).
The time to exhaustion on a cycling ergometer was significantly longer for CRE + CAF (1087.2±123.9 s) compared with BASE (1009.2±86.0 s) or CRE + PLA (1040.3±96.1 s).
This study indicated that a single dose of caffeine following short-term creatine supplementation did not hinder the creatine–caffeine interaction. In fact, it lengthened the time to exhaustion during an incremental maximum exercise test. However, this regime might lead to the accumulation of lactate in the blood.
