THE EFFECT OF CAFFEINE INGESTION AFTER CREATINE SUPPLEMENTATION ON PEAK TORQUE PRODUCTION

The purpose of this study was to examine the acute effects of caffeine ingestion on isokinetic torque production after a period of oral creatine supplementation and caffeine abstinence. Twelve sports university students performed 5 sets of 30 unilateral knee extensions under baseline (BASE), creatine (CRE) and creatine plus caffeine (CRE+CAF) conditions. Each set of knee extensions was performed at maximal intensity and was separated by 60 seconds of rest. Following the establishment of the BASE condition, participants were administered CRE (0.3 mg.kg -1 .day -1 of creatine for 6 days followed by a placebo 1 h prior to testing) or CRE+CAF (0.3 mg.kg -1 .day -1 of creatine for 6 days followed by 3 mg.kg -1 of caffeine 1 h prior to testing) in a randomized order, with a 4-week washout period separating the conditions. CRE (164.7 ± 31.3 N·m, 4858.7 ± 977.2 W) and CRE+CAF (170.8 ± 33.2 N·m, 5037.9 ± 946.9 W) significantly increased (p 0.05). In addition, neither peak torque nor total work significantly differed in subsequent sets between conditions (p>0.05). Heart rate (HR) was significantly elevated (p<0.05) in CRE+CAF (156.6 ± 5.4 bpm) compared to BASE (146.1 ± 4.6 bpm) in all sets. In conclusion, these data suggest short-term creatine supplementation can augment initial torque production in the first bout of isokinetic exercise. However, a single dose of caffeine following creatine loading may not provide an additive ergogenic effect on isokinetic performance.