Oral Creatine Supplementation Augments the Repeated Bout Effect.http://www.ncbi.nlm.nih.gov/pubmed/23349298AbstractPURPOSE:
We examined the effects of creatine supplementation on the response to repeated bouts of resistance exercise.METHODS:
Young men (24.1 ± 5.2 yr) were divided into Creatine (CM, n = 9) and Placebo (PL, n = 9) groups. On day (D) 1 and D15, subjects performed four sets of bicep curls at 75% 1-RM to concentric failure. On D8-D13, subjects consumed either 20g/d creatine monohydrate or placebo. Muscle soreness and elbow joint range of motion (ROM) were assessed on D1-D5 and D15-D19. Serum creatine kinase activity (CK) was assessed on D1, D3, D5, D15, D17, and D19.RESULTS:
The first exercise bout produced increases in muscle soreness and CK, and decreases in ROM in both groups (p < 0.001). The second bout produced lesser rises in serum CK, muscle soreness, and a lesser decrease in ROM (bout effect, p < 0.01 for all), with greater attenuation of these damage markers in CM than PL. CK levels on D17 were lower (+110% over D15 for CM vs. +343% for PL), muscle soreness from D15-19 was lower (-75% for CM vs. -56% for PL compared to first bout), and elbow ROM was decreased in PL, but not CM on D16 (p < 0.05 for all).CONCLUSIONS:
Creatine supplementation provides an additive effect on blunting the rise of muscle damage markers following a repeated bout of resistance exercise. The mechanism by which creatine augments the repeated bout effect is unknown, but is likely due to a combination of creatine's multifaceted functions.