Supplementation of Creatine Monohydrate Improves Sprint Performance but Has no Effect on Glycolytic Contribution: A Nonrandomized, Placebo-Controlled Crossover Trial in Trained Cyclists.

Background: Sprint performance may be crucial for athletes in sprint and endurance sports. In this regard, the maximal glycolytic rate (νLa) is a variable within Mader's model of metabolism that is commonly tested in a 15-s all-out sprint test. The product of lactate accumulation (ΔLa) and lactate distribution space approximated by fat-free mass (FFM) is strongly linked to sprint performance. Creatine monohydrate is a widely used ergogenic aid known for increasing anaerobic performance and FFM and the phosphagenic system contributes most to a 15-s all-out sprint.

Objectives: The aim of the study was to analyze the influence of creatine supplementation of 15-s work, FFM, and ΔLa.

Methods: Twenty male and 5 female cyclists underwent a placebo-controlled, crossover design with 4 laboratory visits. After a familiarization trial, baseline measurements were performed. Placebo (4 × 5 g/d maltodextrin) and creatine monohydrate (4 × 5 g/d) were administered for 5 d before the respective trials. All participants underwent this order of trials and performed a 15-s all-out sprint test on a Cyclus2-ergometer. Capillary blood was sampled before and every minute (for 8 min) after the sprint to determine ΔLa. Body composition was determined employing bioelectric impedance analysis.

Results: Creatine supplementation significantly increased 15-s work output and FFM compared with baseline and placebo conditions. However, no significant differences were found in capillary blood lactate accumulation (ΔLa) or glycolytic contribution.

Conclusions: The results indicate potential differences in limitations of sprint performance of participants. Responders to creatine supplementation are potentially limited by mechanical or metabolic factors. The findings of this study highlight the importance of considering supplementation of creatine monohydrate when undergoing testing for the maximal glycolytic rate.