Influence of creatine monohydrate ingestion on muscle metabolites and intense exercise capacity in individuals with multiple sclerosis

OBJECTIVE: To evaluate the effectiveness of ingesting creatine monohydrate in elevating intramuscular creatine stores and improving exercise capacity in individuals with multiple sclerosis (MS). DESIGN: Randomized, double-blind, placebo-controlled, pre-posttrial. SETTING: A university-based exercise physiology laboratory. PARTICIPANTS: Sixteen individuals with relapsing-remitting MS (median Expanded Disability Status Scale score, 4.75; range, 1.5-6.0). INTERVENTION: Eight individuals with MS were randomized to the creatine group (20g/d of creatine monohydrate for 5d), and 8 others were randomized to the placebo group. Needle biopsies were performed on the vastus lateralis at rest before and after treatment. Subjects performed 3 bouts of 30 maximal knee extensions and flexions at 180 degrees /s with 1 minute of recovery between bouts before and after treatment. MAIN OUTCOME MEASURES: Intramuscular total creatine, phosphocreatine, free creatine, and total work output. RESULTS: Creatine ingestion did not significantly elevate intramuscular total creatine, phosphocreatine, or free creatine or improve total work production. CONCLUSION: Creatine ingestion had no significant effect on muscle creatine stores or high-intensity exercise capacity in individuals with MS.