Short-term creatine supplementation does not enhance work capacity in multiple sclerosis individuals
Date
2006
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Publisher
University of Delaware
Abstract
Multiple Sclerosis (MS) is characterized by demyelinization of the white matter surrounding nerves that contributes to impaired muscle metabolism and physiology. Recently, the use of creatine (Cr) supplementation as an alternative therapeutic approach to pharmacotherapy treatment has been demonstrated to improve muscle strength as well as oppose fatigue in neurologically diseased individuals. Previously only one study had investigated the use of Cr supplementation in MS individuals (20g/d for 5 days) and showed no effects on total work. The purpose of this study was to evaluate the effect of exogenous Cr on total work over a 14-day period in MS individuals to determine if an extended duration would improve work capacity. Work capacity was defined as the ability to improve fatigue resistance, effort levels and total work during exercise. Eleven MS subjects (18-60y; Expanded Disability Status Score 3.2 ± 0.3) partook in a randomly assigned double-blind cross-over trial with a 14-day ingestion period of exogenous Cr (5g, 4 times daily, day 1-7: 2.5g, 2 times daily, day 8-14), 3-week wash-out, and a 14-day ingestion period of placebo. Total work was measured by a Biodex Dynamometer for 3 bouts of 30 maximal knee extensions and flexions at 180°/s with 1 minute of recovery between bouts. Fatigue Severity Scale (control=3.61 ± 1.54 vs. treat=3.54 ± 1.66; p=0.73) and Rates of Perceived Exertion (control=13.55 ± 1.91 vs. treat=13.13 ± 2.72; p=0.48) were also assessed and found to be non-significant between periods. Total work was non-significant for between groups effect (control=1329.66J ± 175.49J vs. treat=1313.14J ± 200.54J; p=0.81) or for test of within-subject effects on knee extension (F (1, 10)=0.425, p=0.52). There was no group difference for knee flexion (control=1308.28J ± 165.56J vs. treat=1302.10J ± 189.64J; p=0.93), or within-subject effects (F (1, 10)=0.212, p=0.46). Therefore, an extended ingestion period of 14-days with Cr supplementation does not result in an improvement on work capacity in MS individuals.