Neuromuscular properties and fatigue in older men following acute creatinesupplementation

The purpose of this study was to investigate the effects of creatine (Cr) s upplementation in 12 older (65-82 years) men. The subjects were randomly as signed to a Cr or a placebo (P) group. Seven men were supplemented with 5 g of Cr and 5 g maltodextrin four times a day for 5 days (Cr), and 5 men con sumed 5 g of maltodextrin four times a day for 5 days (P). Following this t reatment body mass increased significantly in the Cr group (1 kg), but did not change in the P group, and measurements of arm anthropometry were not a ffected in either group. Prior to and following supplementation maximal iso metric voluntary force (MVC), muscle activation, contractile properties and surface electromyography (EMG) were measured in the elbow flexor muscles a t baseline, during a fatiguing task and over 10 min of recovery. The fatigu e protocol involved both voluntary and contractile stimulated. Stimulated c ontractile properties, MVC, and muscle activation were not affected by Cr s upplementation. Furthermore, there were no changes in time to fatigue, decl ine in MVC force, muscle activation, EMG or contractile properties during t he fatigue protocol. The rates of recovery of voluntary force, and stimulat ed contractile force did not change following Cr supplementation. These res ults indicate that short-term Cr supplementation in older men does not infl uence isometric performance of the elbow flexor muscles.