Influence of caffeine on force and EMG in rested and fatigued muscle

At present, it is unclear how caffeine induced alterations in neuromuscular function might affect force production and EMG signal characteristics during isometric exercise. These data suggest that acute caffeine ingestion (7 mg/kg) has no significant effect on force production during a maximal isometric hand grip contraction or endurance during a sustained submaximal contraction. Further, maximal motor unit activation, the relationship between submaximal motor unit activation and subsequent force production, and frequency content of the EMG signal were not significantly altered following caffeine ingestion. These results indicate that although caffeine may be a potential ergogenic aid for some activities, its ingestion may not improve performance in activities requiring strength and/or short-term endurance.