King Grub
2014-07-17, 08:55
The purpose of this study was to examine the effects of caffeine on strength and muscle activation of the elbow flexors. Thirteen recreationally active male volunteers (mean ± SD, age: 21.38 ± 1.26 years) came to the laboratory four times. Visit one served as a familiarization visit. During visits two through four, subjects ingested a randomly assigned drink, with or without caffeine (0, 5, or 10 mg·kg of body mass), and performed three maximal isometric muscle actions of the elbow flexors sixty minutes after ingestion. Maximal strength and rate of torque development (RTD) were recorded. Electromyographic (EMG) and mechanomyographic (MMG) amplitude and frequency, and electromechanical delay (EMD) and phonomechanical delay (PMD) were measured from the biceps brachii. The results indicated that the ingestion of 0 (placebo), 5 or 10 mg·kg of body mass of caffeine did not significantly influence (P > 0.05) peak torque, RTD, normalized EMG amplitude or frequency, normalized MMG amplitude, or EMD and PMD. Normalized MMG frequency was significantly lower (P < 0.05) following ingestion of five mg·kgof body mass of caffeine compared to the placebo trial. This was most likely an isolated finding as MMG frequency was the only variable to have a significant difference across all trials. The results suggested that ingestion of either five or ten mg·kg of body mass of caffeine does not provide an ergogenic effect for the elbow flexors during isometric muscle actions.
J Strength Cond Res. 2014 Jul 15. Acute Effects of Caffeine on Strength and Muscle Activation of the Elbow Flexors.
J Strength Cond Res. 2014 Jul 15. Acute Effects of Caffeine on Strength and Muscle Activation of the Elbow Flexors.