Verbal encouragement: effects on maximum effort voluntary muscle action.

Abstract

To examine the effects of verbal encouragement on the peak force of the elbow flexors during an isometric muscle action. A crossover design whereby 20 subjects were divided into 10 2 x 2 Latin squares was undertaken. Peak forces were measured on a Kin-Com dynamometer, and electromyographic (EMG) activity was also recorded from the biceps brachii. All subjects completed trials with and without verbal encouragement. Mean peak force increased (P < 0.05) from 296 to 311 N (5%) when verbal encouragement was presented. A spectral analysis of the EMG activity showed no changes (P > 0.05) to the median frequency in the condition where verbal encouragement was present. These findings have ramifications for training and exercise therapy. An awareness of the effects of verbal encouragement is important when motivating athletes and patients to attain maximum performance during exercise.