Verbal encouragement: Effects on maximum effort voluntary muscle action

Abstract

Objective - To examine the effects of verbal encouragement on the peak force of the elbow flexors during an isometric muscle action. Methods - 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. Results - 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. Conclusions - 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.