Igor Stirn¹, Vojko Strojnik¹

¹University of Ljubljana, Faculty of Sport, Ljubljana, Slovenia

TWITCH AMPLITUDE AFTER THREE REPETITIONS OF EXHAUSTING ISOMETRIC CONTRACTIONS AT DIFFERENT STARTING INTENSITIES DOES NOT CHANGE

Sport Mont 2010, VIII(23-24), 178-183

Abstract

The amplitude of a twitch presents one of the measures used to evaluate peripheral muscle fatigue. The aim of the study was to evaluate peripheral fatigue after the isometric muscle contractions of different starting intensities: at 60 %, 80 % and 100 % of maximal voluntary contraction. Twelve male students (22.2 ± 2.6 years of age) performed three fatiguing protocols in three days. Each fatiguing protocol consisted of three consecutive isometric contractions with a one minute rest in-between. The starting intensities of contractions were set at 60%, 80% or 100% for fatiguing protocols FP60, FP80 and FP100 respectively. Torque and duration of contractions and the amplitude of the muscle twitches provoked after the fatiguing contractions were measured. The comparison of the amplitudes of the muscle twitches provoked after three consecutive exhausting isometric contractions with different starting contraction intensities (60% MVC, 80% MVC, and 100% MVC) as well as the torque at the end of contractions did not show any statistically significant differences. In conclusion, no differences in accumulated peripheral fatigue were found after isometric contractions of different starting intensities.

Keywords

isometric contraction, muscle fatigue, twitch, amplitude

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