The Effects of Work-to-Rest Ratios on Torque, Electromyographic, and Mechanomyographic Responses to Fatiguing Workbouts

Authors

Ethan C. Hill, University of Nebraska-LincolnFollow
Terry J. Housh, University of Nebraska-LincolnFollow
Cory M. Smith, University of Nebraska-LincolnFollow
Kristen C. Cochrane, California State Polytechnic UniversityFollow
Nathaniel D.M. Jenkins, Oklahoma State UniversityFollow
Richard J. Schmidt, University of Nebraska-LincolnFollow
Glen O. Johnson, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2017

Citation

International Journal of Exercise Science, 2017; 10(4): 580–591.

Comments

CC-BY-ND license

Abstract

The purpose of the present study was to examine the effects of 2 different work-to-rest ratios, but the same mean load, cycle time, and total duration of the exercise bout, on maximal voluntary isometric contraction torque and neuromuscular responses to fatiguing, intermittent, submaximal, isometric, forearm flexion muscle actions. Ten men performed 2 fatiguing protocols with different work-to-rest ratios (4 s contraction, 4 s rest vs. 4 s contraction, alternating 6 and 2 s rest) that consisted of 50 intermittent, submaximal (65% of maximal voluntary isometric contraction), isometric, forearm flexion muscle actions. Electromyographic and mechanomyographic signals from the biceps brachii were recorded before, during, immediately and 5 min after performing the fatiguing protocols. In addition, maximal voluntary isometric contraction torque was assessed before, immediately and 5 min after. Both protocols resulted in decreases in maximal voluntary isometric contraction torque, electromyographic mean power frequency, and mechanomyographic mean power frequency, but no changes in electromyographic amplitude or mechanomyographic amplitude. The results of the present study indicated that differences in work-to-rest ratio did not affect maximal voluntary isometric contraction torque or the associated neuromuscular parameters as a result of fatiguing, intermittent, isometric muscle actions when mean load, cycle time, and total duration of exercise were equivalent.