Four weeks of high- versus low-load resistance training to failure on the rate of torque development, electromechanical delay, and contractile twitch properties

N. D.M. Jenkins, T. J. Housh, S. L. Buckner, H. C. Bergstrom, C. M. Smith, K. C. Cochrane, E. C. Hill, A. A. Miramonti, R. J. Schmidt, G. O. Johnson, Joel T. Cramer

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

The purpose of this study was to investigate the effects of 4-weeks of high- versus low-load resistance training to failure on rate of torque development (RTD), electromechanical delay (EMD), and contractile twitch characteristics. Fifteen men (mean±SD; age=21.7±2.4 yrs) were randomly assigned to either a high- (80% 1RM; n=7) or low-load (30% 1RM; n=8) training group and completed elbow flexion resistance training to failure 3 times per week for 4 weeks. The participants were tested at baseline, 2-, and 4-weeks of training. Peak RTD (pRTDV) and RTD at 0-30 (RTD30V), 0-50 (RTD50V), 0-100 (RTD100V), and 0-200 (RTD200V) ms, integrated EMG amplitude (iEMG) at 0-30, 0-50, and 0-100 ms, and EMD were quantified during maximal voluntary isometric muscle actions. Peak twitch torque, peak RTD, time to peak twitch, 1/2 relaxation time and the peak relaxation rate were quantified during evoked twitches. Four weeks of high-load, but not low-load resistance training, increased RTD200V. There were also increases in iEMG during the first 30 ms of muscle activation for the high- and low-load groups, which may have indirectly indicated increases in early phase motor unit recruitment and/or firing frequency. There were no significant training-induced adaptations in EMD or contractile twitch properties.

Original languageEnglish (US)
Pages (from-to)135-144
Number of pages10
JournalJournal of Musculoskeletal Neuronal Interactions
Volume16
Issue number2
StatePublished - Jun 2016

Keywords

  • Electromyography
  • Rapid torque production
  • Skeletal muscle

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Physiology
  • Orthopedics and Sports Medicine

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