Experimental Brain Research

, Volume 162, Issue 1, pp 122–132 | Cite as

Age-related differences in rapid muscle activation after rate of force development training of the elbow flexors

  • Benjamin K. BarryEmail author
  • Geoffrey E. Warman
  • Richard G. Carson
Research Article


In young adults, improvements in the rate of force development as a result of resistance training are accompanied by increases in neural drive in the very initial phase of muscle activation. The purpose of this experiment was to determine if older adults also exhibit similar adaptations in response to rate of force development (RFD) training. Eight young (21–35 years) and eight older (60–79 years) adults were assessed during the production of maximum rapid contractions, before and after four weeks of progressive resistance training for the elbow flexors. Young and older adults exhibited significant increases (P<0.01) in peak RFD, of 25.6% and 28.6% respectively. For both groups the increase in RFD was accompanied by an increase in the root mean square (RMS) amplitude and in the rate of rise (RER) in the electromyogram (EMG) throughout the initial 100 ms of activation. For older adults, however, this training response was only apparent in the brachialis and brachioradialis muscles. This response was not observed in surface EMG recorded from the biceps brachii muscle during either RFD testing or throughout training, nor was it observed in the pronator teres muscle. The minimal adaptations observed for older adults in the bifunctional muscles biceps brachii and pronator teres are considered to indicate a compromise of the neural adaptations older adults might experience in response to resistance training.


Ageing Strength Resistance training Biceps brachii Motor unit 



Maximum voluntary contraction


Rate of torque development




Root mean square


Rate of EMG rise



The authors wish to thank Mr Jonathan Shemmell, and Mr Andrew Popple for their assistance in data analysis, Mr Angus Ross for his helpful comments on the manuscript, and the volunteers who so generously donated their time. This work was supported by The Australian Research Council and The National Health and Medical Research Council.


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Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • Benjamin K. Barry
    • 1
    • 2
    Email author
  • Geoffrey E. Warman
    • 1
  • Richard G. Carson
    • 1
  1. 1.Perception and Motor Systems Laboratory, School of Human Movement StudiesThe University of QueenslandSt LuciaAustralia
  2. 2.Neural Control of Movement Laboratory, Department of Integrative PhysiologyUniversity of ColoradoBoulderUSA

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