Neuromuscular fatigue in young and older men using constant or variable resistance

  • Walker S
  • Peltonen H
  • Avela J
 et al. 
  • 4


    Mendeley users who have this article in their library.
  • N/A


    Citations of this article.


The purpose of the present study was to determine: (1) if different acute neuromuscular responses occur between constant versus variable external resistance machines, two commonly used resistance machines and (2) whether the potential differences in fatigability between young and older men influence the magnitude of acute response between these resistance machines. Twelve young men (28 ± 5 year) and 13 older men (65.4 ± 4 year) performed 15 × 1 repetition maximum and 5 × 10 repetitions isotonic knee extension resistance loadings with both constant and variable resistance (four loadings in total). Maximum isometric knee extension torque, superimposed twitch, resting twitch torque, maximal M wave properties, electromyograph, and blood lactate concentration measured the effects of loading. Concentric torque reduced to a greater extent during variable 15 × 1 versus constant loading in young men only (P < 0.05). While three out of the four loadings caused decreased voluntary activation in young men, only 15 × 1 using variable resistance caused reductions in older men (P < 0.05). 5 × 10 variable resistance loading significantly increased M wave duration and decreased EMG median frequency, which was not observed following constant resistance loading in both age groups. Acute decreases in force production were significantly greater in young men following all loading protocols (P < 0.05). Both young and older men showed indications of greater fatigue from variable resistance loadings. Differing muscle properties may have led to different magnitudes of fatigue between groups, and older subjects may benefit from specifically tailored training programs. © 2012 Springer-Verlag Berlin Heidelberg.

Author-supplied keywords

  • Adult
  • Age Factors
  • Aged
  • Aging
  • Analysis of Variance
  • Biological Markers
  • Biomechanics
  • Conduction velocity
  • Electric Stimulation
  • Electromyography
  • Equipment Design
  • Finland
  • Humans
  • Isometric Contraction
  • Knee extension
  • Lactic Acid
  • Male
  • Middle Aged
  • Muscle
  • Muscle Fatigue
  • Quadriceps
  • Resistance Training
  • Resting twitch
  • Skeletal
  • Torque
  • Volition
  • Voluntary activation
  • Young Adult
  • adult
  • age
  • aged
  • analysis of variance
  • article
  • biological marker
  • biomechanics
  • blood
  • cognition
  • comparative study
  • controlled clinical trial
  • controlled study
  • electromyography
  • electrostimulation
  • equipment
  • equipment design
  • human
  • innervation
  • lactic acid
  • male
  • middle aged
  • muscle fatigue
  • muscle isometric contraction
  • randomized controlled trial
  • resistance training
  • skeletal muscle
  • torque

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • S Walker

  • H Peltonen

  • J Avela

  • K Häkkinen

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free