Inter-repetition rest training and traditional set configuration produce similar strength gains without cortical adaptations

J Sports Sci. 2016 Aug;34(15):1473-84. doi: 10.1080/02640414.2015.1119299. Epub 2015 Dec 2.

Abstract

This study compared the functional and neural effects of two strength training programmes differing in set configuration. Thirteen participants performed 10 sessions, over a period of 5 weeks, of unilateral leg extensions with different set configurations but with identical work-to-rest ratios for each limb: a traditional configuration (4 sets of 8 repetitions, 10RM load, 3-min pause between sets) and an inter-repetition rest configuration (32 repetitions, 10RM load, 17.4 s of rest between each repetition). Mean propulsive velocity of the traditional sessions was lower than for inter-repetition rest sessions (0.48 ± 0.06 vs. 0.54 ± 0.06 m · s(-1); P < 0.001), while perceived exertion was higher (8.3 ± 0.9 and 6.56 ± 1.6 for traditional training and IRT; P = 0.002). One repetition maximum (RM), work with 10RM load, maximum mean propulsive power, maximum voluntary contraction and time to failure with 50% of maximum isometric force improved similarly in both legs (time effect, P < 0.001; effect size range, 0.451-1.190). Time and set configuration did not show significant main effects or interactions for cortical adaptations (motor-evoked potentials, short-interval intracortical inhibition, intracortical facilitation). There were no significant correlations between changes in cortical and peripheral neural adaptations and strength improvement. In conclusion, inter-repetition rest configuration was as effective as traditional training in improving muscle performance.

Keywords: Resistance training; cluster training; cortical adaptations; peripheral adaptations; voluntary activation.

MeSH terms

  • Adaptation, Physiological*
  • Anthropometry
  • Evoked Potentials, Motor
  • Female
  • Humans
  • Isometric Contraction
  • Male
  • Muscle Strength / physiology*
  • Muscle, Skeletal / innervation
  • Muscle, Skeletal / physiology
  • Perception
  • Physical Exertion
  • Recruitment, Neurophysiological
  • Resistance Training / methods*
  • Rest
  • Young Adult