title: Set Configuration in Resistance Exercise: Muscle Fatigue and Cardiovascular Effects.
abstract: OBJECTIVE
  Cardiovascular responses of traditional resistance (TS) training have been extensively explored. However, the fatigue mechanisms associated with an intra-set rest configuration (ISR) have not been investigated. This study compares two modalities of set configurations for resistance exercise that equates work to rest ratios and measures the central and peripheral fatigue in combination with cortical, hemodynamic and cardiovascular measures.
  
  
  METHODS
  11 subjects performed two isometric knee extension training sessions using TS and ISR configurations. Voluntary activation (VA), single twitch amplitude, low frequency fatigue (LFF), Mwave, motor evoked potential (MEP), short intracortical inhibition (SICI), intracortical facilitation (ICF) and heart rate variability were evaluated before and after each training session. During each session beat to beat heart rate, blood pressure and rate pressure product (RPP) were also evaluated.
  
  
  RESULTS
  After exercise VA decreased significantly for TS but not for ISR (P < 0.001), single twitch amplitude and LFF values were lower for TS than ISR (P < 0.004), and SICI was reduced only for the TS configuration (P = 0.049). During exercise RPP values were significantly higher for the TS than for ISR (P = 0.001). RPP correlated with VA for TS (r = -.85 P < 0.001) suggesting a relationship between central fatigue and cardiovascular stress.
  
  
  CONCLUSIONS
  We conclude that ISR induced lower central and peripheral fatigue as well as lower cardiovascular stress in comparison with TS configuration. Our study suggests that set configuration is a key factor in the regulation of the neuromuscular and cardiovascular responses of resistance training.
authors.affiliation: Learning and Human Movement Control Group, Department of Physical Education and Sport Faculty of Sports Sciences and Physical Education, University of A Coruna, A Coruna, Spain.
authors.forename: Dan
authors.initials: D
authors.lastname: Río-Rodríguez
authors.affiliation: Performance and Health Group, Department of Physical Education and Sport, Faculty of Sports Sciences and Physical Education, University of A Coruna, A Coruna, Spain.
authors.forename: Eliseo
authors.initials: E
authors.lastname: Iglesias-Soler
authors.affiliation: Learning and Human Movement Control Group, Department of Physical Education and Sport Faculty of Sports Sciences and Physical Education, University of A Coruna, A Coruna, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Fernández Del Olmo
mesh_terms: D000328:Adult; D001794:Blood Pressure; D004558:Electric Stimulation; D004576:Electromyography; D015444:Exercise; D006339:Heart Rate; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D018763:Muscle Fatigue; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult