title: The impact of repetition mechanics on the adaptations resulting from strength-, hypertrophy- and cluster-type resistance training.
abstract: OBJECTIVE
  The purpose of this study was to examine the acute and chronic training responses to strength-, hypertrophy- and cluster-type resistance training.
  
  
  METHODS
  Thirty-four trained males were assigned to a strength [STR: 4 × 6 repetitions, 85 % of one repetition maximum, (1RM), 900 s total rest], hypertrophy (HYP: 5 × 10 repetitions, 70 % 1RM, 360 s total rest), cluster 1 (CL-1: 4 × 6/1 repetitions, 85 % 1RM, 1400 s total rest), and cluster 2 (CL-2: 4 × 6/1 repetitions, 90 % 1RM, 1400 s total rest) regimens which were performed twice weekly for a 6-week period. Measurements were taken before, during and following the four workouts to investigate the acute training stimulus, whilst similar measurements were employed to examine the training effects before and after the intervention.
  
  
  RESULTS
  The improvements in 1RM strength were significantly greater for the STR (12.09 ± 2.75 %; p < 0.05, d = 1.106) and CL-2 (13.20 ± 2.18 %; p < 0.001, d = 0.816) regimens than the HYP regimen (8.13 ± 2.54 %, d = 0.453). In terms of the acute responses, the STR and CL-2 workouts resulted in greater time under tension (TUT) and impulse generation in individual repetitions than the HYP workout (p < 0.05). Furthermore, the STR (+3.65 ± 2.54 mmol/L(-1)) and HYP (+6.02 ± 2.97 mmol/L(-1)) workouts resulted in significantly greater elevations in blood lactate concentration (p < 0.001) than the CL-1 and CL-2 workouts.
  
  
  CONCLUSIONS
  CL regimens produced similar strength improvements to STR regimens even when volume load was elevated (CL-2). The effectiveness of the STR and CL-2 regimens underlines the importance of high loads and impulse generation for strength development.
authors.affiliation: Carnegie School of Sport, Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Fairfax Room 107, Headingley Campus, Leeds, LS6 3QT, UK. g.nicholson@leedsbeckett.ac.uk.
authors.forename: G
authors.identifier: http://orcid.org/0000-0002-9559-0562
authors.initials: G
authors.lastname: Nicholson
authors.affiliation: Carnegie School of Sport, Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Fairfax Room 107, Headingley Campus, Leeds, LS6 3QT, UK.
authors.forename: T
authors.initials: T
authors.lastname: Ispoglou
authors.affiliation: Carnegie School of Sport, Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Fairfax Room 107, Headingley Campus, Leeds, LS6 3QT, UK.
authors.forename: A
authors.initials: A
authors.lastname: Bissas
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D000072696:High-Intensity Interval Training / Q000379:methods*; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D064797:Physical Conditioning, Human / Q000379:methods*; D010807:Physical Endurance / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology; D055070:Resistance Training / Q000379:methods*
chemical_list: D019344:Lactic Acid
keywords: Cluster; Hypertrophy; Lactate; Muscle activity; Rest interval