title: Strength gain through eccentric isotonic training without changes in clinical signs or blood markers.
abstract: BACKGROUND
  Localized exercises are widely used in rehabilitation processes. The predominant options are exercises with an emphasis on either concentric or eccentric contractions. Eccentric exercises promote greater strength gains compared to classical concentric stimuli, but can cause muscle damage. The aim of present study was to compare strength training composed of 10 sessions with progressive loads between groups with a predominance of concentric versus eccentric contraction through an analysis of isotonic strength, pressure pain threshold, creatine kinase, tumor necrosis factor-alpha and cortisol.
  
  
  METHODS
  One hundred twenty male subjects were divided into four groups: C1 and E1--single session of maximum strength with emphasis on concentric and eccentric contraction, respectively; C10 and E10--10 sessions with progressive loads from 80% to maximum strength with emphasis on concentric and eccentric contraction, respectively.
  
  
  RESULTS
  Isotonic strength increased by 10% in E10 following the ten training sessions. C1 and E1 exhibited a lower pressure pain threshold 48 hours after the sessions in comparison to C10 and E10, respectively. Creatine kinase was increased in C1 in comparison to baseline, with significant differences (p ≤ 0.05) in comparison to E1 at 48 and 96 hours as well as C10 at 48, 72 and 96 hours. No significant differences were found in TNF-α or cortisol among the groups or evaluation times.
  
  
  CONCLUSIONS
  Eccentric contraction training promotes functional adaptation. Moreover, both concentric and eccentric contraction training have a protective effect on the muscle in relation to a single session of maximum strength exercise.
  
  
  BACKGROUND
  RBR-75scwh.
authors.forename: Thâmara
authors.initials: T
authors.lastname: Alves
authors.forename: Flávia A
authors.initials: FA
authors.lastname: Guarnier
authors.forename: Fernanda A S
authors.initials: FA
authors.lastname: Campoy
authors.forename: Mariana O
authors.initials: MO
authors.lastname: Gois
authors.forename: Maíra C
authors.initials: MC
authors.lastname: Albuquerque
authors.forename: Patrícia M
authors.initials: PM
authors.lastname: Seraphim
authors.forename: Jayme
authors.initials: J
authors.lastname: Netto
authors.forename: Luiz Carlos Marques
authors.initials: LC
authors.lastname: Vanderlei
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Padovani
authors.forename: Rubens
authors.initials: R
authors.lastname: Cecchini
authors.affiliation: Department of Physical Therapy, Univ Estadual Paulista, Presidente Prudente, Brazil. pastre@fct.unesp.br.
authors.forename: Carlos Marcelo
authors.initials: CM
authors.lastname: Pastre
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood*; D064368:Healthy Volunteers; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D055070:Resistance Training / Q000379:methods*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D014409:Tumor Necrosis Factor-alpha; D003402:Creatine Kinase; D006854:Hydrocortisone