title: The effect of rate of weight reduction on serum myostatin and follistatin concentrations in competitive wrestlers.
abstract: OBJECTIVE
  To evaluate anthropometric measures and serum markers of myostatin-pathway activity after different weight-reduction protocols in wrestlers.
  
  
  METHODS
  Subjects were randomly assigned to a gradual-weight-reduction (GWR) or rapid-weight-reduction (RWR) group. Food logs were collected for the duration of the study. Anthropometric measurements and serum samples were collected after an 8-h fast at baseline and after the weight-reduction intervention. Subjects reduced body mass by 4%. The GWR group restricted calories over 12 d, while the RWR group restricted calories over 2 d. A series of 2×5 repeated-measures (RM) ANOVAs was conducted to examine differences in nutrient consumption, while separate 2×2 RM ANOVAs were conducted to examine differences in anthropometric measures and serum markers. When applicable, Tukey post hoc comparisons were conducted. Significance for all tests was set at P<.05.
  
  
  RESULTS
  There were no between-groups differences for any anthropometric measure (P>.05). Subjects in both groups experienced a significant reduction in body mass, fat mass, lean mass, and percent body fat (P<.05). There were no between-groups differences in serum markers of myostatin-pathway activity (P>.05), but subjects in the RWR condition experienced a significant increase in serum myostatin (P<.01), a decrease in follistatin (P<.01), and an increase in myostatin-to-follistatin ratio (P<.001).
  
  
  CONCLUSIONS
  Although there were no between-groups differences for any outcome variables, the serum myostatin-to-follistatin ratio was significantly increased in the RWR group, possibly signaling the early stages of skeletal-muscle catabolism.
authors.affiliation: Dept of Physical Education and Sports Sciences, Ferdowsi University of Mashhad, Mashhad, Iran.
authors.forename: Mohamad S
authors.initials: MS
authors.lastname: Motevalli
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Dalbo
authors.forename: Reza S
authors.initials: RS
authors.lastname: Attarzadeh
authors.forename: Amir
authors.initials: A
authors.lastname: Rashidlamir
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Tucker
authors.forename: Aaron T
authors.initials: AT
authors.lastname: Scanlan
mesh_terms: D000273:Adipose Tissue; D000328:Adult; D015992:Body Mass Index; D031204:Caloric Restriction / Q000379:methods*; D003163:Competitive Behavior / Q000502:physiology; D015930:Diet Records; D038681:Follistatin / Q000097:blood*; D006801:Humans; D008297:Male; D055435:Myostatin / Q000097:blood*; D015431:Weight Loss; D014952:Wrestling / Q000502:physiology*; D055815:Young Adult
chemical_list: D038681:Follistatin; D055435:Myostatin