Anabolic and catabolic hormones and energy balance of the male bodybuilders during the preparation for the competition

J Strength Cond Res. 2010 Apr;24(4):1074-81. doi: 10.1519/JSC.0b013e3181cb6fd3.


The purpose of the study was to investigate simultaneous effects of energy balance, caloric intake, and the hormonal anabolic-catabolic balance in bodybuilders prior to competition. Fourteen male bodybuilders took part in an 11-week energy-restricted period to reduce body fat. The subjects were divided into the energy-restricted group (ERG) (n = 7), who were preparing for the competition, or the control group (CG) (n = 7) who continued to train regularly and did not change their dietary or training pattern. Participants were tested at 11 weeks (T1), 5 weeks (T2), and 3 days (T3) before competition for diet, body composition, and fasting hormonal assessment. Body mass and body fat percentage of ERG were significantly (p < 0.05) decreased during the study period. In ERG, insulinlike growth factor-1 (IGF-1) and insulin decreased significantly during the 11-week weight-reduction period (p < 0.05). Testosterone was decreased only from week 11 to week 5 (from 20.3 +/- 6.0 to 18.0 +/- 6.8 nmol/L). Changes in IGF-I concentration were significantly related to changes in insulin (r = 0.741), fat mass (r = 0.705), lean body mass (r = 0.696), and body mass (r = 0.652). Changes in insulin concentrations were significantly related to changes in fat mass (r = 0.630) and lean body mass (r = 0.725). These data indicate that severe energy restriction to extremely low body energy reserves decreases significantly the concentrations of 3 anabolic pathways despite high protein intake. Monitoring of insulin and IGF-1 concentration is suggested to prevent losses in muscle mass in energy-restricted conditions. Other nutritional strategies might be needed to prevent possible catabolic effect during preparation of bodybuilders to competition.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / metabolism
  • Adult
  • Athletes
  • Athletic Performance / physiology*
  • Blood Glucose / analysis
  • Body Mass Index
  • Caloric Restriction
  • Case-Control Studies
  • Competitive Behavior
  • Dietary Proteins / administration & dosage
  • Energy Intake*
  • Energy Metabolism / physiology*
  • Human Growth Hormone / blood
  • Humans
  • Hydrocortisone / blood
  • Insulin-Like Growth Factor I / metabolism
  • Male
  • Physical Education and Training / methods*
  • Resistance Training*
  • Statistics, Nonparametric
  • Testosterone / blood
  • Weight Lifting / physiology*
  • Weight Loss / physiology*
  • Young Adult


  • Blood Glucose
  • Dietary Proteins
  • Human Growth Hormone
  • Testosterone
  • Insulin-Like Growth Factor I
  • Hydrocortisone