Testosterone, growth hormone and IGF-I responses to acute and chronic resistive exercise in men aged 55-70 years

Int J Sports Med. 1995 Oct;16(7):445-50. doi: 10.1055/s-2007-973035.


We investigated the responses of serum testosterone (T) and human growth hormone (hGH) concentrations to a bout of heavy resistive exercise and the responses of T, hGH, and insulin-like growth factor I (IGF-I) to a 16 wk progressive resistive training program in 13 men (60 +/- 4 yrs). Body composition via hydrostatic weighing and muscle strength using a 3 repetition maximum (3RM) test on 6 variable resistance exercise machines were assessed before and after the training program. Fasting blood samples were drawn on 2 consecutive days prior to training and again on 2 consecutive days after the last day of exercise. Blood was also drawn immediately before and approximately 10 min after a single exercise session during the first wk of training, and after an exercise session of the same relative resistance during the last wk of training. The training program resulted in a 37% increase in upper body strength and a 39% increase in lower body strength (both p < 0.01). Lean body mass increased significantly (61.8 +/- 2.1 vs 63.7 +/- 7.8 kg; p < 0.001) while % fat decreased (26.5 +/- 1.5 vs 24.9 +/- 6.0%; p < 0.01) as a result of training. Serum T concentration was unchanged, but GH increased approximately 18-fold in response to a single bout of resistive exercise before (0.24 +/- 0.08 vs 4.60 +/- 1.35 mg/l) and after (0.26 +/- 0.06 vs 4.66 +/- 1.46 mg/l; p < 0.01) training. Baseline serum concentrations of T, hGH, and IGF-I were unaffected by the training program. We conclude that an acute bout of resistive exercise causes a substantial hGH response in older men, but 16 wks of progressive resistive training does not affect baseline concentrations of the anabolic hormones.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Energy Intake
  • Exercise / physiology*
  • Growth Hormone / blood*
  • Humans
  • Insulin-Like Growth Factor I / analysis*
  • Male
  • Middle Aged
  • Physical Education and Training
  • Physical Endurance
  • Testosterone / blood*


  • Testosterone
  • Insulin-Like Growth Factor I
  • Growth Hormone