Six weeks of conditioning exercise increases total, but not free testosterone in lifelong sedentary aging men

Aging Male. 2015;18(3):195-200. doi: 10.3109/13685538.2015.1046123. Epub 2015 Jun 1.


Introduction: Advancing age is associated with a gradual decline in circulating androgens, and the putative role of exercise training on systemic androgens remains to be adequately defined.

Methods: The present investigation examined the impact of 6 weeks of supervised exercise training on resting levels of systemic hormones in a cohort of lifelong sedentary men [SED (n = 28), 62.5 ± 5.3 years], compared with a positive control group of age-matched lifelong exercisers [LE (n = 20), 60.4 ± 4.7 years, >30 years training history]. Blood hormones were sampled pre- and post-intervention from an antecubital forearm vein and analysed using electrochemiluminescent immunoassay. Cardiorespiratory fitness ([Formula: see text]) was determined via indirect calorimetry during an incremental cycle test to volitional exhaustion.

Results: Analysis of variance (ANOVA) revealed a lack of significant change in any parameter amongst LE, whilst SED experienced a significant exercise-induced improvement in cardiorespiratory fitness and total testosterone (all p < 0.05). Concurrent increases in sex hormone-binding globulin (SHBG; p < 0.05) resulted in a lack of change to either bioavailable or calculated free testosterone (p > 0.05) amongst SED.

Conclusions: Although resting levels of systemic total testosterone increased in response to 6 weeks of exercise training, increases in SHBG negated any potential relationship between calculated-free or bioavailable testosterone. These findings indicate that increases in bioavailable testosterone fraction are not required for cardiorespiratory fitness improvements in aging men.

Keywords: Aging; exercise; sex hormone-binding globulin; testosterone.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging / physiology
  • Analysis of Variance
  • Humans
  • Male
  • Middle Aged
  • Outcome Assessment, Health Care
  • Physical Conditioning, Human / physiology*
  • Physical Fitness / physiology
  • Sedentary Behavior*
  • Sex Hormone-Binding Globulin / analysis
  • Testosterone / blood*


  • Sex Hormone-Binding Globulin
  • Testosterone