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

Lawrence D. Hayes*, Nicholas Sculthorpe, Peter Herbert, Julien S. Baker, Roberto Spagna, Fergal M. Grace

*Corresponding author for this work

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

IntroductionAdvancing 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. 
MethodsThe 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, 430 years training history]. Blood hormones were sampled pre- and post- intervention from an antecubital forearm vein and analysed using electrochemiluminescent immunoassay. Cardiorespiratory fitness (VO2peak) was determined via indirect calorimetry during an incremental cycle test to volitional exhaustion. 
ResultsAnalysis 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 hormonebinding globulin ( SHBG; p<0.05) resulted in a lack of change to either bioavailable or calculated free testosterone ( p>0.05) amongst SED. 
ConclusionsAlthough 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.
Original languageEnglish
Pages (from-to)195-200
Number of pages6
JournalThe Aging Male
Volume18
Issue number3
DOIs
Publication statusPublished - 3 Jul 2015

Keywords

  • Aging
  • exercise
  • sex hormone-binding globulin
  • testosterone

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