Resting steroid hormone concentrations in lifetime exercisers and lifetime sedentary males

IntroductionAdvancing age in men is associated with a progressive decline in serum testosterone (T) and interactions between exercise, aging and androgen status are poorly understood. The primary aim of this study was to establish the influence of lifelong training history on serum T, cortisol (C) and sex hormone binding globulin (SHBG) in aging men. A secondary aim was to determine the agreement between serum and salivary measurement of steroid hormones in ageing men. 
MethodsSerum and salivary steroid hormones (serum C, T and SHBG, and salivary measures of C and T) were determined and compared between two distinct groups; lifelong exercising males (LE [n = 20], 60.4 +/- 4.7 year) and age matched lifelong sedentary individuals (SED [n = 28], 62.5 +/- 5.3 years). 
ResultsT-test revealed a lack of significant differences for serum C or SHBG between LE and SED, while Mann-Whitney U revealed a lack of differences in total T (TT), bioavailable T (bio-T) or free testosterone (free-T). Further, salivary T (sal-T) did not correlate with serum markers of T in LE, SED, or when pooled (r = 0.040; p>0.05). 
ConclusionsFindings from this investigation suggested that resting levels of serum T and calculated free-T was unable to distinguish between diverse lifelong training histories in aging men. Further, sal-T was not an appropriate indicator of serum T and calculated free-T values in older males and considerable caution should be exercised when interpreting sal-T measurements in aging males.