Salivary hormonal responses to resistance exercise in trained and untrained middle-aged men

The aim of the present study was to investigate if there are differences in salivary hormonal responses to resistance exercise between long-term strength-trained and untrained men.

Twenty-eight subjects were recruited to this study, matched into a strength-trained group (SG, N=13) and an untrained group (UG, N=15). Upper and lower body absolute muscle strength was measured through the one-repetition maximum (1-RM) test. Saliva samples were collected at rest and after a resistance exercise protocol (REP) with intensity relative to 1-RM values. With these samples, testosterone (TES), dehydroepiandrosterone (DHEA) and cortisol (COR) were determined.

SG subjects demonstrated significantly higher values in all muscle strength variables. While a significant increase in TES after REP was found in the SG (0.114 + or - 0.1 vs. 0.15 + or - 0.09 pg/mL, P<0.05), no differences were observed in the UG (0.144 + or - 0.1 vs. 0.17 + or - 0.1 pg/mL). In both groups, there were increases in salivary COR (SG: 1.4 + or - 0.6 vs. 2.06 + or - 1; UG: 1.5 + or - 0.8 vs. 2.3 + or - 1.2 ug/dL, P<0.05) and DHEA (SG: 0.6 + or - 0.3 vs. 0.9 + or - 0.6; UG: 0.65 + or - 0.3 vs. 0.97 + or - 0.7 ng/dL, P<0.05).

These results suggest the possible presence of adaptation of TES responses to resistance exercise in long-term strength-trained men, with these subjects presenting higher responses to the same stimulus, compared with untrained subjects, while no such adaptation was seen at the adrenocortical level in these subjects as the responses observed were similar in both groups.