THE EFFECTS OF SHORT-TERM RESISTANCE TRAINING ON ENDOCRINE FUNCTION IN MEN AND WOMEN 408

Abstract

The primary purpose of this investigation was to examine the hormonal changes to acute resistance exercise over an 8 week training period in untrained men and women. The training protocol consisted of eight weeks of high intensity lower body resistance training. Blood samples were obtained pre-exercise (Pre-Ex), immediately post-exercise (IP), and 5 min post-exercise(5-P) during the first week of training (T-1), after 6 weeks (T-2) and 8 weeks(T-3) of training. Men did not demonstrate a significant increase in testosterone (T) due to exercise until T-2. A significant increase in pre-exercise concentrations of T were observed in both men and women at T-2 and T-3. Significant increases in cortisol (CORT) above pre-exercise values were observed for men at all training phases and at T-2 and T-3 for women. A significant reduction in CORT concentrations at rest were observed in both men and women at T-3. No significant changes with training were observed for growth hormone (GH) concentrations. Significant exercise-induced increases in GH above pre-exercise values were observed at all groups. No exercise-induced increases were observed in men over the training period but women significantly increased SHBG with exercise at T-3. SHBG concentrations in women were also significantly higher at T-2 and T-3 when compared to T-1 values. No significant differences were observed between men and women for response of increases in serum lactate to acute resistance exercise. These hormonal adaptations may influence and help to mediate other adaptations in the nervous system and muscle fibers which have been shown to be very responsive in the early phase of strength adaptations with resistance training.