SERUM ESTRADIOL RESPONSE TO RESISTANCE EXERCISE IN POSTMENOPAUSAL WOMEN

Abstract

Acute resistance exercise (RE) has been shown to increase circulating estradiol concentration in eummenorrheic women while chronic, heavy resistance training can lead to a decrease in sex hormone production. This study examined the influence of RE on serum estradiol concentration in postmenopausal women differing in hormone status before (BT) and after (AT) 10 weeks of resistance exercise training (3x per week). Twenty-seven women (age 72 ± 6.2yr) were assigned to one of 4 groups: hormone replacement (HRT, n = 10), no hormone replacement (NHR, n = 7), selective estrogen receptor modulator (SER, n = 5), or non-exercise control (CON, n = 5; no hormone replacement). After one week acclimation to resistance exercise, HRT, NHR, and SER performed 3 sets of 10 resistance exercises at 80% of their 1 repetition maximum BT and AT. CON sat quietly in the lab during these trials. Blood samples were collected pre-exercise (PR), immediately post-exercise (PO), and two hours post-exercise (2H), or at the same times for CON. Serum samples were analyzed for estradiol using a double antibody radioimmunoassay and were expressed in pmol/L. HRT had significantly greater estradiol values compared to the other groups at all time points (p < 0.001). Considerable variability existed in all groups. Depending on group, serum estradiol concentration increased from 5 – 111% immediately post-exercise; however, these changes were not statistically significant (p > 0.05). In conclusion, neither acute RE nor 10 weeks of RE training significantly influenced serum estradiol concentration in any group. Additional research with larger subject numbers might help to identify any potential significant influence of RE or RE training on serum estradiol concentration in postmenopausal women.Table