The Relationship between Bone Adaptations to Resistance Exercise and Reproductive-Hormone Levels

Abstract

This study examined the relationships between high-intensity resistance exercise and bone mass in postmenopausal women and serum reproductive-hormone levels and bone-mass changes in response to resistance exercise. Women 45–65 years old were assigned to an exercise or a control group. They trained 3 times weekly for 18 weeks at 90,70, and 80% of their 1-RM. Groups were not different in age, height, body mass, muscle strength, or lean body mass. Initial muscle strength increased significantly in the training group. Total hip and intertrochanter bone-mineral density (BMD) increased in the training group. Estradiol, testosterone, osteocalcin, and CrossLaps concentration did not change in either group. Serum estradiol was significantly related to change in BMD at the hip, femoral neck, and intertrochanter, as well as change in lean mass. Results suggest that high-intensity resistance exercise can increase BMD of the hip and that serum estrogen concentrations might influence bone and muscle adaptations to resistance exercise in postmenopausal women.