The Bone Metabolic Response to a Period of High-Intensity Intermittent Exercise Along with Calcium and Vitamin D Consumption in Postmenopausal Women

Abstract

Background: Estrogen deficiency and increasing its reabsorption are determining factors in reducing bone density in postmenopausal women. Objectives: The purpose of this study was to investigate the response threshold of alkaline phosphatase (ALP) and parathyroid hormone (PTH) to resistance training along with calcium and vitamin D intake in postmenopausal women. Methods: In the present study, 17 postmenopausal women (50 - 60 years old) in Zahedan were randomly selected and divided into two groups, exercise + supplement (n = 9) and control (n = 8). The exercise + supplement group received 1,500 mg of calcium and 600 IU daily of vitamin D. Each of them performed resistance training movements in three sets with eight repetitions, with an intensity of 55% 1RM in the first week to 65% 1RM in the fourth week for three sessions/week during four weeks. Sampling was performed before the first training session and 24 hours after the last session from the first to fourth weeks. Data were analyzed with repeated-measures analysis of variance using SPSS software version 19 (P≤0.05). Results: The results showed that calcium and vitamin D supplementation and resistance training significantly affected PTH (P = 0.004) and ALP (P = 0.02) levels. Also, it was shown that the ALP response started in the second week (P = 0.001), while the PTH response started in the third week (P = 0.001). Conclusions: According to the findings of the present study, it can be said that in postmenopausal women, the threshold for the response of ALP to resistance training and calcium and vitamin D intake is the second week and the threshold for the response to PTH is the third week.