Journal of Exercise & Organ Cross Talk

Abstract The aim of our study was to examine the effect of 12 weeks of moderate-intensity aerobic exercise on bone mineral density (BMD), lymphocyte alkaline phosphatase (ALP) mRNA expression, and biochemical markers of bone turnover in postmenopausal women (PMWs). Twenty-four healthy sedentary PMWs aged 45-70 years were randomly assigned to exercise (EX, n=12) and control (C, n=12) groups. The EX group performed walking/jogging (50-60min/day, 3days/week at 65%-70% HRmax reserve) for 12-week while the C group participated in no intervention and continued their normal lifestyle. The BMD and lymphocyte ALP mRNA were determined by DXA and qRT-PCR, respectively. After 12 weeks, the increase in the lymphocyte ALP mRNA expression and its serum (P=0.008 and P=0.001), PTH (P=0.001), Vit-D (P=0.002), and VO2max (P=0.001) were significantly higher in the EX group compared to the C group, whereas body fat was significantly decreased (P=0.028). Our study indicates that 12 weeks of moderate-intensity aerobic exercise intervention improves bone turnover by increasing the ALP mRNA expression, serum levels of PTH, ALP, and Vit-D which can lead to the prevention of aging-induced osteopenia among PMWs.

Abstract PH stress can be caused by menopause, poor nutrition, high protein intake, old age, prolonged strenuous and anaerobic exercise, anemia, diabetes, AIDS, and respiratory diseases. High calcium enters the bloodstream from the bones during the proton buffering due to metabolic acidosis, which the renal system excretes a significant amount of this calcium to eliminate the acidosis condition and regulate body pH. At the bone surface, this increase in hydrogen ions due to metabolic acidosis can destroy osteoblastic and strengthen osteoclast activity, which negative bone turnover and increases the amount of excreted calcium, thus accelerating the progress of osteoporosis. Due to the widespread prevalence of osteoporosis in postmenopausal women and the provision of various therapies such as medication, estrogen therapy, and proper diet, in recent studies, special attention has been paid to the role of endurance and resistance exercise to decrease osteoporosis or prevent the development of this disease. Also exercise training increases irisin secretion from muscle tissue, which this myokine has beneficial effects on other tissues especially on bone. Irisin increases osteocytic survival and production of sclerostin in bone tissue, which is associated with bone remodeling. However, exercise training in some intensity through metabolic mechanisms can increase pH stress and acidosis and may contribute to the development of osteoporosis in postmenopausal women.  As a result, the hypothesis of different intensities of exercise and their induced acidosis stimuli in postmenopausal women should be considered.