MINERAL DENSITY OF BONE TISSUE AND INDICATORS OF BONE REMODELING IN HIGHLY SKILLED ATHLETES IN THE ANNUAL TRAINING CYCLE

Abstract

Aim. The article aims at studying the relationship between the mineral density of heel bone and bone remodeling in cyclistduring the annual training cycle. Materials and methods. The study involved 14 highly skilled male cyclists (cycle track, MS, MSIC) aged 20–25 years with a sports experience of 5 to 16 years. The measurements were performed in the preparatory, pre-competitive and competitive periods of the annual training cycle. Bone mineral density (BMD) was measured by the method of quantitative ultrasound densitometry (QUS) using the Achilles Express ultrasonometer (Lunar, USA). BMD was estimated as a percentage of the peak norm for a given section of the skeleton (reference norms for 20–29 years). Results. The dynamics of BMD in the annual cycle correlates with a change in bone remodeling and phosphorus-calcium metabolism. A decrease in BMD during the competitive period is associated with an increase in β-Cross Laps and a decrease in osteocalcin, alkaline phosphatase, ionized calcium and serum phosphorus. Conclusion. A decrease in BMD is associated with an increase in the activity of osteoclasts and a decrease in osteoblastic activity. Indicators of bone remodeling and phosphorus-calcium metabolism reflect the status of bone tissue and the processes of general adaptation to training loads, and can be used as markers of risk of decreased BMD. The heel bone QUS method can be used to identify athletes at risk for hypotrophic conditions.