This pilot study compared bone speed of sound (SOS), bone turnover and insulin-like growth factor 1 (IGF-1) between 20 Caucasian, postmenarcheal, adolescent synchronized swimmers (SS) and 20 aged- and maturity-matched nonswimmers (NS). Daily dietary intake and physical activity levels were also assessed. Bone SOS was measured by quantitative ultrasound. Blood samples were analyzed for osteocalcin, cross-linked N-teleopeptide of type I collagen (NTx), IGF-I and 25-OH vitamin D. Although no differences in bone SOS or turnover markers were observed between groups, the lower IGF-1 and vitamin D intake found in synchronized swimmers, in combination with their higher strenuous activity levels, should be further explored.
Ludwa, Falk, Yao, Corbett, and Klentrou are with the Dept. of Physical Education and Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, Ontario, Canada L2S 3A1.