Bone and Inflammatory Responses to Training in Female Rowers over an Olympic Year

Introduction/Purpose To examine whether fluctuations in training load during an Olympic year lead to changes in bone mineral densities and factors that regulate bone (sclerostin, osteoprotegerin [OPG] and receptor activator of nuclear factor kappa-B ligand [RANKL]), energy metabolism (insulin-like growth factor-1 [IGF-1] and leptin), and inflammation (tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]) in elite heavyweight female rowers. Methods Blood samples were drawn from 15 female heavyweight rowers (27.0±0.8y, 80.9±1.3 kg, 179.4±1.4 cm) at baseline (T1 – 45 weeks pre-Olympic Games) and following 7, 9, 20, 25 and 42 weeks (T1-6, respectively). Ongoing nutritional counselling was provided. Total weekly training load was recorded over the weeks prior to each time point. BMD was measured by dual energy X-ray absorptiometry at T1 and T6. Results Total BMD increased significantly pre- to post-training (+0.02 g[BULLET OPERATOR]cm−2), however was below the least significant change (±0.04 g[BULLET OPERATOR]cm−2). OPG, IGF-1, and leptin remained stable across all time points. Fluctuations in training load (high vs. low) were accompanied by parallel changes in TNF-α (2.1±0.2 vs. 1.5±0.2 pg[BULLET OPERATOR]ml−1), IL-6 (1.2±0.08 vs. 0.8±0.09 pg[BULLET OPERATOR]ml−1), and sclerostin (high=993±109 vs. low=741±104 pg[BULLET OPERATOR]ml−1). Conclusion In this population of young female athletes with suitable energy availability, sclerostin and inflammation markers responded to fluctuations in training load while BMD and BMC were stable during the season, suggesting that training load periodization is not harmful for the bone health in athletes. Corresponding Author: Panagiota Klentrou, Department of Kinesiology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, Canada, L2S 3A1. Tel: (905) 688-5550 x.4538. Fax: (905) 688-8364. nklentrou@brocku.ca The study was funded by the Canadian Sports Institute Ontario, and partially funded by Natural Sciences of Engineering Research Council of Canada. Nigel Kurgan holds an Ontario Graduate Scholarship. The authors report no conflict of interest, and the results of this study do not constitute endorsement by ACSM and they are presented clearly, honestly, and without fabrication, falsification or inappropriate data manipulation. © 2018 American College of Sports Medicine

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