doi:10.1007/s11657-018-0415-yengOlmedillas, H.Gonzalez de Agüero, A.Rapún-López, M.Gracia-Marco, L.Gomez-Cabello, A.Pradas de la Fuente, F.Moreno, L.A.Casajús, J.A.Vicente-Rodríguez, G.Bone metabolism markers and vitamin D in adolescent cyclistsART-2018-104529Summary: This study aimed to describe bone metabolic activity in adolescent competitive cyclists compared to age-matched controls. The main result is that younger subjects present a higher bone turnover than the older ones. Moreover, cyclists under the age of 17 have higher scores on all markers than age-matched controls. Purpose: The purpose of this study was to describe bone metabolic activity in adolescent competitive cyclists compared to age-matched controls. Methods: Twenty-two male adolescent cyclists between 14 and 20 years (y) and 20 age-matched controls participated in this study. Serum osteocalcin (OC), aminoterminal propeptide of type I procollagen (PINP), and ß-isomerized C-telopeptides (ß-CTX) were analyzed by electrochemiluminescence immunoassay (ECLIA); plasma 25 hydroxyvitamin D [25(OH)D] was analyzed by enzyme-linked immunosorbent assay (ELISA). Results: Analysis of variance revealed no significant differences in bone metabolism markers and vitamin D between cyclists and controls. Cyclists over 17 y had a significantly lower concentration in bone formation and resorption biochemical markers compared to cyclists under 17 y (all P < 0.05). Moreover, controls over 17 y presented lower concentration for PINP (P < 0.05) compared to their peers under 17 y. Comparisons between cyclists and controls under 17 y revealed higher concentrations of OC and PINP (P < 0.05) in cyclists. Group interaction by age was found for OC, PINP, and ß-CTX (P < 0.01). Cyclists over 17 y had higher concentrations of [25(OH)D] (P < 0.05) than age-matched controls. Conclusions: The present results support the idea that cycling during adolescence may be associated to a decrease in bone turnover that may affect bone health later in life.2018http://zaguan.unizar.es/record/13183810.1007/s11657-018-0415-yhttp://zaguan.unizar.es/record/131838oai:zaguan.unizar.es:131838info:eu-repo/grantAgreement/ES/MEC/21-UPB20-10info:eu-repo/grantAgreement/ES/ISCIII/DPS2008-06999Archives of osteoporosis 13, 11 (2018), [8 pp]All rights reservedhttp://www.europeana.eu/rights/rr-f/info:eu-repo/semantics/openAccess