Wilks Désirée C, Gilliver Sally F, Rittweger Jörn
Institute for Biomedical Research into Human Movement and Health, Manchester Metropolitan University, Manchester, United Kingdom.
Med Sci Sports Exerc. 2009 Mar;41(3):566-73. doi: 10.1249/MSS.0b013e31818a0ec8.
Cycling is very popular; however, it is often believed to be associated with below average bone mass. This study compared bone measures of sprint- and distance-trained cyclists competing at World Master Track Championships, along with sedentary controls (30-82 yr), and examined the associations of bone measures with age.
Radius and tibia epiphyseal and shaft bone mineral density (BMD), bone mineral content (BMC), and cross-sectional area along with shaft polar moment of resistance (RPol) and endocortical/periosteal circumferences were assessed by peripheral quantitative computed tomography. Intergroup differences were assessed by ANOVA and age relationships by correlation analyses.
Sprint cyclists had the largest bone shafts and bone strength surrogates; the difference in diaphyseal BMC, area, and RPol compared with controls being >or=10% in the tibia and >or=8% in the radius (P < 0.01). Distance cyclists versus control group differences were smaller (tibia: approximately 4-10%; radius: <2%), reaching statistical significance only for tibial BMC and area (P < 0.05). Generally, epiphyseal bone measures showed no group differences. In the radius, age correlations were negative for both the sprinters' and the controls' diaphyseal and the sprinters' epiphyseal BMD; they were positive for the controls' diaphyseal endocortical and periosteal circumferences (P < 0.05). In the cyclists' tibiae, neither epiphyseal nor diaphyseal bone measures were correlated with age.
Sprint cyclists and to a lesser extent distance cyclists had greater tibia and radius bone strength surrogates than the controls, with tibial bone measures being well preserved with age in all groups. This suggests that competition-based cycling and the associated training regime is beneficial in preserving average or above-average bone strength surrogates into old age in men.
骑自行车非常流行；然而，人们通常认为它与低于平均水平的骨量有关。本研究比较了参加世界大师级场地自行车锦标赛的短跑和耐力训练自行车运动员的骨骼测量值，以及久坐不动的对照组（30 - 82岁），并研究了骨骼测量值与年龄的关系。
通过外周定量计算机断层扫描评估桡骨和胫骨骨骺及骨干的骨矿物质密度（BMD）、骨矿物质含量（BMC）、横截面积以及骨干抗扭极矩（RPol）和骨内膜/骨膜周长。通过方差分析评估组间差异，通过相关分析评估年龄关系。
短跑自行车运动员的骨干和骨强度指标最大；与对照组相比，胫骨骨干BMC、面积和RPol的差异在胫骨中≥10%，在桡骨中≥8%（P < 0.01）。耐力自行车运动员与对照组的差异较小（胫骨：约4 - 10%；桡骨：<2%），仅胫骨BMC和面积达到统计学显著性（P < 0.05）。一般来说，骨骺骨测量值没有组间差异。在桡骨中，短跑运动员和对照组骨干以及短跑运动员骨骺的BMD与年龄呈负相关；对照组骨干骨内膜和骨膜周长与年龄呈正相关（P < 0.05）。在自行车运动员的胫骨中，骨骺和骨干的骨测量值均与年龄无关。
短跑自行车运动员以及在较小程度上耐力自行车运动员的胫骨和桡骨骨强度指标比对照组更大，所有组的胫骨骨测量值随年龄增长保持良好。这表明基于竞赛的骑行和相关训练方式有利于男性在老年时保持平均或高于平均水平的骨强度指标。
