Purpose: 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.
Methods: 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.
Results: Sprint cyclists had the largest bone shafts and bone strength surrogates; the difference in diaphyseal BMC, area, and RPol compared with controls being ≥10% in the tibia and ≥8% in the radius (P < 0.01). Distance cyclists versus control group differences were smaller (tibia: ∼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.
Conclusions: 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.
Institute for Biomedical Research into Human Movement and Health, Manchester Metropolitan University, Manchester, UNITED KINGDOM
Submitted for publication December 2007.
Accepted for publication August 2008.
Address for correspondence: Désirée Wilks, MRC Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, UK; E-mail: firstname.lastname@example.org.