Total and regional bone density in male runners, cyclists, and controls

Abstract

STEWART, A. D., and J. HANNAN. Total and regional bone density in male runners, cyclists, and controls. Med. Sci. Sports Exerc., Vol. 32, No. 8, pp. 1373–1377, 2000. Male athletes who were runners (N = 12), cyclists (N = 14), or both (N = 13) were compared with nonexercising age-matched controls (N = 23) for total and regional bone mineral density (BMD). All athletic subjects had competed for a minimum of 3 yr and trained for a minimum of 4 h·wk−1. Runners undertook no cycling and cyclists undertook no running training. All subjects were scanned for whole body and L1–L4 spine BMD using a Hologic QDR 1000W scanner (Hologic Inc., Bedford, MA). There were no differences in age, height, weight, body mass index (BMI), % fat, or hours of training between any of the athletic groups (P > 0.05), although compared with controls, runners and cyclists had lower body mass index (P < 0.01) and all athletic groups had lower % fat (P < 0.001). Compared with controls, runners had greater total and leg BMD (P < 0.05), cyclists had reduced spine BMD (P = 0.05), and athletes of the “both” group had greater total (P < 0.05) and arm BMD ( P < 0.01). Running is associated with increased bone density, particularly in the leg, whereas cycling is associated with a mild decrease in bone density in the spine. In athletes who do both, running exerts a stronger influence than cycling.