title: Bone loss over 1 year of training and competition in female cyclists.
abstract: OBJECTIVE
  To observe changes in hip, spine, and tibia bone characteristics in female cyclists over the course of 1 year of training.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  Female cyclists (n = 14) aged 26-41 years with at least 1 year of competition history and intent to compete in 10 or more races in the coming year.
  
  
  METHODS
  Women who train and compete in road cycling as their primary sport.
  
  
  METHODS
  Total body fat-free and fat mass and lumbar spine and proximal femur areal bone mineral density (aBMD) and bone mineral content (BMC) assessments by dual-energy x-ray absorptiometry. Volumetric BMD and BMC of the tibia were measured by peripheral quantitative computed tomography at sites corresponding to 4%, 38%, 66%, and 96% of tibia length. Time points were baseline and after 12 months of training and competition.
  
  
  RESULTS
  Weight and body composition did not change significantly over 12 months. Total hip aBMD and BMC decreased by -1.4% ± 1.9% and -2.1% ± 2.3% (P < 0.02) and subtrochanter aBMD and BMC decreased by -2.1% ± 2.0% and -3.3% ± 3.7% (P < 0.01). There was a significant decrease in lumbar spine BMC (-1.1% ± 1.9%; P = 0.03). There were no significant bone changes in the tibia (P > 0.11).
  
  
  CONCLUSIONS
  Bone loss in female cyclists was site specific and similar in magnitude to losses previously reported in male cyclists. Research is needed to understand the mechanisms for bone loss in cyclists.
authors: *Division of Geriatric Medicine, Department of Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado; †Department of Health, Exercise, and Rehabilitative Sciences, Winona State University, Winona, Minnesota; and ‡Department of Preventative Medicine and Biometrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
authors: Vanessa D
authors: VD
authors: Sherk
authors: Daniel W
authors: DW
authors: Barry
authors: Karen L
authors: KL
authors: Villalon
authors: Kent C
authors: KC
authors: Hansen
authors: Pamela
authors: P
authors: Wolfe
authors: Wendy M
authors: WM
authors: Kohrt
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D001642:Bicycling / Q000502:physiology*; D015519:Bone Density; D001862:Bone Resorption / Q000209:etiology*; D001842:Bone and Bones / Q000502:physiology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D055815:Young Adult