title: Reduced training is associated with increased loss of BMD.
abstract: This 8-year controlled, follow-up study in 66 Swedish soccer women evaluated the effect of training and reduced training on BMD. The players who retired during the follow-up lost BMD in the femoral neck, whereas the controls did not.
  
  
  BACKGROUND
  Physical activity during adolescence increases BMD, but whether the benefits are retained with reduced activity is controversial.
  
  
  METHODS
  At baseline, DXA evaluated BMD in 48 active female soccer players with a mean age of 18.2 +/- 4.4 (SD) years, in 18 former female soccer players with a mean age of 43.2 +/- 6.2 years and retired for a mean of 9.4 +/- 5.3 years, and in 64 age- and sex-matched controls. The soccer women were remeasured after a mean of 8.0 +/- 0.3 years, when 35 of the players active at baseline had been retired for a mean of 5.3 +/- 1.6 years.
  
  
  CONCLUSIONS
  The players still active at follow-up had a higher BMD at baseline than the matched controls in the femoral neck (FN; 1.13 +/- 0.19 versus 1.00 +/- 0.13 g/cm2; p = 0.02). The yearly gain in BMD during follow-up was higher in the active players than in the controls in the leg (0.015 +/- 0.006 versus 0.007 +/- 0.012 g/cm2, p = 0.04). The soccer players who retired during follow-up had a higher BMD at baseline than the matched controls in the FN (1.13 +/- 0.13 versus 1.04 +/- 0.13 g/cm2; p = 0.005). The players that retired during follow-up lost BMD, whereas the controls gained BMD during the study period in the FN (-0.007 +/- 0.01 versus 0.003 +/- 0.02 g/cm2 yearly; p = 0.01). The soccer players already retired at baseline had higher BMD at study start than the matched controls in the leg (1.26 +/- 0.09 versus 1.18 +/- 0.10 g/cm2; p = 0.01). The former players who were retired at study start lost BMD, whereas the controls gained BMD during the study period in the trochanter (-0.006 +/- 0.01 versus 0.004 +/- 0.014 g/cm2 yearly; p = 0.01). This study shows that, in girls, intense exercise after puberty is associated with higher accrual of BMD, and decreased physical activity in both the short-term and long-term perspective is associated with higher BMD loss than in controls.
authors.affiliation: Department of Orthopaedics, Malmö University Hospital, University of Lund, Malmö, Sweden. Ornolfer.Valdimarsson@med.lu.se
authors.forename: Ornólfur
authors.initials: O
authors.lastname: Valdimarsson
authors.forename: Henrik G
authors.initials: HG
authors.lastname: Alborg
authors.forename: Henrik
authors.initials: H
authors.lastname: Düppe
authors.forename: Fredrik
authors.initials: F
authors.lastname: Nyquist
authors.forename: Magnus
authors.initials: M
authors.lastname: Karlsson
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D015519:Bone Density; D001842:Bone and Bones / Q000502:physiology*; D016022:Case-Control Studies; D015444:Exercise; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D010809:Physical Fitness; D011627:Puberty; D012916:Soccer; D013177:Sports; D013548:Sweden