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.Introduction: Physical activity during adolescence increases BMD, but whether the benefits are retained with reduced activity is controversial. Materials and 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. Results and 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/cm