This cross-sectional study was done in order to ascertain whether there is a lifelong beneficial effect on bone mineral density (BMD) of early, long-lasting, and intense physical exercise. Forty-eight male ex-weight lifters, mean age 64 years (range 50-79) participated. They had followed a training program of an average of 10 hours/week (range 4-20) for an average of 13 years (range 1-34). They had all retired from competitive sport an average of 30 years (range 7-50) ago. Sixty-six age-matched volunteers served as controls. The bone mineral density (BMD, areal density, g/cm2) in the total body, spine, and hips and the fat content and lean body mass were measured with the LUNAR DPX bone mass scanner. In ex-weight lifters 50-64 years of age, the BMD was greater than in controls. After 65 years, no difference was found between the former weight lifters and their controls.