BONE-MINERAL DENSITY IN WEIGHT LIFTERS

The effect of intense physical training on the bone mineral content (BMC) and soft tissue composition, and the development of these values after cessation of the active career, was studied in 40 nationally or internationally ranked male weight lifters. Nineteen were active and 21 had retired from competition sports. Fifty-two age- and sex-matched nonweight lifters served as controls. The bone mineral density (BMD) in total body, spine, hip, and proximal tibial metaphysis was measured with a Lunar Dual-energy X-ray absorptiometry (DXA) apparatus and the BMD of the distal forearm was measured with single photon absorptiometry (SPA). Seventeen of the lifters had been measured earlier with SPA in the forearm and 23 in the tibial condyle during their active career in 1975. The BMD was significantly higher in the weight lifters compared with the controls (10% in the total body P < 0.001, 12% in the trochanteric region P < 0.001, and 13% in the lumbar spine P < 0.001). All measured regions except the head showed significant higher bone mass in the weight lifters compared with the controls. In older lifters, the difference from the controls seemed to increase in total body and lumbar vertebrae (BMD), but remained unchanged in the hip. Significant correlation was found between the SPA measurements in 1975 and the corresponding measurements 15 years later in both the forearm (r = 0.51, P < 0.05 at the 1-cm level and r = 0.87, P < 0.001 at the 6-cm level) and in the tibial condyle (r = 0.61, P < 0.01). There was no difference in BMD for any region between active and retired weight lifters that was not explained by difference in age. The weight lifters were on average 5 cm shorter but of the same weight as the controls. In the weight lifters, the body mass index (BMI) was increased as was the lean body mass, but not the fat content.