EFFECTS OF ZINC SUPPLEMENTATION AND VERTEBRAL AND FEMORAL BONE MASS IN RATS ON STRENUOUS TREADMILL TRAINING EXERCISE

The hypothesis that a zinc (Zn) deficit may cause osteopenia in athlet es is well founded, Hn rats exposed to strenous exercise, we evaluated the effect of a zinc supplement on femoral and vertebral bone mass de termined by dual-energy X-ray absorptiometry Four lots of 93-day-old f emale Wistar rats were studied. A control group of 30 rats were not ma nipulated (Zn-Ex-group), The experimental group of 40 rats was fed a d iet supplemented with an additional 20% of Zn/kg of feed; this group w as divided into two groups of 20 rats each, one that did not exercise (Zn+ Ex-) and one that did (Zn+ Ex+), A group of 15 rats exercised hut did not receive a zinc supplement (Zn- Ex+ group), Training consisted of treadmill running for 5 out of 7 days over an 11-week period. Init ial speed, running time, and treadmill speed mere increased gradually, Analysis of variance with the Bonferroni/Dunn test showed that the le ngth, weight, hone mineral content (BMC), and hone mineral density (BM D) of the femur were less in the Zn- Ex+ group than in the others (p < 0.008), and the weight, BMC, and BMD of the fifth lumbar vertebra als o mere lower in the Zn- Ex+ group than in the others (p < 0.008). Thes e findings confirm the adverse effects of strenuous exercise (treadmil l running) on bone tissue int rats and the effectiveness of zinc suppl ementation in preventing it.