EFFECT OF ENDURANCE TRAINING ON POSTEXERCISE PARATHYROID-HORMONE LEVELS IN ELDERLY MEN

The present study was designed to evaluate the effects of 6-wk enduran ce training on serum parathyroid hormone (PTH) levels and on other par ameters at rest and after a maximal exercise test (MET) in 24 55- to 7 3-yr-old men. Before training, MET was found to induce a significant i ncrease in PTH levels as compared with resting values. This MET-induce d rise in PTH was accompanied by enhanced total calcium, phosphate, al kaline phosphatase (ALP), osteocalcin, and albumin levels. After the t raining period (75-80% maximal heart rate, 1 h.d(-1), 4 d.wk(-1)), the changes induced by MET in calcium, phosphate, ALP, and albumin levels followed the same pattern as before training. Conversely, the MET-ind uced increase in PTH levels was found markedly more pronounced after t raining than in untrained conditions (+21.9% vs +11.1%, respectively, P < 0.05). Furthermore, lower values of osteocalcin were found after t raining as compared with pretraining values, both at rest and after ma ximal exercise. These findings indicate that 6 wk of endurance trainin g enhanced exercise-related release of PTH and reduced osteocalcin lev els in elderly men. This might be of importance regarding bone status in the elderly, as exercise is proposed as a preventive measure agains t osteopenia.