PTH and osteoporosis: PTH measurements were prompted by the known role of this hormone’s pulsatile secretion during exercise or administration in promoting bone formation [28,29], the fact that PTH secretion during exercise was reported to increase in both men [30] and postmenopausal women [31], and the success of reducing the risk of osteoporosis with intermittent administration of the PTH analog Teriparatide [32].