The primary aim of the present Ph.D. thesis was to investigate the osteogenic stimulus of acute exercise and longitudinal training for postmenopausal women and to contribute to the development of knowledge-based training recommendations for the prevention of bone loss and related bone fractures. A secondary aim was to investigate the impact of including bone mineral density (BMD) in the calculation of future fracture risk by the FRAX instrument. The thesis encompasses three human studies: One randomized controlled crossover study, one evaluation study and one observational study. In addition, a preliminary literature review of the response of biochemical bone turnover markers (BTM) to exercise and training is a part of the thesis. It was evident from the preliminary literature review that the overall usage of BTM in exercise studies was characterized by a large variation in standardization of the method, which makes the comparison between different interventions and different populations very difficult. It is therefore highly warranted that future studies follow the recommendations of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and the International Osteoporosis Foundation (IOF). The randomized, controlled crossover study investigated the acute response of BTM to three highimpact jumps, and a highly significant association between the three-dimensional ground reaction forces (GRF) produced by jumping and the acute BTM response was reported. It was concluded that high-impact jumping had an acute osteogenic impact on bone turnover with no difference between the three different jumps that were compared. Based on the results, inclusion of movements in various directions (odd-impact exercise) and multimodal training was recommended when planning osteogenic training programs. The evaluation study investigated the longitudinal osteogenic impact of a health promotional training initiative in a local community over nineteen weeks. Despite the fact that the training was based on current theories on osteogenic training principles, the osteogenic effect was sparse, no matter whether it was evaluated by assessment of BMD or BTM. However, the multimodal training program had health enhancing effects on body composition and bone mass, together with a single increase in femoral trochanter BMD. It was hypothesized that the finding of limited osteogenic effect was partly due to a suboptimal study design with a relatively low statistical power and an inadequate control of the individual training intensity, frequency, and volume. The observational study investigated the relevance of including BMD in reliable fracture risk assessment (FRAX) for women diagnosed with early non-metastatic breast cancer. It was reported that when BMD was included in the calculation, the number of high-risk FRAX scores of hip fracture and major osteoporotic fractures were significantly lower (p<0.001), while the number of low-risk FRAX scores were significantly higher (p<0.001). Thus, it was concluded that when calculating the 10-year probability of hip fracture or major osteoporotic fractures in these patients it is important to include BMD to avoid overestimation of the fracture risk and thus, a possible overtreatment of the patient.