Traditionally, well-known functions of bones include protecting brain/internal organs, serving as a reservoir of mineral, supporting body, providing leverage system for various movements and producing blood cells. Recently novel findings suggest that bone is not only a tissue served as a recipient of hormonal inputs but also an organ actively mediating energy metabolism, which includes blood sugar regulation. Insulin has been verified to act through insulin receptor (IR) located on osteoblast, and the downstream reactions of osteoblast IR which would directly stimulate the secretion of osteocalcin from osteoblast as well as indirectly up-regulate the bone resorption released osteocalcin from bone matrix. And, it is the undercarboxylated osteocalcin further stimulating insulin secretion from β-cell of pancreas and enhancing the efficiency of blood glucose down-regulation. Endurance exercise and dietary manipulations (e.g caloric restriction) are behavioral modifications, which have well-proven efficiencies in body weight reduction and also in promoting energy metabolic sensitivity. However, the effects of those two interventions frequently accompany with lower bone mass as well as smaller bone sizes. Hence, endurance exercise and caloric restriction have been considered not beneficial for bone health. The first purpose of the current review was to integrate the new knowledge of bone serving as an endocrine organ with traditional bone regulating mechanisms. Then, we provided a brand-new opinion with regard to endurance exercise and dietary manipulations caused low bone mass as well as smaller bone size. Discussions of interactions between bone metabolism and energy metabolism were included. In spite of correlating with lower bone mass/size, endurance exercise and dietary manipulation actually ameliorate the metabolism profile (e.g. lower inflammatory response, down-regulated oxidative stress) which would further benefit to bone metabolism. In addition, arguments regarding the validity of densitometric measurements and bone quality were also included to elucidate the effects of endurance exercise and dietary manipulations on bone health.