Exercise and bone health

Abstract

Bone mass begins to decrease well before the menopause in women (as early as the 20s in the femur of sedentary women), and accelerates in the perimenopausal years, with continued declines into late old age. Similar patterns are seen in men, without the acceleration related to loss of ovarian function seen in women (Glynn et al. J Bone Miner Res 10:1769-1777, 1995). As with losses of muscle mass and strength (sarcopenia), many genetic, lifestyle, nutritional, disease, and medication-related factors enter into the prediction of bone density at a given age. It is important for health care professionals to understand the rationale and current recommendations for the use of exercise in the prevention and treatment of osteoporosis and osteoporotic fracture, and to place it in context with the other available strategies for this syndrome. The optimal use of exercise in this syndrome is dependent upon the prescription and adoption of a sustained, adequate dose of an evidence-based modality of exercise/physical activity in the target populations, while minimizing the risk of side effects. The phase of the lifecycle is of particular relevance to bone health, as the goal of exercise for fracture prevention shifts dramatically over the course of the lifespan; from an emphasis on achievement of peak bone mass in childhood and adolescence, to the preservation of bone and muscle strength and mass in middle age, to the optimization of gait and balance, muscle strength, frailty, undernutrition, neuropsychological function and polypharmacy in old age. A summary of the current evidence base, as well as the author’s recommendations for effective and safe implementation of physical activity in various settings is reviewed in this chapter.