Based on the accumulation of evidence gathered from
cross-sectional, prospective, and exercise intervention
studies over the past several decades, numerous public
health and governmental bodies [9–16] now recognize
and promote physical activity and exercise as a means
of aiding in the development and maintenance of musculoskeletal
health and fitness and the prevention of
osteoporotic fracture. However, when prescribing activity
it is important to distinguish between the terms physical
activity and exercise. Physical activity refers to any
body movement produced by skeletal muscle contractions
resulting in an increase in energy expenditure. In
contrast, exercise represents a planned, structured, and
repetitive movement designed to improve or maintain
one or more components of fitness [17]. Importantly, it
is the muscle forces resulting from physical activity and
exercise which place the greatest loads on the skeleton
[18]. Numerous reviews focusing on the prevention and
management of osteoporosis include exercise or physical
activity as a preventive and treatment strategy [19–21]. In
addition, exercise is recognized to have beneficial effects
on multiple risk factors for falls, including impaired balance
and gait, loss of muscle mass, strength, and power,
as well as cognitive function. However, many questions
still remain as to what type, intensity, frequency, and
duration of physical activity or exercise is optimal to benefit
the aging skeleton and prevent osteoporotic-related fractures.