Effects of Exercise and Physical Interventions on Bone: Clinical Studies - Skeletal Aging and Osteoporosis: Biomechanics and Mechanobiology - page 232

Effects of Exercise and Physical
Interventions on Bone: Clinical Studies

Wendy M. Kohrt, Karen L. Villalon and Daniel W. Barry

Abstract Perhaps the best evidence that physical activity is essential for the
maintenance of bone mass and strength is the rapid and profound loss of bone
mineral that occurs during conditions of disuse, such as immobilization, bed rest,
and spaceflight. Physical activity throughout the lifespan has the potential to
reduce the risk for osteoporotic fracture by augmenting the development of peak
bone mass during childhood, maintaining bone mass during early adulthood, and
slowing the inevitable loss of bone mass in old age. However, the types and
amounts of physical activity needed to optimize skeletal integrity across the
lifespan and reduce osteoporotic fracture risk have not been precisely defined. This
chapter reviews the clinical evidence that physical activity is associated with
reduced fracture risk and that exercise training can increase or slow the decline in
bone mineral density (BMD) in adults. The clinical relevance of the key deter-
minants of the response of bone to mechanical loading that have evolved from
preclinical studies of animals (e.g., high strain magnitude, high strain rate, few
repetitions, unique strain distribution) is discussed. Novel factors that may influ-
ence the skeletal adaptation to exercise in humans are also discussed.

W. M. Kohrt ( ) K. L. Villalon D. W. Barry

Department of Medicine, University of Colorado Denver,
Aurora, CO, USA
e-mail: [e-mail]

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