Objectives-To examine whether there is a role for exercise in improving bon
e mineral density (BMD), particularly in postmenopausal women. The effects
of different types of exercise are examined together with their effects at
selected skeletal sites. The role of activity in reducing falls and hip fra
ctures will also be considered as well as the potentially negative effects
of excessive exercise.
Methods-A literature search over the past 20 years was conducted and landma
rk papers selected.
Results-Certain types of exercise have been found to exert moderate benefit
s on BMD of the wrist, spine, and hip. Most studies do not detect a differe
nce between the effects of endurance activities and strength training for B
MD of the spine. It has been more difficult to isolate the optimal type of
activity for effecting an osteogenic response at the hip, but recent eviden
ce suggests that high impact work such as stepping and jumping may be effec
tive at this site. The combination of hormone replacement therapy and exerc
ise would appear to be more effective than either intervention on its own.
Certain types of exercises have additional benefits, such as muscle strengt
hening, which could reduce the incidence of falls. Excessive exercise can l
ead to menstrual disturbances in female athletes and this in turn can cause
bone loss, particularly from the spine.
Conclusions-Exercise across the life span should be encouraged in order to
maximise peak bone mass, reduce age related bone loss, and maintain muscle
strength and balance. Although the effects of exercise on BMD later in life
are small, epidemiological evidence suggests that being active can nearly
halve the incidence of hip fractures in the older population. This effect i
s most probably multifactorial through the positive effects on bone, muscle
strength, balance, and joint flexibility. Younger women should be aware of
the dangers to the skeleton of menstrual disorders.