Abstract
Purpose:
(a) to determine if 110 postmenopausal breast cancer survivors
(BCS) with bone loss who participated in 24 months of strength and weight
training (ST) exercises had improved muscle strength and balance and had
fewer falls compared to BCS who did not exercise; and (b) to describe type
and frequency of ST exercises; adverse effects of exercises; and participants’
adherence to exercises at home, at fitness centers, and at 36-month follow up.
Design:
Findings reported are from a federally funded multicomponent inter-
vention study of 223 postmenopausal BCS with either osteopenia or osteo-
porosis who were randomly assigned to an exercise (
n
=
110) or comparison
(
n
=
113) group.
Methods:
Time points for testing outcomes were baseline, 6, 12, and
24 months into intervention. Muscle strength was tested using Biodex Ve-
locity Spectrum Evaluation, and dynamic balance using Timed Backward Tan-
dem Walk. Adherence to exercises was measured using self-report of number
of prescribed sessions attended and participants’ reports of falls.
Findings:
Mean adherence over 24 months was 69.4%. Using generalized
estimating equation (GEE) analyses, compared to participants not exercising,
participants who exercised for 24 months had significantly improved hip flex-
ion (
p
=
0.011), hip extension (
p
=
0.0006), knee flexion (
p
<
0.0001, knee ex-
tension (
p
=
0.0018), wrist flexion (
p
=
0.031), and balance (
p
=
0.010). Gains in
muscle strength were 9.5% and 28.5% for hip flexion and extension, 50.0%
and 19.4% for wrist flexion and extension, and 21.1% and 11.6% for knee
flexion and extension. Balance improved by 39.4%. Women who exercised
had fewer falls, but difference in number of falls between the two groups was
not significant.
Conclusions:
Many postmenopausal BCS with bone loss can adhere to a
24 month ST exercise intervention, and exercises can result in meaningful
gains in muscle strength and balance.
Clinical Relevance:
More studies are needed for examining relationships be-
tween muscle strength and balance in postmenopausal BCS with bone loss and
their incidence of falls and fractures