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JOURNAL
OF
SPORTS SCIENCE &
MEDICINE
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Research
article
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SWIMMING ENHANCES BONE MASS ACQUISITION IN GROWING FEMALE RATS |
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Joanne McVeigh  ,
Steven Kingsley, David Gray and Lisa Carole Loram |
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Exercise Laboratory, School of Physiology, Medical School, University of the Witwatersrand, Johannesburg, South Africa |
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© Journal of Sports Science and Medicine (2010) 9, 612 - 619 |
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| ABSTRACT | |||
| Growing bones are most responsive to mechanical loading. We investigated
bone mass acquisition patterns following a swimming or running exercise
intervention of equal duration, in growing rats. We compared changes in
bone mineral properties in female Sprague Dawley rats that were divided
into three groups: sedentary controls (n = 10), runners (n = 8) and swimmers
(n = 11). Runners and swimmers underwent a six week intervention, exercising
five days per week, 30min per day. Running rats ran on an inclined treadmill
at 0.33 m.s-1, while swimming rats swam in 25oC water. Dual energy X-ray
absorptiometry scans measuring bone mineral content (BMC), bone mineral
density (BMD) and bone area at the femur, lumbar spine and whole body were
recorded for all rats before and after the six week intervention. Bone and
serum calcium and plasma parathyroid hormone (PTH) concentrations were measured
at the end of the 6 weeks. Swimming rats had greater BMC and bone area changes
at the femur and lumbar spine (p < 0.05) than the running rats and a
greater whole body BMC and bone area to that of control rats (p < 0.05).
There were no differences in bone gain between running and sedentary control
rats. There was no significant difference in serum or bone calcium or PTH
concentrations between the groups of rats. A swimming intervention is able
to produce greater beneficial effects on the rat skeleton than no exercise
at all, suggesting that the strains associated with swimming may engender
a unique mechanical load on the bone.
Key words: Weight-bearing exercise, swimming, treadmill, DXA, bone mass, rats. |
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