Effect of exercise intensity on bone density, strength, and calcium turnover in older women
Author(s)
Humphries, B
Newton, R
Bronks, R
Marshall-Gradisnik, Sonya
McBride, Jeff
Triplett-McBride, T
Hakkinen, Kejo
Kraemer, William J
Humphries, N
Griffith University Author(s)
Year published
2000
Metadata
Show full item recordAbstract
Purpose: This study examined the effects of 24 wk of high intensity strength
training or low intensity walking on lumbar bone mineral density (BMD), muscular strength, and calcium turnover in Australian women
either taking hormone replacement therapy (HRT) or not taking HRT. Methods: A subject pool of 64 women between 45–65 yr and
randomly allocated into weights (N 5 21), walking (N 5 20), weightsHRT (N 5 14), and walkingHRT (N 5 9) groups completed this
study. All subjects trained twice weekly in either a 50-min walking or weight-training program (60–90% 1RM). Measurements
included maximal isometric knee strength, 1RM bench ...
View more >Purpose: This study examined the effects of 24 wk of high intensity strength training or low intensity walking on lumbar bone mineral density (BMD), muscular strength, and calcium turnover in Australian women either taking hormone replacement therapy (HRT) or not taking HRT. Methods: A subject pool of 64 women between 45–65 yr and randomly allocated into weights (N 5 21), walking (N 5 20), weightsHRT (N 5 14), and walkingHRT (N 5 9) groups completed this study. All subjects trained twice weekly in either a 50-min walking or weight-training program (60–90% 1RM). Measurements included maximal isometric knee strength, 1RM bench press, 1RM squat, isokinetic back strength, lumbar (L2-L4) BMD, serum osteocalcin, and urinary deoxypyridinoline crosslinks (Dpd). Results: No significant group differences in BMD were evident at the completion of training. However, a significant (P , 0.05) within group change was apparent for the walking group since BMD decreased 1.3% below baseline testing. Osteocalcin levels increased significantly (P , 0.05) in the walking (22%) group. Maximal bench press and squat strength improved significantly (P , 0.05) in the weights (25.8% and 37.7%) and weightsHRT (25.4% and 35.7%) groups. The weights group also increased significantly (P , 0.05) in isokinetic back strength (22.2%). Conclusion: It was concluded that short-term high intensity resistance training provides an effective means for increasing muscular strength in women between 45 and 65 yr. The training effects on lumbar BMD were not apparent in the present study.
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View more >Purpose: This study examined the effects of 24 wk of high intensity strength training or low intensity walking on lumbar bone mineral density (BMD), muscular strength, and calcium turnover in Australian women either taking hormone replacement therapy (HRT) or not taking HRT. Methods: A subject pool of 64 women between 45–65 yr and randomly allocated into weights (N 5 21), walking (N 5 20), weightsHRT (N 5 14), and walkingHRT (N 5 9) groups completed this study. All subjects trained twice weekly in either a 50-min walking or weight-training program (60–90% 1RM). Measurements included maximal isometric knee strength, 1RM bench press, 1RM squat, isokinetic back strength, lumbar (L2-L4) BMD, serum osteocalcin, and urinary deoxypyridinoline crosslinks (Dpd). Results: No significant group differences in BMD were evident at the completion of training. However, a significant (P , 0.05) within group change was apparent for the walking group since BMD decreased 1.3% below baseline testing. Osteocalcin levels increased significantly (P , 0.05) in the walking (22%) group. Maximal bench press and squat strength improved significantly (P , 0.05) in the weights (25.8% and 37.7%) and weightsHRT (25.4% and 35.7%) groups. The weights group also increased significantly (P , 0.05) in isokinetic back strength (22.2%). Conclusion: It was concluded that short-term high intensity resistance training provides an effective means for increasing muscular strength in women between 45 and 65 yr. The training effects on lumbar BMD were not apparent in the present study.
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Journal Title
Medicine and Science in Sports and Exercise
Volume
32
Issue
6
Publisher URI
Subject
Exercise Physiology
Human Movement and Sports Sciences
Medical Physiology
Public Health and Health Services