Effects of a one-year high-intensity versus low-intensity resistance training program on bone mineral density in older women
| Autor: | Robert Marcus, Leslie A. Pruitt, Dennis R. Taaffe |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
musculoskeletal diseases
medicine.medical_specialty Endocrinology Diabetes and Metabolism Physical fitness Physical exercise Physical strength Absorptiometry Photon Bone Density Humans Medicine Orthopedics and Sports Medicine Life Style Rachis Aged Aged 80 and over Bone mineral Analysis of Variance Hip Lumbar Vertebrae Physical Education and Training business.industry Estrogen Replacement Therapy Middle Aged Intensity (physics) medicine.anatomical_structure Physical Fitness Hip bone Exercise intensity Physical therapy Calcium Female business Biomarkers |
| Zdroj: | Journal of Bone and Mineral Research. 10:1788-1795 |
| ISSN: | 0884-0431 |
| DOI: | 10.1002/jbmr.5650101123 |
| Popis: | The purpose of this study was to determine the effects of a 12-month resistance training program, of two different intensities, on bone mineral density (BMD) in healthy, older women. Twenty-six Caucasian women (aged 65-79 years) completed the study. Subjects were randomly assigned to one of three groups: high-intensity (HI; n = 8), low-intensity (LI; n = 7), and control (CON; n = 11). The active groups performed 10 exercises, 3 days/week under supervision. Exercise intensity was maintained at 80% of one-repetition maximum (1-RM) for the HI groups, and at 40% 1-RM for the LI group. The volume of work was maintained constant between the two groups by assigning the LI group twice as many repetitions for each exercise. Maximal muscular strength and BMD of the lumbar spine and total hip were measured at baseline and at 12 months. Strength was evaluated using the 1-RM method, and BMD was determined by dual-energy X-ray absorptiometry. Exercise session attendance was similar for the two groups (81.0% HI; 76.8% LI). Muscular strength improved in the exercisers compared with the CON group (por = 0.05). Percentage change in lumbar spine BMD was 0.7 +/- 1.9%, 0.5 +/- 2.4%, and -0.1 +/- 2.3% for the HI, LI, and CON groups, respectively. Percentage change in total hip BMD was 0.8 +/- 2.3% (HI), 1.0 +/- 1.7% (LI), and 0.9 +/- 1.3% (CON). Group differences in BMD change were not significant (p0.05). These findings suggest that high-intensity and low-intensity resistance training regimens effectively increase muscular strength, but not lumbar spine or total hip BMD, in healthy, older women. |
| Databáze: | OpenAIRE |
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