title: Effects of resistance and endurance exercise on bone mineral status of young women: a randomized exercise intervention trial.
abstract: A substantial body of cross-sectional data and a smaller number of intervention trials generally justify optimism that regular physical activity benefits the skeleton. We conducted an 8 month controlled exercise trial in a group of healthy college women (mean age = 19.9 years) who were randomly assigned to a control group or to progressive training in jogging or weight lifting. We measured the following variables: bone mineral density (BMD) of the spine (L2-4) and right proximal femur using dual-energy x-ray absorptiometry, dynamic muscle strength using the 1-RM method, and endurance performance using the 1.5 mile walk/run field test. A total of 31 women completed the 8 month study. For women completing the study, compliance, defined as the percentage of workout sessions attended, was 97% for the runners (range 90-100%) and 92% (range 88-100%) for the weight trainers. Body weight increased by approximately 2 kg in all groups (p less than 0.05). Weight training was associated with significant increases (p less than 0.01) in muscle strength in all muscle groups. Improvement ranged from 10% for the deep back to 54% for the leg. No significant changes in strength scores were observed in the control or running groups. Aerobic performance improved only in the running group (16%, p less than 0.01). Lumbar BMD increased (p less than 0.05) in both runners (1.3 +/- 1.6%) and weight trainers (1.2 +/- 1.8%). These results did not differ from each other but were both significantly greater than results in control subjects, in whom bone mineral did not change.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Musculoskeletal Research Laboratory, GRECC, Department of Veterans Affairs Medical Center, Palo Alto, California.
authors.forename: C
authors.initials: C
authors.lastname: Snow-Harter
authors.forename: M L
authors.initials: ML
authors.lastname: Bouxsein
authors.forename: B T
authors.initials: BT
authors.lastname: Lewis
authors.forename: D R
authors.initials: DR
authors.lastname: Carter
authors.forename: R
authors.initials: R
authors.lastname: Marcus
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001835:Body Weight; D015519:Bone Density / Q000502:physiology*; D015444:Exercise; D005260:Female; D005269:Femur; D006801:Humans; D008159:Lumbar Vertebrae; D009132:Muscles; D010807:Physical Endurance