Differential effects of strength versus power training on bone mineral density in postmenopausal women: a 2-year longitudinal study. Issue 10 (5th June 2007)

• Record Type: Journal Article
• Authors: von Stengel, Simon; Kemmler, Wolfgang; Kalender, Willi A; Engelke, Klaus; Lauber, Dirk
• Is Part Of: British journal of sports medicine. Volume 41:Issue 10(2007)
• Page Start: 649
• Page End: 655
• Publication Date: 2007-06-05
• Subjects: postmenopausal women -- exercise -- strength training -- power training -- bone mineral density; Sports medicine -- Periodicals; 617.1027
• DOI: 10.1136/bjsm.2006.033480
• Languages: English
• ISSNs: 0306-3674

Abstract

Abstract : Objectives: To investigate the effect of two different schemes of loading in resistance training on bone mineral density (BMD) and pain in pretrained postmenopausal women. Methods: 53 pretrained women (mean (SD) age 58.2 (3.7) years) who carried out a mixed resistance and gymnastics programme were randomly assigned to a strength training (ST) or power training (PT) group. The difference between the two groups was the movement velocity during the resistance training (ST, 4 s (concentric)/4 s (eccentric); PT, explosive/4 s). Otherwise both groups carried out periodised progressive resistance training (10–12 exercises, 2–4 sets, 4–12 repetitions at 70–92.5% of the one-repetition maximum (2/week) for 2 years. Mechanical loading was determined with a force measuring plate during the leg press exercise. At baseline and after 2 years, BMD was measured at different sites with dual x -ray absorptiometry. Pain was assessed by questionnaire. Results: Loading magnitude, loading/unloading rate, loading amplitude and loading frequency differed significantly (p<0.001) between the two groups. After 2 years, significant between-group differences were detected for BMD (PT, −0.3%; ST, −2.4%; p<0.05) and bone area (PT, 0.4%; ST, −0.9%; p<0.05) at the lumbar spine. At the hip, there was a non-significant trend in favour of the PT group. Also the incidence of pain indicators at the lumbar spine was more favourable in the PT group. Conclusion: The results show that PT may be superior for maintaining BMD in postmenopausal women. Furthermore, PT was safe as it did not lead to increased injury or pain.