von Stengel Simon, Kemmler Wolfgang, Kalender Willi A, Engelke Klaus, Lauber Dirk
Institute of Medical Physics, University of Erlangen, Henkestr 91, 91052 Erlangen, Germany.
Br J Sports Med. 2007 Oct;41(10):649-55; discussion 655. doi: 10.1136/bjsm.2006.033480. Epub 2007 Jun 5.
To investigate the effect of two different schemes of loading in resistance training on bone mineral density (BMD) and pain in pretrained postmenopausal women.
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.
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.
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.
研究两种不同负荷方案的抗阻训练对已接受过训练的绝经后女性骨密度（BMD）及疼痛的影响。
53名已接受过训练的女性（平均（标准差）年龄58.2（3.7）岁），她们进行了抗阻与体操混合训练项目，被随机分为力量训练（ST）组或功率训练（PT）组。两组之间的差异在于抗阻训练期间的运动速度（ST组，4秒（向心）/4秒（离心）；PT组，爆发性/4秒）。除此之外，两组均进行了周期性渐进抗阻训练（10 - 12项练习，2 - 4组，每组重复4 - 12次，负荷为一次重复最大值的70 - 92.5%（每周2次），持续2年。在腿举练习期间，使用测力板测定机械负荷。在基线期和2年后，使用双能X线吸收法在不同部位测量骨密度。通过问卷调查评估疼痛情况。
两组之间的负荷量、加载/卸载速率、加载幅度和加载频率存在显著差异（p<0.001）。2年后，在腰椎部位，两组之间的骨密度（PT组，-0.3%；ST组，-2.4%；p<0.05）和骨面积（PT组，0.4%；ST组，-0.9%；p<0.05）存在显著组间差异。在髋部，有倾向于PT组的非显著趋势。此外，PT组腰椎疼痛指标的发生率也更有利。
结果表明，在维持绝经后女性骨密度方面，功率训练可能更具优势。此外，功率训练是安全的，因为它不会导致损伤或疼痛增加。
