SKELETAL-MUSCLE ADAPTATIONS TO ENDURANCE TRAINING IN 60-YR-OLD TO 70-YR-OLD MEN AND WOMEN
SKELETAL-MUSCLE ADAPTATIONS TO ENDURANCE TRAINING IN 60-YR-OLD TO 70-YR-OLD MEN AND WOMEN
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DOI：
10.1152/jappl.1992.72.5.1780
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发表时间：
1992-05-01
影响因子：
3.3
通讯作者：
HOLLOSZY, JO
中科院分区：
文献类型：
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作者：
COGGAN, AR;SPINA, RJ;HOLLOSZY, JO
以前对老年男性和女性进行耐力运动训练的研究通常发现，骨骼肌对训练的适应程度很低。为了评估这可能是由于训练刺激不足的可能性，我们研究了23名健康的老年男性和女性(+/-3岁)，他们在训练前后以最大心率的80%步行/慢跑，每天45分钟，每天4天，每周9-12个月。这项训练计划导致最大耗氧量增加了23%。训练前后取腓肠肌外侧肌针刺活检标本，进行组织化学和酶学特性分析。I型肌纤维的百分比不随训练而改变。然而，IIb型纤维的百分比从19.1+/-9.1下降到15.1+/-8.1%(P<；0.001)，而IIa型纤维的百分比从22.1+/-7.7增加到29.6+/-9.1%(P<；0.05)。训练还导致I型纤维(12%；P<；0.001)和IIa型纤维(10%；P<；0.05)的横截面积增加。由于毛细血管与纤维的比率和与每根纤维接触的毛细血管数量增加，毛细血管密度从培训前的257+/-43根/mm~2增加到训练后的310+/-48根/mm~2(P<；0.001)。乳酸脱氢酶活性下降21%(P<；0.001)，而线粒体琥珀酸脱氢酶、柠檬酸合成酶和β-羟基酰辅酶A脱氢酶活性增加24-55%(P<；0.001-0.001)。我们的结论是，在适当的训练刺激下，老年男性和女性的骨骼肌经历了类似于年轻人观察到的耐力运动训练的适应。
Previous studies of endurance exercise training in older men and women generally have found only minimal skeletal muscle adaptations to training. To evaluate the possibility that this may have been due to an inadequate training stimulus, we studied 23 healthy older (64 +/- 3 yr) men and women before and after they had trained by walking/jogging at 80% of maximal heart rate for 45 min/day 4 days/wk for 9-12 mo. This training program resulted in a 23% increase in maximal O2 consumption. Needle biopsy samples of the lateral gastrocnemius muscle were obtained before and after training and analyzed for selected histochemical and enzymatic characteristics. The percentage of type I muscle fibers did not change with training. The percentage of type IIb fibers, however, decreased from 19.1 +/- 9.1 to 15.1 +/- 8.1% (P < 0.001), whereas the percentage of type IIa fibers increased from 22.1 +/- 7.7 to 29.6 +/- 9.1% (P < 0.05). Training also induced increases in the cross-sectional area of both type I (12%; P < 0.001) and type IIa fibers (10%; P < 0.05). Capillary density increased from 257 +/- 43 capillaries/mm2 before training to 310 +/- 48 capillaries/mm2 after training (P < 0.001) because of increases in the capillary-to-fiber ratio and in the number of capillaries in contact with each fiber. Lactate dehydrogenase activity decreased by 21% (P < 0.001), whereas the activities of the mitochondrial enzymes succinate dehydrogenase, citrate synthase, and beta-hydroxyacyl-CoA dehydrogenase increased by 24-55% in response to training (P < 0.001-0.05). We conclude that, given an adequate training stimulus, the skeletal muscles of older men and women undergo adaptations to endurance exercise training similar to those observed in young people.