Suter E, Hoppeler H, Claassen H, Billeter R, Aebi U, Horber F, Jaeger P, Marti B
Institute of Social and Preventive Medicine, University of Zurich, Bern.
Int J Sports Med. 1995 Apr;16(3):160-6. doi: 10.1055/s-2007-972985.
The study was aimed at investigating if endurance training of moderate intensity and longer duration, intended to promote health rather than performance, evokes ultrastructural changes in skeletal muscle tissue comparable to those observed after high-intensity protocols. Twenty healthy, middle-aged men enrolled in a 6-month, home-based jogging program of 120 min/wk at 75% VO2max. Only 12 men showed a sufficient exercise adherence over the 6 months (> or = 60 min/wk on average) and were included into statistical analysis. Their average training activity was 105 +/- 31 min/wk. The results revealed significant increases in VO2max (+8.4%, p < 0.01) and submaximal power output (+18.1%, p < 0.01). Total mitochondrial volume density in M. vastus lateralis increased by 20% (p < 0.05) with a larger increase in subsarcolemmal volume compared to central volume (50% vs 15%). No changes in volume of intracellular lipid droplets, capillary density, capillary per fiber ratio, fiber mean cross-sectional area and muscle fiber type could be observed. Body composition analysis showed a decrease in trunk fat mass (-7.3%, p < 0.05) and an increase in trunk lean mass (+1.7%, p < 0.05), while changes in the legs were not significant. It can be concluded that a moderate-intensity, health oriented endurance training beneficially affected cardiovascular and muscle oxidation capacity as well as body composition in the trunk area. No adaptations in capillaries or lipid metabolism could be demonstrated. The results support the hypothesis of thresholds for induction of adaptation processes in muscle skeletal tissue depending on the intensity of the exercise stimulus.
该研究旨在调查中等强度、较长持续时间的耐力训练（旨在促进健康而非提高运动表现）是否会引起骨骼肌组织的超微结构变化，这些变化与高强度训练方案后观察到的变化相当。20名健康的中年男性参加了一项为期6个月、每周在家慢跑120分钟、强度为最大摄氧量75%的项目。只有12名男性在6个月内表现出足够的运动依从性（平均每周≥60分钟），并被纳入统计分析。他们的平均训练时长为每周105±31分钟。结果显示，最大摄氧量显著增加（+8.4%，p<0.01），次最大输出功率增加（+18.1%，p<0.01）。股外侧肌的线粒体总体积密度增加了20%（p<0.05），肌膜下体积的增加幅度大于中央体积（50%对15%）。未观察到细胞内脂滴体积、毛细血管密度、每根纤维的毛细血管比例、纤维平均横截面积和肌纤维类型的变化。身体成分分析显示，躯干脂肪量减少（-7.3%，p<0.05），躯干瘦体重增加（+1.7%，p<0.05），而腿部的变化不显著。可以得出结论，以健康为导向的中等强度耐力训练对心血管和肌肉氧化能力以及躯干区域的身体成分有有益影响。未发现毛细血管或脂质代谢有适应性变化。结果支持了这样一种假设，即根据运动刺激的强度，肌肉骨骼组织中适应过程的诱导存在阈值。
