Chen Trevor Chung-Ching, Tseng Wei-Chin, Huang Guan-Ling, Chen Hsin-Lian, Tseng Kuo-Wei, Nosaka Kazunori
Department of Physical Education, National Taiwan Normal UniversityTaipei, Taiwan.
Department of Physical Education, Health and Recreation, National Chiayi UniversityChiayi, Taiwan.
Front Physiol. 2017 Apr 10;8:209. doi: 10.3389/fphys.2017.00209. eCollection 2017.
It has been reported that eccentric training of knee extensors is effective for improving blood insulin sensitivity and lipid profiles to a greater extent than concentric training in young women. However, it is not known whether this is also the case for elderly individuals. Thus, the present study tested the hypothesis that eccentric training of the knee extensors would improve physical function and health parameters (e.g., blood lipid profiles) of older adults better than concentric training. Healthy elderly men (60-76 years) were assigned to either eccentric training or concentric training group ( = 13/group), and performed 30-60 eccentric or concentric contractions of knee extensors once a week. The intensity was progressively increased over 12 weeks from 10 to 100% of maximal concentric strength for eccentric training and from 50 to 100% for concentric training. Outcome measures were taken before and 4 days after the training period. The results showed that no sings of muscle damage were observed after any sessions. Functional physical fitness (e.g., 30-s chair stand) and maximal concentric contraction strength of the knee extensors increased greater ( ≤ 0.05) after eccentric training than concentric training. Homeostasis model assessment, oral glucose tolerance test and whole blood glycosylated hemoglobin showed improvement of insulin sensitivity only after eccentric training ( ≤ 0.05). Greater ( ≤ 0.05) decreases in fasting triacylglycerols, total, and low-density lipoprotein cholesterols were evident after eccentric training than concentric training, and high-density lipoprotein cholesterols increased only after eccentric training. These results support the hypothesis and suggest that it is better to focus on eccentric contractions in exercise medicine.
据报道，在年轻女性中，膝伸肌的离心训练比向心训练在更大程度上能有效改善血液胰岛素敏感性和血脂水平。然而，老年个体是否也是如此尚不清楚。因此，本研究检验了这样一个假设：膝伸肌的离心训练比向心训练能更好地改善老年人的身体功能和健康参数（如血脂水平）。健康老年男性（60 - 76岁）被分为离心训练组或向心训练组（每组n = 13），每周进行一次30 - 60次膝伸肌的离心或向心收缩。在12周内，离心训练的强度从最大向心力量的10%逐渐增加到100%，向心训练的强度从50%增加到100%。在训练期开始前和结束后4天进行结果测量。结果显示，在任何训练后均未观察到肌肉损伤的迹象。与向心训练相比，离心训练后功能性体能（如30秒坐立试验）和膝伸肌的最大向心收缩力量增加得更多（P≤0.05）。稳态模型评估、口服葡萄糖耐量试验和全血糖化血红蛋白仅在离心训练后显示胰岛素敏感性有所改善（P≤0.05）。与向心训练相比，离心训练后空腹三酰甘油、总胆固醇和低密度脂蛋白胆固醇的降低更显著（P≤0.05），高密度脂蛋白胆固醇仅在离心训练后增加。这些结果支持了该假设，并表明在运动医学中关注离心收缩更好。
