Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
J Exp Biol. 2020 Aug 13;223(Pt 15):jeb218776. doi: 10.1242/jeb.218776.
The increase or decrease in isometric force following active muscle lengthening or shortening, relative to a reference isometric contraction at the same muscle length and level of activation, are referred to as residual force enhancement (rFE) and residual force depression (rFD), respectively. The purpose of these experiments was to investigate the trainability of rFE and rFD on the basis of serial sarcomere number (SSN) alterations to history-dependent force properties. Maximal rFE/rFD measures from the soleus and extensor digitorum longus (EDL) of rats were compared after 4 weeks of uphill or downhill running with a no-running control. SSN adapted to the training: soleus SSN was greater with downhill compared with uphill running, while EDL demonstrated a trend towards more SSN for downhill compared with no running. In contrast, rFE and rFD did not differ across training groups for either muscle. As such, it appears that training-induced SSN adaptations do not modify rFE or rFD at the whole-muscle level.
主动拉长或缩短肌肉后，与同一肌肉长度和激活水平的等长收缩相比，等长力的增加或减少分别称为残余力增强（rFE）和残余力抑制（rFD）。这些实验的目的是基于历史相关力特性的串联肌节数（SSN）改变，研究 rFE 和 rFD 的可训练性。比较了经过 4 周上坡或下坡跑步以及无跑步对照后大鼠比目鱼肌和趾长伸肌（EDL）的最大 rFE/rFD 测量值。SSN 适应训练：与上坡跑步相比，下坡跑步时比目鱼肌的 SSN 更大，而 EDL 则表现出与下坡跑步相比，与无跑步相比，SSN 更倾向于更多。相比之下，两种肌肉的 rFE 和 rFD 在训练组之间没有差异。因此，似乎训练引起的 SSN 适应不会改变整个肌肉水平的 rFE 或 rFD。
