Barry Benjamin K, Warman Geoffrey E, Carson Richard G
Perception and Motor Systems Laboratory, School of Human Movement Studies, The University of Queensland, 4072 St Lucia, Queensland, Australia.
Exp Brain Res. 2005 Mar;162(1):122-32. doi: 10.1007/s00221-004-2127-3. Epub 2004 Dec 15.
In young adults, improvements in the rate of force development as a result of resistance training are accompanied by increases in neural drive in the very initial phase of muscle activation. The purpose of this experiment was to determine if older adults also exhibit similar adaptations in response to rate of force development (RFD) training. Eight young (21-35 years) and eight older (60-79 years) adults were assessed during the production of maximum rapid contractions, before and after four weeks of progressive resistance training for the elbow flexors. Young and older adults exhibited significant increases (P<0.01) in peak RFD, of 25.6% and 28.6% respectively. For both groups the increase in RFD was accompanied by an increase in the root mean square (RMS) amplitude and in the rate of rise (RER) in the electromyogram (EMG) throughout the initial 100 ms of activation. For older adults, however, this training response was only apparent in the brachialis and brachioradialis muscles. This response was not observed in surface EMG recorded from the biceps brachii muscle during either RFD testing or throughout training, nor was it observed in the pronator teres muscle. The minimal adaptations observed for older adults in the bifunctional muscles biceps brachii and pronator teres are considered to indicate a compromise of the neural adaptations older adults might experience in response to resistance training.
在年轻人中，抗阻训练导致的力量发展速率的提高，在肌肉激活的最初阶段伴随着神经驱动的增加。本实验的目的是确定老年人在接受力量发展速率（RFD）训练时是否也表现出类似的适应性变化。在对肘屈肌进行四周渐进性抗阻训练之前和之后，对8名年轻人（21 - 35岁）和8名老年人（60 - 79岁）在进行最大快速收缩时进行了评估。年轻人和老年人的峰值RFD均显著增加（P<0.01），分别增加了25.6%和28.6%。对于两组而言，RFD的增加伴随着肌电图（EMG）在激活最初100毫秒内均方根（RMS）振幅和上升速率（RER）的增加。然而，对于老年人来说，这种训练反应仅在肱肌和肱桡肌中明显。在RFD测试期间或整个训练过程中，从肱二头肌记录的表面肌电图中未观察到这种反应，在旋前圆肌中也未观察到。在肱二头肌和旋前圆肌这两块双功能肌肉中观察到的老年人的最小适应性变化，被认为表明了老年人在抗阻训练中可能经历的神经适应性的受损。
