Centre for Physical Activity and Life Sciences, Faculty of Art, Science and Technology, University of Northampton, Northampton, NN1 5PH, UK.
Eur J Appl Physiol. 2023 Oct;123(10):2131-2143. doi: 10.1007/s00421-023-05226-z. Epub 2023 May 22.
Eccentric muscle actions generate high levels of force at a low metabolic cost, making them a suitable training modality to combat age-related neuromuscular decline. The temporary muscle soreness associated with high intensity eccentric contractions may explain their limited use in clinical exercise prescription, however any discomfort is often alleviated after the initial bout (repeated bout effect). Therefore, the aims of the present study were to examine the acute and repeated bout effects of eccentric contractions on neuromuscular factors associated with the risk of falling in older adults.
Balance, functional ability [timed up-and-go and sit-to-stand], and lower-limb maximal and explosive strength were measured in 13 participants (67.6 ± 4.9 year) pre- and post-eccentric exercise (0, 24, 48, and 72 hr) in Bout 1 and 14 days later in Bout 2. The eccentric exercise intervention was performed on an isokinetic unilateral stepper ergometer at 50% of maximal eccentric strength at 18 step‧min per limb for 7 min (126 steps per limb). Two-way repeated measures ANOVAs were conducted to identify any significant effects (P ≤ 0.05).
Eccentric strength significantly decreased (- 13%) in Bout 1 at 24 hr post-exercise; no significant reduction was observed at any other time-point after Bout 1. No significant reductions occurred in static balance or functional ability at any time-point in either bout.
Submaximal multi-joint eccentric exercise results in minimal disruption to neuromuscular function associated with falls in older adults after the initial bout.
离心肌肉运动以较低的代谢成本产生高强度的力量，因此是对抗与年龄相关的神经肌肉衰退的合适训练方式。高强度离心收缩引起的暂时性肌肉酸痛可能解释了它们在临床运动处方中的有限应用，但是任何不适通常在最初的回合后（重复回合效应）得到缓解。因此，本研究的目的是检查离心收缩对与老年人跌倒风险相关的神经肌肉因素的急性和重复回合效应。
在回合 1 中，13 名参与者（67.6±4.9 岁）在离心运动前（0、24、48 和 72 小时）和 14 天后的回合 2 中（13 天）测量平衡、功能能力[起立行走和坐立站起]和下肢最大和爆发力。在每个肢体的 50%最大离心强度下，在等速单侧踏步式测力计上以 18 步·分钟-1 的速度进行 7 分钟（每个肢体 126 步）的离心运动。进行了双向重复测量方差分析，以确定任何显著影响（P≤0.05）。
在回合 1 中，离心力量在运动后 24 小时明显下降（-13%）；在回合 1 后的任何其他时间点都没有观察到显著减少。在两个回合的任何时间点，静态平衡或功能能力都没有明显下降。
亚最大多关节离心运动在初始回合后对与老年人跌倒相关的神经肌肉功能几乎没有干扰。
