Proehl Exercise Physiology Laboratory, Kinesiology Department, State University of New York at Cortland, Cortland, NY,USA.
Digital Aurora Inc., Manchester Center, VT,USA.
J Sport Rehabil. 2022 Apr 21;31(6):803-808. doi: 10.1123/jsr.2021-0379. Print 2022 Aug 1.
Previous work has demonstrated an improvement in running economy during sustained running on a lower body positive pressure treadmill, but neuromuscular and spatiotemporal measures have only been investigated during short-duration running bouts on these devices. The current study sought to replicate the noted metabolic response and investigate whether neuromuscular and/or spatiotemporal adaptations underlie the noted improvements in running economy.
Cross-sectional.
Fifteen trained runners (11 males and 4 females) ran three 15-minute trials with 30% bodyweight support at 70% of the speed that elicited their peak oxygen consumption while running on a standard treadmill. A series of 1-way analyses of variance with repeated measures were used to explore differences in dependent variables over the 45 minutes of running. Dependent variables included oxygen consumption, root-mean-square electromyography of the vastus medialis and medial gastrocnemius during stance, and spatiotemporal parameters.
Oxygen consumption decreased after the initial exposure, with no further reductions after 20 minutes. Root-mean-square electromyography of the vastus medialis and medial gastrocnemius also decreased over time, with no further reductions after 20 and 10 minutes, respectively. No differences in spatiotemporal parameters were found.
Future research should provide sufficient time for runners to develop a more economical gait pattern prior to collecting dependent variables, and previous findings using lower body positive pressure treadmills may need to be reconsidered. Athletes using these devices for training or rehabilitation should note that increased economy will lower the intensity of a given treadmill setting over time.
之前的研究已经证明，在使用下肢正压跑步机进行持续跑步时，跑步经济性会有所提高，但这些设备上的短时间跑步只调查了神经肌肉和时空测量。本研究旨在复制观察到的代谢反应，并研究神经肌肉和/或时空适应是否是跑步经济性提高的基础。
横断面研究。
15 名训练有素的跑步者（11 名男性和 4 名女性）在标准跑步机上以 70%的速度跑 3 个 15 分钟的试验，其中 30%的体重由跑步机支撑。使用重复测量的单向方差分析来探索 45 分钟跑步过程中依赖变量的差异。依赖变量包括氧耗量、在支撑阶段的股直肌和内侧腓肠肌的均方根肌电图以及时空参数。
氧耗量在最初暴露后下降，20 分钟后没有进一步下降。股直肌和内侧腓肠肌的均方根肌电图也随时间减少，分别在 20 分钟和 10 分钟后没有进一步减少。时空参数没有差异。
未来的研究应该在收集依赖变量之前，为跑步者提供足够的时间来发展更经济的步态模式，并且之前使用下肢正压跑步机的发现可能需要重新考虑。使用这些设备进行训练或康复的运动员应该注意，随着时间的推移，经济性的提高会降低给定跑步机设置的强度。
