Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Canada.
Exercise Research Laboratory, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Exp Gerontol. 2020 May;133:110877. doi: 10.1016/j.exger.2020.110877. Epub 2020 Feb 14.
Studies have suggested that older individuals are more fatigable than young adults when power loss, measured during single-joint contractions, is considered the fatigue index; however, age-related differences in fatigue considering power measurements during multi-joint movements (e.g., cycling) have not been fully elucidated yet. This study examined age-related differences in dynamic and isometric measures of fatigue in response to three cycling exercises. Ten young (27 ± 4 years) and ten old (74 ± 4 years) men performed exercises on different days, 30-s Wingate, 10-min at severe-intensity, and 90-min at moderate-intensity. Dynamic measures-maximal power, torque, and velocity-were assessed after cycling and during recovery (1-8 min post-exercise) through 7-s cycling sprints and isometric force and fatigue etiology (central and peripheral components) through isometric contractions. There were no age-related differences in the relative reduction of dynamic and isometric measures following the Wingate and moderate-intensity tasks. Maximal power, isometric force, and indices of peripheral function (e.g., high-frequency doublet) decreased more in young compared with older individuals after the severe-intensity exercise (all p < .05). The only observed age-related difference in the recovery of NM fatigue was a slower recovery of power and torque from 1 to 8 min (p < .05) and at 4 min (p = .015), respectively, in younger males after the Wingate. Age-related fatigue and recovery depend on the fatiguing exercise intensity and duration and on the fatigue assessment mode. This study provides novel information on age-related neuromuscular fatigue responses to multi-joint dynamic exercises performed at different intensities and durations.
研究表明，当以单一关节收缩时的能量损失来衡量疲劳指数时，老年人比年轻人更容易疲劳；然而，对于多关节运动（例如，骑自行车）时的与年龄相关的疲劳差异尚未完全阐明。本研究检查了与年龄相关的动态和等长疲劳测量差异，以响应三种骑自行车运动。十名年轻男性（27 ± 4 岁）和十名老年男性（74 ± 4 岁）在不同的日子里进行了锻炼，分别是 30 秒的瓦格宁根测试、10 分钟的高强度和 90 分钟的中等强度。通过 7 秒的自行车冲刺和等长收缩评估了骑自行车后的动态测量-最大功率、扭矩和速度-以及在恢复期间（运动后 1-8 分钟）的疲劳病因（中枢和外周成分）。在瓦格宁根和中等强度任务之后，动态和等长测量的相对减少没有年龄相关性差异。与老年人相比，在剧烈运动后，年轻人的最大功率、等长力和外周功能指数（例如高频双重）下降更多（所有 p < 0.05）。在 NM 疲劳恢复中唯一观察到的与年龄相关的差异是在瓦格宁根之后，年轻人从 1 到 8 分钟（p < 0.05）和 4 分钟（p = 0.015）的功率和扭矩恢复较慢。与年龄相关的疲劳和恢复取决于疲劳运动的强度和持续时间以及疲劳评估模式。本研究提供了关于多关节动态运动在不同强度和持续时间下的与年龄相关的神经肌肉疲劳反应的新信息。
