Solianik Rima, Kreivėnaitė Lina, Streckis Vytautas, Mickevičienė Dalia, Skurvydas Albertas
Institute of Sports Science and Innovations, Lithuanian Sports University, Sporto str. 6, Kaunas, Lithuania.
Institute of Sports Science and Innovations, Lithuanian Sports University, Sporto str. 6, Kaunas, Lithuania.
J Electromyogr Kinesiol. 2017 Feb;32:61-69. doi: 10.1016/j.jelekin.2016.12.001. Epub 2016 Dec 20.
The aim was to assess the effects of sex and age on fatigability and recovery from sustained maximal voluntary contraction (MVC) of the knee extensor muscles. The central (central activation ratio (CAR) and electrical activity amplitude) and peripheral (electrically evoked torque and muscle contractile properties) factors contributing to fatigue and recovery of 24 young adults (12 males) aged 23.2±3.6years and 20 older adults (12 males) aged 70.6±4.4years were compared. The increase in central and peripheral fatigue was greater (p⩽0.01) in the young adults vs the older adults. Sex differences (p=0.002) regarding MVC were attributed to the greater (p<0.01) peripheral fatigue of males vs females. The recovery rate of MVC was greater (p<0.001) in the young adults vs the older adults, with no sex effect. The recovery of MVC was correlated with the CAR in older adults (p=0.001). Thus, the greater endurance observed with age is caused by differences in central and peripheral mechanisms, whereas the greater endurance in females is caused by a difference in a mechanism located within the muscle. The impaired recovery from fatigue in older adults relied more on the recovery of central factors.
目的是评估性别和年龄对膝关节伸肌持续最大自主收缩（MVC）的疲劳性及恢复情况的影响。比较了24名23.2±3.6岁的年轻成年人（12名男性）和20名70.6±4.4岁的老年人（12名男性）在疲劳和恢复过程中涉及的中枢因素（中枢激活率（CAR）和电活动幅度）及外周因素（电诱发扭矩和肌肉收缩特性）。与老年人相比，年轻人中枢和外周疲劳的增加更为明显（p⩽0.01）。MVC方面的性别差异（p = 0.002）归因于男性比女性外周疲劳更严重（p<0.01）。年轻人MVC的恢复率比老年人更高（p<0.001），且不存在性别效应。在老年人中，MVC的恢复与CAR相关（p = 0.001）。因此，随着年龄增长观察到的更强耐力是由中枢和外周机制的差异导致的，而女性更强的耐力是由肌肉内一种机制的差异引起的。老年人疲劳恢复受损更多依赖于中枢因素的恢复。
