Department of Health and Exercise Science, University of Oklahoma, Norman, OK 73019, USA.
Department of Health and Human Performance, University of Texas Rio Grande Valley, Edinburg, TX 78539, USA.
Int J Environ Res Public Health. 2021 Apr 23;18(9):4477. doi: 10.3390/ijerph18094477.
The purpose of this study was to examine age-related differences in muscle performance in women divided into young (YW, 20-39 years, = 29) middle-aged (MAW, 40-59 years, = 33), and older (OW, ≥60 years, = 40) age groups.
Hand grip strength, vertical jump performance, and knee extensor (KE) strength (0 deg/s, 60 deg/s, and 240 deg/s), speed of movement (SoM; at 1 Nm, 20%, 40%, and 60% isometric strength), and endurance (30-repetition test at 60 degs/s and 240 deg/s) were assessed. Computed tomography-acquired muscle cross-sectional area (mCSA) was measured and included to determine specific strength (KE strength/mCSA).
Hand grip strength was similar across groups, while jump performance declined with age (YW and MAW > OW, < 0.001). KE strength declined significantly with age (all conditions < 0.01), while specific strength was similar across groups. SoM was significantly higher for YW and MAW compared to OW (both < 0.01). An age × velocity interaction revealed YW KE endurance was similar between conditions, whereas MAW and OW displayed significantly better endurance during the 60 deg/s condition. OW displayed impaired KE endurance at 240 deg/s (vs. YW and MAW, < 0.01) but improved at 60 deg/s (vs. YW, < 0.01). Dynamic torque decline increased with age (YW < OW, = 0.03) and was associated with intramuscular adipose tissue (r = 0.21, = 0.04).
Performance declines were most evident among OW, but few performance deficits had emerged in MAW. Interestingly, strength declines disappeared after normalizing to mCSA and endurance appears to be velocity-dependent.
本研究旨在探讨不同年龄段女性肌肉性能的差异，将其分为年轻组（YW，20-39 岁，n=29）、中年组（MAW，40-59 岁，n=33）和老年组（OW，≥60 岁，n=40）。
评估握力、垂直跳跃表现、膝关节伸肌（KE）强度（0 度/秒、60 度/秒和 240 度/秒）、运动速度（SoM；在 1 Nm、20%、40%和 60%等长强度下）和耐力（60 度/秒和 240 度/秒的 30 次重复测试）。使用计算机断层扫描（CT）获取肌肉横截面积（mCSA），以确定特定强度（KE 强度/mCSA）。
握力在各组之间相似，而跳跃表现随年龄增长而下降（YW 和 MAW>OW，<0.001）。KE 强度随年龄显著下降（所有条件下均<0.01），而特定强度在各组之间相似。YW 和 MAW 的 SoM 明显高于 OW（均<0.01）。年龄×速度的交互作用表明，YW 的 KE 耐力在不同条件下相似，而 MAW 和 OW 在 60 度/秒条件下的耐力更好。OW 在 240 度/秒时的 KE 耐力受损（与 YW 和 MAW 相比，均<0.01），但在 60 度/秒时耐力提高（与 YW 相比，均<0.01）。动态扭矩下降随年龄增长而增加（YW<OW，=0.03），并与肌内脂肪组织相关（r=0.21，=0.04）。
OW 表现下降最为明显，但 MAW 中出现的表现缺陷很少。有趣的是，强度下降在正常化到 mCSA 后消失，而耐力似乎与速度有关。
