School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia.
Faculty of Rehabilitation Sciences, Nagoya Gakuin University, Nagoya, Japan.
Eur J Appl Physiol. 2020 May;120(5):1015-1025. doi: 10.1007/s00421-020-04341-5. Epub 2020 Mar 13.
We compared high- and low-intensity eccentric cycling (ECC) with the same mechanical work for changes in muscle function and muscle soreness, and examined the changes after subsequent high-intensity ECC.
Twenty men performed either high-intensity ECC (1 min × 5 at 20% of peak power output: PPO) for two bouts separated by 2 weeks (H-H, n = 11), or low-intensity (4 min × 5 at 5% PPO) for the first and high-intensity ECC for the second bout (L-H, n = 9). Changes in indirect muscle damage markers were compared between groups and bouts.
At 24 h after the first bout, both groups showed similar decreases in maximal isometric (70° knee angle, - 10.6 ± 11.8%) and isokinetic ( - 11.0 ± 8.2%) contraction torque of the knee extensors (KE), squat ( - 7.7 ± 10.4%) and counter-movement jump ( - 5.9 ± 8.4%) heights (p < 0.05). Changes in KE torque and jump height were smaller after the second than the first bout for both the groups (p < 0.05). Increases in plasma creatine kinase activity were small, and no significant changes in vastus lateralis or intermedius thickness nor ultrasound echo-intensity were observed. KE soreness with palpation was greater (p < 0.01) in H-H (peak: 4.2 ± 1.0) than L-H (1.4 ± 0.6) after the first bout, but greater in L-H (3.6 ± 0.9) than H-H (1.5 ± 0.5) after the second bout. This was also found for muscle soreness with squat, KE stretch and gluteal palpation.
The high- and low-intensity ECC with matched mechanical work induced similar decreases in muscle function, but DOMS was greater after high-intensity ECC, which may be due to greater extracellular matrix damage and inflammation.
我们比较了高强度和低强度离心训练（ECC）在肌肉功能和肌肉酸痛方面的变化，并观察了随后高强度 ECC 后的变化。
20 名男性分为两组，每组 11 人，分别进行 2 周间隔的高强度 ECC（1 分钟×5 次，20%峰值功率输出：PPO）或低强度 ECC（4 分钟×5 次，5% PPO）。比较两组和两回合之间的间接肌肉损伤标志物的变化。
第一回合后 24 小时，两组的膝关节伸肌最大等长（70°膝关节角度，-10.6±11.8%）和等速收缩（-11.0±8.2%）扭矩、深蹲（-7.7±10.4%）和反向跳跃（-5.9±8.4%）高度均有相似的下降（p<0.05）。两组第二回合的 KE 扭矩和跳跃高度变化均小于第一回合（p<0.05）。血浆肌酸激酶活性升高较小，股外侧肌和中间肌厚度或超声回声强度无明显变化。第一回合后，H-H 组（峰值：4.2±1.0）的触诊股四头肌酸痛明显高于 L-H 组（1.4±0.6）（p<0.01），但第二回合后 L-H 组（3.6±0.9）高于 H-H 组（1.5±0.5）（p<0.01）。深蹲、KE 伸展和臀肌触诊也有类似的结果。
高、低强度 ECC 在机械工作匹配的情况下，肌肉功能下降相似，但高强度 ECC 后延迟性肌肉酸痛更明显，这可能是由于细胞外基质损伤和炎症更大。
