School of Health Studies, University of Memphis, Memphis, TN.
Med Sci Sports Exerc. 2018 Mar;50(3):510-515. doi: 10.1249/MSS.0000000000001452.
Running speed is slower in middle-age compared with younger runners due to reduced ankle but not hip and knee kinetic output. Running-specific training helps attenuate age-related declines in measures of endurance, muscle strength, and gait speed. Considering the adaptability of the human body in response to imposed stresses, maintaining training volume and intensity may play a role in modifying running biomechanics in middle-age runners.
To compare running biomechanics between young and middle-age runners when controlling for the confounding effects of training volume and intensity.
Fifteen middle-age runners, 15 young runners with similar training volume as the middle-age group and, 15 young runners with similar preferred training paces (i.e., intensity) as the middle-age runners participated in the study. Lower-limb joint kinetics were calculated from kinematic and ground reaction force data during overground running at a submaximal speed and compared among groups.
Middle-age runners ran with similar peak ankle power compared with volume-matched younger runners although peak plantarflexor moment was 10.5% lower in the middle age group (P = 0.046; Cohen d = 0.78). Middle-age runners ran with similar ankle plantarflexor moment and joint power compared with training pace-matched young runners. As expected, no age-related differences were observed in hip and knee kinetics when training volume or pace were matched between age groups. These results suggest that training pace may be more effective in attenuating age-related declines in plantarflexor kinetics in middle-age runners.
From these findings, we propose the hypothesis that both training volume and training pace may play a role in maintaining plantarflexor kinetics but that training pace may have a greater impact on ankle plantarflexor kinetics in middle-age runners.
与年轻跑者相比，中年跑者的跑步速度较慢，这是由于脚踝的动力学输出减少，而髋部和膝部的动力学输出没有减少。专门针对跑步的训练有助于减缓与年龄相关的耐力、肌肉力量和步速下降。考虑到人体对施加的压力的适应性，保持训练量和强度可能在改变中年跑者的跑步生物力学方面发挥作用。
在控制训练量和强度的混杂效应的情况下，比较年轻和中年跑者的跑步生物力学。
15 名中年跑者、15 名具有与中年组相似训练量的年轻跑者和 15 名具有与中年组相似首选训练速度（即强度）的年轻跑者参加了这项研究。在次最大速度下进行地面跑步时，从运动学和地面反力数据中计算出下肢关节动力学，并在组间进行比较。
尽管中年组的峰值跖屈肌力矩低 10.5%（P=0.046；Cohen d=0.78），但中年跑者的峰值踝关节功率与具有相似训练量的年轻跑者相似。中年跑者的踝关节跖屈肌力矩和关节功率与具有相似训练速度的年轻跑者相似。当在年龄组之间匹配训练量或速度时，与年龄相关的髋部和膝部动力学差异没有观察到。这些结果表明，训练速度可能更有效地减轻中年跑者中与年龄相关的跖屈肌动力学下降。
从这些发现中，我们提出了一个假设，即训练量和训练速度都可能在维持跖屈肌动力学方面发挥作用，但训练速度可能对中年跑者的踝关节跖屈肌动力学有更大的影响。
