Gilgen-Ammann Rahel, Wyss Thomas, Troesch Severin, Heyer Louis, Taube Wolfgang
Int J Sports Physiol Perform. 2018 Jan 1;13(1):88-94. doi: 10.1123/ijspp.2016-0746. Epub 2018 Jan 4.
Successful elite sprint to long-distance runners are known to have shorter ground-contact time (GCT) than their less successful counterparts.
To investigate whether augmented feedback (aF) about GCT can reduce the time on ground (TOG) per minute in long-distance runners and, if so, whether this reduction improves running performance.
Thirty well-trained runners were allocated to 3 groups. The intervention group (IG) received visual aF about their GCT during 8 high-intensity interval sessions in the 4-wk training period and were instructed to minimize GCT. The 1st control group (CG1) trained with the IG but was not given any feedback. The 2nd control group (CG2) followed their own training routine. Data were obtained pre- and postintervention for all 3 groups. The dependent variable was TOG per minute, computed from step frequency and GCT.
The IG significantly reduced TOG (P = .043, -1.7%, 90%CL -3.1;-0.3) and improved their mean 10 × 400-m performance time (P < .001, -1.5%, 90%CL -1.9;-1.1). In contrast, the 2 control groups revealed unchanged values, indicating that normal high-intensity training and an individualized routine without aF were not able to reduce TOG. The fact that CG1 received the same instructions and participated in the same training sessions as the IG underlined that aF was crucial to reduce TOG.
The provision of aF about GCT seems to be a promising approach that should be considered during training practice of well-trained runners.
成功的精英短跑和长跑运动员的地面接触时间（GCT）比不太成功的运动员短。
研究关于GCT的增强反馈（aF）是否能减少长跑运动员每分钟的地面时间（TOG），如果可以，这种减少是否能提高跑步成绩。
30名训练有素的跑步者被分为3组。干预组（IG）在为期4周的训练期内的8次高强度间歇训练中接受关于其GCT的视觉aF，并被要求尽量缩短GCT。第一对照组（CG1）与IG一起训练，但未得到任何反馈。第二对照组（CG2）遵循自己的训练常规。在干预前后获取所有3组的数据。因变量是每分钟的TOG，由步频和GCT计算得出。
IG组显著减少了TOG（P = 0.043，-1.7%，90%置信区间-3.1；-0.3），并改善了他们10×400米的平均成绩时间（P < 0.001，-1.5%，90%置信区间-1.9；-1.1）。相比之下，2个对照组的值没有变化，表明正常的高强度训练和没有aF的个性化常规训练无法减少TOG。CG1与IG接受相同的指导并参加相同的训练课程，这一事实强调了aF对于减少TOG至关重要。
提供关于GCT的aF似乎是一种有前景的方法，在训练有素的跑步者的训练实践中应予以考虑。
