Piirainen Jarmo M, Salmi Jukka A, Avela Janne, Linnamo Vesa
Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland.
J Strength Cond Res. 2008 Nov;22(6):1916-25. doi: 10.1519/JSC.0b013e3181854dc1.
The dropout rate in the Finnish military service has increased during the past two decades. At the same time, the physical fitness level of young Finnish males has decreased, possibly leading to overtraining in new conscripts. The purpose of the present study was to examine whether body composition would influence neuromuscular function during the 8-week basic training (BT) period. Eighteen healthy male subjects (19 +/- 1 years) were divided into three different groups according to their body fat %. Group 1 (<10%), group 2 (10-13%) and group 3 (>13%). The soleus H-reflex response was measured in the standing position. In the seated position (knee 160 degrees and hip 110 degrees), the V-wave response was measured during maximal voluntary contraction, and the single twitch response was measured in passive conditions. In body composition (fat-free mass and fat mass) was observed small but not significant changes during 8-week period. H-reflex activity increased in groups 2 (10.9% not significant [ns]) and 3 (2.8% ns) but decreased in group 1 (-34.8%, p < 0.05) during the 8-week period. V-wave values decreased in all groups, and the biggest decrement was observed in group 2 (-34.7%, p < 0.05), whereas in group 1 and group 3 no significance was observed. For each group the single twitch torque (G1 ns, G2 and G3 p < 0.05) increased during the 8-week period. The major finding of the study was that the BT period did not cause overtraining in conscripts. Increased activity of the H-reflex and single twitch torque supports this finding. V-wave activity was decreased in all groups, which may also indicate that the training did not stimulate neural activity. In general, the observed changes in neuromuscular system supports the main finding.
在过去二十年中，芬兰军队的新兵流失率有所上升。与此同时，芬兰年轻男性的身体素质水平有所下降，这可能导致新兵过度训练。本研究的目的是探讨在为期8周的基础训练（BT）期间，身体成分是否会影响神经肌肉功能。18名健康男性受试者（19±1岁）根据其体脂百分比分为三个不同组。第1组（<10%），第2组（10 - 13%）和第3组（>13%）。在站立位测量比目鱼肌H反射反应。在坐位（膝关节160度，髋关节110度），在最大自主收缩期间测量V波反应，并在被动条件下测量单收缩反应。在8周期间，身体成分（去脂体重和脂肪量）观察到微小但不显著的变化。在8周期间，第2组（10.9%，无显著性差异[ns]）和第3组（2.8%，ns）的H反射活动增加，但第1组下降（-34.8%，p<0.05）。所有组的V波值均下降，第2组下降最大（-34.7%，p<0.05），而第1组和第3组无显著性差异。每组的单收缩扭矩在8周期间均增加（第1组无显著性差异，第2组和第3组p<0.05）。该研究的主要发现是基础训练期并未导致新兵过度训练。H反射活动增加和单收缩扭矩增加支持这一发现。所有组的V波活动均下降，这也可能表明训练并未刺激神经活动。总体而言，神经肌肉系统观察到的变化支持主要发现。
