Okamoto T, Masuhara M, Ikuta K
Welfare and Health Management, Institute of Health Science and Applied Physiology, Kinki Welfare University, Kanzaki-gun, Hyogo, Japan.
J Hum Hypertens. 2009 Jul;23(7):470-8. doi: 10.1038/jhh.2008.152. Epub 2008 Dec 18.
Muscle contractions in normal resistance training are performed by eccentric (ECC, lowering phase) and concentric (CON, lifting phase) muscle contractions. However, the difference in effects of timing of muscle contraction during resistance training on arterial stiffness is unknown. This study investigated the effect of muscle contraction timing during resistance training on vascular function in healthy young adults. Thirty healthy men were randomly assigned to group of resistance training with quick lifting and slow lowering (ERT, n=10), group of resistance training with slow lifting and quick lowering (CRT, n=10) and sedentary groups (SED, n=10). The ERT and CRT groups underwent two supervised resistance-training sessions per week for 10 weeks. The ERT group performed the on set of 8-10 repetitions with 3 s ECC and 1 s CON muscle contractions. In contrast, the CRT group performed the on set of 8-10 repetitions with 1 s ECC and 3 s CON muscle contractions. Brachial-ankle pulse wave velocity (baPWV) after ERT did not change from baseline. In contrast, baPWV after CRT increased from baseline (from 1049+/-37 to 1153+/-30 cm s(-1), P<0.05). No significant changes in flow-mediated dilation were observed in the ERT and CRT groups. These values did not change in the SED group. These findings suggest that although both training does not deteriorate a vascular endothelial function, resistance training with quick lifting and slow lowering (that is, ERT) prevent the stiffening of arterial stiffness.
正常阻力训练中的肌肉收缩是由离心（ECC，下放阶段）和向心（CON，上举阶段）肌肉收缩完成的。然而，阻力训练期间肌肉收缩时机对动脉僵硬度影响的差异尚不清楚。本研究调查了阻力训练期间肌肉收缩时机对健康年轻成年人血管功能的影响。30名健康男性被随机分为快速上举和缓慢下放的阻力训练组（ERT，n = 10）、缓慢上举和快速下放的阻力训练组（CRT，n = 10）和久坐组（SED，n = 10）。ERT组和CRT组每周进行两次有监督的阻力训练，共10周。ERT组以3秒的离心收缩和1秒的向心收缩进行8 - 10次重复动作。相比之下，CRT组以1秒的离心收缩和3秒的向心收缩进行8 - 10次重复动作。ERT训练后的臂踝脉搏波速度（baPWV）与基线相比没有变化。相比之下，CRT训练后的baPWV较基线增加（从1049±37增至1153±30 cm·s⁻¹，P < 0.05）。ERT组和CRT组的血流介导的血管舒张未见显著变化。SED组这些值没有改变。这些发现表明，尽管两种训练都不会使血管内皮功能恶化，但快速上举和缓慢下放的阻力训练（即ERT）可防止动脉僵硬度增加。
