Tsumiyama Wakako, Oki Sadaaki, Umei Namiko, Shimizu Michele Eisemann, Ono Takeya, Otsuka Akira
Department of Physical Therapy, Faculty of Health and Welfare, Prefectural University of Hiroshima, Japan ; Program in Biological System Sciences, Graduate School of Comprehensive Scientific Research, Prefectural University of Hiroshima, Japan.
Department of Physical Therapy, Faculty of Health and Welfare, Prefectural University of Hiroshima, Japan.
J Phys Ther Sci. 2014 Jan;26(1):125-6. doi: 10.1589/jpts.26.125. Epub 2014 Feb 6.
[Purpose] The purpose of the present study was to investigate if lactate thresholds in rats could be accurately determined during downhill running in rats. [Subjects] Twenty-four female Wistar rats were used in this study. Rats were randomly divided into two groups: the level running group and downhill running group. [Methods] Catheters were inserted into the right external jugular veins of the rats. Two days after the operation, the rats performed incremental exercise tests. The level running group ran on a treadmill at a 0° incline; the downhill running group ran on a treadmill at a -16° incline. The lactate threshold was determined using the 2-line combination that minimizes the total sum of squares for fitting all data. [Results] Maximal running speeds and running speeds at the lactate threshold for the downhill running group were significantly higher than those for the level running group. [Conclusion] In this study, it was possible to accurately determine the lactate threshold during downhill running. These findings suggest that when the treadmill speed is the same, downhill running can be done at lower metabolic intensity than level running.
[目的]本研究旨在探究大鼠下坡跑时乳酸阈能否被准确测定。[对象]本研究使用了24只雌性Wistar大鼠。大鼠被随机分为两组：水平跑组和下坡跑组。[方法]将导管插入大鼠右侧颈外静脉。手术后两天，大鼠进行递增运动测试。水平跑组在坡度为0°的跑步机上跑步；下坡跑组在坡度为-16°的跑步机上跑步。乳酸阈采用使所有数据拟合的总平方和最小化的二线组合法来确定。[结果]下坡跑组的最大跑步速度和乳酸阈时的跑步速度显著高于水平跑组。[结论]在本研究中，下坡跑时能够准确测定乳酸阈。这些发现表明，当跑步机速度相同时，下坡跑可以在比水平跑更低的代谢强度下进行。
